Food Science Exam 4

nutrients, food additives, preservatives, toxins. everything that is good or bad in a food is a chemical

chlorophylls, carotenoids, anthocyanins, betalains

solanine, amygdaline

citric acid, benzoic acid

papain

pigments, toxins, preservatives and enzymes

Anthocyanins, Betalains, Carotenoids, Chlorophylls

are water soluble compounds ranging from purple to orange. eggplant, radish, red potato

purple to red-yellow. Beets

fat soluble ranging from yellow to red-orange

temperature, humidity, washing/soaking, cutting/slicing, heating, freezing

reaction rates vary

wilting or spoilage

leaching

enzymatic change

flavor and texture

slows reaction

porphyrin ring. an iron atom at its center with a binding site that can bond any atom that is able to donate a pair of electrons

cooking, drying, freezing, pasteurizing

flavor, color, texture

flavor

microbial reduction

purple. reduced Fe+2

red. oxygenation and reduced Fe+2

grayish and brownish. oxidation and oxidized Fe +3

pink. cured meat (cooked)

food scientists make use of specific chemicals in ingredients to produce a desired result

ingredients is defined as the physicochemical properties that affect performance in a food during processing, storage, and preparation

toxic compounds, preservatives, food additives, colors/flavors, nutrients, enzymes, water

Bacterial toxins, mycotoxins, Pesticides, Endogenous

solanine, amygdaline, Myristicin, Safrole, Thiocyanate, coumarin, hydrazine

Toxicity of a chemical is related to dose. large amounts of otherwise harmless chemicals may cause problems. Additives with known toxicity are monitored and regulated with a 100X safety factor

FDA must approve the uses of all food additives to ensure safety. Threshold level is the dose above which adverse effects are produced

all food additives have potential to cause harm or toxicity

work slowing, stopping or killing microbes. salt and sugar are most common, they decrease water activity.

any substance added to food.

must be approved by the food and drug administration

developed to identify the mutagenic potential of chemical substances. bacterial cells to chemical substances.

contaminants but are often anticipated at a minimal level

antibiotics, Dioxins, dirt, har, hormones, insects, microwave packaging

acidulants: malice acids, tartaric acid, citric acid, vinegar, phosphoric acid. Alkaline compounds: sodium hydroxide

pigment used to impart color to a food or beverage. is an additive. Natural and artificial colorant.

certified as safe for food, drug, or cosmetic applications

water soluble for entire foods

insoluble for food surfaces

Annatto from seeds of a tropical evergreen. cochineal from dried cochineal insects. caramel from non enzymatic thermal processing of sugars. paprika extract

are associated with particular products. ex- Benzzaldehyde: cherry or almond. Isoamyl acetate: banana

are made by heating amino acids with reducing sugars

alcohol as solvent

steam distillation

oil-soluble extract

perform as both flavorings and enhancers

is derived from soybeans

is a flavor enhancer for the savory (umami) character in meat products

monosaccharides, disaccarides, oligosaccharides, polysaccharides, dietary fiber

hydrated starch granules swell during heating to release soluble starch molecules that provide thickening

long chain polymers that can be linear or branched. uses are thickening, gelling and binding Ex: Xanthan gum, Guar gum, Carrageenan and alginate, gum arabic

does not provide energy but does avert or decrease some problems

acids are one that the body can't synthesize. lysine, methionine, tryptophan, valine

can cause problems. lack of glucose for the brain. ketoacidosis. hush urea in urine.

required for proper brain function and to produce key hormones. progesterone and testosterone

water soluble substances that transport fat and cholesterol in blood.

carries cholesterol from liver to body cells

carry cholesterol and TGs from liver to body

carry cholesterol back to the liver

intake will accumulate in arteries (heart disease) and contribute to overall weight gain (obesity)

less than or equal to 30% of calories from fat. less than or equal to 10% of calories from saturated fat. no more than 300 mg of cholesterol

animal starch stored in muscles as a source of energy. when glycogen requirements are met, excess glucose is converted to fat

besides the accumulation of fat associated with eating too many calories, there are additional problems. dental caries, diabetes

lower limit: 55% of caloric intake. upper limit: 75% of caloric intake. sugars less than 10% of caloric intake. fiber: 20-35 g/day

includes B- vitamins and vitamin C

include A,D, E, and K

alcohol. provides 7 kcal/gram and is the 4th source of calories

weight gain, impaired motor skills, poor judgement

removes dietary fiber so many people now seek whole grain products

source of carbohydrates and dietary fiber. oat fiber is good form of fiber

high in pectin and lower in cellulose than fiber from grain

provide minerals, vitamins and dietary fiber. high in moisture and low in fat and sugar

contribute vitamins, minerals and fiber to the diet. have more sugar and less starch than vegetables. processed juices have less dietary fiber than whole fruits

high in calcium, protein, potassium and vitamin D. cheeses high in fat. lactose-intolerant individuals may consume yogurt which is low in lactose but delivers calcium and vitamin D

protein is primary nutrient. many also rich in B-vitamins, iron and zinc. animal products tend to be higher in fat, minerals, and balances proteins

fats are solid at room temperature and have higher levels of saturated fats than oils. peanuts, soybeans, sunflower seeds and canola seeds are sources.

oils provide this. needed for absorption of fat-soluble vitamins

refers to the degree to which nutrients are digested and absorbed

food processing may diminish some nutrients, but enrichment is also possible to replace losses. primary purposes of processing are to increase shelf-life or safety and to reduce waste

responsible for the digestion or breakdown of food molecules into absorbable units. are protein molecules that cause chemical reactions to occur without being altered in the process.

defined as chemical compounds that are soluble in organic solvents but not soluble in water. 3 groups of lipids: triglycerides, phospholipids, cholesterol

fatty acids are saturated if there are no carbon to carbon double bonds

fatty acids are unsaturated if there are one or more double bonds. oils more unsaturated and thus have a lower melting point than fats

involves splitting oils into high and low melting point components

forced addition of hydrogen atoms to the unsaturated bonds of fatty acids to raise the melting point of the fat (harden)

breakdown of triglycerides is the breakdown of triglycerides into glycerol and fatty acids

rearrangement or recombination of fatty acids from a triglyceride

result of oxygen reacting with the double bonds of unsaturated fatty acids to produce a rancid flavor or aroma

fatty acids can occur after fatty acids are hydrolyzed from glycerol

important macronutrients and provide essential amino acids. provide structure in foods and often serve as enzymes in reactions. are Polymers of amino acids. every protein has an acid end and an amino end

linear sequence of amino acids

refers to the alpha helix or beta sheet configuration

describes the 3 dimensional shape of the protein molecule

overall spatial structure if the protein has more than one polypeptide

unfolding of protein structure without disrupting covalent bonds. starches, lipids and vitamins do not denature

results in degradation to primary structure by enzymes, heat, extremes of pH

specialized proteins that catalyze specific reactions converting substrate to products

utilizes enzymes to break large molecules into smaller fragments. carbs, lipids

reactions involve enzymes that cause changes in chemical structures. polyphenol oxidase

involve the condensation f molecules into polymers

most abundant chemical in foods. may be solid liquid or gas. known as a the universal solvent. important for safety and quality of products

is a measure of the availability of water molecules. calculated as the ratio of water vapor pressure of the substance divided by the vapor pressure of pure water at the same temperature

ability to retain moisture during application of external forces like heating, grinding, and pressing

many foods and beverages are dispersions where a discontinuous phase is dispersed in a continuous phase. ex: solutions, gels, suspensions, foams, and emulsions

two phase system in which one phase is dispersed in the other. oil in water and water in oil are examples.

occurs when digested nutrients enter the bloodstream through capillaries of the small intestine.

Nutrients

small lipids and water

water-soluble vitamins

glucose and amino acids

the delivery of nutrients and oxygen to all of the body's cells by the vascular system. Exchange of nutrients and wastes takes place across the walls of capillaries

calcium deficiency diseases

responsible for almost all food borne illness and cause most food spoilage

study of the physiology, genetics, growth characteristics, survival, and behavior of microbes

are living entities that are too small to be seen with the naked eye

unicellular prokaryotes found almost everywhere

molds and Yeasts

multi or unicellular eukaryotes. growth is evidenced by mycelium

unicellular eukaryotes. grow faster than molds. oval

single-celled eukaryotes. do not grow in foods, but are parasites that require a host to complete their life cycle

all viruses are parasitic and are generally host-specific.

most reproduction is by cell division under optimum conditions, division may take a little as 30 minutes

no or slow growth, getting used to the environment

rapid growth

environmental characteristics that surround food. temperature, relative humidity, gaseous environment

food composition and characteristics that influence microbial growth in the food. EX- water activity, pH, nutrients

food, acidity, temperature, time, oxygen, moisture

vary with the type of organism, but most foods provide high nutrient availability for microorganisms

the pH in which microbes live is a particular range defined by minimum, maximum, and optimum

those that have a natural pH of 4.6 or less

low acid foods to which acids are added

those with a pH greater than 4.6 and aw of .85 or more

cannot tolerate oxygen

require oxygen

chemical compounds that slow the growth of microbes

chemicals produced by bacteria that inhibit others

biological process in which microorganisms induce a series of chemical reactions leading to food preservationf

common spoilage bacterial genera. ex- canned foods, cold cuts, bread

a toxin is formed by the microorganism prior to ingestion

the live microorganism must be ingested to cause disease