Food Science and Nutrient Composition of Foods (25%) Flashcards
(202 cards)
what are the components of milk?
88% water, 5% CHO, 3.5% PRO, 3.3% FAT
________ is the chief CHO in milk
lactose
what does lactose breakdown into?
glucose + galactose
what percentage of milk protein is casein?
80%
what is the remaining protein in milk?
whey
what are milk precipitates that form in an acidic medium?
curd
what is whey? does it denature easily?
whey is the liquid that drains from the curd (coagulated milk used in cheese making)
yes. whey denatures easily causing the cooked flavor of milk
how many vitamins are needed for human nutrition that are present in milk?
all vitamins needed for human nutrition are present
what vitamin in milk is sensitive to ultraviolet light and needs to be protected
riboflavin (vitamin B2)
is milk a good source of vitamin C? explain.
no, d/t pasteurization process degrading vitamin C during the heating treatment
is milk a good source of iron?
no; however, research does not support milk consumption reducing/affecting iron absorbability. https://milk.procon.org/view.answers.php?questionID=000848
milk is the best source of ____________
calcium
list the types of milk products (7)
fluid milk, whole milk, UHT, filled milk, evaporated milk, sweetened condense milk, and dry milk
reduced fat (2%), low fat (1%), fat-free (skim)
fluid milk (labeled according to fat content)
not less than 3.25% milk fat and not less than 8.25% milk solids ( lactose, caseins, whey proteins, and minerals )
whole milk
what is the difference between pasteurization and homogenization?
pasteurization = the use of heat to kill disease causing microorgaisms in milk and increase milk safety homogenization = the use of high pressure which reduces the size of fat globules in milk to evenly distribute the fat and prevent separation of fat and liquid when packaged
uses a fat other than milk fat to create a substitute for milk (any milk, cream, or skim milk that has been reconstituted with fats, usually vegetable oils, from sources other than dairy cows)
filled milk
60% of the water is removed; must contain 6.5% butterfat and not less than 25% total milk solids
evaporated milk
15% sugar is added and volume is reduced to 1/3 of the original amount
sweetened condensed milk
usually made by removing 2/3 of the water from skim milk under a vacuum, then spraying this milk concentration into a chamber of hot filtered air; about 3% moisture content
dry milk
process of heating milk up and then quickly cooling it down to eliminate certain bacteria.
pasteurization
most commonly used method in the US; milk is pasteurized at 161°F (72°C) for 15 seconds; these conditions provide fresh tasting milk that meets the requirements for consumer safety.
HTST = High-Temperature-Short-Time Treatment
milk is pasteurized at 145°F (63°C) for 30 minutes
Hold or LTLT = Low-Temperature-Long-Time Treatment; less common practice
milk heated to 138°C and held for 2 seconds (kills all microorganisms); makes it possible to store milk in closed contaiers at room temperature for 6 months
UHT = ultra high temperature