Carbohydrate unavailable 20

A wide variety of animal species are subjected to the administration of drugs during their lifetime.The various animal species can encounter drugs and other dietary additives by different routes and this is dependent on the environment in which they are kept. Intensively reared animals tend to have considerable consistency in the components of their diets and thus are much less likely to encounter the range of naturally produced compounds that extensively produced animals encounter. The desire for less expensive dietary constituents and increased efficiency of use has induced feed manufacturers and producers to add enzyme supplements to diets of most farmed animals to reduce the negative effects of indigestible dietary carbohydrates, refactory proteins and unavailable minerals such as phosphorus. This use of dietary additives to improve nutrient utilization and environmental consequences of feeding animals intensively has been the subject of intense research activity in the last five years. " The... 

Southgate DTA. Determination of carbohydrates in foods. 2.—Unavailable carbohydrates. J. Sci. Food Agric. 1969 20 331-335. 

Humans lack enzymes to hydrolyse cellulose, and some odier carbohydrates in food. However, bacteria in the intestine can hydrolyse and ferment some of this carbohydrate to produce short-chain fatty acids, which are used by the colon and the liver. It is estimated that for each gram of unavailable carbohydrate in the diet, 8.4 kJ of energy is made available in this way, although this is influenced by factors such as ripeness of fruit or the way leguminous seeds are cooked. Nonetheless, these effects will be small and can be ignored unless the amount of such carbohydrate is high or very accurate results are required. (The subject of unavailable carbohydrate and fibre in the diet is discussed in Chapters 4, 6 and 15). 

During starvation or in uncontrolled diabetes mel-litus, when carbohydrates are either unavailable or not properly utilized, cellular proteins are used as fuel. 

While the determination of total lysine is rather straightforward, the determination of free or available lysine is more problematic. In this situation, the term free is meant to imply that the e-amine of the lysine side chain has not reacted with various components of the sample matrix (most commonly carbohydrates via Maillard browning). This is important because reaction of the e-amine can render lysine nutritionally unavailable and the nutritive value for that protein is then diminished if lysine is the limiting amino acid (which is often the situation with soy proteins). While enzymatic digestion in the human gut may not release the modified lysine in a nutritionally available state, often these lysine adducts are labile to the standard acid hydrolysis in 6N HC1 at 110°C. This results in total lysine values that overestimate the amount of nutritionally available lysine. 

Most of the compounds that had been reported (before March, 1942) to show cleavage oxidation by periodic acid are recorded in the table the substances are listed alphabetically in the following groups of related compounds (1) carbocyclic compounds (2) carbohydrates (3) a-diketones and a-ketols (4) hydroxyamino compounds (5) polyhydroxy and hydroxyketo acids (6) polyhydroxy alcohols (7) steroids (8) miscellaneous compounds. French journals after May, 1940, and the majority of other foreign publications after June, 1941, were unavailable for the survey. 

The acetyl CoA formed in fatty acid oxidation enters the citric acid cycle only if fat and carbohydrate degradation are appropriately balanced. The reason is that the entry of acetyl CoA into the citric acid cycle depends on the availability of oxaloacetate for the formation of citrate, but the concentration of oxaloacetate is lowered if carbohydrate is unavailable or improperly utilized. Recall that oxaloacetate is normally formed from pyruvate, the product of glycolysis, by pyruvate carboxylase (Section 16.3.1). This is the molecular basis of the adage that fats burn in the flame of carbohydrates. 

The term unavailable complex carbohydrate (UCC) is also used and refers to NSP plus undigested ( resistant ) starch. 

Trinidad, T.P., Wolever, T.M. and Thompson, L.U. 1996. Availability of calcium for absorption in the small intestine and colon from diets containing available and unavailable carbohydrates an in vitro assessment, Int. J. Food Sci. Nutr., 47( 1) 83—88. 

Table I. Pectin and Unavailable Carbohydrate Content of Fruits, Nuts, and Vegetables...

Dry matter Pectin Unavailable Ca Pectate Carbazol carbohydrate Fresh weieht of edible nortion (2) ... 

In the 1800s, Johannes Mulder came up with the name protein, a term derived from a Greek word that means "of first importance." Indeed, proteins are a very important class of food molecules because they provide an organism not only with carbon and hydrogen, but also with nitrogen and sulfur. These latter two elements are unavailable from fats and carbohydrates, the other major classes of food molecules. 

Pulsed amperometric detection is used for the direct detection of a variety of polar aliphatic compounds, many of which, like carbohydrates, peptides and sulfur-containing compounds are of biological interest [171,197-200]. Most aliphatic compounds are not amenable to constant potential amperometric detection. Free-radical products from the oxidation of aromatic molecules can be stabilized by it-resonance hence the activation barrier for reaction is decreased. This mechanism is unavailable for stabilizing aliphatic free radicals. The activation barrier for oxidation of aliphatic compounds can be decreased at noble-metal electrodes with partially unsaturated d-orbitals (e.g. gold, platinum) that can adsorb and thereby stabilize free radical oxidation products and intermediates. Carbon electrodes are not electrocatalytic and are unsuitable for pulsed amperometric detection. 

Both fiber and food form can modify the glycemic response to "available carbohydrate. Available carbohydrate, as distinguished from unavailable carbohydrate, was first... 

The fat in coffee whiteners is encapsulated within a water-soluble carbohydrate matrix, making it unavailable to extracting solvents. Dry powder extraction will typically achieve only 1—5% of the fat. To obtain the total fat ... 

Among carbohydrates, only glucogenic varieties such as glucose, glycogen, dextrin and starch are available to humans. Dietary fibre, now recognised to be an important dietary component, has little nutritive value since it consists of unavailable carbohydrate, mainly cellulose, and noncarbohydrate lignin. 

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