HBT 2336 Food Biotechnology

• HBT 2336 Food Biotechnology is a course in the Medical Biotechnology Programme, lectured by Njagi Shadrack, with contact details [email protected], and 0712322557

• Course assessment includes:

• Practicals at 10%

• Assignments at 5%

• CATs (Continuous Assessment Tests) at 15%

• End of semester examination

• The course learning outcomes are:

• Demonstrate understanding of food biotechnology

• Describe the application of biotechnology in food preservation

• Describe techniques used in food biotechnology

• Demonstrate understanding of bio-fortification of foods

• Explain the regulatory and social aspects of food biotechnology

• Key textbooks are:

• "Food Biotechnology: Principles and Practice" by V.K.Joshi and R.S.Singh (2012)

• "Food Microbiology" by Martin R Adams and Maurice O Moss (2007)

• "Food Biotechnology" by B. H. Lee (2014)

• Key journals are:

• Annual Review of Food Science and Technology

• Food Microbiology

• Trends on Food Science and Technology

Introduction to Food Biotechnology

• Food biotechnology applies biological techniques and processes to improve, modify, or create new food products and ingredients
• The field combines principles from biology, genetics, microbiology, and food chemistry
• It enhances food production, processing, quality, and preservation
• A central goal is to develop innovative and sustainable solutions for food security, nutritional value, and safety challenges
• Food processing origins are not a modern concept
• Early agricultural societies required food storage and preservation
• Egyptians (3000–1500 BC) used sun drying to preserve fish and poultry
• They also used fermentation to produce alcohol, cereal grinding, and ovens for leavened bread
• Pastoral societies adopted these techniques to preserve food against famine, improve eating quality, and diversify diets
• By 1500 BC, all major food plants except sugar beet were cultivated
• Societal development led to specialization, revolutionizing food processing
• Modern biotechnology techniques have since been introduced in food production

Promise and Potential of Food Biotechnology

• Biotechnology methods in food and agriculture greatly impact society
• By 2050, >10 billion people expected, raising concerns about resources for the world population
• Hunger and malnutrition claim 24,000 lives a day in developing countries in Asia, Africa, and Latin America
• Many in industrialized countries still lack proper nourishment despite food abundance
• Recent biotechnology advancements enable production of more nutritious, safer, tastier, and healthier food

Aims of Food Biotechnology

• Extend shelf-life
• Increase variety in diet by providing attractive flavors, colors, aromas, and texture
• Enhance food processing technology
• Provide required nutrients
• Generate income for manufacturing companies and their shareholders

Properties of Foods: Composition

• Foods are composed of biochemical components determining properties and applications
• Understanding biochemical composition is crucial for understanding food properties
• Properties include factors such as physical, sensory, and nutritional qualities and utility
• Biochemical components affect food quality, safety, processability, nutritional value, and utility

Biochemical Components of Food

• Macromolecular components: carbohydrates, lipids, proteins, and water
• Micro-components: vitamins, minerals, and natural colorants

Macromolecules: Carbohydrates

• A carbohydrate is a biomolecule of carbon, hydrogen, and oxygen atoms
• Carbohydrates found in healthy and unhealthy foods: bread, beans, milk, popcorn, potatoes, cookies, spaghetti, soft drinks, corn, and cherry pie
• Abundant forms include sugars, fibers, and starches

Categories of Carbohydrates

• Monosaccharides or ‘simple sugars’
• Between three and nine carbon atoms, cannot be broken down by hydrolysis, for example glucose, fructose and arabinose
• Oligosaccharides
• Contain about 2–20 monosaccharides
• Includes sucrose (table sugar) from glucose and fructose
• Lactose (milk sugar) from glucose and galactose, fermented to lactic acid by lactic acid bacteria in yoghurt and other fermented milk products
• Maltose consists of two glucose molecules
• Polysaccharides
• Contain more than 20 monosaccharide units
• Most abundant form of carbohydrate
• Plants store starch, cellulose, and pectin
• Plus a range of gums, guar, locust bean, xanthan and carrageenan
• Animal tissues-glycogen is polysaccharide stored in the muscle and liver
• The molecular structure enables the individual units to form hydrogen bonds with water
• As a result, polysaccharide particles readily hydrate, swell and dissolve partially or completely
• Often used to control water in food systems and the physical viscosity and functional properties

Lipids

• Fatty or oily compounds soluble in non-polar organic solvents; insoluble in polar solvents like water
• The difference between 'fats' and 'oils' is based on whether a lipid is solid or liquid at room temperature
• At room temperature, oils are liquid and fats are solids
• Plant lipids include vegetable oils from coconut, cottonseed, olive, palm/palm kernel, peanut (groundnut), and soybean

Building Blocks and Types of Lipids

• Building blocks of fats are fatty acids
• Long hydrocarbon chain (carbon and hydrogen atoms) with carboxyl group (-COOH) at one end
• Saturated fatty acids (SFAs)
• Have no double bonds between the carbon atoms
• Unsaturated fatty acids (USFAs)
• Have double bonds between carbon atoms;
• Monounsaturated fatty acids (MUFAs): have only one double bond,
• Polyunsaturated fatty acids (PUFAs): have more than one double bond
• Types
• Phospholipids are lipids that contain phosphoric acid and are present in cell walls and biological membranes
• Sterols
• Another example of lipids, includes cholesterol, sterol found in animals
• Plant sterols are known as phytosterols and include beta-sitosterol, campesterol, and stigmasterol

Proteins

• Complex polymers made up from a pool of 20 amino acids
• Protein sources: beef, lamb, veal, pork, poultry (chicken, turkey, duck), emu, goose, bush birds, fish and seafood, octopus, cereals
• Classification based on size:
• Oligopeptides: peptides containing fewer than 25 amino acids
• Polypeptides: anything beyond oligopeptides
• Grouped according to shapes:
  • Globular proteins: Have spherical shapes due to folding of polypeptide chains
  • Fibrous proteins: Have twisted linear polypeptide chains

Micro-components in Foods

• Biochemicals found in small quantities
• Vitamins:
• Thirteen organic compounds essential for normal metabolism in animals
• They’re often not synthesized in the body or are synthesized in inadequate quantities
• Vitamins must be obtained from the diet/food
• Act as coenzymes, components of defense systems, factors in genetic regulation, and in specialized functions. ex vision
• Vitamins are categorized into two broad groups: fat-soluble vitamins and water-soluble vitamins

Water-Soluble Vitamins

• The water-soluble vitamins are: Vitamin C, B vitamins (B1, B2, B3, B6, B7, B12), folic acid and pantothenic acid
• Vitamin-rich foods: fruit, vegetables, egg, meat, and grains

Minerals

• Inorganic chemical elements required by living organisms, other than carbon, hydrogen, nitrogen, and oxygen Found in minerals are found in nearly foods, but concentrations vary
• Grouped into:
• Major minerals
  • Intakes of >100 mg/day
  • Include calcium, phosphorus, magnesium, sodium, potassium, chlorine, and sulfur
• Trace elements
• Intakes of <100 mg/day
• Include iron, zinc, manganese, cobalt, copper, iodine, selenium, and chromium
• Food minerals do not diminish in heat.
• Minerals functions within the body:
• Maintain water balance
• Contribute to the structural basis and activity of many proteins
• Act as cofactors to many enzymes