Principles of Food Science
MFN 008 Solved Free Assignment 2023
IGNOU MFN 008 Solved Free Assignment January 2023
Q 1. a) What is amylose and amylopectin? Enlist different properties of starch and its application in food industry.
Ans. a) Amylose and amylopectin are two types of polysaccharides that are present in starch, a carbohydrate storage molecule found in plants.
Amylose is a linear chain of glucose molecules linked by α-1,4-glycosidic bonds, while amylopectin is a highly branched molecule composed of glucose units linked by α-1,4-glycosidic bonds and α-1,6-glycosidic bonds.
Different properties of starch include its ability to form gels, thicken, stabilize and bind ingredients together. MFN 008 Solved Free Assignment 2023
In the food industry, starch is commonly used as a thickener, stabilizer, texturizer, binder and emulsifier in a wide range of products such as soups, sauces, desserts, baked goods, processed meats, and dairy products.
b) Discuss the role of modified starches in food and confectionery industries.
Ans b) Modified starches are starch derivatives that have been chemically or physically altered to enhance their functional properties.
Modified starches are used in the food industry to improve the texture, stability, viscosity, and shelf life of food products.
In the confectionery industry, modified starches are used as a gelling agent, to control crystallization, and as a binder in the production of gummies, marshmallows, and jellies.MFN 008 Solved Free Assignment 2023
c) What is agar? Write about its application in food industry.
Ans c) Agar is a polysaccharide derived from red algae and is commonly used as a gelling agent, thickener, and stabilizer in the food industry.
Agar has a high gel strength and is able to form gels at low concentrations, making it a popular choice for gelling applications.
Agar is commonly used in the production of desserts, confectionery products, and as a medium for microbiological cultures. Agar is also used as a vegetarian alternative to gelatin in many products.
Q 2. a) What are the different deteriorative changes that occur in fats and oils? Describe briefly.
Ans. a) Fats and oils are prone to deteriorative changes due to their chemical composition and susceptibility to oxidation.
Some of the deteriorative changes that can occur in fats and oils include hydrolysis, oxidation, polymerization, and rancidity. MFN 008 Solved Free Assignment 2023
Hydrolysis occurs when fats and oils react with water, resulting in the breakdown of ester bonds and the formation of free fatty acids.
Oxidation occurs when fats and oils are exposed to air or light, resulting in the formation of peroxides and other reactive oxygen species that can cause off-flavors and off-odors.
Polymerization occurs when unsaturated fatty acids react with each other, resulting in the formation of dimers, trimers, and other higher molecular weight compounds.
Rancidity occurs when fats and oils undergo oxidative and hydrolytic reactions, resulting in the formation of compounds with unpleasant odors and flavors.
b) Describe the different biological functions of protein in our body.
Ans b) Proteins are essential biomolecules that serve many important functions in the body. Some of the biological functions of proteins include:
Structural support: Proteins provide structural support to cells and tissues, helping to maintain their shape and integrity. Examples of structural proteins include collagen and elastin.MFN 008 Solved Free Assignment 2023
Enzymatic activity: Many proteins act as enzymes, catalyzing biochemical reactions in the body. Enzymes are responsible for processes such as digestion, metabolism, and DNA replication.
Hormonal regulation: Some proteins, such as insulin, act as hormones, regulating physiological processes such as metabolism and growth.
Immune defense: Antibodies are proteins that help the body defend against infections by recognizing and neutralizing pathogens such as bacteria and viruses.
Transport and storage: Proteins such as hemoglobin and transferrin are involved in the transport and storage of important molecules such as oxygen and iron.
c) What is tyndall effect?
Ans c) The Tyndall effect is a phenomenon in which light is scattered by colloidal particles in a transparent medium, making the path of the light visible.
The Tyndall effect is named after the Irish physicist John Tyndall, who first described the phenomenon in the 19th century. MFN 008 Solved Free Assignment 2023
The Tyndall effect is commonly observed in everyday life, such as when sunlight passes through a dusty room and makes the particles visible.
In the food industry, the Tyndall effect is used to detect the presence of colloidal particles in liquids such as milk, indicating the presence of contaminants or other impurities.
Q 3. a) What is invert sugar ? Give an example. Explain its uses in food industry.
Ans. a) Invert sugar is a mixture of glucose and fructose formed by the hydrolysis of sucrose. This hydrolysis can be catalyzed by heat or by enzymes such as invertase.
An example of invert sugar is golden syrup, which is a viscous, amber-colored syrup made by hydrolyzing corn syrup.MFN 008 Solved Free Assignment 2023
Invert sugar is commonly used in the food industry as a sweetener, and it has several advantages over other sweeteners such as sucrose.
For example, invert sugar is more soluble, more hygroscopic, and has a lower freezing point than sucrose.
These properties make it useful in the production of products such as ice cream, sorbets, and candies.
b) What is Rheology of foods? What are the different textural parameters observed in foods?
Ans b) Rheology is the study of the flow and deformation of materials, including foods. In the food industry, rheology is used to study the texture and sensory properties of foods. Different textural parameters that can be observed in foods include:MFN 008 Solved Free Assignment 2023
Viscosity: Viscosity is a measure of a food’s resistance to flow. High viscosity foods are thick and sticky, while low viscosity foods are thin and pourable.
Elasticity: Elasticity is a measure of a food’s ability to deform and then return to its original shape. Foods with high elasticity are springy and chewy.
Yield stress: Yield stress is the minimum amount of stress needed to initiate flow in a material. Foods with high yield stress require more force to initiate flow.
Hardness: Hardness is a measure of the force required to deform a food. Hard foods require more force to bite or chew than soft foods.
c) Write about the different methods of pasteurization
Ans c) Pasteurization is a process used to destroy microorganisms in food products, primarily through the application of heat. There are several methods of pasteurization, including:MFN 008 Solved Free Assignment 2023
High-temperature short-time (HTST) pasteurization: This method involves heating the food product to a high temperature (usually around 72°C to 76°C) for a short time (usually 15 to 30 seconds), followed by rapid cooling.
Ultra-high temperature (UHT) pasteurization: This method involves heating the food product to a very high temperature (usually above 135°C) for a very short time (usually 1 to 5 seconds), followed by rapid cooling.
Low-temperature long-time (LTLT) pasteurization: This method involves heating the food product to a lower temperature (usually around 63°C to 66°C) for a longer time (usually 30 minutes to 1 hour).MFN 008 Solved Free Assignment 2023
Pulsed electric field (PEF) pasteurization: This method involves applying short bursts of high-voltage electricity to the food product, which destroys microorganisms by disrupting their cell membranes.
Each method has its own advantages and disadvantages, depending on the type of food product being pasteurized and the desired shelf life.
Q 4. a) Briefly describe the role of irradiation and fermentation in food industry.
Ans. a) Irradiation is a process in which food products are exposed to ionizing radiation, such as gamma rays, X-rays, or electron beams.
The purpose of irradiation is to destroy microorganisms, reduce spoilage, and extend shelf life. It is used primarily for fresh fruits and vegetables, meat and poultry, and spices.MFN 008 Solved Free Assignment 2023
Fermentation is a process in which microorganisms such as yeast, bacteria, or molds are used to convert carbohydrates to alcohol, acids, or gases.
This process is used to produce products such as beer, wine, cheese, yogurt, and sourdough bread. Fermentation can improve the shelf life of some foods and create unique flavors and textures.
b) Describe the alterations that occur in egg during processing and storage.
Ans b) Egg processing and storage can result in several alterations, including:
Loss of carbon dioxide: Eggs naturally contain carbon dioxide, which helps maintain their quality. During processing, carbon dioxide may be lost, leading to a higher pH and a less desirable texture.MFN 008 Solved Free Assignment 2023
Shell contamination: During processing, eggs may become contaminated with bacteria, leading to spoilage and potential foodborne illness.
Yolk discoloration: Over time, the yolk may become more yellow and less translucent due to the breakdown of pigments.
Albumen quality: The albumen, or egg white, may become thinner and more watery over time, which can affect its coagulation properties in cooking.
c) What are the factors that affect the quality of taste in food?
Ans c) The quality of taste in food is affected by several factors, including:
Flavor compounds: The presence of certain flavor compounds, such as sugars, amino acids, and fatty acids, can affect the taste of food.
Texture: The texture of food can also affect its taste. For example, a creamy texture may be perceived as richer and more indulgent than a watery texture.
Temperature: The temperature at which food is served can affect its taste. Some foods are best served warm, while others are best served cold.
Personal preferences: Individual preferences for sweet, salty, sour, bitter, and umami tastes can vary, which can affect the perceived quality of taste in food.
Food pairing: The combination of different foods can affect their taste. For example, the pairing of sweet and salty flavors can create a unique and desirable taste experience.MFN 008 Solved Free Assignment 2023
Q 5. a)What is atmospheric dehydration ? Enlist the different dryers used in the food industry.
Ans. a) Atmospheric dehydration is a process of removing moisture from food products using natural or ambient air.
This process is commonly used for fruits, vegetables, and herbs, as it preserves the natural flavors and colors of the products.
Different types of dryers used in the food industry include tray dryers, tunnel dryers, fluidized bed dryers, and drum dryers.
b)Briefly discuss the primary processing of the following:
Ans i. Cereals: The primary processing of cereals involves several steps, including cleaning, grading, conditioning, milling, and packaging.
Cleaning: Cereals are first cleaned to remove any foreign material, such as dirt, stones, or broken grains.MFN 008 Solved Free Assignment 2023
Grading: The cleaned cereals are then graded according to their size, shape, and quality.
Conditioning: The graded cereals are then conditioned to soften the outer layer and improve the milling process.
Milling: The conditioned cereals are then milled to remove the outer layer or bran, and the endosperm is ground into flour.
Packaging: The milled flour is then packaged in different sizes for distribution.
Ans ii. Pulses: The primary processing of pulses involves several steps, including cleaning, soaking, boiling, and drying.
Cleaning: Pulses are first cleaned to remove any foreign material, such as dirt, stones, or broken pulses.MFN 008 Solved Free Assignment 2023
Soaking: The cleaned pulses are then soaked in water to soften them and reduce cooking time.
Boiling: The soaked pulses are then boiled until they are fully cooked.
Drying: The boiled pulses are then dried to remove any excess moisture and improve their shelf life. Drying can be done using different methods, such as sun drying, hot air drying, or fluidized bed drying.
Q 6. a) Briefly discuss different phases of developing a new product.
Ans. a) Developing a new product involves several phases, including:
Idea generation: The first step in developing a new product is to generate ideas for potential products. This can be done through brainstorming, market research, or customer feedback.MFN 008 Solved Free Assignment 2023
Concept development: Once an idea has been generated, the next step is to develop a concept for the product. This includes defining the target market, product features, and benefits.
Product design: The product design phase involves creating a prototype of the product, including packaging and labeling.
Testing: The product prototype is then tested for quality, safety, and consumer acceptance.
Launch: Once the product has been developed and tested, it is ready for launch. This includes developing a marketing plan, setting a price, and selecting distribution channels.MFN 008 Solved Free Assignment 2023
Monitoring: After the product has been launched, it is important to monitor its performance and make adjustments as needed to ensure its success.
b) Discuss the functional role of sugars in foods.
Ans b) Sugars play several functional roles in foods, including:
Sweetness: Sugars provide sweetness to foods, which is one of the primary reasons they are added to products.
Flavor: Sugars can also enhance the flavor of foods, providing a rich and complex taste profile.
Texture: Sugars can contribute to the texture of foods, providing a smooth and creamy mouthfeel.MFN 008 Solved Free Assignment 2023
Color: Sugars can also contribute to the color of foods, providing a desirable golden-brown color when baked or caramelized.
Preservation: Sugars can act as a preservative in some products, helping to extend their shelf life by reducing water activity and inhibiting the growth of microorganisms.
Fermentation: Sugars can be fermented by yeast or bacteria to produce alcohol, acids, and gases, which are used in the production of products such as beer, wine, and bread.
Q 7. a) What are biocatalysts? Explain their role in food industry.
Ans. a) Biocatalysts are biological molecules, typically enzymes, that catalyze chemical reactions.
In the food industry, biocatalysts are used to modify food components or to produce new food ingredients. MFN 008 Solved Free Assignment 2023
For example, enzymes are used to break down complex carbohydrates in starch to produce sweeteners, such as high-fructose corn syrup.
They are also used in the production of cheese, bread, and beer, where they help to break down proteins and carbohydrates, leading to changes in texture, flavor, and aroma.
b) Write in brief about foams and emulsions.
Ans b) Foams are formed by trapping gas bubbles in a liquid or solid matrix. In the food industry, foams are used to add texture and volume to food products, such as whipped cream, meringue, and sponge cake.
Emulsions are formed by mixing two immiscible liquids, such as oil and water, with the help of an emulsifying agent, such as egg yolk or lecithin.
Emulsions are commonly used in food products such as mayonnaise, salad dressings, and ice cream.MFN 008 Solved Free Assignment 2023
c) Explain different properties of solution which are important in food preparation.
Ans c) Different properties of solutions that are important in food preparation include viscosity, surface tension, and pH.
Viscosity is a measure of a fluid’s resistance to flow and is important in determining the texture of food products, such as sauces, dressings, and creams.
Surface tension is a measure of the force that holds the surface of a liquid together and is important in the formation of emulsions and foams.
pH is a measure of the acidity or basicity of a solution and can affect the flavor, texture, and color of food products.
For example, a high pH can cause browning reactions in foods such as bread and pretzels, while a low pH can lead to the coagulation of proteins in dairy products such as yogurt and cheese.MFN 008 Solved Free Assignment 2023
Q 8. a) Explain different freezing systems used in food industry.
Ans. a) Different freezing systems used in the food industry include air-blast freezing, plate freezing, and cryogenic freezing.
Air-blast freezing involves circulating cold air over the food product to freeze it quickly.
Plate freezing involves placing the food product between two plates that are cooled by refrigerants.
Cryogenic freezing involves the use of liquid nitrogen or carbon dioxide to rapidly freeze the food product.
Each system has its advantages and disadvantages depending on the type of food product being frozen.MFN 008 Solved Free Assignment 2023
b) Discuss the role of sensory evaluation in food product development.
Ans b) Sensory evaluation is an essential tool in food product development. It involves using human senses to evaluate the appearance, aroma, flavor, texture, and overall acceptability of food products.
Sensory evaluation can provide valuable information about consumer preferences, product quality, and product shelf life.
It is often used in the development of new food products, as well as in the optimization of existing products.
Sensory evaluation is typically conducted by trained panels of sensory experts, although consumer panels can also be used in some cases.
c) What is functional food? Explain by giving examples.
Ans c) Functional food is a food product that has been designed to provide additional health benefits beyond basic nutrition.
Examples of functional foods include probiotics, which contain live bacteria that can improve gut health, and omega-3-fortified foods, which contain high levels of omega-3 fatty acids that can reduce the risk of heart disease.
Other examples include fiber-rich foods that can improve digestive health, and antioxidant-rich foods that can help to prevent cell damage.
Functional foods are becoming increasingly popular as consumers become more health-conscious and seek out foods that can provide additional health benefits.
Section B – OTQ (ObjectiveTypeQuestions)
Q 1. Explain the following briefly in 2 –3 lines:
I. Monomeric enzymes
II. Whey Protein Concentrate
IV. Class I and class II preservatives
V. Minimally processed foods
Ans. I. Monomeric enzymes are single-unit enzymes that are composed of only one polypeptide chain.MFN 008 Solved Free Assignment 2023
II. Whey Protein Concentrate is a high-protein powder made from whey, the liquid that remains after milk has been curdled and strained during cheese production.
III. Antioxidants are compounds that can prevent or slow damage to cells caused by free radicals, which are unstable molecules that can cause oxidative stress and contribute to the development of chronic diseases.
IV. Class I and Class II preservatives are categories of food preservatives. Class I preservatives are natural preservatives, such as salt and vinegar, while Class II preservatives are synthetic preservatives, such as benzoates and sorbates.
V. Minimally processed foods are foods that have been processed to a lesser degree than traditional processed foods, with the aim of preserving the nutritional quality and flavor of the food while increasing convenience for the consumer.
Q 2. Differentiate between the following:
i) Caramelization and Maillard Reactions
ii) Protein Concentrate and Protein Isolate
iii) Cellulose and Hemicellulose
iv) Solar drying and Mechanical dehydrator
v) Pasteurization and canning
Ans. i) Caramelization and Maillard Reactions:
Caramelization is a non-enzymatic browning reaction that occurs when sugar is heated and begins to break down, resulting in a brown color and a characteristic flavor. MFN 008 Solved Free Assignment 2023
Maillard reactions, on the other hand, are a series of chemical reactions that occur between amino acids and reducing sugars when heated, resulting in the characteristic flavor and color of baked, roasted, or grilled foods.
ii) Protein Concentrate and Protein Isolate:
Protein concentrate is a protein-rich product that has been partially purified, typically containing around 70-80% protein.
Protein isolate, on the other hand, is a more highly purified product, typically containing over 90% protein.
iii) Cellulose and Hemicellulose:MFN 008 Solved Free Assignment 2023
Both cellulose and hemicellulose are complex carbohydrates that are found in plant cell walls. Cellulose is a linear polymer made up of glucose units and is highly resistant to breakdown by enzymes.
Hemicellulose, on the other hand, is a branched polymer that contains a variety of sugars and is more easily broken down by enzymes.
iv) Solar drying and Mechanical dehydrator:
Solar drying involves drying food products using the heat of the sun and air movement, while mechanical dehydration involves using equipment such as air dryers, freeze dryers, or vacuum dryers to remove moisture from food products.
v) Pasteurization and canning:
Pasteurization is a heat treatment process that destroys harmful microorganisms in food products, typically used for liquids such as milk, juice, and beer.
Canning, on the other hand, involves heating food products in sealed containers to destroy microorganisms and create a shelf-stable product, typically used for solid or semi-solid foods such as fruits, vegetables, and meats.
Q 3. Match the following:
|I Zymase||A. Cobalt-60|
|II Food Irradiation||B. Food preservative|
|III Sulphur dioxide||C. Microbial protein|
|IV Curdlan||D. Fermentation|
|V SCP||E. Microbial polysaccharide|
Ans. I D Fermentation
II. A Cobalt-60
III. B Food preservative
IV. E Microbial polysaccharide
V. C Microbial protein