Radio Frequency Heating

Radio-frequency heating is a mechanism in which we are heating the dielectric materials (especially food) at high frequency using the electromagnetic and radio frequency waves. Radio-frequency heating contains electromagnetic spectrum in terms of frequency and wavelength. As most of our food is dielectric in nature that means it contains polar molecules like water which having dipole moment and both negative and positive charges are centered inside it. Some of its applications are pasteurization, drying of milk, sterilization, etc. Microwave heating is used over conventional dairy processes to extend the shelf life of milk and various milk products. While in contrast to MWH, Radio Frequency heating provides better penetration of waves in food than MWH because of its low frequency and large wavelength nature and has easier system configuration than microwave heating. Radio Frequency heating provides uniform heating to the product.

An alternative to Radio frequency heating, is Microwave heating, it also has same applications in food processing like Radio frequency heating.

Working Principle

Radio Frequency heating follows the volumetric process to heat up any dielectric material like food products through the radio waves that are emerging from the magnetron and triode valve via electrodes. In this process, the dielectric substance is placed in the cavity between the electrodes and the high radio-frequency voltage is applied across the electrode, and the emerging radiations penetrate through the food system and interact with its component like protein, fat, salt, etc., and generate the heat within the food due to the frictional interaction between the molecules and that produces a high energy efficiency with the lower heating time factor.       


Dielectric and ionic interaction is the two mechanisms that are required to achieve radio-frequency heating in food processing, in ionic interaction process, there are several ions present in food such as sodium and chloride, salts, etc that produce ionic conduction by the ionic movement towards oppositely charged electrode and rapid change in polarity causes the resistance heating, which ultimately results in multiple collisions of ionic molecules and distributed bond and produces heat. Dissolved ions are important contributors to heating compare to water dipoles. The basic component of most of the dairy food is water. Which is dipole in nature. When the high-frequency oscillation of water molecules under the influence of electromagnetic field collides with each other, then the higher rate of dielectric heat is generated.

Factors Having Impact on Radio-frequency heating (RFH)

There are some factors like frequency, temperature, the shape of the sample, etc that alter the heat generation process so we have to look over that in order to get the desired outcome for example: the non-uniform heat generated by microwaves creates the temperature gradients within the product that affect the volumetric heat generation process.       


1. Frequency is one of the most important factors in radio frequency heating, the lower the frequency -the higher the depth of Frequency also influences the dielectric characteristics of the sample. But we have some restrictions over the selection of frequency in food processing. The frequency range of 915MHz is legally permitted in the USA and Australia for Industrial applications.

2. Composition refers to sample ingredient components and with the change in the processing stage, the composition positions of the dielectric material also vary as well as the different heating behavior need to be accounted for. As the composition of the material changes then it leads to change the dielectric properties which in turn varies in the rise of temperature. Different compositions having different loss factor, dielectric constant, and temperature of heating. The amount of water, fat, protein, minerals present in dielectric material contributes to the heat generation process. As free water and protein are favorable towards the heat generation, the amount of free water increases loss factor and dielectric constant. Milk heats at a faster rate than water due to the presence of protein and ionic components in it.

3. The shape, size, and volume of the dielectric material decided the required wavelength and power consumption in the heat-generating process, higher in the density leads to higher in heating ratio, and higher in the volume results in higher power consumption, compositions like viscosity, specific heat electrical conductivity also affects the heating rate, for example, milk fat having a low dielectric property but its heats up faster than milk because of its lower specific heat.

Radio-frequency heating factors also depend on several system-level configurations like how the system(oven) is built, its shape and size, a cavity of the oven for the flow of charged ions, generated radio waves in the system, position placement of the dielectric material, the volume of the sample, static and dynamic behavior, heating in batch or continuous, etc which directly influence the rate and the pattern of heating and for that, a power test is used to indicate the required power consumption in the given volume of sample.

Microbiological Safety of Dairy Products

One of the major issues in dairy products is food infection and how effectively we can inactivate microorganisms through treatment. We have pest control for these insects but the chemicals used in that lead to environmental concern, and also harmful for the human body. Nutrients of the dairy products are also affected by these chemicals. So, the thermal treatment came into the picture. In the thermal process, we go for the cold spot and make sure that the cold spots achieve the required temperature to guarantee the safety of dairy products. We have z value (i. e temperature coefficient) which states that bacteria are more sensitive to heat as compared to nutrients as the z value of bacteria and nutrients are around 10∘C and 25∘C.Radio-frequency heating offers the possibility of fat heating in solid and semi-solid foods by direct interaction between electromagnetic waves.

Application and effect on the quality of milk products  

The effect of radio frequency heating is effectively destroyed pathogen such as Listeria innocua and E-coli k-12, in milk also be effective in pasteurization milk E-coli is more sensitive to Radio frequency heating than Listeria also using of radio frequency system, complete inactivation of pathogen was reported in <1 minute when temperature is around (60-65degree).

Some of the common applications of microwave are heating, precooking, tempering, blanching, pasteurization, sterilization, drying, etc. Both MWH and RFH are capable of pasteurization of milk. these technologies neutralize phosphatase enzyme in milk the technology mode has specified equivalent features compared to conventional pasteurization. Hence the quality of milk is exceeding and provides microbial protection. Differential heating effects of MW have been used in the development of wide variety of products using in dairy ingredient. Some of its other applications like. Drying and Baking, Defrosting, Sterilization and Pasteurization, Disinfestation.






World Food Day, 2020: Band Together against Hunger


World Food Day is an international event celebrated  globally around the world on 16th, October to commemorate the date of the founding of the United Nations Food and Agriculture Organization  and to highlight the importance of food security. It is celebrated across the world to acknowledge the contributions of the food and dairy sector to sustainability, economic development, farmer’s welfare, livelihood, and nutrition.


The first-ever World Food Day was celebrated in the year 1945, when United Nations Food and Agriculture Organization (FAO) was born. It is celebrated worldwide by various other organizations like World Food Programme and International fund for agricultural developments to raise awareness about issues behind poverty and hunger and ensure the need for food security and nutritious diets for all.

United Nations Food and Agriculture Organization (FAO)

The Food and Agriculture Organization of the United Nations has it headquarter situated in Italy and runs various campaigns around the world to defeat hunger. Its primary goal is to achieve food security and make sure that all people have regular access to high-quality food for leading healthy and active lives. With over 194 member states, FAO works in over 130 countries worldwide. It acts as a neutral forum where all nations meet as equals to negotiate agreements and debate policy. FAO is also a source of knowledge and information. They help developing countries to modernize and improve agriculture, forestry and fisheries practices and ensure good nutrition for all.

Theme: 2020

This year’s World Food Day marks the 75th Anniversary of the founding of FAO, with a view to look towards the future we need to build together. The theme for this year will be “Grow Nourish, sustain Together- Our actions are our Future.

Presently all countries are dealing with the widespread effects of the COVID-19 pandemic, So the main objective of this year’s World Food Day will be to highlight how food and agriculture can help in recovering losses. World Food Day 2020 will call for global cooperation and solidarity to help the most vulnerable to recover from the crisis. It will call on countries to build back better by making food systems more resilient and robust so they can withstand increasing volatility and climate shocks, deliver healthy and sustainable diets for all, and decent livelihoods for food system workers.

World Food Day 2020 will also acknowledge the efforts of the people involved in various stages of food supply chain system like food production, harvesting, packaging, storage, and transportation for meeting the demand-supply gap of food commodities.

Ways to Celebrate International Food Day


1) If you are someone belonging to the food, or health and nutrition sector, then you may register your campaign/online event/ webinar on and share your knowledge with the audience all across the world.

2) You can also enjoy this day as a participant by enrolling yourself in various online events enlisted on the above website.

3) You can also enjoy this day with your family members at home. You can involve your family member to prepare snacks, main courses, and desserts items that uses seasonal and healthy ingredients.

4) Take a pledge to learn something new about food products and avoid eating unhealthy food products and spread it among your near and dear ones.

5) As we all know Sharing is Caring and it is the best time to implement this as COVID-19 pandemic is making the lives of people miserable. It would be a great idea to donate some food packets to needy people and feed street dogs

6) You can also make this day memorable enjoying binge-watching documentaries that based on the processing of food products along with your family member with a bowl of Bhel- puri or Popcorn.


Metal Contamination in Food Industry- Detection & Reduction

Metal Contamination is type of contamination where product is contaminated with metal particles that comes in contact with manufacturing  product and is a primary concern of consumer safety and product quality. Occurrence of  contamination in food can be by various ways and is considered as a big headache in industries such as food, beverage, pharma, chemicals and packaging industries.

  1. Sources of Metal Contamination in Food

Contaminated raw material, not following Good Manufacturing Practices inside processing hall, poor installation and lack of maintenance can be major source of metallic contamination. In food industry most common type of metallic contamination are categorized into three category.

Some of the major source of metal contamination in food industry are shown in the below diagram.

  1. Preventing Metal Contamination

To develop any preventive measure it is essential to have full understating of all possible way of metal contamination can occur in food product. Most effective method of preventing metallic contamination is having a fully developed and efficient metal detection system

2.1. Primary screening of Ingredient

Processing ingredients should be inspected and checked for metallic contamination if any, as there is chances or metal being disintegrated into fragments during processing and hard to detect in later processing steps. Following points to be confirmed before accepting raw material-

  • Raw material containers to be staple free as there are chances of staple pins to fall in product during de-bagging the product.
  • Avoid using meat and carcass with metal tag on them as they are sources of metallic contamination.
  • Passing all incoming ingredients through metal detector or magnet traps for early detection and prevention.

2.2. Preventive Maintenance Plan 

  • Identification of any defective or faulty equipment to be shared and required steps for maintenance to be take care immediately.
  • Maintenance should be carried out in a planned way, aiming for minimum rear and tear.
  • Critical location, prone to metallic contamination to be specified
  • Keeping record of maintenance and corrective action carried out
  • Maintenance and checked details to be indicated on equipment itself for information purpose.

2.3. Following Good Engineering Practices

  • Maintenance inside processing area can led to remaining of metallic components in processing line or any adjacent area, hence all maintenance work should be done outside the processing building where ever possible.
  • After maintenance, equipment should be thoroughly cleaned before re-installation.
  • All maintenance tools should be codes or marked when being taken into processing section.

2.4. Following Good Manufacturing Practices

Operators or workers being exposed to food product or entering food facility should avoid carrying items such as watch, paper clips, staples, finger ring, earrings, pin, non-metallic pen, neck piece, bracelet, or any metallic item that is forbidden in the processing facility. 

 Metal Detection System

3.1. Introduction

A way forward to fight this serious condition is developing an effective metal detection system in food industries. Following evident advantages can be easily achieved by incorporating a metal detection system in existing food safety system of manufacturing units:

  1. Metal free high quality and safe product increasing brand trust and retailers confidence.
  2. Compliance of all regulatory and legislative requirement in reference to industry standards.
  3. No product failure hence low probability of product recall.
  4. Identification of superior quality raw material suppliers.

These points helps manufacturer in achieving better brand value along with reduced overall operating cost. 

3.2. Components – Metal Detecting System

Metal detector consist of following principle parts

  1. Detector Coil- Product passes through aperture, an opening, and detector coils in them are responsible for the detection of metallic contaminants. There are many technologies out in market involved; however, there are majorly two main categories of detector coils.
  2. Search Head Type detector coil– Able to detect metal contaminants of ferrous, non-ferrous and SS nature in foods that are packed or unpacked in metalized films.
  3. Foil in Foil Type detector Coil- Able to detect metal contaminants of ferrous and SS nature in foods that are packed in Aluminum foils.
  4. User Interface- It is a control panel that helps operator set various parameter and to check during processing for any required changes.
  5. Transport System- In most cases it is a conveyor or pipe chute, which helps in the forward movement of product through aperture.
  6. Automatic Rejection System- System for rejection of detected contaminated product from the uncontaminated product. Mostly fitted to transport system they are of various kind like air blast, push arm etc. and are selected on basis of product, process requirement, etc.
  7. Accessories
  8. Collection Bin- Lockable container for holding rejected product and is equipped with alarm to let know the bin is full.
  9. Covering Lid- Cover both detector and rejection device in full length
  10. Alarm System- Safety Alarm for faulty metal detector
  11. Reject confirmation devise- Senses the rejected item and time of rejection for future reference of validation & verification. 

3.3. Metal detector

Metal detectors are equipment that are now being widely used in food & pharma industry for safe and superior quality item production. Metal detectors are one of the important front line metal detection system and advisable to used and even considered as CCP before finished good dispatch.  

Metal detector comprises of coils (Multiple coils for more effective magnetic field)  connected to high frequency radio transmitter and when a metal passes through the first coils this high frequency field is disturbed. This disturbance causes changes in the voltage that is interpreted as output.

Metal detectors can be used at various stages of production-

  1. After processing line- Detection of any metal residue from maintenance, broken metal particle from processing equipment and human errors. Before filling & Packing line, metal detector can prevent the dispatch of faulty final product.
  2. Before processing line- For raw material inspection at material reception. This helps as primary screening and rejection of metal contaminants by initial screening preventing usage of contaminated material for processing.
  3. In-processing- Integrating metal detectors in process CCP can be used for detection of any chances of malfunctioning of equipment such as breaking of blade or any part into the product or that can result in the failure of processing equipment that can result in high cost maintenance.

3.4. Sensitivity

Actual operating sensitivity gets fluctuates and factors affecting loss in sensitivity are

3.4.1. Metal Type-

Metal contaminants found widely in food industry can be categorized in

  1. Ferrous– Easily detected as it is both magnetic and conductive
  2. Non- Ferrous– Doesn’t possess magnetic nature but is good conductor
  3. Stainless Steel – Most difficult to detect, as its poor conductor as well as shows non-magnetic feature.

The below table can be considered for general acceptable limit in both dry and liquid product.

Aperture Height

Dry Product

Wet Product

Wet Product


Ferrous & Non- Ferrous


Non- Ferrous

Up to 50mm




Up to 125mm




Up to 200mm




3.4.2. Orientation and shape of metal

Orientation affect is of great importance as orientation of metal passing in particular direction can be easily detected than another position, when the size of contaminant is lesser than the set required sensitivity.

  1. Ferrous contamination– Easy to detect if in parallel to direction of movement while difficult if in right angle to moving direction.
  2. Non Ferrous contamination– Easy to detect if in right angle to direction of movement while difficult if in parallel orientation.

3.4.3. Aperture Size-

Sensitivity of smaller opening or aperture is more than large opening.

3.4.4. Product Characteristics-

Dry products with contaminants can be easily detected when passed through detector compared to wet product due to the product effect signal generated from product influences the sensitivity of the detector, which can be maintained by using low frequency range of detection.

Metal detectors for food provide effective protection against metals contamination and can be installed in every step of the production process of various product such as for the inspection of bread and bakery products, meat and sausage product, fruit, vegetables, dairy products, spices, sugar, etc. Today, the food industry produces goods with the utmost efficiency, creating as much quality products as possible and also the detection technology meets HACCP requirements.



Food Allergens

Food allergy is the term given to hypersensitive response induced in a healthy human individual due to certain food or food additive. And food allergen is naturally occurring proteins in food & food additives that can trigger the immune response causing hypersensitivity. Being a global problem, approximately 25% population in India suffers from a food allergy, which is comparatively low to western countries where the percentage is high up to 40%. The percentage of food allergies in children is higher than that in adults. Allergies can be out-grown with age, might develop in the later phase of life, or may remain lifelong. Earlier due to lack of knowledge regarding consequence and non-specific and a wide range of symptoms of food allergy, medical or concerned authorities did not entertain cases. Hence, the first reported case was in the 20th century and allergy caused was due to dairy products.

As the effect of food allergens can toxic or nontoxic in nature, food manufacturing industries, as well as government regulatory authorities, are putting considerable effort into combating the issues caused by food allergens by promoting awareness and prevention methods and one such initiative is the labeling of allergens on the packs. The non-existence of any specific cure to food allergy, prevention possible by getting self-aware of the food items one is allergic and avoiding the consumption of all foods containing the allergen.

The response of Food Allergen

Hypersensitivity by individual Food allergens can stimulate different types of responses. It can be either toxic or nontoxic in nature. Figure 1 shows the response and its classification and figure 2 summarizes the sub-classification used for food Allergen & food intolerance.

Fig.1 Classification depending Responses of Food Allergen


Fig. 2 Subclassification of Nontoxic type of allergen

Food sensitivity response can be

  1. Immediate Type Food Allergy Response – Most commonly seen in young children that show an allergic reaction when containing allergic food. In adults it’s generally observed, when a specific food item is combined with alcohol, exercise, or non-steroidal drugs chances are quite high to an allergic reaction.
  2. Delayed-onset Type Food Allergy Response– Occurrence of allergic response is after several hours or days. It is an autoimmune disease (Type III food allergy), where immune cells in the body recognize the allergen protein and produce compounds such as histamines and other chemicals.

Is Food intolerance the same as that to Food Allergen?

Two terms are highly confused to be same but it is not. Food intolerance is the body’s abnormal reaction to food, but in a way that does not involves the immune system. On the other hand, a food allergy is triggered by an immune response. When comparing the two, a food allergy poses a much greater health risk than food intolerance.

Mechanism of Allergen

The human immune system tends to produce antibodies against the entry of any pathogenic or foreign compound. These produced antibodies in response to pathogen entry that may be caused due to the entry of pathogens. This is how the human body protects itself through the inbuilt immune system. Food Allergens develop quite similar conditions in the human body in case of an IgE mediated allergic reaction. When food allergens are ingested, our body’s defense system secretes and distributes IgE antibodies (Immunoglobulin E) in the body. Some of the IgE antibodies come in contact with mast cells and form the sensitized cell. Sensitized cells react with allergic proteins, forming chemical substances such as histamines and other compounds that escalate the allergic symptoms in the body known as hypersensitivity.

Food Allergens

All food poses a threat of being food allergen, however, Codex Alimentarius Commission (CAM)   published a list of most common IgE mediated allergy-causing food.

  1. Cow’ milk
  2. Chicken Eggs
  3. Legumes (Peanuts, gram beans, green peas)
  4. Tree Nuts (Almonds, Cashew, Pistachio, Walnut)
  5. Sea Foods (Crustaceans, Fish)
  6. Cereals (Wheat, Barley, Rice, Corn, Sorghum)
  7. Spices (Turmeric, Cumin seeds)

Other Allergens- Apart from the above-stated list, there are few fruits and vegetables (Apple, Peach, Carrot, Tomato, and Banana, etc.)  that has shown the potential of being allergic but has not been included by CAM and causes Oral Allergy Syndrome (OAS)


Allergy causing protein can affect the functioning of the human body leading to disease related to skin, gastrointestinal, digestive, respiratory, and cardiovascular. Most common symptoms are skin rashes, flushed skin, hives, itchy sensation in the mouth, swelling of face, lips & tongue, abnormal cramps, vomiting, nausea, diarrhea, or constipation, wheezing & coughing, difficulty in breathing and loss of consciousness.

Apart from such unspecific & common issues, at times, a food allergy can pose a threat to life. Anaphylaxis is one of the most common conditions that yearly results in deaths. This condition leads to a drop in blood pressure, suffocation, and breathing problems due to swelling in the throat and airways in the lungs.    

Fig. 3 List of Organ & health issue caused   

Food Induced Disorders

Some of the major disorders along with their symptoms on infected individual along with the common causal food ingredient has been listed in the table below:- 



Causal Food

Urticaria/ angioedema

  1. Ingestion or direct skin contact
  2. Acute urticaria
  1. Major allergens

Oral allergy syndrome

  1. Pruritus, mild edema confined to the oral cavity
  2. Anaphylaxis
  1. Raw- fruit/vegetables
  2. Cooked- apple, peach, pear, Carrot, melons

Rhinitis, asthma

  1. food-induced allergic reaction
  1. Major allergens


  1. Cardiovascular collapse
  1. Peanut, tree nuts, shellfish, fish, milk, egg




(Food triggers anaphylaxis only if ingestion followed temporally by exercise)

  1. Wheat, shellfish, celery

Atopic dermatitis

  1. Moderate-to- severe rash
  1. Major allergens
  2. Egg and milk



  1. Inflammation
  2. Esophageal: dysphagia and pain
  3. Ascites, weight loss, edema, obstruction
  1. Major allergens

Dietary protein


  1. Emesis
  2. Diarrhea
  3. poor growth
  4. lethargy
  1. Cow’s Milk, soy, rice, oat

Dietary protein


  1. Mucus-laden
  2. Bloody stools in infants
  1. Milk (through breastfeeding)

 Precautionary Steps  

  1. Avoidance: Avoidance is the rejection of foods that can cause an allergic reaction in any individual is highly recommended. It shall be helpful to be fully aware and note down of any history pf allergic reaction by consuming any specific food item and eliminating it from the diet.
  2. Food Labelling: Manufacturing Industry should let know their consumer if the product contains any type of allergen material or has been processed in a line that has been used for manufacturing allergen-containing products. This type of cautionary label is required, as chances of cross-contamination cannot be denied if the same processing line is being used for allergen and non-allergen products.

Way Forward

Allergen management in the food industry is highly advisable and for more detailed information and understanding of DO’s and DO NOT’s of the food industry, refer the following link.

Having a diverse food culture in India, there are many food items that can lead to food allergy however, the majority of them are not life-threatening. Sometimes mild symptoms during the early phase may escalate with time leading to conditions such as anaphylaxis. Children being prone to these allergies due to weak immune system have chances of outgrowing the allergy with time. No current treatment has led to avoidance as an only preventive method, which has opened up vast opportunities for research & development in this field. It is one of the most challenging clinical problems and has major public importance.



Accessories for Quality Maintenance

Food safety is an international concern, as huge number of food borne cases have been reported since past few years after consumption of unsafe food. According to the latest report published by WHO, every year about 4, 20,000 people across world dies due to food poisoning. These reported cases of food borne diseases have resulted in decreasing confidence of consumers towards Ready to eat food products. In order to regain that  trust, industries are  making all necessary efforts to transform their premises into food safety compliant, one which have all basic requirements for either avoiding or reducing the risk of making food unfit for consumption. Installment of Food Quality Accessories is one such effort on which company invests significantly to render product safety.

Food Quality Accessories can be defined as the umbrella term for all the supporting instruments, tools or equipments that helps in achieving food safety inside the food manufacturing industries for proper handling and storing of food in a way that effectively reduces the risk of individuals exposing to hazard.

Food Safety Accessories can be grouped into four classes depending on the principles of food safety for avoiding contamination of food and causing food diseases.

  1. Maintaining personal hygiene:

It is important for any food service safety that their workers must be familiar with general hygiene practices that help to maintain hygiene and prevent the spread of diseases. The quality accessories which help in maintaining the personnel hygiene are described below:

  • Hair Net- Disposable caps to stop hair falling into food, sensitive machinery or onto paintwork by providing full head coverage. Generally, made from soft polypropylene, are ideal for use in laboratories, food production area.
  • Gloves: People who work in the food and beverage industry use disposable polypropylene gloves on a regular basis, which act as a barrier in order to prevent the spread of germs and keep consumables from becoming contaminated.
  • Hand Dryer: Generally installed inside toilets, food production area and manufacturing premises for drying wet hands of the person for preventing microbial contamination as wet hands, becomes the fastest vector for spreading food borne microbes. Hand dryer with SS 304 and Polycarbonate ABS casing construction are suitable for installation within food industries.
  • Shoe Covers: Disposable shoe covers made from cast polyethylene to prevent contamination of the workplace from debris or bacteria brought in on from worker’s shoes, and protect footwear from splashes or staining. Each shoe cover has an elasticated opening that makes them quick and simple to put on and take off, while also ensuring that they stay securely in place.
  • Over sleeves: Disposable over sleeves are designed to protect forearms and sleeves without having to put a jacket or set of overalls on. Generally, these are elasticated at both ends to ensure that they stay securely in place and help prevent splashes from entering underneath.
  • Beard Net: Disposable beard snoods which are made from soft non-woven polypropylene, and are elasticated to ensure that they stay securely in place while working. Wearing a disposable beard snood or beard net protects against small hairs falling into food, sensitive machinery. The use of a beard snood also helps to reduce the risk of long hair being caught in rotating equipment.
  • Disposable Aprons: These are disposable LDPE aprons which are ideal for protecting clothes from stains caused by splashes and dirt in the workplace, and have waist ties that offer a close fit and help to ensure that the disposable apron doesn’t get in the way of work or caught in machinery.


  1. Properly cleaning and sanitizing all surfaces, equipment and utensils

Cleaning and sanitizing are the most important aspects of any sanitation program; therefore, sufficient time should be given to outline proper procedures and parameters. Detailed procedures must be developed for all food-product contact surfaces (equipment, utensils, etc.) as well as for non-product surfaces such as non-product portions of equipment, overhead structures, shields, walls, ceilings, lighting devices, refrigeration units and Heating, Ventilation and Air Conditioning (HVAC) systems, and anything else which could impact food safety. Identification of type of the cleaning tool is the crucial step of any plant sanitation program. Tools used for the cleaning in food industry are described below:

  • Wall Bracket: These are not only used for storage of cleaning equipments but also ensures good hygiene practices and extends shelf life of brush wares. This must be designed such that there are no crevices for bacteria buildup and are easy to clean. These are generally made up of Stainless Steel and Polypropylene.
  • Brooms: A broomis a cleaning tool consisting of usually stiff fibers (often made of materials such as polypropylene, polyesters and Stainless Steel) attached to, and roughly parallel to, a cylindrical handle, the broomstick. It must be designed in such way that provides effective cleaning.
  • Dustpan: It is usually used in combination with broom for collection of food debris and dust from floors and work surfaces. It is generally made up of Stainless Steel and polypropylene.
  • Brush: These are used for easy cleaning of equipments and hard-to-reach corners. The suitable material of construction is Stainless Steel and polypropylene.
  • Scrappers: These are Ideal for cleaning powder towers and other surfaces where extra force is needed to loosen dirt. Generally, scrappers used in food processing industry are made up of Polypropylene or Stainless Steel 304/316.


  1. Maintaining Controlled Environment:

Uncontrolled temperature and moisture in any part of the food production cycle can often leads to the growth of bacteria, mildew, or mold which can mean the difference between a product being safe and fresh versus unsafe and spoiled. Fortunately, these risks can be easily mitigated by using quality accessories like:

  • Air Curtains: These are also known as air doors which are installed at doors and windows of food processing facilities for reducing energy costs, containing smells, maintaining temperature and keeping flying insects out.

  • Strip Curtains: Food process industries uses strip curtains that are transparent curtain made up of non-phthalate material which are ideal for maintaining an ambient temperature of warehouse or cold store or any other area, keeping out dust/flies/pests, restricting the movement of air pollutants and control noise.

  • HVAC System: HVAC systems are milestones of building mechanical systems that is designed on the principles of thermodynamics, fluid mechanics and heat transfer which provides thermal control and indoor comfort for product and workers respectively.
  • Floor Marking Tapes: These are Vinyl tapes which are used to demark specific area to maintain safety standards in the industry. It also helps workers to put materials and equipment back in right place.


  1. Implementing effective pest control

In food processing environments, flies and rodents infestation are considered as a big problem which can put product and business reputation at risk. Therefore, Pest control is an essential part of Good Manufacturing Practice in food processing from a hygiene, economic and regulatory viewpoint. Various Quality Accessories that act as gold standard in pest control are described below as follows:

  • Rodabox: These are rat catcher which is installed with mouse glue trap that act as wonderful tool to get rid of mouse as it more looks like surface of ordinary carton and box thus this easily traps mousse/rats. This is usually made up of iron and strong build.
  • Fly Catchers: It is an electrical device, which uses ultraviolet light to attract insects toward an electrified wire grid where they are electrocuted (making a zapping sound). These are used as chemical alternatives for pest control. They work by attracting all kinds of flying insects to a blue ultra-violet light. The insects then hit the killing board situated behind the fluorescent tubes. A small electrical current safe to our touch is passed through the ‘killing board’ humanely and instantly killing all types of flying insects. Usually, they are of two types, Fly Cather without glue pad and with glue pad. Former is installed in non-food processing areas whereas later one is installed in food processing area as it prevents the scattering of ashes of electrocuted insects.


It is of utmost importance that quality accessories being used inside food manufacturing premises can lead to the unhygienic conditions as well. Hence, it is recommended to use or give special preference to the selection of accessories being used, like its MOC, design and other parameters that can cause hazard. Just installation won’t be that effective, and each accessories requires specific cleaning and maintenance schedule should be strictly adhered with.




Good Document Practices

A famous saying goes like “If it isn’t documented, it didn’t happen”- therefore, it becomes mandatory for all food processors, ingredient manufacturers, and packaging suppliers to develop, document, implement and maintain all necessary documentation in order to maintain Food Safety Management System for establishing business in global level. Nowadays, even small businesses are expected to maintain documentation, or else they will fail to display FSMS in their premises. This need of proper document and record keeping has led to the birth of Good Documentation Practices (GDP) or Good Record Keeping Practices.

A. Good Documentation Practices-An Introduction

Good Documentation Practices is a mandate requirement for overall quality management systems (QMS) and risk management strategies (QRM). These are referred to, as practices that collectively and individually ensure documentation (whether paper or electronic) is attributable, legible, traceable, permanent, contemporaneously recorded, original and accurate. These practices have direct or indirect impact on all aspects of the quality of food substances/products and demonstrate evidence of adherence to GMP standards and/or any other applicable regulatory requirements. Good Document Practices help in achieving HACCP, FSSC 22000, HALAL, GFSI, BRC, SQF and other certifications and thus helps in gaining confidence of customers apart from complying to required guidelines.

B. Need of GDP

Following GDP in one’s food facility ensures-

  1. defined specifications and procedures for all materials being handled in facility,
  2. defined methods of manufacture and control,
  3. awareness in operators and all personnel – what to do and when to do it,
  4. proper flow of information among team, necessary for release of product,
  5. documented evidence, traceability, records and audit trail for investigation,
  6. availability of data for validation, review and statistical analysis

C. Basic Features for documentation

C.1. Attributable: Capturing information in the record form such that it is uniquely identified and used as per requirement on time.

C.2 Legible: Captured data should always be readable, understandable and should allow understanding of sequencing of steps or events in the record.

C.3. Contemporaneous: Process of documentation (on paper or electronically) at the time of the occurrence of an activity

C.4. Original: The data captured at source of data or information and should be fully reconstruct the conduct of the GMP activity.

C.5. Accurate: Data in documents should be correct, truthful, valid and reliable.

C.6. Complete: All data from analysis, including any data generated before a problem is observed, data generated after repeating part or all of the work, or re-analysis performed on the sample should be included in the data record.

C.7. Consistent: All elements of the analysis, such as the sequence of events, follow on and data files are date-stamped (all processes) and time stamped (when using a hybrid or electronic system) in the expected order and such data should be included in the record.

C.8. Enduring: All data recorded on authorized media should be preserved for a period of time, Data recorded on scrap paper or any other media which can be discarded later (e.g., backs of envelopes, laboratory coat sleeves or Post-It notes, etc.) are not considered enduring

C.9. Available: The complete collection of records should be available, accessed or retrieved for review and audit or inspection over the lifetime of the record.

D. Documentation Process:

  1. Preparation of Document:
    • All Documents must be accurate, consistent, completed and must be traceable.
    • Pages in the master document must be numbered as A of C (e.g., Page 25 of 50).
    • All documents must have the signature and date of the person who prepared, reviewed and approved the document.
    • All documents must have an effective date and a review period if applicable.
    • Full text spelling with the abbreviations in brackets must be used for the first time. Abbreviations must be used in place of full text spelling in the remaining part of the document.
    • Definitions shall be included in the document for reference. This is most effectively done by including the definitions in a table format, at the start or end of the document.
    • All documents shall have a unique identification number (including the version number).Use of uncontrolled documents and temporary recording practices (e.g., scraps of paper) shall be prohibited.
  1. Review and Approval of Documents
    • Documents within the Quality Management System to be regularly reviewed and kept up to date.
    • Unsigned or incomplete documents or records not be used to perform any task or considered as evidence of a completed task.
    • All GDP documents to be approved by Quality Assurance Manager.
  1. Issuance of GDP documents
    • Records shall be maintained for issuance and retrieval of documents with proper traceability of the person who issued the document.
    • Master copies of controlled documents (paper-based and electronic) must be stored in a secure manner and accessible only to authorized individuals.
  1. Recording/data capture on GMP documents
    • Handwritten entries to be made in a clear, legible, indelible manner.
    • Indelible ballpoint pen to be used to record data. Pencil or erasable or water-soluble ink pen shall not be used to complete the GMP documents.
    • Use of white ink, correction fluid or sticky notes (e.g., post-it notes) to correct the entry in GMP documents shall not be permitted.
    • Entries shall always be recorded at the time of activity in a contemporaneous manner. Date and time of completion of activity to be recorded in a predefined standard format as found suitable by the firm. The format of date and time should remain consistent throughout all the documentation formats across the firm. In case a printout generated by equipment/instrument/system has a different format, it shall be converted to the standard format while entering in logbooks/GMP documents.
    • Data to be recorded only in the format duly issued and approved by Quality Assurance.
    • Logbooks shall be kept for major or critical analytical testing, production equipment, areas where product has been processed and other usage logs.
    • If there is any repetition in any observation/signature/date then it should be rewritten again. Avoid using markings such as Ditto (–”–), “as above” or “do” shall not be used.
    • Handwritten signatures must be unique to the individual and listed within the Specimen signature register to ensure that the signature is traceable to the concerned
    • Any employee should not be permitted to sign for another member of staff unless delegated. Signatures must never be forged.
    • A single strike-out line must be used always to mark the incorrect entry in such a manner that original entry remains readable.
    • There shall be pre-defined retention periods for different sets of documents. An inventory of documents within the quality management system should be maintained.

  1. Revision of  documents
    • All revised documents shall mention its revision history.
    • Periodic reviews of controlled documents and forms shall be done as per approved procedure and shall be handled through a change approval process.
    • Versions of documents created shall be managed through logbooks.
    • A record shall not be destroyed before its stated retention period or validity without appropriate justification and consultation with Quality Assurance.
    • Any approved or under approval document shall not be discarded or destroyed without the appropriate stamp authorizing cancellation/obsolescence.

Documentation helps to build up a detailed map of what manufacturing function has done in the past and what it is doing now and thus provides the foundation of what it will do in future. GDP must be incorporated as an essential component of FSMS in all small and large-scale food industries and appropriate care must be taken to ensure its compliance with regulatory bodies.


Hurdle Technology

Food processing, food preservation and food security, these sums up the modern era requirement of safe food. Rate of food spoilage is quite high, which can be estimated by recent report of FAO stating one third of the total harvested food is wasted and is not available for consumption. In majority of cases, microorganisms were the lead cause for the spoilage or poisoning of food products.

Despite the availability of wide range of preservation techniques like freezing, blanching, pasteurization, canning etc. spoilage of food materials by microorganisms is still a major challenge, thus for achieving microbial safety & stability in food products, a new technology was discovered by Leister, termed as hurdle technology which combines non-thermal food processing with traditional or other emerging technologies. This technology preserves the food product by using more than one preservation techniques for arresting the growth of microbes in food product, without disturbing food products in built chemical composition and organoleptic characteristic.


What Is Hurdle Technology

Hurdle technology, a gentle and effective preservation technique, using intelligent combination of “hurdles” for production of safe, stable, nutritious, tasty, and economic foods. These hurdles can be defined as physical or chemical parameters that can be adjusted to ensure the microbial stability and safety of foods. There are more than 60 potential hurdles for processed food products, where as the principal hurdles preservative factors in food safety are temperature (higher or lower), water activity (aW), acidity (pH), redox potential (Eh), chemical preservatives (nitrite, sorbate, sulfite), vacuum packaging, modified atmosphere, HHP/HPP, UV, and competitive microorganisms.

Concept behind Hurdle Technology

Hurdle technology makes use of “hurdles” which the pathogen has to overcome if it has to remain active in the food. The right combination of hurdles can ensure elimination of all pathogens to safer limit. In this a preservation parameter can be used at an optimum level in order to get a maximum lethality against microorganisms by a combination of two or more such parameters.

The whole concept of hurdle technology mechanism is based on various responses given by any microorganism. The whole phenomenon can be understood by following:

  1. Homeostasis: It is a tendency of any organism to maintain its internal status. Homeostasis of microorganism plays a major role in food preservation. Food preservation can be achieved by disturbing the homeostasis of microorganism, temporarily or permanently, as any hurdle disturbing the homeostasis of these microorganisms impacts on its ability to reproduce and thus they remain constant in number or will die before the re-establishment of homeostasis.
  2. Metabolic Exhaustion: Another important phenomenon for food preservation is metabolic exhaustion of microorganisms. As a response to the hurdles applied to foods, microorganisms try to stable their homeostasis, for this they utilize all their energy and become metabolically exhausted. This leads to an auto-sterilization of such foods. The foods which are preserved with the concept of hurdle technology are microbiologically stable, become safer during storage at ambient temperature. The microbes can respond better to the hurdles at ambient temperature than at refrigeration and become metabolically exhausted.
  3. Stress Reactions: As a response of various hurdles e.g. heat, pH, water activity, ethanol, oxidative compounds, as well as starvation, a stress shock protein is produced by some bacteria. These stress proteins may hamper food preservation and could turn out to be problematic for the application of hurdle technology if only one hurdle has been applied. If different stresses are received by the microorganism at the same time, the activation of genes for the synthesis of stress shock proteins, would be difficult. Synthesis of many stress shock proteins due to simultaneous exposure to different stresses will be very energy-consuming and would lead to metabolic exhaustion of the microorganism.

4. Multi-Target Preservation: A combined effect could be achieved by hitting various targets within the microbial cell (e.g., cell membrane, DNA, enzyme systems, pH, aW, Eh) by using different hurdles simultaneously. This disturbs the homeostasis of the microorganisms present in several respects. In this case, the replenishment of homeostasis and activation of stress shock proteins becomes more difficult. Therefore, simultaneous application of different hurdles in a particular food would lead to optimal microbial stability.

Classification of Hurdles

We can classify various hurdles on the basis of their function, nature and their type which is discussed in brief. Generally classified into physical, chemical & biological parameters.

[1] Hurdles grouped according to Primary Function

  1. Microcidal hurdles reduces microbiological load: These contains a group of mild techniques, which reduces the microbial flora to safer limit without changing the original chemical composition. Technologies used for achieving this function are: Bactofugation, Competitive Micro flora, Microfiltration, Theorization, High Pressure Treatment, Ultrasonification etc.
  2. Micro biostatic Hurdle limit or/and prevent growth by biochemical means: These include hurdles such as pH, carbon dioxide, use of preservatives, redox potential, lacto peroxidase system etc.
  3. Micro biostatic hurdles limit or prevent growth by physical means: It includes the techniques, which arrests the growth of microbes by means of refrigeration, pasteurization and freezing.
  4. Hurdle preventing Contamination: These include various types of packaging and coatings, which helps in protecting the contents from damage, dust, dirt, leakage, pilferage, evaporation, watering, contamination and so on.

[B] Primary types of Hurdles

  1. High Temperature: Most common and oldest forms of microbial control. It is applied in food preservation techniques like canning, pasteurization, UHT, Retort Processing etc. Heat kills microbes by altering their membranes and denaturing proteins. The thermal death time (TDT), is the length of time needed to kill all microorganisms in a sample at a given temperature, which is used as an important parameter to describe sterilization procedures that use high heat. Different microorganisms will respond differently to high temperatures, with some (e.g., endospore-formers such as  botulinum) being more heat tolerant.
  2. Low temperature: exposing microbes to low temperatures can also be an easy and effective method of microbial control, with the exception of psychrophilic, which prefer cold temperatures. Refrigerators maintain low temperatures which inhibits microbial metabolism, slowing the growth of microorganisms significantly and helping to preserve food products such as foods or medical supplies.
  3. Water activity: The concept of aw has been very useful in food preservation and on that basis many processes could be successfully adapted and new products designed. Water has been called the universal solvent as it is a requirement for growth, metabolism, and support of many chemical reactions occurring in food products. Free water in fruit or vegetables is the water available for chemical reactions, to support microbial growth, and to act as a transporting medium for compounds. In bound state, water is not available to participate in these reactions as it is bound by water soluble compounds such as sugar, salt, gums, etc. (osmotic binding), and by the surface effect of the substrate (matrix binding). Water activity can be reduced by using techniques such as Curing, Drying etc.
  1. Chemical Preservatives: These are substances which, under certain conditions, either delay the growth of microorganisms without necessarily destroying them or prevent deterioration of quality during manufacture and distribution. Example include Sugar, salt, SO2
  1. Acidity: Microorganisms, including yeasts, molds, and bacteria are sensitive to food’s pH. Very low or very high pH values will prevent microbial growth. 
  2. Bio preservatives:These are compounds derived from natural sources or formed in food, able to prevent or retard spoilage related with chemical or biological deterioration that prolong product shelf life.

Hurdle technology not only improves product quality and microbial safety but also saves money, energy and several other resources. Food remain stable and safe, high in sensory and nutritive value due to gentle process applied. It does not affect the integrity of food pieces and can be applicable in both large and small-scale industries. This technology is used for making new products and for reducing energy-consuming hurdles or chemical preservatives. It is gratifying to know that this technology has a bright future in food industry as it can be used in manufacturing of minimally processed food and RTE foods which can be stored without refrigeration.



IQF Technology

The frozen food market is one of the largest and most dynamic sectors of the food industry. In spite of considerable competition between the frozen food industry and other sectors, extensive quantities of frozen foods are being consumed all over the world. Freezing being one of the best technique for food preservation is widely used for retaining taste, texture, and nutritional value in agricultural products over long storage periods since time immemorial. It provides combination of the beneficial effects of low temperatures preventing microbial growth, reduced chemical reactions, and delayed cellular metabolic reactions.

Freezing, regarded as superior to canning and dehydration, due to its requirement of shortest processing time. During late 1800, frozen storage cabinets were developed which used natural occurring ice and snow for preserving food outside. With the advancement in freezing technology, IQF has evolved as a most promising technology for preserving food and vegetables for longer time in same farm-fresh condition without bringing much alteration in its sensory and physio-chemical attributes. The safety and nutrition quality of frozen products are enhanced when high quality raw materials are used and good manufacturing practices are employed in the preservation process, and the products are kept in accordance with specified required temperatures.

Introduction- IQF Technology:

In Food Processing Industry, IQF stands for Individual Quick Freezing, indicating to each individual piece of food frozen separately from each other’s. Originally developed as a specific solution to block or cluster freezing of small-sized products, to preserve quality and to give unparalleled convenience to end-users. This method of freezing has a unique ability as it freezes all its components individually by keeping them separate from each other. This makes it easy to individually freeze and store products like peaches, berries, grapes, corn, peas, fish, shrimp and poultry products.

The major market segments for IQF are:

  • Retail outlets for direct consumption
  • Hotels, restaurants, caterers and eateries
  • Food industries which use fruits and vegetables as raw material and want to process during the lean season

Working Principle

IQF relies on ultra-quick freezing i.e. freezing the product quickly for which there is requirement of very low temperatures of approx. -30°C to -40°C, for halting the activities of the microorganisms that are responsible for the spoilage of food product. This technology freezes each piece of food individually using fluidization technique, i.e. product is suspended on high velocity air, which leads to freezing of food products in 10 to 12 minutes which otherwise takes at least 3 to 4 hours. Thus, most of the properties of the parent food is preserved, as formation of big crystals does not takes place, which damages the tissues of food material. Moreover, it also presents the advantage of saving energy and time as one does not have to thaw or defrost the whole packet to take out only a portion and the rest shall remain frozen until further requirement.

Types of IQF System

Three extensively used technologies fluidized bed, plate freezing & Cryogenic freezing are very efficient, prevent product stickage, and produce a 100% IQF freezing output.

I. Direct Freezing

 1. Fluidized Bed Freezing:

Commercially rapid freezing rates are achieved by introducing food product in an insulated tunnel having vigorous circulation of cold air. Food commodities are passed through this chilled tunnel on trays/ belt. Food is fluidized to form a bed of particles, which is then frozen by forcing cold air upward through the particles. Upward motion of the air through bed partially lift or suspend the particles, which leads to the speedy drying of the particles. This is a direct methord of freezing as cold air comes in direct contact with the product. Here the temperature of the air is approximately -18 to – 34°C and the velocity of the air kept high in the range of 2 – 5 m/sec. This process is economical for producing IQF products as variety of sizes and shapes can be accommodated. The depth of the bed of particles varies with the product. E.g. Solid food particles of the size of pea’s up to strawberries can be frozen with a depth of 1 to 5″ whereas Green beans/French beans are partially fluidizable products, and requires a depth of 8 to 10 inches.

  1. Cryogenic Freezing:

Few products like mushroom, tomatoes, strawberries and raspberries requires ultrafast freezing which can only be achieved by immersing them either in liquid nitrogen or liquid Carbon Dioxide at low temperature (below -60°C) for freezing the outer surface of the product instantaneously.

II. In Direct Freezing:

 1. Plate freezing:

It is an indirect way of freezing food product. Food products are placed in contact with metal plates, which are indirectly cooled using cold brine or vaporizing refrigerants. This process is suitable for unpacked food stuffs e.g. shrimps. It is quite economical as it minimizes the problem of dehydration, defrosting and packet bulging.


  1. It produces the better quality frozen product possessing similar organoleptic and nutritional attributes as their raw form.
  2. One of the biggest benefits of individual quick freezing is having small portions of frozen food available at any time. IQF makes it easy to just defrost only the amount you need instead of thawing out an entire bag of frozen chicken breasts.
  3. It does not require any kind of chemical preservation for increasing shelf life.

Some of the IQF-able products are chopped spinach, chicken breast, peas, corn, shrimp, sliced tomatoes, beans, fruit berries etc. Agriculture produce and meat products are the gold mine of food industry which are considered as the main stay for economy and IQF helps in preserving this treasure efficiently without compromising with its nutritional and sensory qualities.



Retort Technology

Changing lifestyle and nuclear families are leading to exponential increase in the demand of ready to eat processed food in developing countries like India. A consumer would prefer traditional food on a daily basis, provided a safe, tasty and processed option is available. Therefore, this modern urban dynamic lifestyle leads to the genesis of discovery of Ready to Eat foods.

Retorting is one of the major technique used for the thermal processing of food products which are packed either in semi-rigid flexible laminates or in metal or alloy cans. Retort Technology provides the advantage of processing the food and packaging together which makes the filled product more commercial stable. This technique is used for commercialization of traditional or ethnic dishes which are important due to their delicacy and are high in demand. It can be defined as the heating of low acid food prone to microbiological spoilage in hermetically sealed container to extend shelf life.

Operating Principle

Retort is the main processing chamber for where the packed food is sterilized, pasteurized or cooked properly to achieve safety and quality. The major objective of this thermal processing is to destroy microorganisms and to deactivate the enzymatic activity which are responsible for shortage of shelf life and changing of physical and chemical properties of food. Retort consists of basket in which packaged food is kept. Then these food products are exposed to the sterilizing temperature (121 Deg. C) mainly by the application of steam and high pressure (15 psi). Compressed air and water are used for sterilizing and cooling for the food products respectively. Principally, it involves seven steps

  1. Preparing the Retorts: Cleaning by washing and steaming for a short time, checking the thermometer, pressure gauge, recorder, inlet, outlet valves etc. before loading the cans
  2. Loading: Cans are Jumble stacked for better steam circulation However, this reduces the retort capacity by about 25% and care should be taken to avoid denting.
  3. Venting: Removal of air from the retort before process timing begins.
  4. Come-up-time: This is the time required to bring up the retort to processing temperature after steam is turned on. Most important thing is to see that all air is driven out through vents before processing starts.. Vent should be closed when process time starts.
  5. Processing: When there is no automatic control, it should be seen that the retort temperature does not fluctuate more than 0.50C, throughout the process.
  6. Blowing Down: Stopping steam supply and opening the vents. The retort pressure should be gradually brought to ‘zero’. Too quick blowing down may result in buckling of cans. Open the retort only after pressure reaches zero.
  7. Unloading: Unload the cans and cool outside promptly.

The processing techniques also differ from product to product and from package to package. Hence, the retort designs and operating procedures also vary. Traditionally, metal cans were used for used for retort processing because of its rigidity but it could not efficiently transfer the heat due to which food in the middle takes larger time to get sterilized. Therefore, to combat this problem of uneven heating, retort pouches were developed which provides efficient heat transfer.

Components of Retort

  1. Steam inlet: It is a valve-controlled pipe of suitable size and the opening through which steam is admitted to the retort. The steam inlet to each retort shall be large enough to provide steam for proper operation of the retort, and shall enter at a point to facilitate air removal during venting.
  2. Steam Spreader: It is a pipe with perforations for uniform distribution of steam inside the retort. Perforated steam spreaders shall be maintained to ensure that they are not blocked during operation.
  3. Safety Valve: It is set to open, when the working pressure has exceeded the safety limit pressure of the retort.
  4. Vent: These are large valve, openings controlled by gate, plug cock, or other adequate valves used for the elimination of air during the venting period

  1. Bleeder: It is a small opening used to remove air entering the retort with the steam and to provide circulation of steam in the retort and shall be open during the entire process, including the come-up time. Bleeder should be positioned at sufficient distances and also near the thermometer and pressure gauges.
  2. Drain Valve: It is an opening used to remove the condensed or cooled steam (water). A non-clogging, water tight drain valve shall be used; screens shall be installed over all drain openings.
  3. Pressure gauge: is used to maintain correct processing pressure corresponding to the temperature to show the pressure inside the retort at all times.
  4. Thermometers: To maintain correct processing temperature and to show the temperature inside the retort during heat processing.
  5. Rails: In case of horizontal retorts only, used for pushing the trolley.
  6. Water inlet and spreader: It is used for spraying cold water on the can for cooling after heat process is over.
  7. Crates, baskets and devices: To hold the cans.

Types of Retort

  1. Batch Retort: It can be either horizontal type or vertical type. The retort has a lid or door with good fastening. It has necessary controls for temperature, pressure and safety devices. They can also be of circular or rectangular cross section. In batch systems, the retort is filled with product, closed and then put through a processing cycle.

  1. Continuous sterilizer in the continuous sterilizers, the cans enter and exit the sterilizer in a continuous manner. There is continuous container handling and intermittent product agitation. The retort system is constructed of a series of cylindrical vessels called shells (typically 1.5 m diameter). Processing and cooling occurs in separate shells connected by transfer valves. To maintain pressure in the shells, containers enter and exit through self-sealing inlet and discharge valves. Agitation occurs when the containers roll on the bottom of a shell. Product agitation increases rate of heat penetration, allows use of higher processing temperature (up to 138°C), and improves product uniformity and quality. Large initial investment and additional critical factors to monitor and control.


Retort processing has evolved one of the major sterilization technique significantly since its incorporation into Department of Defence and NASA food system. While the technology still relies on aggressive application and penetration of heat throughout foods, recent advancement in process engineering coupled with evolution of packaging technology have allowed for overall improvement of the technology. Retort processing presents the advantage of increased shelf life with less loss of nutrients due to which it can be applied to process ready to meal, marinades, vegetable curry, soups and rice.


COVID19- The contagion

World is facing the warmth of Coronavirus outbreak, initially reported on 31st December 2019 and was then declared as global pandemic by WHO (World Health Organisation) in the statement released by its Director General’s opening remark  on 11 March 2020, due to its instant increase in the cases all over the world affecting large no of people. Before declaring it as pandemic, outbreak of COVID-19 was declared as global health emergency on 30 January 2020. Pandemic term has been used instead of epidemic due to its widespread rise in cases over a wide geographical area, unlike epidemic where there are stable number of cases during outbreak.

Summary to SARS-CoV-2

Coronavirus had been known dated back since 1960’s, having ability of causing illness in animals & humans, mostly affecting respiratory system causing disease such as MERS (Middle East Respiratory Syndrome) and SARS (Severe Acute Respiratory Syndrome).

SARS-CoV-2 i.e. Severe Acute Respiratory Syndrome Corona Virus-2 is a new infectious virus responsible for the transmission of coronavirus disease 2019 also known as COVID-19. Coronavirus are positive stranded RNA viruses with layer of protein & enveloping layer of lipid. They primarily target cells of respiratory and gastrointestinal tract of humans and animals including birds and mammals. Its epidemiological information are yet unknown.


Origination & Transmission  

Its origination was marked from Huanan seafood market (Live animal & seafood market in Wuhan), China. Several patients were hospitalized on 31 December 2019 with symptoms of severe pneumonia and subsequent increase in similar cases in China, people having travel history to China and people coming in contact with respiratory symptoms. Source of SARS-CoV-2 is believed to be from bats or possibly pangolins but its yet to be confirmed.

Virus have proliferation capacity when it is inside host and hence can be said they are incapable of multiplying independently. In humans, virus can reach respiratory or gastrointestinal cells either through ocular mucosa (eyes), nasal mucosa (Nose) or buccal mucosa (Mouth) and attacks the cells over their by multiplying aggressively.

Transmission of corona virus in humans are mainly either by direct transmission or indirect transmission.

  1. Direct Transmission: When healthy person comes in contact with respiratory secretion of infected person such as droplets from coughing & sneezing.
  2. Indirect Transmission: When healthy person comes in contact with infected objects or surface that are infected by the respiratory droplets of infected person.   Healthy person coming in contact with infected objects and touching their skin, cloth, eyes, nose etc. can transmit the virus.

Corona virus is able to survive on surfaces for certain period of time. Please refer below table for details-


Surface Type

Survival Time

(Approx. Hours)














  1. Currently respiratory mode is the only known way of virus transmission from human to human.
  2. Incubation period for this disease is between 2- 14 days.


Major drawback researchers are facing right now are not having enough information on its epidemiology. Trends shows this virus is majorly impacting respiratory system, with early symptoms being of flu like symptoms such as high fever, dry cough, difficulty in breathing, muscle pain, headache, running nose, sore throat, diarrhea, congestion and weakness. While patients with severe cases are observed with severe pneumonia, acute respiratory distress, sepsis and sepsis shock that can lead to death.

Relatively lower cases in children has been reported, and severely affected cases are of elderly people and those having history of health problem of high BP, heart issues, diabetes or lack of immunity.     


  1. People may be infected even without showing any of the above-mentioned symptom.
  2. People showing no symptoms are also potent of transmitting the virus.   


Guidelines has been released by WHO on prevention of infection for the public, which are basic preventive measures including frequent washing of hand, avoid touching of eyes, mouth, nose and skins, avoid touching of skin, proper disposal of respiratory discharge, avoiding contact with infected person, good respiratory hygiene.

Some of the general preventive method that can be consider are-

  1. Avoiding handshake & maintaining approx. one-meter distance from people having flu type symptoms.
  2. Avoiding crowded place, travelling, having foods from outside.
  3. Observing self-isolation & social distancing in case of having flu like symptoms.
  4. Covering face using mask in case suffering from any flu like symptoms.
  5. Frequent Hand Wash especially before & after touching one’s eyes, mouth, nose, switches, doorknobs, or surfaces that are publically used and before having food. Soap is able to disintegrate its outer lipid layer that is soluble in non-polar components.
  6. Incorporating diet consisting of high amount of Vitamin C.
  7. Use of warm water for consumption as well as for washing to increase the efficiency of cleaning.
  8. Sanitizing hands with sanitizer with more than 65% alcohol content
  9. Sanitizing masks & other personal, health care items under UV light that can breakdown the protein structure of virus.
  10. Prefer to be in dehumidified, dry, warm, bright and naturally ventilated space.


No specific treatment or vaccines for COVID-19 has been yet developed. Researchers from all over the world are working on vaccines for this disease and it shall not be wrong to say that for present scenario, prevention is the only possible way that can reduce the spread of COVID-19. A best possible way to prevent the spread of disease is to identify the person susceptible to virus and have them in proper isolation. Antiviral medicines used for treatment of MERS-CoV are being investigated for treatment of SARS-CoV-2.

Country and Technical Guidance for COVID-19 has been provided and published by WHO on their official website. (  2019/technical guidance).

It is of enormous importance to have awareness and knowledge on the recent update and advancement on COVID-19. Prevention and preparedness are the only way out of this crisis. Even measures imposed by government can be effective only if they are properly implemented and  acknowledged by citizen of the country.

“Break The Chain”.