MILK PT. 2 Flashcards
whats homogenization
mechanical process that breaks up fat globules in milk into smaller globules that do not clump together and are permanently dispersed
does homogenization have an effect on nutrient content
no, purely mechanical
what sensory properties change with homogenization
creamier texture and whiter
describe the mechanical process of homogenization
milk pumped under high pressure (~2000 psi) through a machine that contains tiny holes to break up the globules
what does milk have to have to be considered fresh fluid cow’s milk
at least 8.25% MSNF
what are the four type of milk
whole, reduced-fat, low-fat, fat-free/nonfat
how much fat in whole
3.25%
how much fat in reduced-fat
2%
how much fat in low-fat and fat free
1% and less than 0.5% in fat free
what other animals get milk
goat, sheep, camel, llama
whats chocolate milk made wth
flavored with either cocoa, chocolate liqueur, or chocolate syrup
what do stabilizers do and what’s a common one
prevent cocoa from settling; common stabilizers us carrageenan (Polysaccharide from seaweed)
whats eggnog
mixture of milk, cream, milk solids, eggs, stabilizers, and spices
how much milk fat in eggnog
6-8% milk fat (double of whole milk)
how are plant-based milks made
plant is soaked in water, ground, and strained
what are two types of canned fluid milk
evaporated milk and sweetened condensed milk
whats evaporated milk
at least 60% of water from whole milk is evaporated
what is sweetened condensed milk
50% of water from whole milk is evaporated and then sugar is added (40-50% of end product weight); ideal for dessert prep
whats dry milk
nonfat dried milk - all moisture is removed from milk
how is dry milk created and used
reconstituted with water and used like fresh milk; absence of fat givens even longer shelf life
whats instant milk
made by exposing NFDM to steam and then re-drying it
what does double-drying do that makes instant milk
makes it instantly dissolve in cold water due to agglomeration of smaller proteins into larger more porous particles
how is buttermilk created
bacteria convert lactose to lactic acid
what does the drop in pH do to buttermillk
makes it taste more sour and causes coagulation of casein proteins which makes it more viscous
whats buttermilk used in
many baked products to add moisture and lankiness and provide an acid for leaving
how is sour cream made
by a similar process except the starting material is a light cream
how is yogurt made
mixing two thermophilic bacteria strains (lactobacillus baulgaricus and streptococcus thermopiles)
what happens to the mixture of bacteria when making yogurt
added to pasteurized milk with additional MSNF (provides more lactose)
what happens next when making yogurt
whole mixture is held at a. warm temp to allow fermentation until desired consistency and flavor reached
what happens to lactose and whats produced
lactose goes to lactic acid and folate is produced as a byproduct of bacterial growth
whats yogurt the most common vehicle for
probiotics and prebiotics
what are probiotics and prebiotics
pro - live microbial food that promote digestive health and pre are non digestible food that support growth of pro
whats keifer
sour, carbonated, slightly alcoholic beverage
how is keifer made
by adding a yeast/bacterial fermentation starter to fluid milk
whats cream
collection of fat droplets that float to top of non-homogenized milk; 18-36% milk fat
how much milk fat is in coffee cream
18-30%
how much milk fat is in whipping cream
30-36%
what does whipping cream expand to
2-3 times in volume
describe whipping cream proteins
mechanically stretched into thin layers that trap air, fat, and liquid
what does the higher fat of whipping cream lead to
more stable whipped cream (fat surrounds air)
how is half and half made
combining cream and milk
how are milk products used in food prep
coagulation and precipitation
what happens to whey proteins at high temps
start to denature, which makes the whey lose solubility and coagulates with casein
what forms at surface of heating milk and why
skin forms at surface of heated milk due to evaporation of water and concentration of milk components
describe skin
scorches easily and can trap steam trying to escape causing the milk to boil over
what does adding acid to milk do
causes casein (not whey) proteins to coagulate
describe casein and charges
normally carry a negative charge and repel each other, but acids will donate H ions to negative charges and make them neutral which causes them to coagulate
what do enzymes do in milk
cause milk coagulation via casein hydrolysis
what the common enzyme used to coagulate milk
chymosinn (or rennin), sold commercially as rennin
what the common enzyme used to coagulate milk
chymosinn (or rennin), sold commercially as rennin
what enzyme is used in cheese production
chymosin/rennin
describe texture of enzymme-prpduce coagulates
tough and rubbery
describe acid-produced coagulated
more fragile
why is milk suspectivble to rancidity
contains a lot of short-chain fatty acids
should you drink milk from container
no, mouth bacteria can wash back into product
how should dry and canned milks be stored
slughtly below room temp
how should milk be stored
all fluid need to be in fridge except unopened ultralight temp pasturaided milk and some canned and dry
