Milk (cow's milk) trivia

Normal milk

　　Milk is an opaque liquid that mammals secrete from the mammary glands to feed young children.

　　Milk produced in cattle 7 days after calving and before the start of the dry milk period is regular milk.

　　The composition of various components in normal milk is generally stable, but it is affected by factors such as cow breed, individual differences, lactation period, age, feed, season, temperature, milking status and health status, among which the largest change is fat, followed by protein, lactose and ash content is relatively stable.

Abnormal milk

　　During the lactation period of dairy cows, due to physiological or pathological and other reasons, the chemical composition and characteristics of milk change, and this changed milk is called abnormal milk.

　　Abnormal milk is divided into physiological abnormal milk, microbial contaminated milk, and chemical abnormal milk

Physiological abnormalities in milk

Colostrum: The milk produced within 7 days of calving is called colostrum.

peculiarity:

●Significant yellow color

●The viscousness has a slightly special odor and bitter taste

●High content of dry matter in milk solids, especially whey protein (globulin); rich in vitamins A and D

●Low lactose content

●Unstable to heat

●Has an immune effect

Milk: The milk produced by cattle in the 15 days before dry milk is called end milk or old milk.

●Higher in addition to milk fat

●It has a bitter and salty taste

●Fat is easy to oxidize The number of bacteria and lipase increases

Microorganisms contaminate the milk

　　Raw milk is heavily contaminated with microorganisms and produces abnormal changes, which become microbial abnormal milk.

　　The most common microbially contaminated milk is rancid milk and mastitis milk. Mastitis milk and other pathogenic bacteria contaminating milk is harmful to the human body.

　　The characteristics of various microorganisms contaminating milk are described below

　　　　　 Various microorganisms contaminate milk traits

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class

Cause bacteria

Properties of cow's milk

Defects and Hazards

Rancid milk

Lactic acid bacteria, propionic acid bacteria, coli bacteria, micrococci, etc

High acidity, alcohol coagulation, fermentation gas production, sour odor, acid coagulation

Heating solidifies, poor flavor, case cheese rancidity, swelling

Mastigmatitis milk

Hemolytic streptococcus, staphylococcus, micrococcus, bacillus, actinomycetes, coli, etc

Mixed with blood and coagulants, alcohol coagulation, heat coagulation, abnormal flavor

Whey protein, sodium, chlorine, catalase, increased pH cell count, fat, lactose, calcium, non-fat milk solids, decreased acidity

Spreads disease and causes food poisoning

Other pathogenic bacteria contaminate the milk

Brucella, Salmonella, Anthrax, Tuberculosis, Foot-and-Mouth Disease Virus, etc

Mixed with pathogenic bacteria

Viscous milk

Cold-loving bacteria, Mingleinella species, etc

Mucination, mucus formation, protein breakdown

Cream, cheese, etc. are viscous

Coloring milk

Cold-loving bacteria, cocci, red yeast

Yellow, red, blue

Changes in color between milk and dairy products

Abnormal coagulation decomposition milk

Protein, lipolytic bacteria, cold bacteria, bacillus

Rennet-like coagulation, pelating, alkalinization, lipolysis stinks, bitter taste

Brings bad flavor and spoilage of dairy products

Bacterial abnormal flavored milk

Protein, lipolytic bacteria, acid-producing bacteria, cold bacteria, coliform bacteria

Odor, odor, all kinds of failure

Milk and dairy products have abnormal flavor and spoiled

Bacteriophages contaminate the milk

Bacteriophages, mainly lactic acid bacteria bacteriophages

The bacteria are dissolved and the number of bacteria is reduced

Failure to manufacture starter cultures and fermented milk

Chemically abnormal milk

Low component milk

　　Low-component milk is milk with too low milk solids content due to the influence of cow breeds, feeding management, nutrient ratios and pathology;

　　It should be improved by strengthening breeding improvement and feeding management.

Low acidity alcohol-positive milk

　　Low-acidity alcohol-positive milk is an abnormal milk that has normal acidity but has coagulation of alcohol. Due to complex reasons such as metabolic disorders, climate changes, and improper feeding, the imbalance of milk salts or the instability of the colloidal system may be the cause of low acidity alcohol-positive milk.

Abnormally flavored milk

　　There are many factors that affect the flavor of individual milk. Abnormal flavor is mainly through the body transfer or absorption from the air feed smell, due to the action of enzymes and the production of lipolysis odor, milk pollution or absorption from the outside world odor or metal odor and so on.

Foreign bodies stained with weeds

　　Foreign body-stained milk is when the milk contains contaminants that are transferred to the milk through the body with feed, or contain substances that are intentionally or unintentionally adulterated into the milk. see

　　　　　　　　　　　 Foreign body stained with the type of milk

Foreign body stained with the type of milk

Medium class

Major foreign bodies

The cause of contamination

The main hazard

Contaminant milk

antibiotic

Treatment of sick cattle

Affects the production of fermented milk, the human body is allergic to melon, and bacterial resistance is generated

hormone

Promotes dairy cow growth

Hormonal disorders in the human body, allergic reactions

Residual pesticides

Herbicides

Plant growth hormone

Radioactive material

Contamination of feed and drinking water

Due to the accumulation of damage to the normal metabolic function of the human body, and chronic poisoning occurs, there may even be potential carcinogenic and teratogenic effects

detergent

Residue during container cleaning

Plastic additives

Container elution

Trace elements (lead, cadmium, mercury, zinc, etc.)

Feed and drinking water pollution, container dissolution

Manpower

Doped milk

water

Increase weight

Reduces milk solids content

Heterogeneous ingredients

Affects nutritional quality

preservative

Illegally maintain milk

Affects the production of fermented milk and violates hygiene regulations

neutralizer

Mask rancid milk

Affects the quality of dairy products and increases the number of bacteria

A thing

Mixed milk

All kinds of dirt (feed, insects, feces, dust, etc.)

Poor hygiene

Bacterial contamination, reduced milkiness, vectors of disease infection

All kinds of debris (metal, cotton yarn, mane, etc.)

Milk extraction is poorly managed, foreign bodies are mixed in

Affects milkiness