Food Science Test 1

• Food Pioneer
• Experimented with food preservation
• Succeeded with soups, jams, dairy products, syrups

• Place product in a can and place it in boiling water
• NOT PASTEURIZATION

• Food Pioneer
• Chemist and microbiologist
• Demonstrated that fermentation was caused by microorganisms
• Treated milk to destroy spoilage organisms
• PASTEURIZATION

• Food engineer
• Food regulation
• Food analysis
• Sensory Science
• Brewing

Complex mixture of chemicals that an organism takes in and assimilates to promote growth, expend energy, replace worn or injured tissue, and prevent certain diseases

• Water
• Proteins
• Carbohydrates (97% of food's mass)
• Lipids
• The rest is made up of thousands of different compound
• -staste
• -odor
• -color
• Vitamins and minerals also exist and are important in many body functions

Nutrition: The composition of foods and the reactions that lead to changes in their constitution and characteristics BIOCHEMISTRY

• too many or calories from saturated fats
• high rates of obesity leads to western disease
• USDA developed guidelines to help in planning a healthy and balanced diet
• Dietary Guidelines for Americans
• Food Guide Pyramid

• Chief constituents of muscle and other tissue
• Major components of enzymes
• Part of extracellular and intracellular structures in animals
• Made up of amino acids
• Proteins are made up of amino acids linked by peptide bonds
• Required for cell growth, repair and maintenance
• Sequence of amino acids in a protein chain determines the functionality of that protein
• A total of 20 amino acids found in proteins
• NOT ALL PROTEINS ARE THE SAME

• Not all proteins supply the needs of the body“High Quality” proteins provide all essential amino acids needed for to support protein tissue formation
• Animal Protein = High Quality  
• Plant Protein = Not Complete
• To form proteins all amino acids necessary have to be there
• Essential amino acids are NOT!!!!! synthesized by the body, they are supplied from food

• 1.Histidine
• 2.Isoleucine
• 3.Leucine
• 4.Lysine
• 5.Methionine
• 6.Phenylalanine
• 7.Threonine
• 8.Tryptophan
• 9.Valine

• 1.Alanine
• 2.Arginine
• 3.Asparagine
• 4.Aspartic acid
• 5.Cysteine
• 6.Glutamic acid
• 7.Glutamine
• 8.Glycine
• 9.Proline
• 10.Serine
• 11.Tyrosine

Linear sequence of amino acids

Look at picture

Shape of a coiled helix: Formed by hydrogen bonds between C=O and the NH groups

Look at picture

Three dimensional structure of a protein: Results from the folding of a chain over itself

Look at picture

Quarternary structure is only present if there is more than one polypeptide chain

Look at picture

• Molecules are quite fragile
• Food scientist must be aware of reactions due to exposure to:
• -Heat
• -Acids
• -Salts
• -Physical forces

• Loss of secondary, tertiary, and quaternary structure
• NO LOSS OF PRIMARY STRUCTURE!!!!!!!
• Caused by heat, acids, solvents, salts or surface force
• Loss of biological activity and changes in physical properties such as solubility

• Control is essential to food scientists
• Inactivation of enzymes --->“Blanching”
• Cheese and yogurt result from protein denaturation
• Whipping of egg whites to foam

• They have a composition of Cn(H2O)n
• They are a source of energy in our diet
• Digestible CHOs provide 4 Kcal/g
• Important carbohydrates for nutrition: sugars, starches, dextrins, glycogen
• Fiber: Non-digestible, does not supply calories

• The simplest forms of CHO’s 
• Can not be broken down to any smaller carbohydrates
• Called Monosaccharides
• Most common ones in foods are called hexoses (six carbon sugars)

• Glucose
• Fructose

• Two monosaccharides linked together
• Composed of either two units of the same monosaccharide or two different monosaccharides
• Bond is called a glycosidic bond!!!!!!

• More than two sugars linked together are called Oligosaccharides
• Very large molecules are called polysaccharides (10 or more units)
• Not sweet
• Texture
• Viscosity
• Mouthfeel
• Consistency

• Starch is the most important polysaccharide from a nutrition point of view (storage CHO in plants)
• Main source of calories in the human diet
• A polymer of glucose
• Composed of two polymers: amylose and amylopectin

• Not soluble in cold water
• When heated the starch molecules sweell and gelatinize
• Viscosity increases forming a paste
• When cooled a gel is formed

• Pastes used to thicken foods
• Gels are modified and used to impart desired texture

• An animal starch
• Stored in the muscles and available for immediate use as energy
• Excess CHO consumption
• Excess glycogen
• Excess CHO is converted to FAT!!!!

• Non-digestible carbohydrates
• Water Soluble
• -Lower serum cholesterol
• Water Insoluble
• -Reduces chances of colon cancer
• -Increases bulk

• Not soluble in water
• Soluble in organic solvents
• Contain 9 calories/gram
• Glyceryl esters of fatty acids
• Glycerol
• Fatty Acid
• Triglycerides

• Saturated fats in the diet lead to increased cholesterol levels
• High cholesterol levels are a contributory factor in heart attack, stroke and coronary problems
• Ingestion of trans-fatty acids is linked to increases in cholesterol levels

• Carriers of flavor
• Carry fat soluble vitamins
• Texture and mouthfeel
• Heat transfer

• Chemicals that are needed in very small amounts
• Should be consumed through our food
• Two different categories:
• 1.Fat soluble
• 2.Water soluble

• Vitamin A
• Vitamin D
• Vitamin K

• B vitamins
• Thiamin
• Riboflavin
• Niacin
• Vitamin B6
• Pantothenic acid
• Folic acid
• Biotin
• Vitamin B12
• Vitamin C

• Bacteria
• Yeasts
• Molds
• Virus
• Algae
• Protozoans

• Bacteria that break down food
• use food as a place to live out their life cycle(feed and reproduce)
• main cause of food deterioration
• Produce changes in food
• -Desirable 
• -Undesirable

• Bacteria, yeast and mold
• ▫Under optimum conditions, the MOs reproduce and in the process synthesize by-products▫
• ▫Ferment sugar, hydrolyze starches, hydrolyze fats, digest proteins, form acid, produce gas, produce toxins

• Rods
• Vibrios
• Spherical (cocci)
• Spirochaetes

Molds are multicellular

• Spherical and cylindrical
• Exist as either single cells or chains

• Occurs via binary fission
• Under favorable conditions doubling rate can be 20 minutes

• Molds: 
• Reproduce by means of spore formation
• Sexual or Asexual
• Yeast:
• Budding
• Fission
• Spore formation

• Vegetative:
• ▫Active, reproducing, metabolizing
• ▫Sensitive to environmental changes
• Spores:
• ▫Dormant state
• ▫Concentrated forms of their vegetative state
• ▫Formed when conditions are unfavorable
• ▫More resistant to heat, acid, pressure

• pH
• Nutritional requirements
• Temperature
• Water
• Oxygen

• Growth and rate of growth are highly affected
• Have an optimum pH at which they grow rapidly
• Ranges where they will not grow
• Molds, Yeast: grow best in acid mediums
• Bacteria: many grow at neutral or slightly alkaline pH

• Bacteria: use nitrogen and CO2 from air
• Yeast: Yeasts: derive their nitrogen from lysisne (amino acid)
• Yeast and mold grow in high concentrations of sugar

• Psychrophiles: grow fastest around 68 – 77 °F
• Mesophiles: grow best around 98 °F
• Thermophiles: grow between 113 – 160 °F
• Mesophiles cause disease in animals
• Growth rates decrease at the low and high ends of the T range
• NO UNIVERSAL KILLING TEMPERATURE!!!!

• Microorganisms only grow in aqueous solutions
• Grow in available water found in food
• Water activity (aw): express availability of water
• Low water activity limits the growth of microbes–
• -Salt
• -–Sugar
• -–Drying

• Anaerobic Bacteria: Won’t grow in the presence of Oxygen
• Aerobic Bacteria: Need oxygen to grow
• Molds: require oxygen
• Yeast: grow best in aerobic conditions (some grow without it)

• ▫Infection – microorganism is present in the food at the time of consumption, grow in the host cause disease –E. coli O157:H7, Listeria, Salmonella
• ▫Intoxication – microorganism produces toxin in the food prior to consumption, cause disease upon ingestion–Staphylococcus aureus, Clostridium botulinum, Aspergillus flavus

• Food handlers poor personal hygiene
• Unclean equipment and work area
• Foods not adequately processed
• Cross-contamination
• Lack of support from management

• Nonsporeforming rods
• Motile
• Abdominal pain, diarrhea, fever, vomiting Main source humans and animals

• Rod shaped
• Grows under conditions of refrigeration
• Meningitis, septicemia, spontaneous abortion
• Raw milk, unpasteurized cheeses, lunch meat

• Staphylococcus aureus is responsable
• Nausea, vomiting, abdominal cramps, diarrhea
• Incubation: 1 to 7 hours
• Toxin produced is not destroyed by normal cooking
• All foods except acid products are susceptible
• Most often: ham, bakery goods with egg, chicken products, potato salad, cheddar cheese
• Humans are the primary reservoirs (nose, hands, arms, mouth, throat)

• Occurs rarely but high mortality rate (30%)
• Vomiting, constipation, double vision, abdominal distention, raw sore throat
• Severe cases produce affect the breathing mechanism and the heart
• Clostridium botulinum

• Anaerobic
• Sporeformer
• Produces toxin
• Some strains can grow low temperature
• ▫Seven different types: A through G▫
• -Only a few nanograms can cause illness
• Spores from varied sources
• -▫Food, dust, soil

• Toxin: Destroyed by boiling
• Spores: Higher temperatures to be inactivated

• Bacteria, yeast and mold can produce desirable changes in foods
• Lactic acid bacteria
• ▫Yogurt, sausages, sauerkraut
• Yeast
• ▫Wine, beer, bread
• Mold
• ▫Cheese, beef

• Institutional Food Services
• ▫Hospitals
• ▫Nursing Homes
• ▫Elementary Schools
• Restaurants
• ▫Fast Food
• ▫Full Service
• Retail Food
• ▫Deli
• ▫Meat & Poultry
• ▫Seafood
• ▫Produce

• Food from unsafe sources
• Inadequate cooking
• Improper holding temperatures
• Contaminated equipment
• Poor personal hygiene

• Home needs to be kept clean by periodic cleaning and setting proper rules of conduct
• 88% of all cases of food poisoning can be traced to handling of food at improper temperatures

• Hot foods: 140-160 degrees
• Cold foods: 32-40 degrees
• 165-212: Water boils, heat and reheat foods at these temps
• 32-0: Water freeze, bacteria survives but does not grow

• Hazard Analysis Critical Control Point
• Developed in 1971 by US Army Natick Laboratories, the National Aeronautics and Space Administration and the Pillsbury Co

• 1. Assess potential hazards in all stages of food production
• -▫Chemical, Physical, Biological
• 2. Determine critical control points (CCP)
• -▫Point in the process where controls are necessary to eliminate or reduce hazards
• 3. Establish requirements to be met at each CCP
• -▫Based on research data, laws/regulations
• -▫Be specific, times, temperatures, procedures
• 4. Establish procedures to monitor each CCP
• 5. Establish corrective actions
• -▫What are you going to do when things go wrong
• 6. Establish record-keeping procedures
• -▫Hand written/electronic
• 7. Establish procedures to monitor effectiveness of HACCP (Validation)
• -▫Laboratory analysis

• To determine the wholesomeness and purity of food
• Protect the consumer from economic fraud and health hazards.
• Protective legislation is passed and enforced after consumers demand government action

• The meat inspection act of 1907
• To prevent adulterated or misbranded meat and meat products from being sold as food and to ensure that meat and meat products are slaughtered and processed under sanitary conditions.

To ban interstate commerce in misbranded and adulterated food and drug products

Provided the government with authority to conduct on-site inspections and provide standards of identity for individual products

• 1- Food and Drug Administration (FDA) (all food except poultry and meat)
• 2- Meat Inspection Division
• 3- Poultry Inspection Service

• Provides guidance, regulation and oversight
• -For all foods except meat and poultry
• -Food Safety, HACCP, retail food production
• -Food contaminants, labeling and nutrition
• Science and research (lab procedures)
• Power to inspect food processing or handling plants and close if needed
• Can seize and destroy adulterated product
• Operates under the Federal Food, Drug, and Cosmetic Act (1938)
• It establishes standards of identity, quality, and fill of containers of food products.
• It develops and enforces regulations for proper food labeling

• 1.Adulteration
• 2.Misbranding

• Easy to determine
• FDA has a GRASS (Generally Recognized as Safe) list of additives
• -Which chemicals may be added
• -How much may be added
• New additives require approval
• -Very expensive process

• 1- It is filthy, putrid, or decomposed.
• 2- It is produced under unsanitary conditions.
• 3- It contains any substance deleterious to health.

• It has a standard of identity and fails to meet the standard.
• It is wrongly labeled It fails to meet the standard for fill of container.

• Standard of Identity
• -Can only contain the ingredients specified in thestandard
• -Misbranded food will be SEIZED AND DESTROYED!!!!!!
• Can be wrongly labeled as to weight, portions, or ingredients if no standard of identity has been established
• Theoretically the FDA can only regulate those foods that are shipped between states

• A branch of the USDA Agriculture Research Service (ARS)
• Was established in 1906 through the Federal Meat Inspection Act
• Slaughter facilities will have inspectors on-site
• Has a list of approved ingredients for cured and processed products

• Very similar to the Meat Inspection Bureau
• Was established to ensure that all poultry sold in interstate commerce is wholesome.

• 1) Basic information
• 2) List of ingredients
• 3) Quality grades
• 4) Nutrition information
• 5) Shelf life data

• Name of product
• Clearly identified
• Frozen dessert, imitation, chicken stir-fry
• Net contents
• Name address of the manufacturer, packer, or distributor

• All ingredients must be listed
• Start with major ingredient (by weight)
• Colors must be listed individually
• Chemical preservatives common or usual name plus function
• If a beverage is said to contain juice, the per cent of total juice must be declared on the information panel

• Certifies their level of quality
• Graded by the USDA (except seafood, USDC)
• Based on organoleptic criteria, physical and production characteristics
• Not mandatory, but requested by the producer, distributor etc
• Meat might be labeled “Prime” or “Choice”

• Food packages with less than 12 square inches of space, must provide address or phone number
• Food packages with less than 40 square inches may present a smaller version of the nutrition information

• Food produced by small businesses
• Food served from immediate consumption
• RTE foods prepared on site
• Food shipped for bulk
• Foods containing no significant amounts of any nutrients

• Product name
• Serving size
• Calories per serving
• Amount of protein, total CHO’s, total fat, sodium
• Vitamins A & C
• Iron and calcium

• Product name
• Service size based on raw or cooked weight
• Calories per serving
• Calories from total fat per serving
• Amount per serving total fat, saturated fat, cholesterol, sodium, total CHO’s, dietary fiber
• Sugars and protein
• Iron, calcium, Vit A and C

• Calcium and a reduced risk of osteoporosis
• Sodium and increased risk of hypertension
• Fiber and reduced risk of cancer
• Fruits and vegetables and a reduced risk of cancer
• Sugar free <0.5 g , reduced sugar <25%
• Fat free < 0.5g, reduced < 25% , low fat ≤ 3 g
• Sodium free < 5 mg, reduced/less sodium ≤ 25%
• High fiber 5 g or more

• Chemical substances deliberately added to foods, directly or indirectly in known and regulated quantities
• Purpose: Assisting in the processing and preservation of foods
• Purpose: Improvement of flavor, texture, or appearance

Generally Recognized as SafeAdditives that have been used without apparent harm for long periods of time (baking powder, citric acid, salt, sugar)

…. no additive shall be deemed to be safe if it is found to induce cancer when ingested by man or animal, or if it is found, after tests which are appropriate for the evaluation of the safety of food additives, to induce cancer in man or animal

• 1.Must perform their intended function
• 2.Must not deceive the consumer/conceal faulty ingredients
• 3.Cannot considerably reduce the food’s nutritional value
• 4.Cannot achieve an effect that could be gained by GMP’s
• 5.A method of analysis must exist to monitor the use of the additive in foods or its incidental occurrence in foods

• To improve or maintain nutritional value
• -▫Enriched or fortified with vitamins or minerals
• To maintain palatability and wholesomeness
• -▫Slows spoilage and rancidity
• To provide leavening or control acidity/alkalinity
• -▫Rise during baking, flavor, taste, color
• To enhance flavor or impart desired color
• -▫Spices, natural and synthetic flavors

• Stabilize foods that would loose quality in the presence of oxygen
• Develops rancidity and discoloration
• Butylated hydroxyanisole (BHA)
• Butylated hydroxytoluene (BHT)

• To aid in a balanced and ample nutrient intake
• Nutritive loss due to processing conditions
• Vitamin A, D, and C

• Natural or synthetic compounds added to produce flavor or modify existing flavors
• Fruit extracts
• Amyl acetate (banana flavor)
• Benzaldehyde (cherry flavor)

• Lower pH and enhance desired flavors
• Lower pH inhibits microbial spoilage
• Vinegar (acetic acid)
• Citric Acid
• Lactic Acid

• Enhance sweetness of food and beverage products
• Natural: Fructose, Honey, Maple Sugar
• Synthetic:Aspartame, Acesulfame K

• Enhance the rising of dough in the manufacture of baked products
• Baking powder
• Ammonium and phosphate salts