The effects of retort distillation (RD) and double distillation (DD) for producing cherry spirits using unique double-kettle equipment were compared, for the first time. RD improved distillation efficiency and kept methanol at a safe level. Compared with DD, the contents of higher alcohols increased with RD: isobutanol, propanol, and benzyl alcohol increased by 15.5, 32.9, and 37.9%, respectively, with the content of ethyl esters being reduced. In contrast, isoamyl formate, with its cherry aroma, was not detected in DD spirits, but was present at up to 10.71 mgL −1 in RD spirits. Six terpenoids were detected in RD spirits, but only four in DD spirits. These changes were also reflected in the sensory scores. Although the purity and elegance of the RD spirits decreased, their complication, richness, and honey aroma increased. These changes are very important for guaranteeing spirits quality, providing a reference for research and production of cherry distilled spirits.
A microbial nest system (MNS) represents a novel and efficient approach to treating solid–liquid mixtures from pig farming instead of the conventional method, which separates the solid and liquid at first using centrifugation before treating the solid and liquid. However, the key environmental factors influencing the efficiency of this system and the microbial structure are still not clear. This study aimed to elucidate the changes in an MNS considering physicochemical properties, spectral analysis, and correlations between microbial community structures and environmental factors during the treatment. The results showed that the MNS underwent three temperature stages during the treatment process of piggery slurry: a warming period, a high-temperature period, and a cooling period. In the high-temperature period, the most abundant bacterium was Bacillus, with a relative abundance of 22.16%, and Chaetomium dominated the fungal community with a relative abundance of 11.40%. Moreover, the moisture content, pH value, and electrical conductivity (EC) exhibited an increasing trend, whereas the carbon-to-nitrogen (C/N) ratio and the ratio of ammonia nitrogen to nitrate nitrogen (NH4+-N/NO3−-N) showed a decreasing trend. The accumulation of humic acid and fulvic acid suggested that the humification process of organic matter was occurring. The moisture content and C/N ratio were identified as crucial factors influencing the bacterial and fungal community structures, respectively. This study provides a theoretical basis for enhancing the efficiency of piggery slurry treatment using an MNS and rational optimisation of the associated processes.
The development of blueberry wine provides an alternative method for maintaining the nutritional value and extending the shelf life of blueberries. However, anthocyanin (ACN) loss and off-flavor compound generation during fermentation impair blueberry wine color and quality. Hydroxycinnamate decarboxylase (HCDC) from yeast can catalyze the conversion of hydroxycinnamic acids to vinylphenols, which later may condense with ACNs to form more stable vinylphenolic pyranoanthocyanins. In this study, 10 non-Saccharomyces yeasts from Daqu that showed HCDC activity were screened. Among the 10 strains, Wickerhamomyces anomalus Y5 showed the highest consumption (34.59%) of the total tested phenolic acids and almost no H2S production. Furthermore, Y5 produced four vinylphenol pyranoanthocyanins (C3G-4-vinylcatechol, C3G-4-vinylsyringol, malvidin-4-vinylguaiacol, and malvidin-4-vinylcatechol) during blueberry wine fermentation, which may improve the color stability of blueberry wine. These findings provide new insights for improving the quality of blueberry wine using non-Saccharomyces yeasts.