Principles of Food Science Unit 1 Review: Food Science & Technology Fundamentals

Key Concepts and Terminology

• Food science applies scientific principles to create, preserve, process, package, and distribute safe, nutritious, and appealing food products
• Involves interdisciplinary fields such as chemistry, microbiology, engineering, and nutrition to ensure food quality and safety
• Food technology utilizes the knowledge gained from food science to develop innovative processing techniques, equipment, and packaging materials
• Sensory evaluation assesses the organoleptic properties of food (appearance, aroma, taste, texture, and sound) using human senses and statistical analysis
• Quality control ensures that food products meet established standards for safety, consistency, and consumer acceptability throughout the production process
• Shelf life refers to the period during which a food product remains safe and retains its desired sensory, chemical, physical, and microbiological characteristics under specified storage conditions
• Hazard Analysis and Critical Control Points (HACCP) is a systematic approach to identify, evaluate, and control potential food safety hazards during production, processing, and handling
• Foodborne illnesses result from consuming contaminated food or beverages, caused by pathogenic microorganisms, toxins, or chemical contaminants

Food Composition and Chemistry

• Carbohydrates, proteins, lipids, water, vitamins, and minerals are the main components of food
  • Carbohydrates include sugars (monosaccharides and disaccharides), starches (polysaccharides), and dietary fibers
  • Proteins are composed of amino acids and play crucial roles in structure, function, and nutrition
  • Lipids encompass fats, oils, and other compounds that are insoluble in water but soluble in organic solvents
• Chemical reactions in food influence taste, texture, appearance, and nutritional value
  • Maillard reaction occurs between reducing sugars and amino acids, resulting in browning and flavor development (caramelization in baked goods)
  • Enzymatic browning involves the oxidation of phenolic compounds by enzymes, leading to discoloration (cut apples turning brown)
• Functional properties of food components determine their behavior and interactions in food systems
  • Emulsification, gelling, foaming, and thickening are examples of functional properties that affect food texture and stability
• Water activity (aw) measures the available water in food that can support microbial growth and chemical reactions, influencing shelf life and safety
• pH indicates the acidity or alkalinity of a food, affecting microbial growth, enzyme activity, and chemical reactions

Food Processing Techniques

• Thermal processing involves the application of heat to preserve food and extend shelf life
  • Pasteurization uses mild heat treatment to inactivate pathogens and enzymes (milk, juices)
  • Sterilization employs high temperatures to eliminate all microorganisms and spores (canned foods)
• Mechanical processing includes physical methods to transform raw materials into finished products
  • Milling reduces particle size and increases surface area (flour, powders)
  • Extrusion combines heating, mixing, and shaping to create textured products (breakfast cereals, snack foods)
• Separation techniques isolate specific components from food matrices
  • Centrifugation separates materials based on density differences (cream from milk)
  • Filtration removes particles or microorganisms from liquids using membranes or screens (clarified juices, beer)
• Fermentation utilizes microorganisms to produce desirable changes in food properties
  • Lactic acid fermentation preserves and enhances the flavor of dairy products (yogurt, cheese)
  • Alcoholic fermentation converts sugars into ethanol and carbon dioxide (beer, wine)
• Drying removes water from food to prevent microbial growth and extend shelf life
  • Sun drying is a traditional method that relies on solar energy (raisins, dried herbs)
  • Freeze-drying preserves quality by sublimating ice crystals under vacuum (instant coffee, fruit powders)

Food Safety and Microbiology

• Microorganisms play crucial roles in food spoilage, fermentation, and foodborne illnesses
  • Bacteria, yeasts, and molds are the main groups of microorganisms associated with food
  • Intrinsic factors (pH, water activity, nutrient content) and extrinsic factors (temperature, atmosphere) influence microbial growth in food
• Foodborne pathogens cause illnesses when consumed in contaminated food
  • Salmonella, Listeria monocytogenes, and Escherichia coli O157:H7 are common bacterial pathogens
  • Norovirus and Hepatitis A are examples of viral pathogens transmitted through food
• Good Manufacturing Practices (GMPs) and Sanitation Standard Operating Procedures (SSOPs) establish guidelines for hygienic food production and handling
• Microbial testing methods detect and quantify microorganisms in food samples
  • Plate count techniques estimate the number of viable cells by counting colonies on agar plates
  • Rapid methods such as PCR and ELISA provide faster results for specific pathogens or toxins
• Food preservation techniques control microbial growth and extend shelf life
  • Refrigeration and freezing slow down or stop microbial growth by lowering temperature
  • Chemical preservatives (benzoates, sorbates) inhibit specific groups of microorganisms

Sensory Evaluation and Quality Control

• Sensory evaluation assesses the organoleptic properties of food using human senses
  • Appearance, aroma, taste, texture, and sound are the main attributes evaluated
  • Trained panelists or consumer tests provide subjective data on food quality and acceptability
• Sensory testing methods include discriminative, descriptive, and affective tests
  • Discriminative tests (triangle test, duo-trio test) determine if differences exist between samples
  • Descriptive tests (flavor profile, texture profile) quantify the intensity of specific attributes
  • Affective tests (hedonic scale, preference ranking) measure consumer liking or preference
• Instrumental analysis complements sensory evaluation by providing objective measurements
  • Colorimeters measure color parameters (L*, a*, b* values) to assess appearance
  • Texture analyzers determine mechanical properties such as hardness, cohesiveness, and adhesiveness
• Quality control ensures that food products meet established standards throughout the production process
  • Raw material inspection, in-process testing, and finished product analysis are critical stages of quality control
  • Statistical process control (SPC) monitors production processes to detect and correct deviations from specifications

Nutrition and Health Aspects

• Food provides essential nutrients for growth, development, and maintenance of health
  • Macronutrients (carbohydrates, proteins, lipids) supply energy and building blocks for the body
  • Micronutrients (vitamins, minerals) are required in smaller amounts but play vital roles in metabolism and physiological functions
• Nutrient density refers to the amount of nutrients per calorie in a food
  • Nutrient-dense foods (fruits, vegetables, whole grains) provide substantial amounts of vitamins, minerals, and fiber relative to their calorie content
  • Energy-dense foods (processed snacks, sugary beverages) are high in calories but low in essential nutrients
• Dietary guidelines provide recommendations for healthy eating patterns
  • Balanced intake of various food groups, limited consumption of saturated fats, added sugars, and sodium
  • Personalized nutrition considers individual differences in genetic, metabolic, and lifestyle factors
• Functional foods and nutraceuticals offer potential health benefits beyond basic nutrition
  • Probiotics are live microorganisms that confer health benefits when consumed in adequate amounts (yogurt, kefir)
  • Omega-3 fatty acids reduce inflammation and support cardiovascular health (fatty fish, flaxseed)
• Diet-related chronic diseases are associated with unhealthy eating patterns and sedentary lifestyles
  • Obesity, type 2 diabetes, cardiovascular diseases, and certain cancers are major public health concerns
  • Food science and technology play a role in developing healthier food options and educating consumers about nutrition

Food Packaging and Preservation

• Packaging protects food from external influences, extends shelf life, and provides information to consumers
  • Materials include glass, metal, paper, and plastics, each with specific properties and applications
  • Active packaging interacts with the food or environment to enhance quality or safety (oxygen scavengers, moisture absorbers)
  • Intelligent packaging monitors the condition of the food or packaging during storage and distribution (time-temperature indicators, freshness sensors)
• Modified atmosphere packaging (MAP) alters the gas composition inside the package to delay spoilage and extend shelf life
  • Oxygen is often reduced or eliminated to prevent oxidation and microbial growth
  • Carbon dioxide is added to inhibit aerobic bacteria and molds (fresh-cut produce, meat products)
• Vacuum packaging removes air from the package to create an anaerobic environment and prevent oxidation
• Aseptic packaging involves sterile filling of commercially sterile products into sterile containers, ensuring long-term shelf stability without refrigeration (UHT milk, fruit juices)
• Food preservation methods extend shelf life by controlling microbial growth, enzymatic activity, and chemical reactions
  • Thermal processing (canning, pasteurization) inactivates microorganisms and enzymes
  • Drying removes water to prevent microbial growth and slow down chemical reactions (dried fruits, jerky)
  • Fermentation produces antimicrobial compounds and lowers pH to preserve food (pickles, sauerkraut)
  • Chemical preservatives (benzoates, sorbates, nitrites) inhibit specific groups of microorganisms

Emerging Trends in Food Science

• Plant-based proteins are gaining popularity as sustainable and healthy alternatives to animal-derived proteins
  • Soy, pea, and wheat proteins are used to create meat analogs, dairy alternatives, and functional ingredients
  • Fermentation technology produces novel plant-based proteins with improved functionality and flavor (mycoprotein, microalgae)
• Cellular agriculture involves producing animal products from cell cultures rather than whole animals
  • Cultured meat, also known as lab-grown or in-vitro meat, is produced by cultivating animal cells in a controlled environment
  • Precision fermentation uses genetically engineered microorganisms to produce specific compounds (enzymes, flavors, vitamins)
• 3D food printing creates customized and complex food structures using computer-aided design and controlled deposition of ingredients
  • Enables personalized nutrition, unique textures, and intricate designs
  • Potential applications in food service, healthcare, and space exploration
• Nanotechnology applies materials and devices at the nanoscale (1-100 nm) to improve food quality, safety, and functionality
  • Nanoencapsulation enhances the bioavailability and stability of bioactive compounds (vitamins, antioxidants)
  • Nanomaterials in packaging materials offer improved barrier properties, antimicrobial activity, and sensing capabilities
• Blockchain technology enhances food traceability and transparency along the supply chain
  • Decentralized and immutable ledger system records transactions and product information from farm to fork
  • Enables quick identification and recall of contaminated products, reducing foodborne illness outbreaks
• Upcycling transforms food processing by-products and waste into value-added ingredients or products
  • Reduces food waste and promotes a circular economy
  • Examples include using spent coffee grounds as a source of dietary fiber and antioxidants, or extracting pectin from citrus peels for use as a gelling agent