In order to solve the global problem of fruit rotting due to microbial infection and water loss after harvest, which leads to a large amount of food waste, this experiment uses degradable biological composite coating to prolong the preservation period of grapes. Chitosan (CH) and Lignosulfonate (LS) were used as Bio-based film materials, CH films, 1% CH/LS films and 2% CH/LS biomass composite films were synthesized by the classical casting method and applied to grape preservation packaging. Its preservation effect was tested by grape spoilage rate, water loss rate, hardness, soluble solids, titratable acid, and compared with plastic packaging material PE film. At the same time, ¹H NMR technology combined with pattern recognition analysis (PCA) and partial least squares discriminant analysis (PLS-DA) was used to determine the nuclear magnetic resonance (NMR) of Cabernet Sauvignon, Chardonnay and Italian Riesling wines from the eastern foothills of Helan Mountain to explore the differences in metabolites of wine. The results of preservation showed that the grapes quality of CH films and 2% CH/LS coating package is better than the control group, the decay rates decreased from 37.71% to 21.63% and 18.36%, respectively, the hardness increased from 6.83 to 10.4 and 12.78 and the soluble solids increased from 2.1 in the control group to 3.0 and 3.2. In terms of wine metabolites, there are similar types of metabolites between cabernet Sauvignon dry red wine and Chardonnay and Italian Riesling dry white wine, but there are significant differences in content. The study found that 2% CH/LS coating package could not only reduce the spoilage rate of grapes, inhibit the consumption of soluble solids and titratable acids, but also effectively extend the shelf life of grapes by 6 days.

In this study, the fermentation mash of Cabernet Sauvignon, Cabernet Franc, and Matheran from Linfen, Shanxi Province, was sequenced using the Illumina MiSeq high-throughput sequencing platform to analyze the structural diversity of fungal communities in different samples. The results showed that a total of 10 phyla, 125 families, and 187 genera were detected in the nine samples of this study. The main fungal phyla were Ascomycota, Basidiomycota, and Mortierellomycota. The main fungal genera are Hanseniaspora, Mortierella, Sclerotinia, Aureobasidium, Saccharomyces, Aspergillus, Clavulina, Candida, etc. Hanseniaspora was the dominant genus in the pre-fermentation stage, accounting for more than 70%; Saccharomyces was the dominant genus in the middle and late fermentation stage, accounting for more than 75% in the middle fermentation stage and up to 90% in the late fermentation stage. This study provides a theoretical basis for monitoring and optimizing winemaking processes and introducing wine grape varieties in the Linfen region of Shanxi.