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Medium-chain fatty acid (MCFA) ethyl esters, as yeast secondary metabolites, significantly contribute to the fruity aroma of foods and beverages. To improve the MCFA ethyl ester content of wine, mixed fermentations with Hanseniaspora uvarum Yun268 and Saccharomyces cerevisiae were performed. Final volatiles were analyzed by gas solid phase microextraction-chromatography-mass spectrometry, and aroma characteristics were quantitated by sensory analysis. Results showed that mixed fermentation increased MCFA ethyl ester content by 37% in Cabernet Gernischt wine compared to that obtained by pure fermentation. Partial least-squares regression analysis further revealed that the improved MCFA ethyl esters specifically enhanced the temperate fruity aroma of wine. The enhancement of MCFA ethyl esters was attributed to the increased contents of MCFAs that could be induced by the presence of H. uvarum Yun268 in mixed fermentation. Meanwhile, the timing of yeast inoculations significantly affected the involving biomass of each strain and the dynamics of ethanol accumulation.

Eleven compounds were isolated from potato peels and identified. Their structures were determined by interpretation of UV, MS, 1D, and 2D NMR spectral data and by comparison with reported data. The main components of the potato peels were found to be chlorogenic acid and other phenolic compounds, accompanied by 2 glycoalkaloids, 3 low-molecular-weight amide compounds, and 2 unsaturated fatty acids, including an omega-3 fatty acid. The potato peels showed more potent radical scavenging activity than the flesh. The quantification of the 11 components indicated that the potato peels contained a higher amount of phenolic compounds than the flesh. These results suggest that peel waste from the industry of potato chips and fries may be a source of useful compounds for human health.

For the purpose of surveying naturally occurring precursors of oestrogenic substances, and their metabolic processes, to mammalian lignans such as enterodiol (END) and enterolactone (ENL), many plant lignans have been studied. Trachelogenin, an aglycone of tracheloside, occurring in the seeds of Carthamus tinctorius L. (safflower), was demonstrated to transform to seven metabolites, including (−)-ENL, by anaerobic incubation with a human faecal bacterial mixture, when the reaction was monitored by LC/MS. The structures of the metabolites were determined by spectroscopic means after a large-scale incubation and purification of the respective metabolites. Moreover, the ligand-binding affinity of these metabolites to oestrogen receptors (ERs) α and β was measured in comparison with that of (+)-ENL. (−)- and (+)-ENL were found to significantly bind to both ERα and β, in which an appreciable difference in affinity was observed between (+)- and (−)-ENL for ERβ, but not for ERα.

Flavan-3-ol oligomers from the stems of Cynomorium songaricum were found to show potent SOD-like activity with one of the dimers being most potent. The flavan-3-ols also showed inhibitory activity on α-glucosidase, implying the beneficial effects of this herb on diabetes patients. The total (extractable and non-extractable) tannin content of this herb was found to be as high as 18.3%. The contents of catechin, flavan-3-ol oligomers and extractable tannins using 70% acetone, methanol or water were analysed. It was found that 70% acetone was the most efficient extract solvent amongst these three solvents, especially for higher flavan-3-ol oligomers.

Flavan-3-ol derivatives, including 3 cysteine conjugates and 3 acetylcysteine conjugates, were prepared using Cynomorium songaricum and edible reagents. The structures were determined, based on NMR and MS spectra. All compounds had stronger radical-scavenging activity than catechin and epicatechin. Moreover, the cysteine conjugates were active against α-glucosidase, whereas catechin and epicatechin were not. Two acetylcysteine flavan-3-ol conjugates, 4β-( l -acetylcysteinyl)-epicatechin 3-O-gallate and 4β-( l -acetylcysteinyl)-epiafzelechin, are novel compounds with better log P values than their cysteine counterparts. These conjugates can be prepared from purified flavan-3-ol polymers or directly from herbal material.