Table of Contents
Q.1. (a) Define Food Science.
Food Science is a branch of science that studies the composition, physical and chemical properties, processing, storage, and preparation of food. It applies the principles of chemistry, biology, and physics to understand and improve the quality, safety, and nutrition of food products. The objective of food science is to create new and innovative food products that meet consumer demands for taste, texture, and convenience, while also ensuring that they are safe and nutritious.
Food science involves various disciplines such as food chemistry, food microbiology, food engineering, and sensory science. Food chemistry deals with the chemical composition and properties of food components, such as proteins, carbohydrates, lipids, and vitamins. Food microbiology studies the microorganisms that grow in and on food, and how they can affect food safety and quality. Food engineering focuses on the design and operation of food processing equipment and systems. Sensory science deals with the evaluation of the appearance, flavor, texture, and aroma of food products by human senses.
Food science is a rapidly growing field due to the increasing demand for safe, nutritious, and convenient food products. It has contributed significantly to the development of new food products, food preservation techniques, and food safety regulations. In addition, food science has played a vital role in improving the quality of life for people around the world by providing a steady supply of nutritious and safe food.
(b) Define flavour and classify it.
Flavour is the combined sensory experience of taste, aroma, and other physical sensations, such as texture and temperature, that are perceived when consuming food or drink. It is a complex and subjective sensation that results from the interaction of the chemical components of food with the sensory receptors in the mouth and nose.
Classification of Flavour
Flavour can be classified into two main categories: primary and secondary.
Primary Flavour
Primary flavours are the basic tastes that are detected by the tongue. They include:
- Sweetness: a pleasant sensation that is perceived when sugar or other sweeteners are consumed.
- Sourness: a tart or acidic taste that is perceived when sour substances, such as lemons or vinegar, are consumed.
- Saltiness: a taste that is perceived when consuming salty substances, such as salt or soy sauce.
- Bitterness: a taste that is perceived when consuming bitter substances, such as coffee or dark chocolate.
- Umami: a savoury taste that is perceived when consuming foods high in glutamate, such as meat, fish, or mushrooms.
Secondary Flavour
Secondary flavours are the aromas and other sensory experiences that are perceived through the nose and mouth. They include:
- Aroma: the distinctive smell that is associated with a particular food or drink.
- Texture: the sensation of how a food or drink feels in the mouth, such as smooth, creamy, or crunchy.
- Temperature: the sensation of hot or cold that is perceived when consuming a food or drink.
- Mouthfeel: the sensation of how a food or drink feels in the mouth, such as dry, oily, or astringent.
- Aftertaste: the lingering taste that is perceived after swallowing a food or drink.
In conclusion, the classification of flavour into primary and secondary categories helps in understanding and describing the different sensory experiences that contribute to the overall flavour of a food or drink.
Q.2. Discuss the effects of dry and moist heat on starch.
Starch is a complex carbohydrate that is found in many foods, such as grains, vegetables, and fruits. It is a major source of energy in the human diet and is commonly used as a thickening agent in food processing. The effects of dry and moist heat on starch can impact the texture and taste of food products.
Dry Heat
Dry heat refers to cooking methods that use hot air or direct contact with a hot surface, such as roasting, baking, or frying. The effects of dry heat on starch include:
- Gelatinization: Starch granules absorb water and swell when heated, causing them to burst and release starch molecules into the surrounding liquid. This process is called gelatinization and is responsible for the thickening of foods, such as sauces and gravies.
- Dextrinization: At high temperatures, the breakdown of starch molecules into smaller chains or individual glucose molecules can occur. This process is called dextrinization and can result in the development of a crispy or crunchy texture in foods, such as bread crusts and crackers.
- Retrogradation: When starch products are stored at cool temperatures after cooking, retrogradation can occur. Retrogradation is the reformation of starch molecules into a more ordered structure, which can lead to the formation of a firm or gritty texture in foods, such as stale bread or reheated rice.
Moist Heat
Moist heat refers to cooking methods that use water or steam, such as boiling, simmering, or steaming. The effects of moist heat on starch include:
- Gelatinization: Similar to dry heat, moist heat causes starch granules to absorb water and swell, resulting in gelatinization and thickening of foods, such as soups and stews.
- Leaching: When starch-containing foods are cooked in water, some of the starch molecules can dissolve and leach into the cooking liquid. This can result in a loss of thickening power and a thinner consistency in the final product.
- Syneresis: When cooked starch products are cooled, water can be released and a gel can form. However, if the gel is heated again, the water can be squeezed out of the gel, resulting in a loss of texture and a weeping or watery appearance. This process is called syneresis and can occur in foods, such as custards and puddings.
In conclusion, the effects of dry and moist heat on starch can impact the texture, thickness, and taste of food products. Understanding these effects can help in the selection of appropriate cooking methods and processing techniques for different food products.
OR What are the factors affecting gelatinization of starch? List the uses of carbohydrates in food preparation.
Gelatinization is the process by which starch granules absorb water and swell when heated, leading to the thickening of foods. The gelatinization of starch can be influenced by several factors, including:
- Type of starch: Different types of starch have different gelatinization temperatures and properties. For example, cornstarch has a lower gelatinization temperature and is commonly used as a thickener in sauces and gravies, while potato starch has a higher gelatinization temperature and is often used in gluten-free baking.
- Concentration of starch: A higher concentration of starch in a food product can lead to a thicker and more viscous texture, as there are more starch molecules available to absorb water and swell.
- Temperature: Gelatinization of starch occurs between certain temperature ranges depending on the type of starch. For example, cornstarch typically gelatinizes between 60-70°C, while potato starch gelatinizes between 70-80°C. Temperature above this range may result in the breakdown of the starch molecules.
- Time: The time of cooking can impact the gelatinization of starch, as longer cooking time can result in more complete gelatinization and a thicker texture.
- pH: The acidity of the environment can impact the gelatinization of starch, with acidic conditions typically leading to a slower gelatinization process.
Uses of Carbohydrates in Food Preparation
Carbohydrates are an important macronutrient in the human diet and play a crucial role in food preparation. Some of the common uses of carbohydrates in food preparation include:
- Sweetening: Carbohydrates, such as sucrose, glucose, and fructose, are commonly used as sweeteners in food products to enhance flavor and add sweetness.
- Thickening: Starches, such as cornstarch and potato starch, are used as thickening agents in food products, such as sauces, gravies, and soups. They can also be used to thicken batters and doughs in baking.
- Binding: Carbohydrates, such as flour and bread crumbs, are used as binding agents in food products, such as meatballs, burgers, and meatloaf, to hold ingredients together.
- Browning: Carbohydrates, such as glucose and fructose, can participate in the Maillard reaction, which is responsible for the browning and development of flavor in baked and roasted foods.
- Fermentation: Carbohydrates, such as sugars and starches, are used as substrates for fermentation, which is a process that is used to make alcoholic beverages, bread, and other fermented foods.
In conclusion, carbohydrates play a vital role in food preparation, providing sweetening, thickening, binding, browning, and fermentation properties that contribute to the taste, texture, and appearance of many food products.
Q.3. What do you mean by rancidity of fats and oils? What measures will you take to prevent rancidity, while storing fats and oils?
Rancidity is a chemical process that occurs when fats and oils are exposed to air, heat, and light, resulting in the breakdown of the fat molecules and the development of off-flavors and odors. Rancidity can occur in both animal and plant-based fats and oils, such as butter, lard, vegetable oils, and nuts.
There are two types of rancidity: oxidative rancidity and hydrolytic rancidity. Oxidative rancidity occurs when fats and oils are exposed to air and oxygen, while hydrolytic rancidity occurs when fats and oils are exposed to water and enzymes.
Measures to Prevent Rancidity while Storing Fats and Oils
Preventing rancidity in fats and oils is important to maintain the quality and safety of food products. Here are some measures that can be taken to prevent rancidity while storing fats and oils:
- Store in a cool and dark place: Fats and oils should be stored in a cool and dark place, away from light and heat sources, as exposure to light and heat can speed up the process of oxidative rancidity. Ideally, fats and oils should be stored in a pantry or cupboard, rather than on a countertop or near a stove.
- Use airtight containers: Fats and oils should be stored in airtight containers to minimize exposure to air and oxygen, which can also accelerate oxidative rancidity. Glass or opaque containers are preferred over plastic containers, as they offer better protection against light.
- Avoid moisture: Fats and oils should be kept away from moisture, as water can cause hydrolytic rancidity. They should be stored in a dry place, and any water that gets into the container should be wiped off immediately.
- Choose fresh oils: When purchasing fats and oils, it is important to choose fresh products that have not been exposed to air, heat, or light for a long time. Check the expiration date and purchase only the amount that can be used before the expiration date.
- Use antioxidants: Some antioxidants, such as vitamin E and rosemary extract, can help prevent oxidative rancidity by slowing down the oxidation process. Some manufacturers add antioxidants to their products to extend their shelf life.
- Rotate stock: It is important to rotate stock and use older fats and oils first, to minimize the chances of rancidity.
In conclusion, preventing rancidity in fats and oils is crucial to maintain the quality and safety of food products. Storing fats and oils in a cool and dark place, using airtight containers, avoiding moisture, choosing fresh oils, using antioxidants, and rotating stock are some measures that can help prevent rancidity while storing fats and oils.
Q.4. Write briefly on the various functional properties of protein.
Proteins are macromolecules that are essential for the structure and function of living organisms. In addition to their nutritional value, proteins also have various functional properties that make them useful in food processing and preparation. Here are some of the main functional properties of proteins:
- Emulsification: Proteins have the ability to stabilize oil and water mixtures, which is important for the production of emulsified products, such as mayonnaise, salad dressings, and sauces. Proteins form a protective layer around the oil droplets, preventing them from coalescing and separating from the water phase.
- Foaming: Proteins can form stable foams when whipped or beaten, which is important for the production of cakes, meringues, and soufflés. The proteins in egg whites are particularly effective in forming stable foams due to their ability to denature and coagulate when exposed to heat or acid.
- Gelation: Proteins can form gels when heated or cooled, which is important for the production of jellies, puddings, and other gel-like products. Gelation occurs when proteins denature and form a network of interlocking strands that trap water and other ingredients in a semi-solid structure.
- Water-binding: Proteins have the ability to bind water and other liquids, which is important for the production of moist and tender meat products, such as sausages and meatballs. The proteins form a gel-like structure that helps retain moisture and prevent the meat from becoming dry and tough.
- Flavor binding: Proteins can bind and enhance flavors, which is important for the production of savory products, such as soups, stews, and sauces. The proteins can also act as flavor carriers, helping to distribute and release flavors in a controlled manner.
- Texture modification: Proteins can modify the texture of foods by altering their viscosity, elasticity, and chewiness. This is important for the production of products such as meat substitutes and protein bars, which require a specific texture for consumer acceptance.
In conclusion, proteins have various functional properties that make them useful in food processing and preparation, including emulsification, foaming, gelation, water-binding, flavor binding, and texture modification. Understanding these properties can help in the selection and optimization of protein ingredients in food products.
OR Discuss the uses of fats and oils in food preparation.
Fats and oils are an essential component of the human diet and play a crucial role in food preparation. They provide a range of functional and sensory properties that contribute to the taste, texture, and appearance of many food products. Here are some of the common uses of fats and oils in food preparation:
- Cooking and frying: Fats and oils are commonly used for cooking and frying foods, as they can provide a high heat capacity and transfer heat efficiently. They are also used as a medium for sautéing, stir-frying, and deep-frying, as they can help to brown and crisp the exterior of food products.
- Baking: Fats and oils are used in baking to provide moisture, texture, and flavor to baked goods. They can be used as a tenderizer and shortening agent in pie crusts, pastries, and cakes, and can also help to promote the rise and texture of baked products.
- Emulsification: Fats and oils are used as emulsifiers in food products, such as mayonnaise, salad dressings, and sauces. They can help to stabilize oil and water mixtures by forming a protective layer around the oil droplets, preventing them from coalescing and separating from the water phase.
- Flavor and texture enhancement: Fats and oils can enhance the flavor and texture of many food products, such as spreads, dips, and sauces. They can contribute to the smoothness, creaminess, and richness of these products, as well as add a distinctive flavor profile.
- Preservation: Fats and oils can be used as a preservative in many food products, such as cheese, meat, and fish. They can help to prevent spoilage and extend the shelf life of these products by creating a barrier that prevents the growth of bacteria and other microorganisms.
- Nutritional value: Fats and oils are a major source of energy and essential fatty acids in the human diet. They also play a crucial role in the absorption of fat-soluble vitamins, such as vitamins A, D, E, and K.
In conclusion, fats and oils are an important ingredient in food preparation, providing functional, sensory, and nutritional properties that contribute to the quality and safety of many food products. Understanding the uses of fats and oils can help in the selection and optimization of ingredients in food products.
Q.5. Explain the five sensory evaluation methods of food.
Sensory evaluation is a scientific method used to assess the sensory properties of foods, such as appearance, flavor, aroma, texture, and overall quality. Sensory evaluation is an important tool for food manufacturers, as it can help to optimize product development, identify consumer preferences, and ensure consistency and quality. There are five main sensory evaluation methods for food:
- Hedonic testing: Hedonic testing is a method used to assess the overall liking or acceptability of a food product by consumers. A panel of evaluators is asked to rate the product on a scale from dislike extremely to like extremely. Hedonic testing is useful for evaluating consumer acceptance of new or modified food products.
- Discrimination testing: Discrimination testing is a method used to determine whether two or more products are different or similar in terms of their sensory properties. A panel of evaluators is asked to identify the differences or similarities between the products using a forced-choice or paired comparison method. Discrimination testing is useful for quality control and product development.
- Descriptive analysis: Descriptive analysis is a method used to identify and quantify the sensory attributes of a food product. A panel of evaluators is trained to identify and describe the specific sensory properties of the product using a standardized vocabulary. Descriptive analysis is useful for product optimization and quality control.
- Time-intensity testing: Time-intensity testing is a method used to measure the intensity of a sensory attribute over time. A panel of evaluators is asked to rate the intensity of a sensory attribute at regular intervals over a period of time. Time-intensity testing is useful for evaluating the temporal aspects of sensory attributes, such as the duration of a flavor or the texture of a food product.
- Consumer testing: Consumer testing is a method used to evaluate consumer preferences and attitudes towards food products. A panel of consumers is asked to evaluate the sensory properties of a food product and provide feedback on their liking and acceptability. Consumer testing is useful for understanding the factors that influence consumer preferences and purchase decisions.
In conclusion, sensory evaluation methods are important tools for evaluating the sensory properties of food products. Hedonic testing, discrimination testing, descriptive analysis, time-intensity testing, and consumer testing are the five main sensory evaluation methods used to assess the sensory properties of foods. These methods can help to optimize product development, ensure consistency and quality, and identify consumer preferences and attitudes towards food products.
OR What do you mean by food processing? Discuss the various objectives of food processing.
Food processing refers to the transformation of raw ingredients into finished food products through various techniques and methods. The purpose of food processing is to make food safe, nutritious, and convenient for consumption while preserving its quality, flavor, and texture. Food processing involves a range of activities, such as cleaning, sorting, grading, preserving, packaging, and labeling.
Objectives of Food Processing
There are several objectives of food processing, including:
- Preservation: One of the primary objectives of food processing is to preserve food by preventing spoilage and extending its shelf life. This is achieved through various preservation techniques, such as canning, freezing, dehydration, and fermentation.
- Safety: Another important objective of food processing is to ensure the safety of food products by reducing the risk of contamination and foodborne illnesses. This is achieved through various techniques, such as pasteurization, irradiation, and sterilization.
- Nutrition: Food processing can improve the nutritional value of foods by fortifying them with vitamins, minerals, and other essential nutrients. This is achieved through various techniques, such as enrichment and fortification.
- Convenience: Food processing can make food more convenient and easier to prepare by removing undesirable parts, such as seeds, skins, and bones, and by providing ready-to-eat or ready-to-cook products. This is achieved through various techniques, such as grinding, slicing, and portioning.
- Flavor and texture: Food processing can enhance the flavor and texture of foods by adding or removing certain components. This is achieved through various techniques, such as seasoning, marinating, and aging.
- Marketability: Food processing can improve the marketability of food products by making them more attractive, uniform, and appealing to consumers. This is achieved through various techniques, such as shaping, coloring, and packaging.
In conclusion, food processing is a critical aspect of the food industry, with various objectives such as preservation, safety, nutrition, convenience, flavor and texture enhancement, and marketability. The use of appropriate food processing techniques can help to ensure the availability of safe, nutritious, and high-quality food products to consumers.
Q.6. What is emulsion? Differentiate between oil / water and water / oil emulsion. Discuss briefly the role of emulsifying agent in food preparation.
An emulsion is a mixture of two immiscible liquids, such as oil and water, that are stabilized by the presence of an emulsifying agent. The emulsifying agent helps to disperse one liquid in the other, forming tiny droplets that are evenly distributed throughout the mixture.
Oil/Water and Water/Oil Emulsion
In an oil/water emulsion, oil is dispersed in water, while in a water/oil emulsion, water is dispersed in oil. The difference lies in the composition of the emulsifying agent used. In oil/water emulsions, the emulsifying agent is typically hydrophilic (water-loving), meaning it is attracted to water and repelled by oil. In water/oil emulsions, the emulsifying agent is typically lipophilic (oil-loving), meaning it is attracted to oil and repelled by water.
Role of Emulsifying Agent in Food Preparation
Emulsifying agents play a critical role in food preparation by helping to stabilize emulsions and prevent them from separating. Emulsifying agents can be natural or synthetic and are typically added to food products during processing.
Here are some examples of the role of emulsifying agents in food preparation:
- Mayonnaise: Mayonnaise is an oil-in-water emulsion that is stabilized by egg yolk, which contains lecithin, a natural emulsifier. The lecithin helps to disperse the oil droplets in water, forming a thick and creamy emulsion.
- Salad dressings: Salad dressings are typically oil-in-water emulsions that are stabilized by various emulsifying agents, such as egg yolk, mustard, or soy lecithin. The emulsifying agent helps to prevent the oil and water from separating, ensuring a smooth and consistent texture.
- Ice cream: Ice cream is a water-in-oil emulsion that is stabilized by various emulsifying agents, such as egg yolks, milk proteins, or mono- and diglycerides. The emulsifying agent helps to disperse the water molecules in the fat, preventing the formation of ice crystals and ensuring a smooth and creamy texture.
- Margarine: Margarine is a water-in-oil emulsion that is stabilized by various emulsifying agents, such as mono- and diglycerides. The emulsifying agent helps to disperse the water molecules in the fat, ensuring a consistent texture and preventing the margarine from separating.
In conclusion, emulsifying agents are important ingredients in food preparation, as they help to stabilize emulsions and prevent them from separating. Emulsifying agents can be natural or synthetic and are used in a wide range of food products, including mayonnaise, salad dressings, ice cream, and margarine.
Q.7. Differentiate between a solution, colloidal dispersion and a suspension.
Solutions, colloidal dispersions, and suspensions are three types of mixtures that differ in their particle size, appearance, and behavior.
Solution
A solution is a homogeneous mixture of two or more substances that are completely dissolved in one another at a molecular level. The particles in a solution are so small that they cannot be seen with the naked eye, and they do not settle out upon standing. Solutions are transparent and have a uniform composition throughout.
Colloidal Dispersion
A colloidal dispersion is a heterogeneous mixture of two or more substances in which one substance is dispersed in another in the form of tiny particles that are larger than molecules but too small to be seen with the naked eye. The particles in a colloidal dispersion are referred to as colloids or dispersed phase, and they are dispersed in a continuous medium, or dispersion medium. Colloidal dispersions are usually opaque or translucent and exhibit the Tyndall effect, which is the scattering of light by the dispersed particles. Examples of colloidal dispersions include milk, blood, and ink.
Suspension
A suspension is a heterogeneous mixture of two or more substances in which one substance is dispersed in another in the form of larger particles that are visible to the naked eye and settle out upon standing. The particles in a suspension are referred to as the suspended phase, and they are dispersed in a continuous medium, or suspension medium. Suspensions are usually opaque and exhibit sedimentation, which is the settling of the particles to the bottom of the container over time. Examples of suspensions include muddy water, blood clots, and paint.
Differences
The main differences between a solution, colloidal dispersion, and suspension are as follows:
- Particle size: The particles in a solution are very small, typically less than 1 nanometer, while the particles in a colloidal dispersion range from 1 to 1000 nanometers, and the particles in a suspension are larger than 1000 nanometers.
- Appearance: Solutions are transparent, colloidal dispersions are usually opaque or translucent, and suspensions are opaque.
- Behavior: The particles in a solution do not settle out, while the particles in a colloidal dispersion may settle out slowly and the particles in a suspension settle out quickly.
- Tyndall effect: Only colloidal dispersions exhibit the Tyndall effect, while solutions and suspensions do not.
In conclusion, solutions, colloidal dispersions, and suspensions are three types of mixtures that differ in their particle size, appearance, and behavior. Solutions are homogeneous and transparent, colloidal dispersions are heterogeneous and usually opaque or translucent, and suspensions are heterogeneous and opaque.
OR What are the application of colloid systems in food preparation?
Colloidal systems play an important role in the food industry, as they are used to improve the texture, appearance, stability, and nutritional quality of many food products. Here are some applications of colloid systems in food preparation:
- Emulsions: Emulsions are colloidal systems in which one liquid is dispersed in another liquid, typically oil in water or water in oil. Emulsions are used in a wide range of food products, such as mayonnaise, salad dressings, margarine, and ice cream, to provide texture, stability, and improved sensory properties.
- Foams: Foams are colloidal systems in which gas bubbles are dispersed in a liquid or solid. Foams are used in many food products, such as whipped cream, meringue, and bread, to provide aeration, volume, and texture.
- Gels: Gels are colloidal systems in which a liquid is trapped in a three-dimensional network of cross-linked molecules. Gels are used in many food products, such as jellies, puddings, and yogurts, to provide texture, structure, and stability.
- Suspensions: Suspensions are colloidal systems in which solid particles are dispersed in a liquid. Suspensions are used in many food products, such as salad dressings, beverages, and sauces, to provide texture, flavor, and nutritional value.
Q.8. Give brief description of the following:
(a) Denaturation of proteins
Denaturation of proteins is a process in which the protein molecule loses its natural shape and function due to changes in its environment, such as changes in temperature, pH, or chemical exposure. The process of denaturation can cause the protein to become inactive or lose its biological activity, such as enzymes that no longer catalyze chemical reactions. Denaturation can also change the physical properties of the protein, such as its solubility, texture, and color. Examples of denatured proteins include cooked eggs, denatured enzymes, and heat-treated milk.
(b) Classification of carbohydrates
Carbohydrates are one of the three main macronutrients found in food, along with proteins and fats. Carbohydrates are classified into three main types, based on their chemical structure and complexity:
- Monosaccharides: Monosaccharides are the simplest form of carbohydrates and cannot be broken down further. They are single sugar molecules, such as glucose, fructose, and galactose.
- Disaccharides: Disaccharides are carbohydrates made up of two monosaccharides joined together. Examples of disaccharides include sucrose (table sugar), lactose (milk sugar), and maltose (malt sugar).
- Polysaccharides: Polysaccharides are complex carbohydrates made up of many monosaccharides joined together. They can be further classified into two main types:
- Starch: Starch is a complex carbohydrate made up of many glucose molecules joined together. Starch is found in plants and is a major source of energy in the human diet. Examples of foods high in starch include potatoes, rice, and wheat.
- Fiber: Fiber is a complex carbohydrate that cannot be digested by humans. It is found in plant-based foods, such as fruits, vegetables, and whole grains, and is important for digestive health.
Q.9. Differentiate between (any five):
(a) Essential and non-essential amino acids
Essential amino acids are those that cannot be synthesized by the human body and must be obtained from the diet. There are nine essential amino acids, including histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Non-essential amino acids, on the other hand, are those that can be synthesized by the human body from other amino acids or from other metabolic pathways.
(b) Difference and descriptive test
Difference tests are sensory evaluation tests used to detect differences between two or more products. Descriptive tests, on the other hand, are sensory evaluation tests used to describe the sensory attributes of a product in detail, such as appearance, flavor, and texture.
(c) Leavening and shortening agent
Leavening agents are substances used in baking to create gas bubbles in dough or batter, which causes it to rise and become light and fluffy. Examples of leavening agents include yeast, baking powder, and baking soda. Shortening agents, on the other hand, are substances used in baking to make the dough or batter more tender and crumbly. Examples of shortening agents include butter, margarine, and lard.
(d) Enzymatic and non-enzymatic browning
Enzymatic browning is a process in which the enzyme polyphenol oxidase in fruits and vegetables causes browning when exposed to air. This type of browning occurs naturally in foods such as apples, bananas, and potatoes. Non-enzymatic browning, on the other hand, is a process that occurs when sugars react with amino acids or proteins in the presence of heat. Examples of non-enzymatic browning include caramelization and the Maillard reaction.
(e) Hydrogenation and polymerization
Hydrogenation is a process in which unsaturated fatty acids are converted into saturated fatty acids by adding hydrogen atoms to the carbon double bonds. This process is used to make vegetable oils more solid and stable at room temperature, such as in the production of margarine. Polymerization, on the other hand, is a process in which monomers, or small molecules, are linked together to form polymers, or large molecules. This process is used in the production of many food products, such as plastics and food packaging materials.
(f) Inversion and caramelization
Inversion is a process in which sucrose, a disaccharide, is broken down into its component monosaccharides, glucose and fructose, by the addition of an acid or an enzyme. This process is used in the production of sweeteners such as high-fructose corn syrup. Caramelization, on the other hand, is a process in which sugar is heated until it melts and turns brown, producing a characteristic caramel flavor and color. This process is used in the production of many food products, such as caramel candies and sauces.
Q.10. Fill in the blanks with the appropriate word:
(a) Milk is an example of _________ emulsions (water in oil / oil in water).
(b) __________ is the enzyme responsible for undesirable browning in food (phenol oxidase, amylase).
(c) Heating of dry starch is known as __________ (caramalization/ dextrinization).
(d) The continuous phase is sol is __________ (sol / liquid).
(e) Triangle test is a __________ test (discrimination test / descriptive test).
(f) Iodine number is the measure of the extent of __________ fatty acids present in fats and oils (saturated / unsaturated).
(g) Hydrolysis of sugar to glucose and fructose in presence of acid is an example of _________ (inversion / caramalization).
(h) The gum and free fatty acids present in fats are removed by __________ (neutralization / bleaching).
(i) __________ is an example of class 1 preservative (salt / sodium benzoate).
(j) _________ is the bond which unites two amino acids in proteins (glycosidic/ peptide)
(a) Milk is an example of oil in water emulsions.
(b) Phenol oxidase is the enzyme responsible for undesirable browning in food.
(c) Heating of dry starch is known as dextrinization.
(d) The continuous phase is sol is liquid.
(e) Triangle test is a discrimination test.
(f) Iodine number is the measure of the extent of unsaturated fatty acids present in fats and oils.
(g) Hydrolysis of sugar to glucose and fructose in the presence of acid is an example of inversion.
(h) The gum and free fatty acids present in fats are removed by neutralization.
(i) Sodium benzoate is an example of class 1 preservative.
(j) Peptide is the bond which unites two amino acids in proteins.