Browning, enzymatic

Sucrose helps minimize earthy tastes of vegetables, while enhancing inherent flavors and aromas, and preserving color and texture (37). Addition of sucrose inhibits enzymatic browning of canned and frozen fmits, and prevents loss of color, flavor, and aroma from fmit during processing (38). 

Salads. A combination of citric acid and ascorbic acid is used as an alternative to sulfites in prevention of enzymatic browning in fresh prepared vegetables (56). 

MANZOCCO L, CALLiGARis s, MASTROCOLA D, NicoLi M c and LERici c R (2001) Review of non-enzymatic browning and antioxidant capacity in processed foods . Trends Food Sci Technol, 11 340-6. 

Microbial growth, enzymatic reactions, non-enzymatic browning (reaction between carbonyl and amino compounds), and lipid oxidation are the major deterioration mechanisms that limit the stability of low moisture (o intermediate moisture foods (o.6o < <0.85) and biological materials. 

To fulfill the needs for long term stability of a biological material, the optimum range of water activity lies between 0.20 and 0.35, This area represents the best compromise between lipid oxidation and non-enzymatic browning. Enzymatic browning is suppressed under these conditions, and growth of microorganisms is impossible. 

Lopez-Nicolas JM, Perez-Lopez AJ, Carbonell-Barrachina A and Garcia-Carmona F. 2007. Kinetic study of the activation of banana juice enzymatic browning by the addition of maltosyl-beta-cyclodextrin. J Agric Food Chem 55(23) 9655-9662. 

Martinez MV and Whitaker JR. 1995. The biochemistry and control of enzymatic browning. Trends Food Sci Technol 6(6) 195-200. 

Goupy P, Amiot MJ, Richard-Forget F, Duprat F, Aubert S and Nicolas J. 1995. Enzymatic browning of model solutions and apple phenolic extracts by apple polyphenoloxidase. J Food Sci 60 497—501, 505. 

Jeon M and Zhao Y. 2005. Honey in combination with vacuum impregnation to prevent enzymatic browning of fresh-cut apples. Int J Food Sci Nutr 56(3) 165—176. 

Luo Y and Barbosa-Canovas GV. 1997. Enzymatic browning and its inhibition in new apple cultivar slices using 4-hexylresorcinol in combination with ascorbic acid. Food Sci Technol Int 3 195-201. 

Ozoglu H and Bayindirli A. 2004. Inhibition of enzymatic browning in cloudy apple juice with selected antibrowning agents. Food Control 13 213-221. 

Delay non-enzymatic browning of fruits and some vegetables. 

Maillard reaction. The Maillard reaction is also known as non-enzymatic browning, non-enzymatic glycosylation, and glycation. It comprises the spontaneous reaction between carbonyl and amino compounds, such as sugars and proteins, respectively. It is especially well-known in the... 

Enzymatic browning. Phenol-oxidizing enzymes (such as tyrosinase and peroxidase) oxidize tyrosine residues into reactive quinone derivatives, which will condense into colored polymers (melanins). Melanins are rich in carboxyl groups and therefore have high affinity for divalent metal ions such as calcium. 

Humic substances. Analogous to the reactions described above, humic substances (the polymeric pigments from soil (humus) and marine sediments) can be formed by both enzymatic and non-enzymatic browning. High concentrations of free calcium and phosphate ions and supersaturation with respect to hydroxyapatite can sustain in soil, because adsorption of humic acids to mineral surfaces inhibits crystal growth (Inskeep and Silvertooth, 1988). A similar adsorption to tooth mineral in a caries lesion can be anticipated for polycarboxylic polymers from either the Maillard reaction or enzymatic browning. 

Amiot, M.J. et al., Influence of cultivar, maturity stage and storage conditions on phenolic composition and enzymatic browning of pear fruits, J. Agric. Food Chem., 43, 1132, 1995. 

Lee, C.Y., Kagan, V., Jaworski, A.W., and Brown, S.K., Enzymatic browning in relation to phenolic compounds and polyphenoloxidase activity among various peach cultivars, J. Agric. Food Chem., 38, 99, 1990. 

Severini, C., Baiano, A., De Pilli, T.,Romaniello,R., Derossi, A. (2004b). Microwave blanching of sliced potatoes dipped in saline solutions to prevent enzymatic browning. / Food Biochem., 28, 75-89. 

Rodriguez-Saona, L., Wrolstad, R., Pereira, C. (1997). Modeling the contribution of sugar, ascorbic acid, chloro-genic acid and amino acids to non-enzymatic browning of potato chips. Journal of Food Science, 62, 1001-1005. 

Numerous review articles (1-20) and a number of books (21-26) have been devoted to the Maillard reaction, viz., the non-enzymatic browning reactions involving amino acids and reducing sugars. 

Organic acids are added to some foods in order to prevent sedimentation or darkening thus, citric, malic, phosphoric, and ascorbic acid are used to reduce or delay enzymatic browning. Melanin formation following production of a quinone is a pH-dependent process (the rate of the former process increases with increasing pH) (8). Polyhydroxyacids such as citric and malic acid... 

---