Effect of gamma-irradiation on the phenolic acids of some Indian spices

Five commercially important spices, namely cinnamon, clove, cardamom, nutme g and mace, were subjected to gamma-irradiation using a dose of 10 kGy, whi ch is recommended for microbial decontamination. Various phenolic acids pre sent in these spices were analysed by high-performance liquid chromatograph y (HPLC). In clove and nutmeg, quantitatively significant changes were note d in some of the phenolic acids upon irradiation. The content of gallic and syringic acids in irradiated clove increased by 2.2-and 4.4-fold respectiv ely, whereas in irradiated nutmeg many of the phenolic acids showed wide in creases and decreases in the range of two- to sixfold compared with the con trol samples. No qualitative and major quantitative changes were, however, observed in the phenolic acids of cinnamon, cardamom and mace upon irradiat ion. The possibility that gamma-radiation induced breakdown of tannins coul d be responsible for the changes in phenolic acids content of clove and nut meg is discussed.