Maillard products, nutritional effects

Nutritional Effects Due to the Presence of the Maillard Products. Many physiological or antinutritional effects have been attributed to the Maillard products. Specific effects have been attributed to the Amadori products deoxyfructosylphenylalanine (a model substance not likely to be present in large quantities in foods) appears to depress the rate of protein synthesis in chicks (32) and to partially inhibit in vitro and in vivo the absorption of tryptophan in rats (33). The compound e-deoxyfructosyllysine inhibits the intestinal absorption of threonine, proline, and glycine and induces cytomegaly of the tubular cells of the rat kidneys (34) as does lysinoalanine. In parenteral nutrition the infusion of the various Amadori compounds formed during sterilization of the amino acid mixture with glucose is associated with milk dehydration in infants and excessive excretion of zinc and other trace metals in both infants and adults (35,36,37). 

Erbersdobler, H. F., von Wangenheim, B., Hanichen, T. Adverse effects of Maillard products — especially of fructoselysine in the organism. Paper presented at XI Intemat. Congress of Nutrition, Rio de Janeiro, Brazil, Aug. 1978. 

Because of the variety of polysaccharides which can be fermented by some Bacteroides species, it is difficult to predict with certainty which polysaccharides in the complex mixture of dietary and host-produced carbohydrates that enter the colon will be degraded most rapidly and most extensively. Further information about how these organisms make choices between different polysaccharides i vitro may help to clarify this issue. However, nutritionists who are interested in catabolism of dietary fiber components iji vivo should be aware that the bacteria may prefer other sources of carbohydrate, such as mucopolysaccharides from host secretions or even Maillard products, to the dietary polysaccharide under study, and that this preference may influence catabolism of a particular polysaccharide in ways which we cannot at present predict. Effects of this sort may be responsible for some of the individual-to-individual variation which is encountered in nutritional studies of dietary fiber utilization. 

While Maillard reactions may represent only a portion of the interactions responsible for alterations in nutritive value of plant materials, the recognition that such reaction may occur at temperatures that can be considered as physiological in plants raises a considerably wider spectrum of possibilities for alterations in nutritive value of feed- and foodstuffs than has generally been assumed. As pressure for increased production efficiency of animals and increased use of nonconventional nutrient sources increases, the effects of processing upon nutritive value of these materials will be studied in greater detail. 

In addition to the nutritional and physiological effects of Maillard browned protein as described in the previous section, it has been shown that the reduced nutritional value of the brown products does not seem to be limited to the loss of amino acids, since supplementation of the diet with those amino acids could not completely restore its biological value (15). This suggests the possible formation of some inhibitory or anti-nutritional compounds during the Maillard reaction, the presence of which cannot be detected with short-term nutritional feeding assays. Moreover, the short-term feeding effects reported in the literature (30) seem to be due in part to nutritional deficiency and not specifically the browning compounds. 

Any detrimental effect of Maillard browned compounds on an animal that cannot be directly linked to a nutritional basis may be considered a potential toxic response. However, it is extremely difficult to separate nutritional related effects from toxic effects in studies involving such complex food systems as illustrated in our discussion. Furthermore, it is clear that the nature of Maillard reaction results in the formation of a tremendous number of chemicals. The constituents of the browning reactants can greatly affect the chemical and biological properties of the products formed. Considerable more wotk is required to definitively identify the compounds responsible for physiological and toxicological effects. 

Chuyen, N.V. Utsunomiya, N. Hidaka, A. Kato, H. 1990. Antioxidative effect of Maillard reaction products in vivo. In The Maillard Reaction in Food Processing, Human Nutrition and Physiology, Finot, P.A. Aesch-bacher, H.U. Hurrell, R.F. Liardon, R., Eds. Birkhauser Verlag Basel, 1990 pp 285-290. 

As far as food products are concerned, the most important and obvious consequences of the Maillard reaction are the development of color and flavor. These effects may or may not be desirable, but they are always accompanied by a decrease in the nutritional value of proteins. In milk for instance, the reaction of lactose with... 

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