BIOLOGICAL STUDIES AND ANTIOXIDATTVE ACTIVITY FOR WHITE TRUFFLE FUNGUS (TUBER BORCHII)

摘要

The white desert truffle fungus Tuber borchii has been evaluated by chemical proximate analysis. Tuber borchii was shown to have 18.9% protein, 6.21% lipids, 9.33% fiber and 52.81% carbohydrates in the dry weight. The phenolic content was 0.93% as tannic acid in the dry weight. At pH 8.5, the total extractable truffle protein (ETP) was 17.1%, while at pH 3.7, the truffle protein isolate (TPI) was 65.7% in the freeze dried matter. The amino acids (except isoleucine) were not limiting. The rat nutritional bioassay showed that the protein efficiency ratios for the extracts were close to that for the control. Either 5% ETP or 5% TPI decreased liver weight, decreased AST activity, but did not decrease ALT activity. Total lipids and total cholesterol were also decreased in rats. The antioxidative activity (AOA) for the methanol and hexane white truffle extracts showed significant activity up to 12 days. The AOA of the methanol and the hexane extracts for 7 days storage were 73.17, and 64.33%, respectively compared to that for vitamin E (91.5%). The AOA for the 10 day storage of methanol extract (94.2%) was higher than that for vitamin E (88.27%). The hexane extract showed prooxidative activity past 16 days, while, the AOA for the methanol extract was (5.02%) past 24 days of storage. The high antioxidative activity for the methanol extract may due to the phenolic content 0.53% and the reducing power of the extract. The methanolic extract proved to inhibit some pathogenic fungi. On the other hand, the hexane extract has low phenolic content (0.02%), no reducing power, and less protection against the pathogenic fungi.