Red meat and nutrition

Red meat is long established as an important dietary source of protein and essential nutrients including iron, zinc and vitamin B12. Meat is defined in food preparation as the edible flesh of domesticated animals. Meats are composed of muscle, connective tissue, fat and bone.

Basically, there are two types of meat –red meat and white meat. Red meat is commonly considered to include beef, pork, lamb and game. The flesh of poultry, including chicken, turkey and duck is termed ‘white meat.’

The chemical composition of meat varies to a large degree. The lean component of red meat is an excellent source of high biological value protein, vitamin B12, niacin, vitamin B6, iron, zinc and phosphorus. Red meat also rich with long-chain omega-3 polyunsaturated fats, riboflavin, pantothenic acid, selenium and, possibly, also vitamin D.

Meat may contain 45-70% water, 15-20% protein and anywhere from 5 to 40% fats depending on the cut and trim.

Red meat is low in total fat, saturated fatty acids – SFAs and salt, whereas untrimmed meat is higher in both total fat and saturated fatty acids, processed meat is generally higher in salt and fat and often contains other components such as nitrites which are added during processing. Saturated fats promote less oxidation, and therefore less rancidity.

Red meat also contains relatively low levels of PUFA. The main PUFA in red meat are the essential fatty acids, linoleic (n-6) and α-linoleic acid (n-3). When consumed, the body can convert α-linoleic acid into the long-chain beneficial n-3 fatty acids EPA and DHA.

Meat is principally composed of protein which provides 17kJ/4kcal of energy per gram, but also contains fat in varying amounts providing 37kJ/9kcal of energy per gram.

The protein is highly digestible, around 94% compared with the digestibility of 78% in beans and 86% in whole wheat. Protein from meat provides all essential amino acids (lysine, threonine, methionine, phenylalanine, tryptophan, leucine, isoleucine, valine) and has no limiting amino acids. Protein is needed for growth, maintenance and repair of the body.

Red meat contains on average 20–24 g protein per 100 g (when raw) and can therefore be considered a high source of protein.

The three types of protein in meats are myofibril, stromal protein and sarcoplasmic protein.

Muscle is approximately 75 percent of water and 20 percent protein with a remaining 5 percent representing a combination of fat, carbohydrate and minerals.
Red meat and nutrition

Minerals in milk

Minerals represent a small portion of milk (about 8-9 g/L) and they occur in different chemical forms: inorganic ions and salts or as parts of proteins, nucleic acids, fats and carbohydrates. Minerals are constituents of the bones, teeth, soft tissue, muscle, blood, and nerve cells. They are vital to overall mental and physical well-being.

When milk is dried and the residue is burned, a white powder is obtained which is known as ash or mineral part of the milk. The major portion of ash is composed of the chlorides and oxides of potassium, calcium and phosphorus. It is of interest to note that these three elements are in greater concentration in milk than in blood, thus the mammary gland exerts a selective action to concentrate these elements.

The mineral content in milk is influenced by many factors ranging from environmental conditions during pasture, feeding, breeding, stage of lactation and climate to post-milking handling, transportation and processing.

The chemical form of mineral elements found in milk and dairy products is very important due to their absorption in the intestine and biological utilization (transport, assimilation in cells and conversion into biologically active form).

Milk contains more calcium than most foods because of the distribution of calcium in milk. About two thirds of the total calcium in milk is in colloidal form as calcium caseinate, citrate and phosphate; the remaining third is in true solution.

Phosphorus in milk is involved in the stabilization of caseins and is present in two forms: organic and inorganic. Organic P is bound to molecules such as proteins, organic acids, phospholipids and nucleotides, mainly in colloidal phase, and inorganic ionic P is mainly present in soluble fraction.
Minerals in milk

Chemical composition of peanut

Peanuts are appreciated worldwide as an affordable, flavorful and nutritionally dense snack food, while also serving as a primary ingredient for peanut butter, confections and nutritional bars, among other finished products.

Since the uniquely delicate and attractive flavor of roasted peanuts and peanut products is principally dependent upon the composition of the raw peanut. On macro level, peanut seeds contain about 6% moisture (after storage), 25% protein, 50% oil, 15% carbohydrates, 2% fiber and 2% ash.

Broken down to their individual components, peanuts contain a variety of vitamins, minerals, amino acids, antioxidants and fatty acids. Many of these components have been shown to benefit human health.

Moisture content is perhaps the most critical factor in the harvesting, drying, storing and marketing of peanuts. Roasting of peanuts, either dry or oil roasting, results in reduction of moisture to below 2%.

The carbohydrate composition in most peanut products tends to have low sugar content with relatively high dietary fiber content, which results in a low glycemic index.

The fatty acids in peanut oil (80-83% unsaturated and 17-20% saturated) are responsible for it stability in cooking/deep frying and its shelf life stability. The unsaturated fatty acids consist of oleic (monoun- saturated) and linoleic (polyunsaturated) acids, with lesser amounts of eicosonoic and nervonic acids. The high ration of monounsaturated fats to saturated fats is similar to olive oil, an oil that promote heart heath.
Chemical composition of peanut

Moisture content in fish

The moisture content of fish is usually expressed on a wet-weight basis – i.e. is the mass of water in a unit mass of the fish.

Water is the principle component (up to 80%) of the edible portions of seafood. Usually the oil and water content together total about 80%.

Depth and altitude of fish catch can influence the moisture content of fish. Fish from deep water and from northern latitudes have higher moisture and lower fat content.

The method of storage as well as further processing, such as freezing determines the final moisture content of the fish flesh. Considerable moisture, as well as soluble nutrients, may be lost in thaw drip. Water retention is highest in fresh fish.

Salmon fish

Finfish moisture contents generally show an inverse relationship to the lipid content. The average percentage of moisture in raw edible flesh, summarized from various sources, is 77.2 with a range of 64.3 – 82.8%.

Raw shellfish moisture contents fall in the same range as finfish, but average is slightly higher, 80.1%. About one fourth of the moisture can be lost during cooking, which results in concentration of other components.

For fish jerky the amount of moisture should be 15 to 20 percent. This low-moisture content is sufficient to inhibit the growth of harmful bacteria without added preservative.

To maintain quality, commercially packaged frozen fishery products should, be placed in the freezer, in their original moisture-vapor-proof wrapper, immediately after purchase. Store in freezer to -18 °C or lower. At the temperature above -18 °C, chemical changes cause the fish to loss color or flavor, texture and nutritive value.
Moisture content in fish

Major constituent of milk

Milk is a complex biological fluid, composition and physical characteristics of which vary from species to species, reflecting the dietary needs of the young mammal.

The major constituent of milk is water, but according to species milk contains varying quantities of lipids, proteins, and carbohydrates which are synthesized within with mammal gland.

Disaccharides lactose in milk imparts sweetness. Human milk has a major concentration of lactose (7.4%) compared to milk of other species. Milk lactose serves to major functions:
*It provides galactose, a structural unit for the growing infant
*In the intestine, it gets metabolized to lactic acid which eliminates harmful bacteria.

The lipid content of mammalian milk varies from 16 g/liter (horse) to 105 g/liter (deer), human milk contains about 38 g of fat per liter.

When milk is dried and the residue is burned, a white powder is obtained which is known as ash or mineral part of the milk. The major portion of ash is composed of the chlorides and oxides of potassium, calcium and phosphorus. It is of interest to note that these three elements are in greater concentration in milk than in blood, thus the mammary gland exerts a selective action to concentrate these elements.

Milk contains more calcium than most foods because of the distribution of calcium in milk. About two thirds of the total calcium in milk is in colloidal form as calcium caseinate, citrate and phosphate; the remaining third is in true solution.

Milk contains lot of vitamins, among them vitamin B complex is dissolved in the water and vitamins A and D in the fat. Only ascorbic (vitamin C) is present in limited amount and it may absent from pasteurized milk.
Major constituent of milk

Human body composition

Human body is composed of various tissues and numerous body cavities filled with body fluid.

Around 1850s, Justus von Liebig found that the human body contains many substances present in food and that body fluids contain more sodium and less potassium than tissues.

The average human body contains about 20 % of fat, 15% protein, much smaller amounts of carbohydrate (perhaps I %) and large amounts of water.

Although fat is found primarily in adipose tissue, intracellular triglyceride pools are also observed in liver, skeletal muscle and other organs, particularly in pathological conditions such as hepatic steatosis and various forms of lipidosis.

Human body also contains substantial amounts of the “major minerals,” from calcium and phosphorus down to sulfur and magnesium as well as trace quantities of most elements.

The water content of the human body is never higher than at birth – about 70% of a term newborn infant’s weight may be water.

By adulthood, body water content is generally 56 to 64%. As the water content of the extracellular fluid is by and large controlled hormonally, the greatest influence upon tissue water content remains the ration of skeletal muscle to adipose tissue.

The human diet reflects this compositional need, and consists of large quantities of water containing, proteinaceous, fatty, and carbohydrate foods, as well as others rich in the minerals.
Human body composition 

Fat composition in human body

The variables of body composition were measured through the following methods: bioelectrical impedance analysis (BIA), near-infrared interactance (NIR), slaughter cutaneous skinfold equations (SKI) and body mass index (BMI).

Body composition generally refers to the absolute amount of fat and nonfat tissue within the body as well as the ratio of fat to total body mass (TBM).

Typically, body composition is assessed to determine the percentage of body fat and of lean body mass (LBM) or fat free mass (FFM).

Although FFM and LBM are often used interchangeably, LBM includes not only all nonfat portions of the human body, but also essential fat deposits, whereas FFM is the total mass of all tissues within the body excluding all fat.

Fat mass (FM) is the total mass (or kilograms) of all fat within the body. Body fat is made-up of about 10% water and 90% adipose tissue.

Essential fat is found associated with the bone marrow, the central nervous system and internal organs. Without fat in these areas, the body cannot function properly.

The essential body fat percentage or minimum level of body fat comparable with health in men is approximately 3-5% and in women is approximately 12-14%.

Many factor such as age, gender, stature heredity, and pregnancy influence body composition.

Young individual tend to have higher resting metabolic rates, are more active, and as a result are lean.
Fat composition in human body