Environmental stress enhances biosynthesis of flavor precursors, S-3-(hexan-1-ol)-glutathione and S-3-(hexan-1-ol)-L-cysteine, in grapevine through glutathione S-transferase activation.

The biosynthesis of S-(3-hexan-1-ol)-glutathione (3MH-S-glut) and S-(3-hexan-l-ol)-L-cysteine (3MH-S-cys), which act as flavour precursors in wines, in Vitis vinifera grapes exposed to various environmental stress conditions is reported here. Ultraviolet (UV-C) irradiation, water deficit, and biological stimulation up-regulated 3MH-S-glut and 3MH-S-cys biosynthesis in grape leaves. 3MH-S-glut and 3MH-S-cys contents in grape berries were increased by cold shock, heat shock, UV-C irradiation, and biological stimulation.

Iron is an essential cause of fishy aftertaste formation in wine and seafood pairing.

Fishy aftertaste is sometimes perceived in wine with fish and seafood pairing. However, what component of wine clashes with seafood or what compound contributes to the unpleasant fishy aftertaste in the mouth remains an open problem. First, intensities of unpleasant fishy aftertaste of wine and dried scallop pairings were rated by sensory analysis.

Improvement of the antitumor activity of black currant polysaccharide by an enzymatic treatment.

A polysaccharide-rich substance isolated from black currant, named cassis polysaccharide (CAPS), was partially digested with beta-galactosidase from Aspergillus oryzae and its immunostimulatory activity was investigated. The in vitro cytokine-inducing effect of CAPS on RAW264 cells was gradually decreased along with lowering of the average MW of CAPS. In vivo, partially digested CAPS with a mean MW of approximately 20,000 showed the most potent antitumor activity against Ehrlich carcinoma in mice.

Immunostimulatory effects of a polysaccharide-rich substance with antitumor activity isolated from black currant (Ribes nigrum L.).

The fruit juice of black currant was found to contain a polysaccharide-rich substance, which was designated cassis polysaccharide (CAPS), with macrophage-stimulating activity. Especially, its interleukin (IL)-1beta-inducing activity was remarkably high, compared with other fruit juice preparations. CAPS was found to consist of rhamnose, mannose, arabinose, galactose, xylose, and glucose in a molar ratio of 11.