Food Science and Technology Definitions

Definitions

• Food Science: Multidisciplinary field involving bacteriology, chemistry, and engineering, addressing food material properties, spoilage, preservation, and modification.
• Food Technology (Processing): Applying physics, chemistry, and engineering to transform food for preservation or convenience; methods to convert raw ingredients into consumable forms.
• Food Safety: Study of the causes, prevention, and communication related to foodborne illnesses.
• Food Microbiology: Examines both positive and negative interactions between microorganisms and foods.
• Food Preservation: Focuses on the causes and prevention of food quality degradation.
• Food Engineering: Deals with the industrial processes involved in food manufacturing.
• Product Development: The innovation and creation of new food products.
• Sensory Analysis: Study of consumer perception of food through their senses.
• Food Chemistry: Analyzes the molecular composition of food and chemical reactions involving these molecules.
• Food Packaging: Examines packaging methods to preserve and contain food during distribution.
• Food Physics: Studies the physical attributes of foods, like viscosity, creaminess, and texture.

Food Production

Concern varies by location. Underdeveloped countries face challenges despite most of the population being involved in food production due to inadequate technology, lack of high-yield varieties, unpredictable rainfall, diminishing arable land, pest destruction, and poverty.

Developed countries have mechanized and efficient food production, with concerns mainly about the effects of processing and added chemicals on food safety, nutritive value, and quality.

Food Categories

Based on water content and perishability:

• Perishable Foods: Water content above 50%, including fresh fruits, vegetables, meat, and milk; further divided into highly and moderately perishable.
• Stable Foods: Water content below 50%, including dried grains and products.

Table 1: Classification of Foods Based on Perishability

Reasons for Processing Foods

• Preservation of Food Quality: Including safety, nutritional value, flavor, and ease of preparation.
• Processing for Convenience: Transforming foods like fruits into beverages or wheat into bread.
• Processing for Preservation: Addressing food wastage and dietary inadequacies, especially in underdeveloped countries.

Addressing Dietary Inadequacies

Requires multifaceted approach:

• Control of world population.
• Increased food supply.
• Decreased food wastage.

Basic Food Composition

Food consists of carbohydrates, fats, proteins, water, minerals, and vitamins.

Water

• Two-thirds of body weight; essential for cell and organ function.
• Source: Drinking water, liquid foods, and metabolism byproducts.
• Recommendation: 6-8 glasses daily.

Carbohydrates

• Organic compounds with the general formula Cm(H2O)n; grouped into monosaccharides, disaccharides, oligosaccharides, and polysaccharides.
• Monosaccharides and disaccharides are sugars with properties like sweetness, solubility, and fermentability.
• Sugars act as preservatives at high concentrations by reducing water activity.
• Reducing sugars cause browning in baked goods via the Maillard reaction.
• Sugar alcohols (e.g., xylitol, sorbitol) are sweet but noncariogenic.

Lipids

• Fats and oils composed of carbon, hydrogen, and oxygen. Triglycerides are common.
• Properties: Aeration, flakiness, tenderness, emulsification, heat transfer, satiety, flavor.

CH2-O-FA

CH2-O-FA

CH2-O-FA

Proteins

• Composed of carbon, hydrogen, oxygen, and nitrogen; building blocks are amino acids.
• Structures: Primary, secondary, tertiary, and quaternary.
• Properties: Amphoteric, water-binding, salting in/out, denaturation, hydrolysis, Maillard browning.

H2N-C-COOH

R

Enzymes

• Proteins that act as catalysts, speeding up chemical reactions. They consist of a protein portion (apoenzyme) and a non-protein portion (coenzyme or cofactor).
• Types: metabolic, digestive, and food enzymes (lipase, lactase, protease, amylase, cellulase).
• Enzymes work by binding to a substrate at the active site, facilitating reactions.
• Factors affecting enzyme activity: pH, temperature & enzyme inhibition.
• Enzymes have several characteristics such as Molecular weight, Amphoteric nature , Colloidal nature , Specificity of enzymes , Heat sensitivity.
• Uses of enzymes include: Meat tenderizing, Making of cheese, Lactose free product Development, Making of low calorie beer & Making of alcohol drinks etc.

Enzymatic Browning

This is a chemical process which occurs in fruits and vegetables by the enzyme polyphenol oxidase which results in brown pigments.

Ways of preventing enzymatic browning include :

• Covering fruits with syrup to block oxygen.
• Application of citric acid or ascorbic acid to cut fruit surface.
• Refrigerating which slows down enzymatic browning.

Food Additives

Food additive is defined as any substance or a mixture of substances other than the basic foodstuff which is present in food as a result of any aspect of production, processing, storage or packaging.

Functions of food additives:

• Maintaining product consistency
• Improving or maintaining nutritive value

Classification of food additives:

• Antioxidants
• Preservatives
• Food colors
• Food flavours
• Emulsifiers and stabilizers
• Artificial sweeteners

Functional role of additives:

• Antioxidants: Chemical additive which when added to food retards or prevents oxidative deterioration of food . Butylated hydroxyanisole (BHA) can be added to ghee, butter, fat spread only.
• Preservatives: Substances added to food to retard, inhibit or arrest the activity of microorganisms
• Food colours: Substances used to correct loss of colour due to food processing or to correct natural variations in food colour. Use of colour is restricted to only specific items of food
• Flavouing agents: Add flavour or correct losses in flavour..
• Emulsifying and stabilizing agents: Substances capable of facilitating a uniform dispersion of oils and fats in aqueous media or vice versa and / or stabalizing such emulsions.
• Sweetening agents: Include calorie sweeteners, low- calorie sweeteners and non-calorie sweeteners (which contain little or no calories)
• Anti- caking agents: Anti- caking agents are anhydrous substances that can pick up moisture without themselves becoming wet and these are added to products such as table salt and dry mixes.
• Sequesterants: Substances that form a complex with transition metal ions like copper, iron, cobalt and nickel.
• Buffering agents (Acids, bases, salts): Buffering agents are materials used to counter acidic and alkaline changes during storage or processing of food, thus improving flavour and increasing stability of foods.
• Anti- foaming agents: Reduce foaming on heating, slow down deteriorative changes e.g. dimethyl polysiloxane in edible oils and fats for deep-fat frying
• Enzymes: Mainly used in industry to split carbohydrates, proteins, lipids, used in cheese, bread production, tenderizing meat
• Leavening agents: Introduction of gas in batter or dough leading to its expansion, improves appearance, texture and taste of foods.