Browning reaction, inhibition

K. Eichner, The influence of water content on non-enzymic browning reactions in dehydrated food and model systems and the inhibition of fat oxidation by browning intermediates, in Water Relations of Foods, R.B. Duckworth (ed), Academic Press, London, 1975, 417 134. 

When the reaction mixture was wetted with an equal weight of water, no amino acid degradation was noticed. Cocoa beans moisture content averaged 5 to 6 % which might be sufficient to inhibit browning reaction at lower temperatures, thus in the early stages of roasting the removal of moisture is important. 

Figure 3-8 Reversible Formation of Glycosylamines in the Browning Reaction. Source From D.T. Hurst, Recent Development in the Study of Nonenzymic Browning and Its Inhibition by Sulpher Dioxide, BFMIRA Scientific and Technical Surveys, No. 75, Leatherhead, England, 1972.

Researchers who use the very complex Maillard browning reaction to study the significance of moisture, Tg and a should be familiar with the complicated pathways, feedback inhibitions, and intermediates that are inherent to the reaction (Hodge, 1953) before validating kinetic data and drawing conclusions as to the mechanism for the influence of moisture on the reaction. Other than the aforementioned considerations, such as matrix... 

Tyrosinase inhibition may be a potential approach to prevent and control the enzymatic browning reactions and improve the quality and nutritional value of food products [20]. Tyrosinase also plays a major key role in the developmental and defensive functions of insects. Tyrosinase is involved in melanogenesis, wound healing, parasite encapsulation, and sclerotization in insects [21-23]. For these reasons, in recent years the development of tyrosinase inhibitors has become an active alternative approach to control insect pests [20]. Additionally, it is now well-recognized that tyrosinase inhibitors are important for their potential applications in medical and cosmetic products [24-26]. 

C6H,N02, Mr 127.14, mp. >199°C (decomp.), [a][> -54.4° (H2O). Non-proteinogenic amino acid in the toadstools Tricholomopsis rutilans Amanita pseudo-porphyria and A. miculifera. Ninhydrin reaction brown. It inhibits L-methionine-S-adenosyltransfe-rase. ... 

C5H,N02. Mr 115.13, mp. ca. 196°C, [a]l -33.7° (H2O). Non-proteinogenic amino acid in the fruit bodies of Amanita pseudoporphyria and A. abrupta. Synthetic A. is long known as an antimetabolite against Escherichia coli and Saccharomyces cerevisiae and as an inhibitor of glutamate decarboxylase (EC 4.1.1.15). Ninhydrin reaction brown. A. inhibits protein synthesis. The 4-chloro derivative of A. [2-amino-4-chloro-4-pentenoic acid, (2S)-form CsHgClNOj, Mr 149.58] is a major constituent of the free amino acids in fruit bodies of Amanita pseudoporphyria. It has antibacterial activity. 

Reaction of amino groups of amino acids, peptides, and proteins with carbonyl groups of carbohydrates or with tyrosine-derived quinone groups encompass changes respectively called nonenzymatic and enzymatic browning reactions (57-75). Such changes may adversely affect the appearance, taste, nutritional quality, and safety of many foods. Until recently, sodium sulfite has been used to inhibit browning... 

Another option to reduce or inhibit the enzymatic browning reaction is the use of chemical reagents. Many substances capable of inhibiting polyphenol oxidases are known, but the mechanism of their action is often unknown. Complexing agents are able to bind copper ions, which the enzyme requires. Interaction with... 

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