STUDIES ON THE EFFECT OF BROWNING REACTIONS ON SOME PRODUCTS OF FIG (Ficus carica).

Abstract

This study was carried out on fig products (syrup, jams and sheets) to investigate the effect of industrial food processing on browning reactions. During processing some changes in fig products are occurred with respect to colour and final aspects change. Thermal treatments during the preparation of fig syrup can effect on its quality through the non-enzymatic browning reactions. Different indicators were assayed to determine the extent of browning which include absorbance measurements at 420nm, colorimetric evaluations and determinations of sugar, furfural, hydroxymethylfurfural (HMF) and total phenols in the final product. hydroxymethylfurfural (HMF) content was increased after processing in fig syrup and sheets. On the other hand, total phenols and total flavonoids were decreased after processing in all products that refer to the activity of polyphenoloxidase. Fig sheets treated with SO2 had higher color score compared with control sheets. Fig jam treated with lemon juice had higher taste and odor scores compared with fig jam produced from the residue of fig juice concentrate. Fig syrup had desirable organoleptic characteristic scores.Regarding to free amino acid concentration, there is a decreased after manufacturing processes in some amino acids as valine, aspartate, glutamate, alanine, argnine, and lysine. This decrease reflects the consumption of these free amino acid during Millard reactions.