2.1 Intro to Milk 🥛 Flashcards
▪ a nutritious liquid extracted from the mammary glands of lactating animals, mostly from cows 🐄
▪ available in fresh, pasteurized,
condensed, and powdered
Milk
milk from animal source with highest protein and fat at 5.8 and 7.9%
Sheep 🐑
▪ contributes to emulsifying and stabilizing
caseinates
▪ assists with gelling
whey proteins
▪ aids with browning of baked goods, confectionary, and frozen desserts
lactose
▪ milk sugar, primary carbohydrate (12 grams per 8 ounce cup)
lactose
▪ product of the metabolism of lactose
▪ 🧀🍦 where flavor of cheeses and fermented milk products are derived from
lactic acid
▪ less soluble than sucrose
▪ may cause it to crystallize into lumps in non-fat dried milk
▪ produce a sandy texture in ice cream
lactose
▪ contains all the essential amino
acids in adequate quantities to support growth and the maintenance of life
▪ 8 grams per 1 cup
Protein
▪ primary protein found in milk
▪ accounts for almost 80% of protein
▪ can be precipitated with acid or certain enzymes
▪ precipitates at pH 4.6
Casein
▪ Another predominant protein found in milk, constitutes about 18%
▪ consist primarily of lactalbumin and lactoglobulin
▪ the liquid portion of milk that remains after cheese production
▪ isolated through ultrafiltration
process
▪ are used as emulsifiers and foaming and gelling agents 🍮
Whey Protein
▪ results in an inability to digest lactose due to insufficient quantities of lactase
lactose intolerance
▪ called milk fat or butterfat
▪ plays a major role in the flavor,
mouthfeel, and stability of milk products
▪ gives creaminess in milk chocolate which softens the characteristic brittleness of cocoa butter
▪ consists of triglycerides surrounded 🧈by phospholipid-protein membranes
Fat
▪ the fluid that remains when fat from whole milk is removed to make butter
buttermilk
▪ milk contains 33 mg in a cup of whole milk, 18 mg in reduced-fat (2%) milk, and 4 mg in fat-free (non-fat) milk
Cholesterol
▪ contains vitamins A and D, riboflavin (B2), and tryptophan (an amino acid important in the formation of the B vitamin niacin)
▪ low in vitamins C and E
Vitamins
▪ major mineral is calcium (300 mg
in a cup)
▪ 2 servings a day provide 1,000 mg Dietary Reference Intake for adults 19-50 years of age
▪ phosphorus, potassium, magnesium, sodium chloride,and sulfur
▪ low in iron
Minerals
▪ the amount of __________ in the
cow’s feed influences its color
▪ ____________ pigments dissolved in
milk fat provide the yellowish tinge
of butter and cream
carotene/ carotenoid
▪ addition of ___________ to milk may
reduce rickets, a bone disease in
children
vit D
▪ a fat-soluble vitamin that is fortified in milk when fat is removed
vit A
▪ has the lowest count (highest
grade); must be pasteurized 🧫
Grade A
▪ responsible for grade
USDA
▪ used to treat wine, beer, and milk
▪ heating milk for a short time to below its boiling point killed microorganisms
▪ destroys 100% of pathogenic bacteria, yeasts, and molds
▪ 95-99% of other non-pathogenic
bacteria
Pasteurization
▪ inactivates many of the enzymes that cause the off-flavors of __________
rancidity
▪ measuring the activity of alkaline
_______________ ensures that sufficient
pasteurization has occurred
▪ the milk is safe for consumption if the enzyme is no longer active🚫
phosphatase
▪ 145°F (63°C) and 161°F (71.5°C) for 30 minutes and 15 seconds, respectively
Pasteurization
▪ presence of 1-5% non-pathogenic
bacteria convert lactose to lactic
acid which may lead to ____________
spoilage
145°F/ 63°C in 30 minutes ♨️⏲
Low-Temp Longer Time
161°F/ 71.5°C in 15 seconds ♨️⏲
Hig-Temp Short-Time
212°F/ 100°C in 0.01 second ♨️⏲
Higher-Heat Shorter-Time
280°F/ 138°C in 2 seconds or more ♨️⏲
Ultrapasteurization
280°F/ 138-150°C in 2-6 seconds ♨️⏲
- refrigerate not required until opened
Ultra-High Temp
▪ uses higher temperatures and
shorter times to extend the shelf-life of refrigerated milk products
Ultra Pasteurization
▪ a sterile packaging technique that uses the same treatment
ultrahigh-temperature processing
(UHT)
▪ mechanical process that breaks up
the fat globules in milk into much
smaller globules that do not clump
together and are permanently
dispersed in a very fine emulsion
Homogenization
▪ prevents the separation of water and fat known
creaming
▪ pasteurizing before homogenization
inhibits rancidity since _______ are
inactivated
lipase
▪ means fat globules separated from milk produced by healthy cows
▪ has a fat content of 10-48%
▪ pasteurized at 85°C for 30 minutes
and homogenized
Cream
▪ the heavier and thicker the cream
is, the _________ the fat content will be
higher
▪ 10.5-18% fat content
▪ combination of pasteurized milk
Half and half
▪ 18-30% fat content
▪ used as creamer in coffee and tea
Light cream
▪ 30-36% fat content
▪ contain added sugars and stabilizers to improve taste and texture
Light whipped cream
▪ 36% fat content
▪ does not whip well and has been pasteurized to be shelf stable
Heavy cream
▪ 18% fat content
▪ sourced by Streptococcus lactis bacteria
Sour cream
▪ development of off-flavor when
____________ reacts with the sunlight-sensitive riboflavin (vitamin B2)
methionine
▪ development of “cooked” flavor
due to the denaturation of ___________ releasing volatile sulfur compounds, which contribute to off-flavors
whey proteins
▪ formation of solid clot or curd under certain conditions
▪ application of heat and the addition of acid, enzymes, polyphenolic compounds, and salt
Coagulation and Precipitation
▪ ______________ (lactalbumin
and lactoglobulin) become insoluble, mesh with the milk’s calcium phosphate, and precipitate under heat
whey protein
▪ __________ will not coagulate unless boiled for long periods of time
▪ canned evaporated milk contains higher concentrations of ___________, may coagulate during sterilization
casein
▪ lemon and lime juices, tomato
products, certain fruits, or
acid-producing bacteria causes ___________ precipitates when the
normal 6.6 pH drops below 4.6
casein
▪ may originate from animal, plant, or microbial sources
enzymes
▪ from the stomach of swine
pepsin
▪ an enzyme used to coagulate milk in the production of cheese and ice cream
rennin
▪ _____________ clots are rich in calcium and have a tough, rubbery texture
rennin-coagulated
▪____________ clots are less elastic and more fragile in consistency
acid
▪ cottage cheese contains 19 mg calcium
made with acid
▪ cheddar cheese contains 204 mg calcium
made with rennin
▪ contribute to the curdling of cream or milk in the preparation of scalloped
potatoes or tomato or asparagus in soup
Polyphenolic compounds
▪ _________ in cured ham, some
canned vegetables, and some seasonings can cause milk to curdle
▪ to prevent curdling, it should be added to the milk base
salt
▪ cream, evaporated milk, and
reconstituted non-fat dried milk can be made into foam by whipping ________ into the _________
air; liquid
▪ _________ is mechanically stretched into thin layers that trap air bubbles, fat particles and liquid
protein
▪ expands two to three times its volume
▪ stability is dependent on fat content, temperature of the cream, age of the cream, sugar content, equipment
used, length of whipping time
Whipped cream
• the higher the fat content, the more stable the cream will be
fat content
• ___________ cream beats more easily
heavy whipping cream
• _________ butterfat has lower moisture content that will prevent pastry crust from sogging
36-40%
• whipping creams with _________ fat result in a softer, less stable form
30-36%
• __________ increases viscosity or firmness and its tendency to clump
cooling
• cream allowed to warm to room temperature has more widely dispersed ____________, which
creates a softer texture
fat globules
• the __________ the cream is, the greater will be its viscosity and ability to foam
older
• must be at least 1 day old in order to allow it to incorporate the air necessary for the optimal increase in volume
age
• increases the stability of whipped cream
sugar
• if added earlier, it will __________ the whipping time and reduce overall volume and rigidity by delaying the clumping of fat
increase
• __________ sugar is used since it dissolves more readily in the cold cream
powdered
• __________ in the powdered sugar act as a stabilizer
cornstarch
• overbeating turns cream into _______ and ________
butter; whey
• formation of stiff, yet moist, peak signals the completion of the whipping
process
Whipping time
▪ whipped three times its volume due to high concentration of milk solids
▪ flavor, texture, and stability are less acceptable
▪ the flavor has the tendency to overpower other flavors
Whipped evaporated milk
▪ _______ and ________ can stabilize the protein and resulting foam
sugar; lemon juice
▪ less stable than whipped cream
foams due to its lower viscosity and lower fat content
Whipped evaporated milk
▪ very unstable, but is less expensive and lower in calories and fat
▪ prepared by dissolving equal parts of non-fat dried milk and cold water, chilling the mixture, and then beating
Non-fat dried milk
▪ Storing milk in proper opaque containers will reduce its
exposure to light, which can trigger ___________, resulting in off-flavors and the loss of ___________
oxidation; vit B2
▪ no more than ___ weeks
3 weeks
▪ Yogurt is best consumed within the first __ days, but can last up to ____ weeks
10 days ; 3-6 weeks
▪ Buttermilk is best used within ____ days after purchase, because it will continue to sour, but it can last up to ___ weeks
3-4 days; 3-4 weeks
▪ Sour cream, unopened, is stored up to ___ month, but is best when used within a few days
1 month
▪ from fungal sources
proteases
