Cailin Kong,Yun Wu,Qi Zhang,Faisal Eudes Sam,Aihua Li,Yongsheng Tao
Extended wine storage often leads to a reduction in volatile compounds, diminishing the fruity aroma. Yeast mannoproteins (MPs) have been identified as a mitigating factor against this effect, although the mechanisms involved remain poorly understood. This study examines the impact of MPs from Pichia strains, noting differences in chemical composition and structure, on the volatility of wine fruity esters. Gas chromatography, high-performance liquid chromatography, and Fourier transform infrared spectroscopy were used to analyze MPs from Saccharomyces cerevisiae SC-19 (MP-SC), Pichia fermentans Z9Y-3 (MP-PF), and Pichia kluyveri MP-PK. The influence of MPs on wine ester volatility was further explored through headspace solid-phase microextraction and gas chromatographic-mass spectrometry, alongside thermodynamic assessments. The findings revealed that mannose predominates in the monosaccharide composition of MPs, with MP-SC presenting the highest mannose levels. MP-PF and MP-PK, however, exhibited higher protein concentrations and significantly more hydrophilic amino acids, contributing to a 3–6-fold reduction in ester volatility compared with MP-SC, likely due to enhanced van der Waals forces and hydrogen bonding.
Xiao Hong Tang,Yan Ding,Ke Zhong,Yu Xia Sun,Xiao Mei Han,Zhi Yu Li,Rui Rui Li
The majority of aroma precursors in grapes exist as odorless glycosidic conjugates, which can be hydrolyzed by β-glucosidase to release free volatile aroma compounds, thereby enhancing the aromatic quality of wine. This study aimed to screen and characterize indigenous non-Saccharomyces cerevisiae strains with β-glucosidase activity for their potential to enhance terpenoid aroma compounds during wine fermentation. Grapes collected from 14 vineyard plots in the Penglai Wine Region (China) underwent spontaneous fermentation and yielded 203 single colonies. Among them, 85 strains of non-Saccharomyces cerevisiae were initially screened based on the geniposide chromogenic method, which were classified into 7 genera and 16 species. Nine high-performance strains were subsequently selected for small-scale fermentation trials using Petit Manseng grape juice. The physicochemical parameters of wines were analyzed by high-performance liquid chromatography (HPLC), while volatile aroma compounds were quantified using a headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC–MS). The results revealed that Starmerella bacillaris CGCD1-9, Pichia fermentans CGCD1-4, and Zygosaccharomyces bailii JDCD01 significantly enhanced glycerol production, which might contribute to improved wine sensory quality. Four Hanseniaspora yeast strains exhibited the ability to increase ethyl acetate content. Among these strains, Hanseniaspora vineae CGCD1-1, Hanseniaspora uvarum CGCD1-3, and Hanseniaspora opuntiae CGCD1-7 showed a pronounced tendency to elevate geraniol levels, whereas Hanseniaspora occidentalis CGCD1-5 selectively promoted the biosynthesis of β-damascenone and 2-furanmethyl acetate. Zygosaccharomyces bailii JDCD01 primarily increased the levels of isobutanol and phenylethyl alcohol, while also exhibiting a slight enhancement in terpenoid production. Notably, S. bacillaris CGCD1-9 significantly enhanced five key terpenoids, namely, linalool, geraniol, citronellol, α-terpineol, and nerolidol, yielding the highest total terpene content among all strains, while increasing the content of alcohols (less than JDCD01). In contrast, Issatchenkia terricola SIVE4101 and Metschnikowia andauensis LFSY0-17 showed preferential accumulation of β-damascenone and total furans, with the former also significantly increasing the acetate ester content. This study provides new ideas and theoretical support for r developing targeted co-inoculation protocols with S. cerevisiae to achieve precise modulation of wine terpenoid profiles.
危险品化学品经营许可证（带存储）