Introduction to Food Science

Overview of Food Science

• Encompasses the chemical, physical, and microbiological properties of food.
• Studies transformations that affect food characteristics and properties.

Definition of Food

• Provides energy, sustains life, builds and repairs tissues.
• Regulates bodily processes, nourishes the body, and satisfies emotional needs.

Aspects of Food Quality

• Nutritional Quality: Involves nutrients categorized as water, carbohydrates, proteins, fats, vitamins, and minerals.
• Digestibility: Involves completeness of digestion, absorption, and the general aftereffects on well-being.
• Palatability: Evaluated by sensory experiences during consumption.
• Economy: Considers costs, time, equipment, and labor involved in food preparation and storage.
• Sanitary Quality: Must be free from contamination (microbiological, biological, chemical, physical, radiological) to prevent food-borne illnesses.

Food-Borne Illnesses

• Food Intoxication: Caused by toxins produced by pathogens.
• Food Infection: Result of consuming food contaminated with pathogens.

Chemical Composition of Food

• Macronutrients: Includes carbohydrates, proteins, fats, and water.
• Micronutrients: Comprised of vitamins and minerals.
• Non-nutritional Components: Incorporates pigments, enzymes, organic acids, and flavoring compounds.

Water in Food

• Most common dispersing medium and the most abundant compound in food.
• Exists in five forms: free water, hydrates, adsorbed water, absorbed in gels, and bound water.

Proteins

• Composed of amino acids linked by peptide bonds; essential for nutrition.
• Classification:
  • Complete Proteins: Sources include meat, poultry, fish, dairy, and eggs.
  • Incomplete Proteins: Primarily from plant sources (grains), excluding legumes.

Functions of Proteins in Food

• Hydration: Ability to form gels and absorb moisture.
• Denaturation: Alteration of protein structure through heat or pH changes.
• Enzymatic Reactions: Proteins facilitate various biochemical processes.

Useful Enzymes in Food Processing

• Rennin/Chymosin: Used in cheese production by converting milk to curd.
• Meat Tenderizers (e.g., Papain, Bromelain): Improve tenderness of meat.
• Pectinase and Amylase: Enhance fruit juice processing and bread-making by improving yield and fermentable sugars.

Undesirable Enzymatic Reactions

• Enzymatic Browning: Phenolic compounds react with oxygen leading to discoloration.
• Rancidity: Decomposition of fats and oils resulting in off-flavors and odors.
• Maturation and Spoilage: Enzymatic activity can lead to undesirable changes in vegetables and the decay of other food items.

Carbohydrates

• Synthesized through photosynthesis; essential as energy sources.
• Classified into two main groups: sugars and polysaccharides.