Chapter 7: Product Processing of Meat, Milk, Eggs

Study Notes

Chapter 7: Product Processing: Meat, Milk, and Eggs

The chapter covers the processing of meat, milk, and eggs.
Meat is the muscle tissue that has undergone extensive post-mortem changes.
Meat is composed of lean, fat, bones, connective tissues, and other elements.
Lean meat is the most important part in terms of human nutrition.
Red meat comes from mammals. It includes beef, pork, mutton, veal, horse meat, carabao, chevon, rabbit meat.
Red meat has slow twitch muscle fibres suited for extended periods of activity like standing or walking. It requires a constant energy source stored in myoglobin which also contributes to its reddish color.
White meat comes from fowl/birds like chicken, turkeys, geese, guinea fowl, excluding the ostrich.
White meat has fast twitch muscle fibers suited for quick bursts of activity such as flight.
Classification is based on different sources (sea food, game meat, nonconventional meat), and whether it is tough or tender.
Meat toughness is dictated by the amount of connective tissue or the animal's age. Further, the part of the animal and its slaughtering methods also contributes to its toughness.
Composition of meat includes fat (10-35%), protein, moisture, and minerals.
Fat types include subcutaneous (under the skin), intramuscular, or intermuscular (in between muscle).
Protein types exist in protoplasmic protein/muscle cell protein/myofibrillar protein, and connective tissue protein.
Moisture content varies among animals and also with aging. Mature fat beef has less moisture than veal.
Bone is 15-17% of the carcass.
Knowledge of bones is important to assess meat cuts.
Bones are a great indicator for meat cut identification, separation, and tenderness.
Minerals in meat include iron and phosphorus (1-3%), as well as minute amounts of other minerals like copper, sodium chloride, potassium chloride, calcium, iron, manganese, zinc, cobalt, magnesium, iodine, and aluminum.
Other components in meat include non-nitrogenous extractives (e.g., lactic acid) and nitrogenous extractives (e.g., creatine, creatinine, purines).
Meat parts include epimysium (outermost connective tissue), fasciculus, perimysium, muscle cell/muscle fiber, and endomysium.

Meat Cooking Methods

Ageing: storing meat after death to improve texture (wet aging for vacuum-packaged meats under refrigeration; dry aging for hanging fresh meats in a controlled environment).
Drying: ancient preservation method, sometimes with smoking, and either salted or unsalted.
Curing: adding salt, sugar, nitrates, or other preservatives to unheated meat to prevent microbial growth, tenderize, and add flavor.
Smoking: hanging meat or suspending meat exposed to smoke and heat for desired sensory and preservative effects.
Fermentation: using microorganisms in meat to improve quality, aroma, flavor.
Different types of meat products like salami, sausages, chorizos, pepperoni.

Milk

Milk is the physiological secretion of the mammary gland; it excludes the secretion obtained 3 days before or 5 days after the calving.
Milk is considered a “nearly perfect food”. It's rich in proteins like casein and whey, fat, lactose, vitamins, and minerals. Milk fat is a key factor in pricing milk.
Milk parts include water, fat, lactose, protein, minerals, and associated substances.

Eggs

Eggs are a compact package of well-balanced nutrients.
Major parts of an egg include the shell, albumin, yolk, chalaza, and air cell.
Egg yolk is the most important source of nutrients.
Eggs have very low carbohydrates and high vitamin A, riboflavin, and vitamin D, and are rich in iron.
Egg parts include the shell, albumin, yolk, and the air cell.
Quality of eggs is assessed by size, shape, color, texture, cleanliness, uniformity, flotation test, candling characteristics, yolk index.