Milk

By: Allison Huang,Yun Ting Xu,Katerina Kountouris,Yinan Cho, Qiujing Hu

2.21.13 Group #2

• Two major domesticated cattle

species

• Animal domestication• Earliest milk consumption

History of Milk

• Different amongst different species

• Basic components of milk

• Cow's milk vs. human milk

Milk Composition

•Whole milk (3.5%)•Reduced-fat milk

(2%)•Low-fat milk (1%)•Fat-free milk aka

Nonfat or Skim milk (0.2%)

-add back fat soluble vitamin

Different Types of Milk

•Organic milk•Lactose-free milk•Flavored milk

• grazing-fresh grass

• Fed grain, hay, or silage

• Utilize growth hormones and antibiotics to increase milk production and decrease spread of diseases

Rearing

• Hand milking–Flexible milking times

• Machine milking–Twice a day–A refrigerated bulk tank truck makes

collections from dairy farms every 24 or 48 hours.

collecting

• raw milk usually keep in a refrigerated bulk milk tank where it is cooled to about 40° F (4.4° C), or colder, for no more than 48 hours

• remains cold and that the milkfat does not separate from the milk.

storing

• milk is transported to factory sites and stored in refrigerated silos before processing.

• special stainless steel bodies-keep the milk cold

• Tanker drivers evaluate the quality of milk

transportation

• two sets of samples

• Farm milk samples are tested for milkfat, protein, bulk milk cell count and bacteria count.

• Samples from the bulk milk tanker are tested for antibiotics and temperature

lab testing

• Spin milk through a centrifuge to separate the cream from the milk.

• cream and remaining-milk are mixed in different ratios depending on desired quality of milk- standardization

–whole milk-3.25% fat–low fat milk- 1% fat–skim milk(nonfat milk)-0.05% fat

Separation

• Heat the milk to 161° F (72° C) for 15 seconds to kill bacteria

• cool again without allowing recontamination

Pasteurization

• Pushing milk through an atomizer to form tiny fat

• Milk fat will not float to the top of the container

• Quickly cooled to 40° F (4.4° C) to avoid harming its taste.

Homogenization

• automatic packaging machines fills and seals the milk into paper cartons or plastic jugs.

• A “sell by” date is printed to show how long the milk will stay fresh.

• Keep refrigerated and delivery to the stores.

Packaging

• Pasteurized milk vs. raw milk• Raw milk:

o milk that has not been pasteurized to kill harmful bacteria. It can carry dangerous bacteria such as Salmonella, E. coli, and Listeria, causing numerous foodborne illnesses

• Pasteurization:o a process that kills harmful bacteria by

heating milk to a specific temperature for a set period of time

Milk Safety

• The Center for Disease Control and Prevention (CDC) has reported that the number of foodborne illness outbreaks in states where raw milk is banned is lower compared with the number that occurs in states that allow the sale of raw milk

• All sources of literature and data show that raw milk does fall into a "riskier" category of foods

Milk Safety

• Pasteurized milk can readily spoil and could cause foodborne illness if not properly protected

• Temperature• Refrigeration• Harmful bacteria can grow rapidly in

milk about 45ºF• For each 18ºF increase in

temperature, the spoilage rate of milk doubles

Milk Safety

• Human Milk• Protects infants from infection• Helps determine the type of bacteria

in GI Tract• Helps build up immune system• Positive effects on cognitive

development

Nutritional Value/Benefits

• Bovine milk• Possible cancer prevention/tumor

growth• Antiviral functions• High amount of Oleic acid- lowers

cholesterol• Favorable omega-6 to omega-3 ratio

(low)• Triggers muscle protein synthesis

Nutritional Value/Benefits