milk compostition and processing Flashcards
dairy products made in home
yogurt, butter, icecream, cheese
fluid products
table milk, cream
derived (industrial products)
cheese, yogurt, butter, icecream (and novelties), evaporated milks, dehydrated milks, whey products
how is the dairy industry managed
supply managed: Production = consumption
there is a production quota and calculated pricing
consumption of dairy products
16.2 billion CAD in 2021, 11.6% of Canadian food and beverage sector
there has been a shift to lower fat products - 3.25&1% fat milks
21.93 &5.85 L/capita in 1990
10.16 &15.12L/capita in 2016
milk production from 01-19
73M to 92.3M hl
Where are most farms and processers in canada
ontario and quebec (367 plants out of 507, 7846 farms out of 9739)
main exporters
EU -about 75%, new zealand, about 13.7%, and USA 5.2%
what is milk
Post-colostrum mammary secretion of cows
what are the five major nutrition groups
carbohydrates, proteins, fatty acids, minerals, vitamins, milk contains all of there in sufficient amounts and in assimilable forms
milk composition by weight
water 87%
lactose 4.9%
fat 3.5-3.7%
protein 3.8%
ash 0.7%
what is the most variable component in milk
fat
true or false Lactose is essentially unique to milk
true
lactose is the major carbohydrate in milk True or false?
true
is lactose an energy source for young animals?
yes
how is fat present in milk
globules (fat globules)
what percentage of fatty acids are saturated, short and medium chain, and trans
saturated-70%
short and medium chain 25%
trans - a few
___________ is a component of the globular membrane
cholesterol
milk is a source of _______ ___________ __________
fat soluble vitamins (ADEK)
what effects fat content in milk
Genetic, physiological, and enviromental factors
breed, individual animal, stage of lactation, milking frequency, season, feed, health of the cow
what is the function of fat in foods
lubrication (mouth feel)
flavour (buttery flavour, rancidity)
taste
reservoir of other flavour compounds
shortening effects(spreadability of butter)
energy provider
nutrients
high fat contents of milk taste, aroma, texture, energy milk is oil in water emulsion
protein exists in both particulate (80%), and soluble (serum, whey, 20%)
casein is heat stable and is present in the form of particles (micelles)
whey (serum) proteins are dissolved in the serum phase, easily denatured by heat
milk is a high protein food
two types of proteins casein in micelles, and soluble whey proteins
minerals (ash)
K, Na, Ca, Mg, P
milk salts
Ca, Mg, Na, k salts of phosphate, citrate, acetate, chloride, carbonate
soluble and insoluble forms
which vitamins in milk are fat soluble
A,D,E,K
which vitamins in milk are water soluble
B and C,
vitamin fortification is mandatory true or false
true
can viatmins be lost from milk through fat seperation
yes
fluid milk accounts for ____ percent of production in Canada (table milk, flavoured milks, and creams)
40
industrial milk accounts for ___ percent of production in Canada (manufactured products (cultured products, cheddar-type cheeses, evaporated/condensed products, dehydrated products, confectionery products))
60%
table milks, creams, flavoured products, uht products, are all products from fluid milk
mimlk entering the processing plant is weighed, sampled, and stored at 1-4°C or lower for up to 3 days
from storage milk is clarified, standardized, vitaminized, homogenized, pasteurization, packaged, stored
clarification
milk is centrifuged to remove extraneous particulate matter - udder cells, white blood cells, dirt, etc
Standardization
adjustment of fat content - part or all of the butter fat is removed (as cream) from milk by centrifugation
vitaminization
addition of vitamins A and D to milk to compensate for losses due to fat removal and variations due to feed and season
homogenization
the relatively large butterfat globules are disintegrated by shearing and impact
pasteurization
milk has been a source of milkborne diseases - today milk is distributed to more population and outbreak can be devastative
- heat treatment to destroy pathogens and as a supplemental benefit , to extend shelf life
target microorganism is coxiella burnetii
cooling
to storage temperature
packaging
cartons, polyethylene film, bottles
storage
at less than 4.5°C
cultured products (yogurt, sour cream, bettermilk, cottage cheese, ,milk, skim milk, cream + lactic acid bacteria are all examples of industrial milk products
cultured products : bacteria produce lactic acid from lactose; synthesize flavour compounds
Ph drops to approximatley 4.6
Lower Ph affects viscosity, flavour, and shekf life of product
industrial milk products
cheddar type cheese, milk may be subjected to a mild initial culture principally for flavour,
rennin enzyme chymosin is added causes precipitation of casein (curd)
cheddar type cheeses, curd is manipulated into a solid mass, cooked, pressed, whey is drained away, cheese is then aged to develop aroma, flavour, texture
evaporated and condensed milk (50%) of water is removed by vacuum evaporation, evaporated/condensed milk is sealed into cans and then heat “sterilized” (120°C, 20 mins)
sweetened condensed milk - a relatively large amount of sugar is added to product prior to batch pasteurization/sealing into cans, dark colour and strong flavour due to heat applied during processing
dehydrated products
skim milk powder
buttermilk product,
whole milk powder, whey powder
products prepared by spray drying
liquid product is concentrated (evaporated/condensed) then sprayed into a high temperature, high velocity air steam
product is recovered as a fine powder
may be agglomated to facilitate rehydration
instantaneous drying preserves product quality due to evaporitive cooling
butter
produced by churning of chilled cream transforms oil-in-water emulsion into a water-in-oil emulsion it contains 80% fat buttermilk by-product
fat destabilization
process for clustering and clumping flocculation partial coalescence coalescence
products from cheddar cheese (sweet) whey
highly versatile, functional ingrediants
whey powder-spray dried whey
whey protein concentrate WPC - protein concentrated by ultrafication and then spray dried
why protein isolates WPI - like WPC but more highly purified
who is resposible for food safety in the dairy industry?
producer, processor, retailer, consumer
what is the responsibilty of the producer in food safety of the dairy industry
cow health, sanitation, refrigeration, documentation, traceability
what is the responsibilty of the processor in food safety of the dairy industry
sanititation, pasteurization, analysis, process control, documentation (HACCP), traceilibilty, refrigeration
what is the responsibilty of the retailer, and consumer in food safety of the dairy industry
refrigeration
