Module 7-fluid milk products and processing Flashcards
what are the two processing streams is milk collected and classified as
fluid milk and industrial milk
what is fluid milk
Fluid milk is any milk product considered to be a beverage
what is industrial milk
Industrial milk is milk used to make dairy-derived products such as cheese, yogurt, butter, ice cream, evaporated milks, dehydrated products and whey products
how much milk is destined to be fluid milk
Forty percent of dairy production in Canada is directed toward fluid milk products
what is included in fluid milk
Fluid milk products include table milks, flavoured milks and cream
what are the more recent specialty milk beverages that have been developed to meet evolving consumer demand
New products include low-lactose and lactose-free milk for people sensitive to lactose, probiotic milk, and milks fortified with plant sterols, protein, calcium, and vitamins
what is the fat content of whole milk
fat content of whole milk is 3.8%
what do table milks include
Table milks including skim milk, 1% milk, 2% milk, and 3.25% milk are reduced in fat content relative to whole milk (3.8 % fat)
how much fat do the creams have
cream milk or half and half (10% fat) or whipping cream (35% fat)
whats in flavoured milks and how are they made
they have sugar, flavour and colour as well as stabilizer added before pasteurization
what is shelf stable milk
Shelf stable milk is provided as a substitute for fresh milk that does not require refrigeration
what is the shelf life of shelf stable milk
Shelf stable milk can be kept without refrigeration for up to nine months unopened and up to twenty days refrigerated after opening.
what is the clarification process
particulate matter removed by centrifugation
what is the standardization process
fat content is adjusted to desired level
what is the victimization process
fat-soluble vitamins A & D are added
what is the pasteurization process
pathogenic microbes destroyed by heating milk
what is the homogenization process
reduction of size in fat globules in milk
what is the packaging process
the final milk products are packaged in cartons, bags, bottles or jugs
what happens to milk during clarification
the milk is centrifuged at high speeds to remove particulates that may be found in the whole milk
what things are being sorted out during clarification
Particulates can include blood cells, bacteria, skin cells from the cow’s udder and dust particles
what happens inside the machine during clarification
Spinning the milk sends the non-milk solids to the periphery of the clarifier where it collects as clarifier sludge. The sludge is automatically discharged from the clarifier periodically
what is standardization necessary for
its necessary to adjust the fat content of the milk to the desired level (0, 1, 2 or 3.25%) by removing part or all of the butterfat
what are high-speed centrifugal separators used for
Centrifugal separators, operating at a higher speed than those used for clarification are used to separate the cream portion from the aqueous phase of the milk
what is slow and high speed centrifugation used for
Slow speed centrifugation is used to clarify the milk by removing small particles of debris and high speed centrifugation is used to separate out the butterfat
what two milk processes can be carried out simultaneously
The clarifying and standardizing operations may be carried out simultaneously
why do vitamins need to be added to milk
Fat soluble vitamins (Vitamins A and D) are added to the milk to compensate for seasonal variations in concentration and for losses which occur when butterfat is removed during standardization
when and why are vitamins added to milk
The vitamins are added before pasteurization so that any pathogens present in the vitamin preparations will be destroyed.
how is pasteurization done
Milk is pasteurized through a heating process designed to destroy pathogenic microbes as well as nonpathogenic microbes that might hasten spoilage of the milk
how does pasteurization help reduce milk spoilage
Pasteurization also lowers the activity of deteriorative enzymes that contribute to milk spoilage
what is low-temperature-hold pasteurization
Low-temperature-hold (LTH) pasteurization involves heating milk to a minimum of 63°C in a stirred, covered vat; the temperature is maintained for at least thirty minutes
when is low temperature-hold pasteurization used for
LTH pasteurization is used in batch pasteurization systems for lower volume specialty products such as egg nog
how is most milk pasteurized
Most milk is pasteurized in high-temperature short-time (HTST) systems heating the milk to 72°C and maintaining this temperature for 15 seconds through a plate heat exchanger
how are high sugar milk products treated and why?
Products with higher levels of fat and/or sugar are treated at higher temperatures and/or for longer times because the fat and sugar protect the microorganisms from the denaturing effects of heat
what pathogens are being destroyed for pasteurization heat treatment
The standard for pasteurizing heat treatment is the destruction of the bacterium Coxiella burnetti, the most heat stable pathogen of concern that is found in fresh milk. C. burnetti is the causative agent of Q fever
does pasteurization effect the milk flavour or nutrients
Pasteurization is a relatively mild thermal process that does not alter the flavour or colour of milk or destroy nutrients contained within the milk
what is ultra-high temperature pasteurization used for
Ultra High Temperature (UHT) processing is used to manufacture shelf stable milk that does not require refrigeration
what temperature and time duration is the ultra-high temperature at
The UHT system involves heating milk to 140°C for five seconds
is ultra-high temperature milk popular in Canada? where is it really popular?
UHT milk has not been popular in the Canadian market although it comprises more than eighty percent of the milk market in some European countries
what does homogenization do to milk
Homogenization of milk reduces the size of the fat globules to prevent them from coming together and rising to the surface of the milk during its useful storage life
what does the process of homogenization involve
The process involves pumping the milk through a series of homogenization valves at high pressure. The homogenization valves reduce the size of the globules by a combination of shearing and impact
after homogenization what prevent the globules from returning to the there original size
The smaller globules are coated with casein which helps prevent them from interacting and coalescing.
what heat may be used to standardize the milk flavor
A brief heat (90-95°C) vacuum treatment may be employed to standardize the flavor of the milk
what are most off flavours of milk associated with
Most off-flavours are associated with seasonal variations following dietary changes
how is flavour standardization applied
The flavor standardization treatment is usually applied to hot, pasteurized milk as it leaves the heat-holding section
what else happens when heat is added to help with the standardization of milk
This treatment also extends the shelf life of the milk products
what is the shelf life of processed milk
The packaged product has a refrigerated shelf life of at least two weeks if it is maintained at temperatures below 4.5°C
what is flavoured milk
Flavoured milks are partially skimmed milks (1 or 2%) with added flavor, sugar and a stabilizer such as vegetable gum to improve the creaminess and keep flavouring particles from settling to the bottom of the container during storage
when is the additional ingredient of flavoured milk added
The additional ingredients are incorporated into the milk before pasteurization or UHT sterilization
does flavoured or regular milk require more pastrization
Flavoured milks require more pasteurization treatment than regular milks because of their high sugar content
how are coffee cream and whipping cream prepared
Coffee cream (10% butterfat) and whipping cream (35% butterfat) are prepared by blending the cream fraction removed from fresh milk with an appropriate amount of skim milk
what requires more pasteurization coffee cream and whipping cream or fluid milk? why?
Both coffee cream and whipping cream require more extensive pasteurization than fluid milks because of their higher fat content
when is coffee cream homogenized
Coffee cream is homogenized after pasteurization to prevent fat separation during storage and to increase its viscosity
when is whipping cream homogenized
Whipping cream is not homogenized because the process would destroy its whipping properties
