Healthy, nutritious, and delicious mulberry wine is loved by everyone, but there is no specific yeast for mulberry wine. To screen for yeasts with low-yield higher alcohols for the fermentation of mulberry wine, we tested five commonly used commercial yeasts available on the market to ferment mulberry wine. All five yeasts were able to meet the requirements in terms of yeast fermentation capacity, speed, and physical and chemical markers of mulberry wine. The national standards were met by the fermentation requirements and the fermented mulberry wine. We identified yeast DV10 as a yeast with low-yield higher alcohols suitable for mulberry wine fermentation. The total higher alcohol content in fermented mulberry wine was 298 mg/L, which was 41.9% lower than that of fermented mulberry wine with yeast EC118. The contents of 17 free amino acids and five sugars in mulberry juice and five yeast-fermented mulberry wines were tested. The results showed that the higher the amino acid and sugar content in yeast-fermented mulberry wine, the higher the content of higher alcohols produced by fermentation. A correlation analysis performed on each higher alcohol produced when yeast DV10 fermented the mulberry wine indicated decreased sugar and related amino acids. The findings demonstrated a substantial negative correlation among the levels of increased alcohol, decreased sugar, and matching amino acid content. Considering the correlation values among increased alcohol, decreased sugar, and related amino acids, the very slight difference suggests that both sugar anabolism and amino acid catabolism pathways have an equivalent impact on the synthesis of higher alcohols during the fermentation of mulberry wine. These results provide a theoretical basis for reducing the content of higher alcohols in mulberry wines, given the history and foundation for producing mulberry wine.

Raisins, known for their delicious taste and high nutritional value, are among the most widely consumed dried fruits globally. The natural waxy layer on the surface of grapes impedes water migration, making pretreatment necessary before drying. This study evaluated the effects of various pretreatment methods on the nutritional and functional quality of seedless purple raisins. By using non-pretreated dry seedless purple raisins as a control, the impact of physical and chemical pretreatment methods on the nutritional and functional qualities of seedless purple raisins was assessed through the analysis of nutrient content, phenolic compounds, and antioxidant activity. Our results demonstrate that physical pretreatment significantly increases the levels of vitamin C, fructose, glucose, total acid, total phenolics, total flavonoids, total anthocyanins, and antioxidant activity compared to chemical pretreatment and the control group. The correlation analysis revealed that phenolic substances were closely linked to antioxidant capacity. Additionally, phenolic compounds, including resveratrol, ferulic acid, chlorogenic acid, ethyl coumarate, and cinnamic acid, were more abundant following physical pretreatment. The OPLS-DA model effectively differentiated the three groups of processed samples, showing that different pretreatments significantly affect the nutritional and functional quality of seedless purple raisins. These findings suggest that physical pretreatment offers considerable potential for improving the drying quality of seedless purple raisins.

To elucidate the impacts of climatic and edaphic factors on the chemical composition and bioactivities of black mulberries, this study conducted a systematic comparative analysis of fruits sourced from four regions in Xinjiang: Turpan (T), Bayingolin Mongol Autonomous Prefecture (B), Hotan (H), and Kashgar (K). H exhibited the highest contents of total phenolics and total tannins, whereas T showed elevated levels of total flavonoids and flavan-3-ols. Notably, samples from B and H demonstrated superior antioxidant potential. Using UPLC-MS/MS, a total of 48 anthocyanin metabolites and 4 non-anthocyanin metabolites were identified in the mulberry fruits. Among these, 6 were region-specific compounds, and 8 were identified as differential metabolites. Furthermore, headspace solid-phase microextraction (HS-SPME) coupled with GC-MS/MS revealed 292 volatile metabolites, of which 15 were identified as differential metabolites based on OPLS-DA and relative odor activity value (rOAV) analyses. Metabolite profiling indicated that B possessed the greatest diversity of volatile metabolites, while T exhibited a remarkable richness in anthocyanin diversity. The observed regional variations in chemical constituents and metabolite profiles collectively accounted for the differences in antioxidant capacity and enzyme inhibitory activities among the black mulberry fruits. These findings provide a theoretical foundation for the regional characterization and targeted processing of black mulberries from the four production areas in Xinjiang.