Adjustment of impact phenolic compounds, antioxidant activity and aroma profile in Cabernet Sauvignon wine by mixed fermentation of Pichia kudriavzevii and Saccharomyces cerevisiae.

Mixed fermentation using saccharomyces cerevisiae and non-saccharomyces cerevisiae has become one of the main research strategies to improve wine aroma. Hence, this study applied the mixed fermentation technique using Pichia kudriavzevii and Saccharomyces cerevisiae to brew Cabernet Sauvignon wine and to investigate the effects of inoculation timing and inoculation ratio on the polyphenolics, antioxidant activity and aroma of the resulting wine. The results showed that mixed fermentation significantly improved the amounts of flavan-3-ols. In particular, S1:5 had the highest amounts of (-)-catechin and procyanidin B1 (73.23 mg/L and 46.59 mg/L), while S1:10 had the highest (-)-epicatechin content (57.95 mg/L). Meanwhile, S1:10 showed the strongest FRAP, CUPRAC and ABTS + activities (31.46 %, 25.38 % and 13.87 % higher than that of CK, respectively). In addition, mixed fermentation also increased the amounts of phenylethanol, isoamyl alcohol and ethyl esters, which enhanced the rose-like and fruity flavor of wine. This work used a friendly non-saccharomyces cerevisiae alongside appropriate inoculation strategies to provide an alternative approach for improved wine aroma and phenolic profile.

Volatile Compounds Analysis and Biomarkers Identification of Four Native Apricot (Prunus armeniaca L.) Cultivars Grown in Xinjiang Region of China.

Flavor (odor and taste) have a significant role in the consumer's acceptance, and volatile compounds are responsible for the odor of apricots. In the present work, headspace solid-phase microextraction with gas chromatography coupled to tandem mass spectrometry (HS-SPME-GC-MS/MS) together with multivariate analysis, i.e., partial least square discrimination analysis (PLS-DA), were applied to construct the volatile fingerprints and biomarkers of apricots in Xinjiang, China. As a result, a total of 63 volatile substances were identified in the fruits of four apricot cultivars, seven of which were considered to serve as volatile biomarkers, which are damascenone for Dabaiyou apricots; acetophenone, myrcenol and 7-hexadecenal for Luopuhongdaike apricots; 2,4-dimethyl-cyclohexanol for You apricots; eucalyptol and salicylaldehyde for Xiaobai apricots. Moreover, Xiaobai apricots were richer in soluble sugars, organic acids and total phenolic and total flavonoid content than the other three apricot varieties. This work helps to characterize the volatile profiles and biomarkers of different apricot cultivars while providing theoretical guidance for developing apricot-flavored foods in practical production.