Assignment Code: MFN-003/AST-3/TMA-3/22-23

Course Code: MFN-003

Assignment Name: Food Microbiology and Safety

Year: 2022-2023

Verification Status: Verified by Professor

Section A -Descriptive Questions (80marks)

There are eight questions in this part. Answer all questions.

1. a) Describe the role of microorganisms in fermented foods. (5)

Ans) The progressive breakdown of organic materials caused by bacteria or complex nitrogenous substances (enzymes) produced from plants or animals is known as fermentation. What is referred to as a metabolic change happens when carbohydrates are oxidised anaerobically or partially anaerobically by either bacteria or enzymes.

Since there is no environment where a particular species of microbe cannot exist, foods inherently contain microbes. These bacteria, whether living or dead, and the biological byproducts they produce, provide specific functions in some foods. These things include things like fermented food. To turn the original meal into a fermented product, certain microorganisms are used in fermented foods. While consuming the original product to develop and reproduce, these bacteria release byproducts into the environment surrounding them and the food. These byproducts and the remnants from the original product make up the fermented food. Fermented foods include dairy, meat, fish, grains, fruits, and vegetable goods. They can either be fermented separately or together to produce the desired outcome.

Although food has been fermented for thousands of years, it's likely that the microbial and enzymatic pathways that resulted in the alterations were mostly unknown. Recently, both our understanding of these mechanisms and how they have been altered for commercialization have evolved.

b)What are the hazards associated with food safety. Explain by giving suitable example. (5)

Ans) Acute and long-term risks to consumers' health from food are what food safety is all about. Both an absolute and a relative definition of food safety are possible.

1. The guarantee that damage or injury from use of a product is impossible is known as "absolute food safety."

2. "Relative food safety" refers to the assurance that a food or ingredient utilised in a reasonable and customary method and quantity won't cause harm or damage.

By identifying hazard and toxicity, two additional fundamental ideas, one may better comprehend food safety. Hazard is the likelihood that harm or injury will occur when a chemical is used in the suggested way and quantity, whereas toxicity is a substance's propensity to cause harm or injury of any sort under all circumstances. Remember that a food's or ingredient's safety shouldn't be determined by how hazardous it is by nature, but rather by whether or not a hazard is introduced.

The characteristics that affect a product's value to a consumer are referred to as food quality. This encompasses both harmful features like spoilage, infection, adulteration, and risks to food safety as well as beneficial attributes like origin, colour, flavour, and texture. Food hygiene is a term that is frequently used while discussing food safety. All conditions and actions required to guarantee the appropriateness and safety of food at every link in the food chain are referred to as food hygiene.

after a thorough analysis of the various terminology used in relation to food and worries about its safety. While some of the foods can be eaten raw, others need to be processed before they can be eaten. Safety Certain foods are processed to create ingredients that could be hazardous to humans. The use of agricultural and environmental chemicals, pharmaceuticals, synthetic substances, and fertilisers are some of the food processes that could result in the formation of potentially dangerous molecules in foods or those that change its nutritional value. As a result, food safety is extremely important and is receiving global attention. In addition to all of these, one of the key issues that calls for special attention is the attitude and information of the consumer regarding food safety. Developing the knowledge and abilities necessary to comprehend and control the risks to food safety is crucial.

2. a) Briefly discuss the characteristic features and reproductive process of different forms of fungi. (5)

Ans) Following are the important characteristics of fungi:

1. Fungi are eukaryotic, non-vascular, non-motile and heterotrophic organisms.

2. They may be unicellular or filamentous.

3. They reproduce by means of spores.

4. Fungi exhibit the phenomenon of alternation of generation.

5. Fungi lack chlorophyll and hence cannot perform photosynthesis.

6. Fungi store their food in the form of starch.

7. Biosynthesis of chitin occurs in fungi.

8. The nuclei of the fungi are very small.

9. The fungi have no embryonic stage. They develop from the spores.

10. The mode of reproduction is sexual or asexual.

11. Some fungi are parasitic and can infect the host.

12. Fungi produce a chemical called pheromone which leads to sexual reproduction in fungi.

13. Examples include mushrooms, moulds and yeast.

Reproductive process of different forms of fungi

Asexual Reproduction of Fungi

There are different ways in which fungi can reproduce asexually. Some details are mentioned here in a comprehensive manner:

Fragmentation: Thallus fragmentation is one of the most common ways in which fungi reproduce. There are a lot of filaments in thallus which help the single-celled living creatures to reproduce. Moreover, they can make colonizations by connecting through these.

Cell Division: When asexually reproducing, the fungi go through fission. It is another way they produce colonies. This is also known as cell division. A simple nuclear division of the cell takes place one after another and a colony is formed.

The Building of Fungi: Filamentous fungi can asexually reproduce with the help of budding. It is one of the common reproductive processes in fungi. The yeast cells mostly take the process of budding to reproduce asexually.

Sexual Reproduction

Sexual reproduction of fungi is vital as it helps to develop the variable genes in the organism and makes it easier for them to get accustomed to new environments. There are many unique ways in which the fungi reproduce sexually. It has three different parts:

Plasmogamy: It is the state of sexual reproduction where the protoplasms go through a fusion and takes the cell to a haploid state.

Karyogamy: When the nucleus goes through a process of fusion it is known as Karyogamy. Here, the fungal cells enter into a phase where the two chromosome sets meet with each other. At this stage, the entire structure is called the zygote.

Meiosis: The meiosis in the fungi takes place as the orgasms start developing mesopores. It is one of the best sexual ways to reproduce in the fungi as total genetic variation takes place with the help of it. This way more unique fungi clusters are formed. These can further reproduce and keep on doing the same.

b) Describe the control and destruction of microorganisms using high temperature processing. (5)

Ans) Any and all temperatures over the room's temperature are considered to be high temperatures. Pasteurization, canning, and sterilisation are the three categories utilised in high temperature microbe control or destruction.

Pasteurization

Pasteurization is the process of utilising low heat to eliminate all pathogenic organisms from food (such as milk) or to reduce organisms that cause food to spoil (such as vinegar). It is known as "pasteurisation" when food is cooked in containers or using other devices to a temperature below 100°C for a predetermined amount of time. Typically, the pasteurisation process entails heating the food for a brief period of time up to an hour to temperatures between 60°C and 85°C. Quick cooling follows the heat treatment on the meal.

Pasteurization of milk kills pathogenic organisms, lowers overall bacterial counts, lengthens storage life, and also inactivates enzymes that could negatively impact milk flavours. Typhoid, scarlet fever, diphtheria, TB, and brucellosis were all too common before milk was pasteurised because conlaminated milk was consumed. Traditionally, milk is pasteurised using the Low Temperature Long Time (LTLT) method, which involves keeping the milk heated between 63 and 65°C for 30 minutes. The milk is heated quickly to 71.7°C in the High Temperature Short Time (HTST) procedure, kept there for 15 seconds, and then quickly cooled to 4°C. Other temperature ranges with various holding times are also used. Milk and other dairy products are cooked at a temperature of 132°C for at least 2 seconds during the Ultra High Temperature (UHT) pasteurisation process.

Canning

Foods that have been preserved by heat processing are more formally referred to as canning. By using heat, it seeks to kill bacteria and their spores. Therefore, the phrase "canning industry" is generally meant to refer to the complete range of goods that are heat-preserved, whether they are packaged in glass, thermostable plastic pouches, tin or aluminium cans, or any other container. The temperature utilised for heat processing during canning ranges from 123°C for low acid foods to 100°C for high acid foods. Temperatures between 1200 and 1500 C or higher may need to be used for the HTST process. When compared to a product that is treated to longer periods of time at lower temperatures, the method typically produces a product of higher quality.

A few crucial elements, including pH, initial bacterial load, salt and sugar contentration in the product, determine the 'leat processing for canning. One of the key elements that affects the temperatures to be used is the pH of the food that will be canned. The pH has an impact on the food product's quality and stability. The lowest pH at which C. botulinum may grow normally is pH 4.5, which is the essential pH on which most operations are based.

3. a) Briefly discuss the spoilage of the following: (5)

(i) Fruits and vegetables

Ans) About 20% of vegetables and fruits harvested for human consumption in the world is lost due to microbial spoilage. Fermented vegetables and fruits can be contaminated with different microorganisms during processing, which can cause spoilage. Spoilage is any change occurring in fruits and vegetables, making them inedible for human. Fresh vegetables and fruits contain natural microflora coming from soil, water, air, and other sources. The presence of air, high humidity, and high temperature as extrinsic factors during storage of vegetables and fruits increases the chances of microbial growth and spoilage. The common fruit fly can contaminate plant foods with microorganisms such as Rhizopus spp. Microbial spoilage in fruits represents significant economic loss throughout the fruit distribution chain. Refrigeration, vacuum packaging (VP), modified atmosphere packaging, washing, freezing, drying, heat treatment, and chemical preservatives are used to reduce microbial spoilage of vegetables and fruits.

(ii) Milk and milk products

Ans) Dairy processing involves pasteurization, commercial sterilization, fermentation, dehydration, refrigeration, and freezing. In this chapter, contamination and spoilage of milk and milk products and interaction of microorganisms with dairy foods are overviewed. Spoilage of milk and milk products results from growth of fermentative bacteria when storage temperatures are sufficiently high for psychrotrophs. Heat-resistant proteinases of psychrotrophic bacteria cause spoilage in processed milk because of enzyme-retaining activity after the heat treatment. The most common fermentative spoilage of fluid milk products is souring caused by thermoduric lactic acid bacteria (LAB). Concentrated milk products can be divided into three groups: evaporated milk, sweetened or unsweetened condensed milk, and concentrated milk. Psychrotrophic bacteria have primary importance in cheese spoilage since these bacteria produce very active proteolytic and lipolytic enzymes. Centrifugation, clarification, or separation will remove some microorganisms from milk.

b)“Spoilage causes chemical changes in food” Justify the statement. (3)

Ans) Chemical reactions take place in the presence of atmospheric oxygen and sunlight. Two major chemical changes, which occur during the processing and storage of fruits and vegetables, are lipid oxidation and non-enzymatic browning which deteriorate sensory quality, colour and flavour .

Lipid oxidation is influenced by light, oxygen, high temperature and the presence of iron and copper, and water activity. Control of these factors can significantly reduce the extent of lipid oxidation or rancidity in foods.

Non-enzymatic browning is one of the major causes of deterioration which takes place during frying, cooking, storage of dried and concentrated foods through Maillard, caramelization and ascorbic acid oxidation. Maillard reaction occurs due to reactions between reducing sugars and amino acids in the presence of heat and results in formation of black, brown insoluble pigments . Caramelization of sugars occurs in presence of high heat and low moisture content in the food. Oxidation of fatty acids to other chemicals like aldehydes, ketones, alcohols and esters also results in off-flavours.

c) List some common food borne intoxications in human. (2)

Ans) Common food borne intoxications in human are as follows:

1. Staphylococcal poisoning

2. Bacillus Cereus Poisoning

3. Botulism

4. a) Give the symptoms, food involved and preventive measures of the following diseases: (4)

i) Aflatoxicosis

Ans) symptoms: Vomiting and abdominal pain, liver necrosis with elevated hepatic enzymes and bilirubin, prolonged clotting times, decreased production of milk and eggs in animals, growth impairment in the young, and reduced immune competence

Food involved: Maize, cereals, nuts, spices, figs, dried fruits, dairy products such as milk and cheese and also animal feed ingredients like groundnut and cottonseed cake.

Preventive measures: Use of resistant varieties, crop rotation, well-timed planting, weed control, pest control especially control of insect pests and avoiding drought and nutritional stress through fertilization and irrigation.

ii) Botulism

Ans) symptoms: Difficulty swallowing, Muscle weakness, Double vision, Drooping eyelids, Blurry vision, Slurred speech, Difficulty breathing, Difficulty moving the eyes.

Food involved: products of fish or marine ' animals, meat, fruits and vegetables, including mushrooms.

Preventive measures: refrigerating leftovers promptly, using foods that are stored in oil within 10 days of opening, keeping foods stored in oil, like vegetables and herbs, in the fridge, making sure products marked 'keep refrigerated' are kept in the fridge.

b) Explain briefly the naturally occurring toxicants in plants foods. (4)

Ans) Many foods, even some that we eat frequently, contain hazardous substances that are best avoided. These substances may naturally occur as proteins, amino acids, alkaloids, or cyanogenic glycosides.

Favism is a disorder that develops after consuming fava beans and is characterised by hemolytic anaemia (red blood cell breakdown). For people who lack the enzyme glucose-6-phosphate dehydrogenase, fava beans, an important source of protein in the Middle and Far East and North Africa, can be dangerous. When these beans are consumed, favism, an illness that causes headaches, nausea, vomiting, discomfort, and fever, develops. The fast breakdown of red blood cells is followed by haemoglobin in the urine, jaundice, and death.

Cotton seed contains gossypol, another toxicant, and if the cotton seed is not handled properly, it could enter the cotton seed oil. Rapeseed and mustard oils contain erucic acid, which has been related to heart disease. In reality, eating bitter cucumber, zucchini, and other squash and gourds can cause severe cramps, diarrhoea, and even collapse. This is brought on by the toxin cucurbitacin's elevated levels in the bitter cucumbers. Therefore, it is advised to avoid eating bitter vegetables.

particular toxins discovered in plant-based meals

1. Toxic amino acids

2. Toxic alkaloids

c) Define food additives and food adulterant. (2)

Ans) Food addistive: Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives have been used for centuries as part of an effort to preserve food, for example vinegar, salt, smoke, sugar, etc. This allows for longer-lasting foods such as bacon, sweets or wines.

Food adulterant: An adulterant is caused by the act of adulteration, a practice of secretly mixing a substance with another. Typical substances that are adulterated include but are not limited to food, cosmetics, pharmaceuticals, fuel, or other chemicals, which compromise the safety or effectiveness of the said substance.

5. a) Differentiate between cleaning agents and disinfectants / sanitizers used to maintain hygiene in a food service establishment. Give appropriate examples. (5)

Ans) Cleaning chemicals dislodge and loosen food debris by lowering the energy of the interaction between it and the surface, and they also suspend the debris in the solution so that it may be washed away. A chemical substance that may eliminate bacteria is a disinfectant. A sanitizer is also known as a disinfectant, and both terms allude to the substances' abilities to keep things clean.

Different cleaning compounds are utilised depending on the type of soil (food debris), water supply, use for certain purposes, region, and type of equipment to be cleaned. Good cleaning agents are affordable, simple to measure, and easily dissolved. Chemical sanitizers are used in food processing and food service activities for various spaces and equipment types.

Examples of cleaning agents: Since the dawn of time, Bengal gramme powder, also known as besan, has been utilised as a natural cleaning agent in India. It has long been used to get rid of grease clings on kitchen tools. Alkaline compounds include carbonates, bicarbonates, and hydroxides of various metals. The pH of alkaline cleaning products ranges from 7 to 14. Strong alkaline cleaners are cleaning agents with a pH level about 14, such as sodium hydroxide, which effectively disperses and emulsifies filth while also destroying microorganisms and dissolving protein.

Examples of chemical sanitizers: Hypochlorites, which release chlorine, are the preferred disinfectants used in the food business. The hypochlorites are potent decontaminants that have a broad spectrum of anti-bacterial activity, including bacterial spore elimination. Many people use hypochlorous acid (HOC1) salts such sodium hypochlorite (NaOCl). Iodine and a detergent are combined when they dissociate to create OC1, the ion that has the bactericidal property. In addition to losing their effectiveness in the presence of organic debris, they are not as effective as hypochlorites against bacterial spore. Although they have a lengthy shelf life, the iodine may vapourize after it has been dissolved. Iodophors are frequently used in the dairy sector because of their ability to kill bacteria and because they contain phosphoric acid, which aids in the prevention of milk stones..

b) Define the term packaging. Briefly discuss its importance in context to food quality. (5)

Ans) Packaging is the science, art and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of designing, evaluating, and producing packages.

Importance of food packaging: After the food item is processed, it needs proper packaging before moving out to the stores, and ultimately, the consumers' homes. The stores are often located miles away from the production and packaging plants. Moving them such long distances can lead to rotting, making the food inconsumable altogether. However, proper packaging protects the food against external elements, such as oxygen (in the air), light, moisture, and even pathogens like bacteria, preventing decomposition and harmful reactions. Resultantly, the food remains chemical-free and fresh with an increased shelf life and hence, stays fit for use for a longer time after production.

Food packaging not just secures the food against external impacts, it also ensures that the items do not get crushed, flattened or punctured. Food products pass through multiple procedures before getting to their final destination. Without proper packaging, they can lose their shape or texture during shipping or storage. For instance, creamed bakery goods must stay upright, meat liquid must not leak out, and fruits must not flatten under pressure, or their juice will spill out.

High-quality food packaging ensures that the food is moved and delivered without any physical damage. It also reduces the amount of care needed to handle the products, resulting in easy shipment and storage. Furthermore, when the food items always reach the consumers in top-class condition, it leads to high market demands and increased consumer trust.

6. a) Why is risk assessment important? Enumerate the four steps involved in risk assessment. (4)

Ans) Risk assessment is crucial because it gives risk management a foundation for managing the use of physical or chemical agents to safeguard human health and the environment. It is included into the decision-making process to guarantee the protection of the public from reasonable risks. Risk characterization, exposure assessment, and hazard identification are all parts of a food or ingredient's risk assessment. This ultimately leads to the choice of whether or not any legal action should be taken to stop the harm caused by this food or component.

Four steps involved in risk assessment

Identification of biological, chemical, and physical factors that can harm human health that may be present in a specific food or group of foods is known as "hazard identification."

Risk classification is "the analysis, both qualitative and quantitative, of the potential harmful effects on health caused by biological, chemical, and physical components found in food. A dose-response analysis should be done for chemical agents. If data are available, a dose-response analysis for biological or physical agents should be done."

The qualitative and quantitative examination of the likely ingestion of biological, chemical, and physical agents via food, as well as exposures from other sources, if appropriate, is known as exposure assessment.

Based on hazard identification, hazard characterization, and exposure assessment, risk characterization is defined as "the qualitative and/or quantitative estimation, including attendant uncertainties, of the probability of occurrence and severity of known or potential adverse health effects in a given population."

b) List and discuss some common adulterants found in food items. (4)

Ans)

c) Give functions and examples of emulsifying and anti-caking agents as food additive. (2)

Ans) Emulsifying food additive: Emulsifiers form and stabilize oil-in-water emulsions e.g., mayonnaise, uniformly disperse oil-soluble flavour compounds throughout a product, prevent large ice-crystal formation in frozen products e.g., ice cream, and improve the volume, uniformity, and fineness of baked products.

Anti-caking agents: Anti-caking agents are anhydrous compounds that are added in small amounts to dry foods to prevent the particles from caking together and to ensure the product remains dry and free-flowing.  Anti-caking agents function by absorption of excess moisture or by coating particles to make them more water repellent. For example, Mannitol, Powdered cellulose , Calcium silicate etc.

7. a) Explain briefly use of plastic and flexible films made from non-fibrous plastic polymers in food packaging. (5)

Ans) The most widely used plastic film is simple cellulose, a glossy, transparent material that has no taste or odour and degrades within 100 days. It is typically applied to goods like fresh bread and some forms of confectionery that don't need a complete moisture or gas barrier. The additional plastic films comprise:

Low density polyethylene (LDPE), medium density, linear low-density (LLDPE), high-density polyethylene (HDPE), and ethylene vinyl acetate copolymer are examples of polyethylene (P) materials. These materials are excellent at sealing, good at blocking moisture, durable at low temperatures, and tear-resistant. LDPE can be heat sealed, has no odour, and contracts when heated. Because it is less expensive than most films, it is utilised frequently, including in shrink or stretch-wrapping applications. Compared to LDPE, HDPE is more brittle, less flexible, thicker, and stronger.

Polypropylenes (PP) (cast PP, Bi-axially oriented PP (BOPP), pearlized PP): It's common to refer to polypropylene as a permeable film. This film is utilised in retort or pasteurised packing but is not a suitable gas barrier because of its moisture barrier and temperature resistance qualities. The material has exceptional flexcrack resistance, high gloss, and superb clarity. Bottles, jars, crisp packets, cookie wrappers, and boil-in-bag films are just a few of the various possibilities for polypropylene packaging materials.

Uncoated polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC): PVC and PVDC are two closely related plastics that were initially created in the 1930s and are a subset of the class of polymers most usually referred to as "vinyl". It can be used to wrap meats in "film," as well as to make water and cooking oil bottles. PVC is most frequently manufactured into very thin plastic "film" (like that used to wrap meat) and into thicker plastic "sheet," which is then moulded into a rigid container with a "clam shell" shape.

Nylon (PA) polyamides and polyethylene modifications: Because of a combination of characteristics, nylon, a strong transparent film made of two fundamental polymers (Type 6 and 66), is appropriate for a wide range of industrial applications. It can be extruded coated, laminated, or printed. It should be emphasised that nylon is a subpar moisture barrier on its own.

b) What is food labeling? Write its requirements and bar coding in detail. (5)

Ans) Food label is any tag, brand, mark, pictorial or other descriptive matter, written, printed, stencilled, marked, embossed or impressed on, or attached to, a container of food or food product.

Requirement of food labelling: Ensuring food safety is a shared responsibility between governments, producers, industry and consumers. Food labelling is one way in which consumers can get knowledge about the food they consider buying. Correctly following the information provided on food labels (such as expiry dates, handling instructions and allergy warnings) can help consumers prevent unnecessary food-borne illness and allergic reactions.

Bar coding: The small image of lines, or bars, and spaces are affixed to nearly everything one can imagine, for identification purposes. Specifically, barcodes use a sequence of vertical bars and spaces that represent numbers and other symbols; typically, a barcode consists of five parts – a quiet zone, a start character, data characters (often including an optional check character), a stop character, and another quiet zone. Much like asset tracking, inventory management makes use of barcoding to optimize efficiency. Organizations must know the location of their products, how they are distributed to locations and customers, how to track sold units, and when to reorder inventory. Inventory management systems that utilize barcodes automate all aspects of inventory management and improve inventory positions and forecasting models. Barcoding increases operational efficiency, allows for better customer service, and results in improved visibility into key business processes and management practices. Accurate information is crucial for business, both in terms of inventory management and asset tracking. Barcoding is reliable and cost effective, as it virtually eliminates human error and saves valuable time. Barcoding helps companies comply with industry regulations and ensures data accuracy and availability. Ensure accurate information in supply chain and operations with barcoding.

8. a) What do you understand by the term HACCP? Discuss its significance.

Ans) HACCP is a management system in which food safety is addressed through the analysis and control of biological, chemical, and physical hazards from raw material production, procurement and handling, to manufacturing, distribution and consumption of the finished product.

Significance of HACCP: HACCP based procedures provide businesses with a cost effective system for control of food safety, from ingredients right through to production, storage and distribution to sale and service of the final consumer. The preventive approach of HACCP based procedures not only improves food safety management but also complements other quality management systems. The main benefits of HACCP based procedures are:

1. Saves the business money in the long run

2. Avoids poisoning the customers

3. Food safety standards increase

4. Ensures compliant with the law

5. Food quality standards increase

6. Organises process to produce safe food

7. Organises the staff promoting teamwork and efficiency

8. Due diligence defence in court.

b) Briefly discuss the role of the following in the area of food safety.

i) World Trade Organization

Ans) Food standards and trade go hand in hand in ensuring safe, nutritious and sufficient food for a growing world population. Together, the FAO and the WTO provide governments with the means to establish a framework to facilitate trade on the basis of internationally agreed food standards. To avoid that food safety issues are being used as a pretext to shield producers from foreign competition, governments are encouraged to base their trade-restrictive measures on science and to follow internationally recognized food safety standards.

ii) ISO

Ans) It provides a framework for measuring and assessing food safety risks and performance, including all aspects of the supply chain. Ensuring the quality and safety of product is why ISO standards are so important. Most food we eat today goes through multiple journeys before reaching our plate. Therefore, it is crucial to take extra precautions when manufacturing, transporting and distributing food. Guaranteeing that the food we consume is safe from a hygienic and bacterial standpoint is vital. Not complying with food safety can result in a consumer becoming seriously ill, which can damage reputation, result in severe fines, and in extreme cases, can directly result in company closure or liquidation.

iii) FAO/WHO

Ans) Keeping food safe is a complex process that starts on the farm and ends with the consumer. FAO is the only international organization overseeing all aspects of the food chain, thereby providing a unique, 360° vision on food safety. A longstanding partnership with the World Health Organization (WHO) enhances this perspective. Through complementary mandates, FAO and WHO cover a range of issues to support global food safety and protect consumers’ health. WHO typically oversees and maintains strong relationships with the public health sector, and FAO generally addresses food safety issues along the food production chain.

Section B - OTQ (ObjectiveTypeQuestions) (20marks)

1. Explain the following briefly in 2-3 sentences each: (10)

i) Genetically modified foods

Ans) Genetically modified foods are foods produced from organisms that have had changes introduced into their DNA using the methods of genetic engineering. Genetic engineering techniques allow for the introduction of new traits as well as greater control over traits when compared to other methods, such as selective breeding and mutation breeding.

ii) Water Activity

Ans) The percentage of equilibrium relative humidity (percent ERH) divided by 100 is known as water activity. The amount of free water vapour present on a product, both at its surface and within its structure, is expressed by the ERH. In numbers, the "Water Activity" of a food is obtained by dividing the ERH by 100.

iii) Bacteria

Ans) Bacteria are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms.

iv) Temperature danger zone

Ans) Bacteria grow most rapidly in the range of temperatures between 40 °F and 140 °F, doubling in number in as little as 20 minutes. This range of temperatures is often called the "Danger Zone."

v) Modified Atmospheric Packaging

Ans) Modified Atmosphere Packaging (or MAP) is the practice of manipulating the atmosphere inside packaging containing perishable foods (for example, beef, pork, chicken, and fish). The goal of the process is to increase the shelf life of the product contained within.

vi) Chemical changes in fish

Ans) Along with microbes, autolytic enzymes also actively contribute to the deterioration of fish, much like they do with meat and poultry. Fish has a higher amount of oxidative rancidity than other animal products because its lipids include a lot of polyunsaturated fatty acids (PUFA).

vii) Shigellosis

Ans) Worldwide, salmonellosis is a prevalent food-borne illness. There are roughly 1600 distinct Salmonella strains. Typhoid is brought on by Salmonella typhimurium, the most prevalent member of the genus.

viii)Lathyrism

Ans) Lathyrism is a condition caused by eating certain legumes of the genus Lathyrus. There are three types of lathyrism: neurolathyrism, osteolathyrism, and angiolathyrism, all of which are incurable, differing in their symptoms and in the body tissues affected 

ix) Coextruded films

Ans) *Co-extruded film is a multilayer film produced by a compound molding technique that extrudes thermoplastic resin with multiple extruders and passes that through a single die to build up layers of melted resin both on the inside and outside of a film.

x) Personal hygiene

Ans) Personal hygiene are the behaviours that must be practised in daily life, starting from morning to sleep time to protect our health. To protect health, body, hair, mouth and teeth must be cleaned regularly and clothes must be washed frequently.

2. Describe the relationship between the following sets of terms (5)

i) Lathyrism and Food adulteration

Ans) The practise of adulterating food or contaminating food ingredients by adding a few compounds, which are collectively referred to as adulterants, is referred to as food adulteration. Eating some legumes from the genus Lathyrus can lead to the neurological condition known as lathyrism. Specifically, Lathyrus sativus, often known as almorta, is linked to this issue. However, food adulteration is just the blending of several ingredients into a product. The primary distinction between lathyrism and food adulteration is this.

ii) Nitrogen and Gas packaging

Ans) Modified Atmosphere Packaging (MAP) is a common industry solution which is used to combat food decay. It works by modifying the natural atmosphere that food is stored in to a modified atmosphere which contains less oxygen, usually less than 1%. The reason why the food industry strive for less oxygen in their packaging is because oxygen within a food package leads to oxidation, resulting in food spoilage. If moisture is also present with the oxygen in the packaging this can create an environment in which bacteria can thrive. By reducing the oxygen within food packaging the food industry can prolong the shelf-life of their products by delaying decay. Some foods which are known to benefit from MAP include coffee, crisps, rice and pasta which are often packaged using Vertical Form Fill and Seal (VFFS) machinery. Nitrogen is widely used in the food industry for Modified Atmosphere Packaging as it is an odourless, colourless and tasteless gas which, coupled with its inertness and dryness, make it a suitable gas to use to displace oxygen from food packaging.

iii) Moisture and Food spoilage

Ans) Food spoilage can be defined as a disagreeable change in a food’s normal state. Such changes can be detected by smell, taste, touch, or sight. These changes are due to a number of reasons — air and oxygen, moisture, light, microbial growth, and temperature. Water is one of the most common substances on earth. It is an essential component of all foods. The amount of water in a food (known as percent water) influences the appearance, texture, and flavor of the food. All living organisms as well as food contain water. Water makes up about 70% or more of the weight of most fresh (unprocessed) foods. Even “dry” foods like beans, flour and cereals contain some water. Fresh fruits and vegetables contain the most water — between 90% and 95% water. Although the water content of a food is expressed as a percent, this number does not reflect how the water exists in the food. Water in food is classified according to its availability, or biological activity and is either “free” or “bound.” Free water is not bound to any components in a food; it can be used for microbial growth and is also available for chemical reactions. Bound water is physically bound to large (molecules) components in the food. It is not available to microorganisms for their growth and it cannot participate in chemical reactions.

iv) Heavymetals and food contamination

Ans) Many different types of metals and metal compounds exist naturally in the earth's crust. Human activities, geological activities and other forces of nature may bring metals up to the surface and can increase the chance of human exposure to metallic contaminants. The history of such exposures goes back to pre-historic time, when humans were exposed to heavy metals via food and water in areas where the levels of heavy metals in the environment were naturally high. More recently, humans are exposed to metals as environmental pollutants from industrial or other human activities via food and water, among other things.

Four metals, namely lead, arsenic, cadmium and mercury, are of particular concern in food because of their toxicity, especially for long term (chronic) intake since they may accumulate in the body and cause organ damage particularly to susceptible groups such as foetuses and young children. Although acute poisoning from these metals is possible, it is more likely that it happens through non-food route. Each of these metals also forms numerous compounds with other elements, which vary in properties and levels of toxicity to humans when ingested.

v) Infective hepatitis and Oral Faecal Route

Ans) A few diseases that can be spread through the fecal-oral route include hepatitis A, hepatitis E, cholera, adenovirus, and E. coli. These diseases occur due to the viruses, bacteria, fungi, and parasites that can spread through fecal-oral transmission. Fecal-oral transmission happens when an infected person's contaminated feces enters the body of another person. This can occur when an infected person's hands aren't washed properly after using the bathroom; anything they touch afterward, such as a doorknob, can become contaminated with bacteria and be picked up by someone else. Eating foods that were washed or harvested from contaminated water can also spread disease in a similar manner. There are many microbes that can be passed along through the fecal-oral route, including two of the hepatitis viruses, hepatitis A and hepatitis E. The other hepatotropic viruses spread by direct contact with infected blood, such as from sharing used needles, bodily fluid, or through childbirth.

3. Match the following: (5)

Ans)