Food Science Exam 1

Factors affecting patterns of eating

Family, social, cultural, time restriction, immigration/acculturation, religious beliefs, consumer care for environment, food availability, economics

Christian dietary

avoids meat during lent

Judaism dietary

Reform Jews= flexible

Orthodox and Conservatory = strict; Kosher: no blood, no pork/shellfish, only seafood with scales. Usually clean, no processing. Passover: no grain products produced

Islam dietary

Halal = lawful. prohibited = birds of prey, pigs, land animals w/o ears, blood, animals slaughtered w/o drained blood. Fish is contraversial

Hinduism dietary

no cows, fish and meat must be sanctified before consumed. Most vege but not required.

Sensory evaluations:

taste, appearance, odor, sound, texture

taste

• not same as flavor. Flavor = blend of taste and odor.

• sensation produced thru taste buds.

  • 5 sensations (sweet, sour, bitter, salty, umami).

5 taste sensations

sweet, sour, bitter, salty, umami

hydroxyl groups and ions for taste

hydroxyl = sweet, ions = salty

trigeminal nerve

transmits taste messages, such as sensation of burning/heat, cooling, tingling

papillae

elevations on tongue where taste buds are found.

Taste pore

leads to taste bud. tastes produced when substances contact taste receptors in the taste pore

brain associates taste with

memories and emotions

olfactory center; orthonasally; retronasally

located on top of nasal cavity. gas from foods stimulate nerve endings in ______. Can be experienced ______ (through nose) or _______ (vaporizing chemicals through chewing stimulate nose from back)

Flavor

• taste + odor

  • response to stimuli from olfactory center, taste buds, tactile receptors, and pungency (sharp, burning, or stinging sensation)

Aging

___ causes loss of taste buds

tactile sense

consistency, shape, tingling feeling from carbonationsen

sensory evaluation

judgement of all senses. 3 main tests: paired, triangle, and duo-tri

comparison test

identify which is sweeter

Triangle test

pick two samples that are the same and 1 that is different

duo-trio

1 sample is control, find the one out of the other two that is like the control

hedonic scale

scale of likeness without works 🙂 ☹

viscometer

measures viscosity

gelometer

measures firmness or strength of gelatin

pH meter

measures acidity

colorimeter

color scale of food

compressimeter

compressibility/ softness (ie of bread)

shear/ cutting apparatus

tenderness of meat

highest risk of foodborne illness

young children, pregnant, elderly, weakened immune systems/ chronic health

ways to limit potential food hazard

pasteurizing, sterilizing, freezing, refrigerating, special packaging.

4 keys to safe food handling

1. wash hands and surfaces

2. no cross contamination

3. proper temperature

4. refrigerate promptly

Temperature for beef, pork, veal, lamb, steak, roast w/ 3 min resting

145 F

temperature for fish

145 F

temperature for beef, pork, veal, lamb, ground

160F

temperature for egg dishes

160 F

Temperature for turkey, chicken, duck

165 F tem

temp danger zone

41 F - 135 F

HACCP system

hazard analysis and critical control points to identify and control hazards

pasteurization

foods heated to kill pathogens. milk, eggs, fruit juices

irradiation

treatment of foods by electron beams, gamma rays, xrays, to reduce bacteria. “cold pasteurization”, kills w/o heating food

high pressure processing

high pressure to reduce vegetative bacteria. raw fruit/veg juice, ready to eat meals, shellfishs

sterilization

boiling, steaming, heating, and canning low acid foods at temps above boiling to kill microorgs. While pasteurization is 140-180 F, ___is 212F +. 3

3 general foodborne illness

infection, intoxication, and toxin mediated infection

food infection

food containing pathogens is consumed

food intoxication

food contaminated with toxins-producing microorgs are comsumed or w/ biological/chemical toxins

toxin-mediated

food contaminated with microorgs consumed, then microorgs produce toxins in intestine

bacteria

require moisture, grow best where conc. of sugar and salt are low and pH is neutral, and moderate temps

viruses

transmitted fecal-oral route (hepatitis A, norovirus)

fungi

molds, yeast, mushroom

prions

normal proteins in animal tissue that become infectious when they are misfolded and abnormal

big 8 allergies (9 with sesame)

peanuts, treenuts, soybeans, crustacea, fish, wheat, milk

3 food intolerance categories

1. anaphylactoid reaction

2. metabolic food disorder (lactose)'

3. idiosyncratic illness

methods of knife sharpening

sharpening stone or whetstone

carbon steel

alloy of iron, easy to sharpen but easy to rust and stain

stainless steel

alloy of iron (15% chromium), not as sharp but resistant to corrosion and cheap.

high carbon stainless steel

best of other two: sharp and resistant

Kingdom of gallon

4 types of recipes

1. standard

2. action style- narrative describing actions with listing of ingredients

3. descriptive- column format of ingredient, quantity, and procedure

   1. narrative- ingredients combined with narrative, best for short easy recipes

F -C conversion

1.8(C) = F - 32

types of heat transfer

1. conduction

2. convection

3. radiation

conduction

heat transferred thru direct contact.

• metal,= good conductors, glass and ceramics not as good as metals

  • good metals = copper, aluminum, iron

convection

heat transfer thru liquid or air currents. foods in water, fat (frying), and hot air (oven)

radiation

waves to cook food, usually infrared.

• generated by hot source like coals

  • broiling, bbq, toasting, microwaving

4 medias for heat transfer

1. air

2. water

3. steam

4. fat

air

roasting, baking, broiling, grill. dry heat

water

boil. simmer, stew, braise, poach

fat

sauteing, panfrying, fat frying

microwave cooking non reccomended materials

• glazed ceramics,

• dinnerware w/ gold and silver lining

• dyed paper and paper bags

• plastic wrap and foam meat trays

• one time use plastic

• metal

• Al

  • foil

microwave advantages

• speed of cooking and reheating

• reduction of nutr loss

• energy conservation

microwave disadvantages

• no surface browning

• foods needed to tenderize and rehydrate not as good

• easy to overheat

• uneven heating

starch

carb stored as energy for plants. made of amylose and amylopectin

refined starch

stripped of nutr value: corn starchcor

corn starch sources

seeds, roots, tubes, cereal grains

amylose

long glucose chain called linear fraction. responsible for the gel characteristics

amylopectin

branched glucose chain, nonlinear, cohesion and thickening properties.

starch granule

where amylose and amylopectin are stored. swell when absorb waterge

gelantinization

• when starch in water is heated slowly, starch granules swell and mixture thickens into a paste/gel.

• point at which loss of birefringence occurs (cross pattern of starch) results in high viscosity

native starch

starch from plants w/o modification: cornstarch, tapioca, potato, arrowroot

• cornstarch is both native and refined. native means basic chemical and molecular structure aren’t altered

modified starch

varying the ratio of amylopectin and amylose to get desired results

dextrinization

starch molecules are broken down into dextrins (polysaccharides composed of glucose units).

• formed in crust of baked flour mixtures, toast, and fried starchy coated foods

roux

• used in espagnole, veloute, bechamel

retrogradation

as gelatinized starch cools and ages, some starch molecules begin to reassociate (amylose and amylopectin begin to reallign)

• responsible for defects in starchy foods, like loss of viscosity in soups and staling of bread

  • starches higher in amylose (like cornstarch) undergo retrograd faster

synseresis

“weeping” results from increase molecular association as starch ages, tiny beads form on surface of foodfac

factors affecting starch paste

1. stirring - minimal

2. heated rapidly - thicker than heated slowly

3. high acidity - dec. thickening power

   1. large amounts of sugar - delays swelling of granules

starch thickened desserts

• cornstarch pudding

• pie filling

• syrup

• high fructose syrup

1 c = ___ fl oz

8 fl oz

effect of dry heat on starch

• more soluble

• less thick

• dextrinization

• brown, nutty, toasty flavor (brown roux)

gelation

• different than gelanitization

• occurs during cooling instead of heating

salmonella

• most deaths and hospitalization

• eggs and poultry

list

listeria monocytogenes

• pregnant women more likely

• compromised immune systems

• raw milk, softened cheese, ice cream, deli meats, raw poultry and meats

E coli

• bacteria causing bloody diarrhea

• leading cause of kidney failure in children

• cattle products

• water, lettuce, apple and apple juice

  • 
    

clostridium botulinum

• results in botulism

• paralysis and death

• improperly home canned foods

  • dented cans

norovirus

• leading cause of outbreaks in us

• diarrhea and vomiting- gastroenteritis

• shellfish, salad, ice