Protein nutrition amino acid supplements

Iyer, U.M. and Mani, LJ.V. (1 990) Studies on the effect of curry leaves supplementation (Murraya koenigii) on lipid profile, glycated proteins and amino acids in non-insulin-dependent diabetic patients. Plant Foods for Human Nutrition (formerly Qualitas Plantarum) 40(4), 275-282. 

Retrospective review. Protein recommendations include amino acid supplements. Intakes prescribed based on Ross nutrition support protocol Retrospective review. Dietary survey. Group without protein supplement had inadequate intake of some nutrients and higher Phe levels... 

Gelatin can be a source of essential amino acids when used as a diet supplement and therapeutic agent. As such, it has been widely used in muscular disorders, peptic ulcers, and infant feeding, and to spur nail growth. Gelatin is not a complete protein for mammalian nutrition, however, since it is lacking in the essential amino acid tryptophan [73-22-3] and is deficient in sulfur-containing amino acids. 

Characteristically, legume seeds are rich in protein and contain intermediate to high levels of lysine and threonine which are important in balancing the deficiencies of these essential amino acids in cereal diets. Certain legume proteins, such as soybean, also exhibit strong functional properties, especially water solubility, water and fat binding and emulsification. Thus soybean flours, protein concentrates and isolates have been used widely as nutritional supplements and functional ingredients in foods. 

A report by Bressani et al. (3J7), which evaluated the nutritional value of diets based on starchy foods and beans, indicated that for the rat, sweet potato protein was of poor nutritional quality. When methionine was added to all diets to raise sulfur amino acids, sweet potato still required the largest amount of supplementation with bean flour to maintain animal weight (Table II). 

By the 1930s many workers had shown that nutritionally inadequate proteins, such as zein from maize, could be effective as a source of nitrogen if supplemented by additional amino acids (for zein, tryptophan). Even if it contained all the essential amino acids, the amount of protein in the diet influenced the results. Osbome and Mendel found that if the diet contained 18% by weight casein, which is low in cystine, young rats grew, but if the amount of protein was diminished, added cystine was required to offset the relative deficiency of this amino acid. Later, after methionine had been discovered, it was shown to replace the need for cystine. 

Amino acid analysis has long been of importance for nutritional purposes. Recently, there has been an increasing interest in assessing the exact amino acid composition of new protein sources, infant formulas, nutraceutical-type products, or supplements targeted at people with unusual metabolic needs. There is also a regulatory necessity to have rapid methods available for amino acid determination to verify product consistency with that declared on the label [196]. 

Animal feeds are a major market, especially for monogastric animals. This is because their nutritional requirements are high and the lysine content of traditional feed such as soy or maize is low. A supplementation of feeds with individual essential amino acids is necessary because a high protein contents lead to excessive manure production, especially by pigs. 

Since animals tend to concentrate in their own proteins the sulfur amino acids contained in the plants diey eat, such animal products (meat. eggs, and cheese) are valuable sources of the essential sulfur amino acids in human diets. In regions where die diet is composed almost entirely of foods of plant origin, deficiencies of sulfur amino acids may be critical in human nutrition. Frequently, persons in such areas (also voluntary vegetarians) are also likely to suffer from a number of odier dietary insufficiencies unless supplemental sources are used. 

Nutritional Availability of Acylated Lysine and Proteins. The successful use of chemically derivatized proteins as food ingredients requires that they be digestible and nontoxic, and that the modified amino acid residues should be available nutritionally. Nutritional studies using modified food proteins are limited. The nutritional availability of several acylated lysines were studied by Bjarnason and Carpenter (105) and Mauron (106) and the results are summarized in Table III. The bioavailability of the acylated lysine varied significantly with the type of the acyl groups (see Table III). In addition acylated proteins (acetylated and succinylated) gave lower responses to the growth activity for the rats than equivalent supplements of unmodified proteins... 

Another large successful commercial application of enzymes is in the amino acid industry. Amino acids for food and feed fortification, nutritional supplements, or as feedstock for downstream products can be made by fermentation processes, from protein hydrolysates or by chemical synthesis. While chemical synthesis is cheaper for a number of amino acids,, it often produces a racemic mixture. The racemic mixture is successfully resolved on a commercial scale by acylating the amino acids, then using an aminoacylase to remove the acyl group from the L-amino acid and separating the free L-amino acid from the still acylated-D-amino acid. Ajinamoto and other companies, especially in Japan, make large amounts of amino acids by this process. 

During the waiting period, it is important to maintain or even improve the patient s nutritional status. Protein tolerance can be monitored by using simple psychometric tests. A protein intake of 1.0-1.5 g/kg BW/day would be ideal. Supplementation by branched-chain amino acids may be helpful. The calorie supply has to be adjusted to the optimal requirement of the patient, (s. pp 741, 850, 861)... 

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