Food Science

shortened cake vs foam cake

(+ what is a cookie?)

• shortened cake: moist, dense, contains fat and uses baking powder/soda as leavening agent

• foam cake: light/fluffy, little to no fat, uses air and steam as leavening agent (like angel food cake)

• a cookie is a modified shortened cake (fatter, and crispier because it’s lower in sugar and liquid)

quick breads + examples

egg/flour, leavened with baking powder/soda instead of yeast so it doesn’t require proofing (ex: muffins)

a pastry is only…

flour, fat, liquid, salt (no sugar)

butter has ____ % water content which is ___ than margarine but ___ than shortening.

how does this impact cookie spread?

20%, less, more (shortening is only fat)

more water = more spread, less water = taller

amount of protein in flour type:

• cake (soft wheat)

• pastry (soft wheat)

• all purpose (blend of hard and soft wheat)

• bread (hard wheat)

• whole wheat

• 5-8%

• 8-9%

• 10-12%

• 12-14%

• 14%

baking at a high altitude requires:

• INCREASE

  • oven temp, liquid, flour

• DECREASE

  • baking powder/soda, fat, sugar

  • time (5 mins for each 30 min of baking)

the flakiness of a pie crust is produced by…

the leaving fat in course particles

a fallen center in a cake is caused by

• too much sugar

• too much fat

• expired baking powder

• under-mixing

• oven temperate that is too low

poor volume (a dense cake) is created by

• too little baking powder

• not enough sugar or fat

a tough, dry, crumbly crumb is created by

• too much flour

• too much egg

• too little fat

• too little sugar

  • overmixing or overbaking

a coarse, crystalline texture is created by

• too much baking powder

• too much sugar

• oven temp too low

• undermixing

tunnels throughout a baked good is created by

overmixing (which decreases co2) results in overdeveloped gluten and a tough, heavy, tunneled product

why would a cake have a hump in the middle?

oven too hot

a bitter flavor is caused by…

too much baking powder

yellowing can be caused by…

excess OR expired baking soda which causes an alkaline environment and loss of thiamin

which chemical leavening agent needs to be combined with acid? which ones already has both acidic and alkali ingredients?

baking soda ; baking powder

disodium phosphate is a

flavor enhancer

titanium dioxide is a

whitening agent

EDTA, BHA, and BHT (sequestrates) prevent

oxidation of fats by forming complexes with metal irons

what pH inhibits the malliard reaction?

acidic

sugar alcohols are used as ____, though sorbitol specifically is a ____

humectants, stabilizer

sodium benzoate, calcium propionate, potassium sorbate, and nitrates/nitrites are

preservatives that hinder the growth of harmful bacteria or prevent spoiling

GRAS

• generally recognized as safe

• intentionally added to food

• does not need to be approved by the FDA to be used in a product

• substances are grandfathered in if used before 1994

Delaney Clause

FDA gained authority and responsibility to require manufacturers to provide safety assessments for all new food additives and prove that it would not cause health impacts

also prevents additives shown to cause cancer from entering the food system

solubility and color of pigments (pH impact?)

• anthoxanthin (flavone)

• anthocyanin

• chlorophyll

• carotenoid

• white, water soluble

  • colorless in acid

  • yellow in alkaline

• red/blue/purple, water soluble

  • bright red / pink in acid (like metals)

  • bluish in alkaline

• green, fat soluble

  • olive green in acid

• yellow/orange, fat soluble

fibrous structure centering egg yolk in the white

chalazae

a cake with coarse cells, thick walls, shiny crust, and crumbly product/fallen center may be…

too high in sugar

climacteric vs non-climacteric fruits

• climacteric: ripen post-harvest

  • peaches, pears, banana, apple, tomato, avocado

• non-climacteric: ripen pre-harvest

  • grape, melon, pepper, citrus

maillard reaction is the interaction between…

protein and CHO to create browning (NON enzymatic) and takes place in an alkaline environment (acid will inhibit)

happens at a lower temp than caramelization

phase changes

• sublimation

• condensation

• freezing

• vaporization

• solid —> gas (decreased in temperature very fast)

  • example: freeze drying

• gas —> liquid

• liquid —> solid

• liquid —> gas

when should you put produce in refrigerator vs on counter?

• fridge: for produce that needs moisture retention

  • sweet corn, lettuce, berries, mushrooms, orange, apple

• counter: moisture retention not important

  • onion, potato, garlic, tomato, banana, avocado, pears

irradiation (what is approved for higher levels?)

kills microbes to extend shelf life (spices are approved for higher amounts of radiation than other foods)

warner-brazler shear

machine that measures meat tenderness OBJECTIVELY

what should NOT be washed until ready to serve?

mushrooms and berries

sodium benzoate is a ____ usually found in ____

mold inhibitor, sodas

glycerol monostearate is a …

humectant

EDTA can also help ______ in potatoes

maintain white color

the farinograph measures

gluten development in dough

is allulose a non-nutritive sweetener?

no - 0.4 kcal/g

fat increases ____ in baked goods because it ___

tenderness, coats gluten

function of egg in baked goods

provides stability, retains leavening agent, emulsifies shortening, introduces air, adds color & flavor

function of salt in baked goods

adds flavor, controls yeast fermentation rate, strengthens gluten

function of water in baked goods

hydrates, develops gluten, starts action of chemical leavening agents, dissolves salt/sugar, and gelatinizes starch

winterization (and which oil cannot be winterized?)

• chilling oil to 45F to remove FA’s with a higher melting point so that it does not congeal when refrigerated … they will be clear and not cloudy

  • olive oil cannot be winterized according to jean inman

hydrogenation

adding H to double bonds in unsaturated FA’s to increase saturation and stability (removes kinks in the carbon chain)

gelatizinization

breaking of starch bonds in presence of H20/heat to dissolve starch granules

aging process of fruit .. what gas accelerates ripening?

starch —> sugar

protopectin —> pectin (ripe) —> pectic acid (overripe)

ethylene gas

suspensions

• sol

• emulsion

• gel

• suspension

• solid in a liquid (gravy)

• liquid in a liquid (salad dressings / mayonnaise)

• liquid in a solid (jello, agar)

• gas in a solid (whipped cream, bread, egg white foam)

examples of natural toxins found in food

• aflatoxin (peanuts)

• caffeine? woah

• oxalic acid (rhubarb)

reminder that clostridium botulinum is a BACTERIA which produces a toxin, not a natural toxin found in food

water temp boils at a ___ temperature when in higher altitude because of _____

lower, lower atmospheric temperature

(since the water will boil at a lower temperature, that’s why we need to extend cooking time as the water will be at a lower temp. because of this longer cooking time more H20 will evaporate so we need to add more water)

extend cooking time when boiling, decrease cooking time when baking

what is the purpose of fat in ice cream?

to create small, smooth ice crystals

not enough fat = grainy

testing methods

• descriptive testing

• affective testing

• paired comparison

• paired preference

• triangle test

• descriptive testing: TRAINED panelists perform flavor/texture profiling of a product

• affective testing: consumer rates like / preference / acceptance

  • rank - order of preference

  • hedonic scale - likability

• paired comparison: testers discern differences between samples

• paired preference: whether there is a preferred product out of two

• triangle test: to determine is one product has a sensory difference from two others, all presented to panelists and tested at same time (vs duo trio that is tested at different times)

a penetrometer tests

tenderness and firmness of baked goods (like a custard)

a high quality custard will have…

high % sag which means more tenderness

low % sag means custard was overcooked

steps for mixing a quick bread

1. mix dry ingredients

2. mix wet ingredients

3. add WET to DRY

   examples: muffin, biscuit, popover

   (you have to be WET to DRY off)

steps for mixing a cake

1. cream fat with sugar

2. add egg

3. mix dry slowly and alternate with mixing and adding portions of liquid mix

example: cookie, traditional cake

steps for mixing a pastry

1. cut fat into flour (course particles)

2. add liquid

what natural enzymes prevent gelatinization?

bromelian (pineapple), papain (papaya)

carrageenan is a…

stabilizer that prevents particle sedimentation

polymerization (when does this happen to fat, and what does it cause?)

linking of monomers

happens to FA when frying at high temp, increases viscosity and is more prone to foaming, decreases quality)

retrogradation

reforming of bonds into crystalline regions in starches, happens during cooling or storage of a starch paste

(example: cooling a gravy)

hydrogenation

making fat/oil more solid @ room temp (happens when making margarine) saturated carbon bonds with hydrogen

phase changes (temps) for water

• freezing < 32F

• lukewarm ~ 100F

• simmering 180-211F

• boiling 212F

flavor enhancer

enhancing flavor profile without adding it’s own flavor- detected at subthreshold levels

(salt, MSG, acid, sugar)

(NOT honey/butter/soy sauce)

a liquid needs ____ in order to foam… what can enhance this? what would make it collapse?

• low surface tension

• egg whites will foam better at room temp than when cold because surface tension ^ when cold

• increased vapor content = collapse

meat substitutes or processed meats often have…

… and what often has wheat?

soy!

gravies may often have wheat to thicken

order of thickening strength of thickeners

• potato (strongest)

  • high amylopectin, low protein

• corn

• rice

• sorghum

• tapioca

• wheat starch

  • low amylopectin, high protein

natural toxin found in nightshades (will also make potato green if let out in the sun) … what does it cause?

solanine - a glycoalkaloid that causes vomiting, weakness, and maybe paralysis

color spectrum of chlorophyll by pH

• chlorophyllin

  • bright green, in alkaline

• chlorophyll (neutral)

  • chloropyllase removes phytol chain

• pheophytin

  • olive green, acidic

  • Mg ion replaced by H

  • can also happen from prolonged / over cooking

what changes need to be made when using bran in a baked good?

^ flour and liquid to combat the more compact volume that will happen

by what process does a concentrated salt solution replace the water content of a vegetable in cooking?

diffusion because salt is moving along a gradient

(NOT osmosis because that would involve just the water moving)

what is the only color pigment that will NOT change based upon pH?

carotenoids

CHO in order of decreasing sweetness

• fructose (most sweet)

• invert sugar

• sucrose

  • glucose + fructose

• glucose

• sorbitol

  • the human body metabolizes slowly

  • 2.6 kcal/g

• mannitol

  • poorly absorbed by intestines

  • 2.4 kcal/g

• galactose

• maltose

  • glucose + glucose

• lactose (least sweet)

  • glucose + galactose

what does the flakiness of a pie crust depend upon?

type of fat - NOT temp, oxidation, or oven temp

what amino acid is gelatin lacking?

tryptophan (and also low in methionine and lysine)

soybeans/legumes are low in

methionine

what flour is BEST for making cakes, and which has the most starch?

all-purpose (according to jean inman which is weird), but cake has the most starch

what will stabilize an egg white foam?

acid

“evidence suggests but doesn’t prove that” is what?

qualified health claim

when substituting buttermilk for whole milk in pastry, increase then…

baking soda - the alkaline of the baking soda will neutralize the acid in the buttermilk

evaporated milk has ____ of the water removed

slightly more than half

sorbitol has ___ kcal/g

2.6

if a white sauce tastes starchy/grainy, the flour was…

uncooked

what kind of heat should be used for cuts of meat near the backbone?

dry heat

moist heat is better for brisket, neck, or should

onions will turn ___ in an aluminum pan

yellow because aluminum is alkaline

which type of cooking is best for turning collagen to gelatin?

braising

continuous commercial method (bread)

dough handled without interruption from mixing to depositing in pan, not dependent on the length of time the dough sits to rise

excess sugar or fat can create a …

fallen center

which type of pasta is MOST likely to have egg?

“noodle”

fatty acid content of oils

• cottonsEEd: highest in vitamin e

• safflower/corn: high in PUFA

• olive/canola: high in MUFAS (olive oil highest)

• soybean: most susceptible to oxidative rancidity :(

fatty acid concentration of butter vs margarine

• butter: SAT (most) —> MUFA —> PUFA

• margarine: PUFA (most) —> MUFA —> SAT

when substituting butter for lard you need to…

use MORE because butter has some water content, lard does not

if a baked good is crumbly / falls apart easily it may…

not have enough protein in the flour

what has the greatest impact on yield of meat cooked to uniform temperature?

cooking time, oven temperature

purpose of adding TVP to meat

add protein

increasing sugar _____ but why?

slows gluten development because sugar absorbs some water (gluten needs water to develop) BUT REQUIRES MORE MIXING

____ is used as a preservative and mold inhibitor in sausage

propyl gallate

______ is a bleaching agent used in flour

benzoyl peroxide

inversion / invert sugar

hydrolysis of sucrose with an acid to form a mixture equal amounts of fructose and glucose

makes it sweeter, higher in moisture, and less prone to crystallization than normal sucrose

cross linking vs dextrinization

• cross linking: linking of polymer bonds that prevents deterioration in starches by creating a shorter texture

• dextrinization: process of heating starch without water, causing starch molecules to break into fragments (think toast)