Preliminary characterization of chemical and sensory attributes for grapes and wines of different cultivars from the Weibei Plateau region in China.

Chemical and sensory attributes play a vital role in evaluating the quality of grapes and wines. This study compared basic physicochemical parameters, organic acids, phenolic compounds, and aroma profiles of grapes and wines of six cultivars using chemometrics. The results showed that the reducing sugar contents of Beibinghong, Gongniang, and Granoir grapes were significantly higher than those of others cultivars, whereas their juice yields were significantly lower. The phenolic compound contents in Moldova, Beibinghong, and Gongniang grape skins and wines were higher than those in others cultivars. The organic acid contents in Beibinghong grape and Dunkelfelder wine were highest. Beibinghong and Gongniang grapes and wines showed richer aldehyde and ester concentrations. Beibinghong wine obtained the highest sensory scores. Ethyl decanoate, coumaric acid, and methyl dodecanoate were characteristic variables distinguishing wine cultivars, exhibiting important contributions to their sensory characteristics. These findings were useful for viticulturists and winemakers to select grape varieties.

Synthesis and anti-tumour activities of sulphated polysaccharide obtained from Momordica charantia.

A native polysaccharide (MCP2) was extracted and isolated from Momordica charantia. Four sulphated derivatives of MCP2 were prepared by chlorosulphonic acid method. The structures of the sulphated derivatives were characterised by FT-IR spectra. Depending on the reaction conditions, the sulphated derivatives showed different degree of substitution (DS) ranging from 0.56 to 1.10, and different weight-average molecular mass (Mw) ranging from 7.2 to 9.3 KDa. It implied the efficient substitution of hydroxyl groups in the polysaccharides by sulphated groups with degradation. The effects of the sulphated derivatives on inhibiting the growth of HepG2 cells and Hela cells in vitro were compared with taking non-modified MCP2 as control. The sulphated derivatives inhibited the growth of HepG2 cells and Hela cells in vitro significantly, which indicated that sulphated modification could enhance the anti-tumour activity of MCP2.