料水比是影响半固态法白酒发酵品质的关键参数之一,但料水比对半固态法白酒品质形成的影响尚不清晰。因此,该研究采用“先固态培菌糖化,后加水液态发酵”的发酵工艺,设置4个料水比水平(2∶1、2∶2、2∶3、2∶4,g∶mL),监测发酵过程的温度、pH、还原糖及乙醇含量等动态变化,并结合GC-MS分析主要挥发性风味物质的生成特征,系统考察了料水比对白酒发酵过程的影响规律。结果表明,各料水比发酵组均呈现出典型的动力学变化特征,且料水比对发酵速率与代谢效率的变化呈现显著影响(P<0.05)。与高料水比组(2∶1)相比,低料水比组(2∶4)体系温度整体较低且波动幅度较小,表现出更强的热稳定性,尤其在发酵前期(d0~d3),2∶1组体系升温速率为2∶4组的1.35倍。随发酵进行,各组pH值均呈先降后升规律,且低料水比组表现出更低的pH值,尤其是在发酵第3天,pH与体系含水量呈显著线性负相关(R2=0.99),水分每增加10%,pH值平均下降约0.11,表明体系含水量越高,酸化程度越强。还原糖与乙醇含量动态变化结果显示,在d1~d2发酵初期阶段低料水比组(2∶4)的还原糖消耗速率较高料水比组提升约3.4倍,表明高含水体系糖化及发酵启动更早。乙醇生成规律与之相反,具体表现为2∶2、2∶3及2∶4组均在发酵第5天达到乙醇峰值(约150 mg/g),而高料水比的2∶1组则滞后至第7天才达到峰值(137.44 mg/g),且最终产量较前者低13.20%。这表明,适度增加体系含水量能有效促进乙醇的生成并缩短发酵周期;挥发性风味物质含量亦随料水比降低显著上升,尤其醇类与酯类含量增加约2倍,显示较高含水量有利于风味物质的合成与积累。该研究明确了料水比通过调节发酵体系的传质传热特性以及微生物代谢活性从而影响半固态白酒的发酵效率与稳定性,为其工艺优化与质量控制提供理论依据。
The material-to-water ratio (MWR) is one of the key parameters affecting the quality of semi-solid fermentation Baijiu.However, the effects of material-to-water ratio on the formation of its quality remain unclear.To clarify these effects, fermentation was carried out using a process involving solid-state saccharification followed by liquid-state fermentation at four MWRs (2∶1, 2∶2, 2∶3, and 2∶4, g∶mL). Dynamic changes in temperature, pH, reducing sugar, ethanol contents and so on were monitored, and volatile flavor compounds were analyzed by GC-MS to systematically investigate the effect of MWR on the fermentation process of Baijiu.The results showed that all fermentation groups exhibited typical kinetic patterns, and the MWR had a significant effect on fermentation rate and metabolic efficiency (P<0.05).Compared with the high-MWR group (2∶1), the low-MWR group (2∶4) showed a lower overall temperature and smaller thermal fluctuations, indicating greater thermal stability.In the early fermentation stage (d0-d3), the temperature rise rate of the 2∶1 group was 1.35 times that of the 2∶4 group.During fermentation, the pH in all groups followed a “decrease-increase” trend, and the low-MWR group maintained a lower pH.At the mid-fermentation stage (d3), pH was significantly and negatively correlated with system moisture content (R2=0.99);a 10% increase in water content led to an average pH decrease of about 0.11, indicating stronger acidification under higher moisture conditions.Dynamic changes in reducing sugar and ethanol showed that in the early fermentation stage (d1-d2), the reducing sugar consumption rate in the low-MWR group (2∶4) was about 3.4 times higher than that in the high-MWR group (2∶1), suggesting that higher moisture accelerated saccharification and fermentation initiation.Ethanol accumulation followed the opposite pattern:the 2∶2, 2∶3, and 2∶4 groups reached ethanol peaks about 150 mg/g on d5, whereas the 2∶1 group reached a lower peak (137.44 mg/g) on d7, with 13.20% less ethanol yield.This indicates that a moderate increase in system moisture effectively enhances ethanol production and shortens the fermentation period.The total content of volatile compounds also increased significantly with decreasing MWR, especially alcohols and esters, which approximately doubled, indicating that higher moisture promotes the synthesis and accumulation of flavor compounds.This study elucidates that MWR influences the fermentation efficiency and stability of semi-solid Baijiu by regulating heat and mass transfer characteristics and microbial metabolic activity, providing a theoretical basis for process optimization and quality control.
[1] Liu H L, Sun B G.Effect of fermentation processing on the flavor of Baijiu[J].Journal of Agricultural and Food Chemistry, 2018, 66(22):5425-5432.
[2] 陈平生, 梁思宇.豉香型白酒酿造工艺的研究进展[J].酿酒, 2022, 49(6):5-10.
Chen P S, Liang S Y.Research progress of Chi Xiang Xing Baijiu brewing technology[J].Liquor Making, 2022, 49(6):5-10.
[3] Zheng X W, Han B Z.Baijiu (白酒), Chinese liquor:History, classification and manufacture[J].Journal of Ethnic Foods, 2016, 3(1):19-25.
[4] Ma R F, Sui L, Zhang J S, et al.Polyphasic characterization of yeasts and lactic acid bacteria metabolic contribution in semi-solid fermentation of Chinese Baijiu (traditional fermented alcoholic drink):Towards the design of a tailored starter culture[J].Microorganisms, 2019, 7(5):147.
[5] Jin G Y, Zhu Y, Xu Y.Mystery behind Chinese liquor fermentation[J].Trends in Food Science & Technology, 2017, 63:18-28.
[6] Gervais P, Molin P.The role of water in solid-state fermentation[J].Biochemical Engineering Journal, 2003, 13(2-3):85-101.
[7] Wang H, Sun C H, Yang S Z, et al.Exploring the impact of initial moisture content on microbial community and flavor generation in Xiaoqu Baijiu fermentation[J].Food Chemistry-X, 2023, 20:100981.
[8] 曹新志, 宋泽丽, 胡琴,等.苦荞小曲酒半固态发酵工艺优化及挥发性风味成分分析[J].中国酿造, 2023, 42(2):102-107.
Cao X Z, Song Z L, Hu Q, et al.Optimization of semi-solid fermentation process and volatile flavor components analysis of tartary buckwheat Xiaoqu Baijiu[J].China Brewing, 2023, 42(2):102-107.
[9] 黄河, 黄婷, 王媚,等.新型黄酒发酵工艺条件优化[J].中国酿造, 2022, 41(7):179-184.
Huang H, Huang T, Wang M, et al.Optimization of the fermentation process conditions of new-type Huangjiu[J].China Brewing, 2022, 41(7):179-184.
[10] Wu X Q, Zhang Y Z, Zhong Q P.Optimization of the brewing conditions of shanlan rice wine and sterilization by thermal and intense pulse light[J].Molecules, 2023, 28(7):3183.
[11] 侯亚丽, 刘好静, 萧犹睿,等.不同料水比对混菌发酵玉米皮品质的影响[J].饲料研究, 2024, 47(15):108-111.
Hou Y L, Liu H J, Xiao Y R, et al.Effect of different material to water ratios on quality of mixed-culture fermentation of corn husk[J].Feed Research, 2024, 47(15):108-111.
[12] 陈金明, 李祎乐, 张晨雷,等.气相色谱法测定花露水中乙醇含量[J].广州化工, 2024, 52(16):35-37.
Chen J M, Li Y L, Zhang C L, et al.Determination of ethanol content in Florida water by gas chromatography[J].Guangzhou Chemical Industry, 2024, 52(16):35-37.
[13] 崔新莹, 吕志远, 张梦梦,等.基于主成分分析法构建浓香型白酒香气分类模型[J].酿酒科技, 2024(2):17-24.
Cui X Y, Lyu Z Y, Zhang M M, et al.Construction of aroma classification model of Nongxiang Baijiu based on principal component analysis[J].Liquor-Making Science & Technology, 2024(2):17-24.
[14] Sun D D, Li W X, Luo L X.Deciphering the brewing process of Cantonese-style rice vinegar:Main flavors, key physicochemical factors, and important microorganisms[J].Food Research International, 2023, 171:113068.
[15] Altwasser V, Pätz R R, Lemke T, et al.A simple method for the measurement of metabolic heat production rates during solid-state fermentations using β-carotene production with Blakeslea trispora as a model system[J].Engineering in Life Sciences, 2017, 17(6):620-628.
[16] Shen C, Yu Y Y, Zhang X, et al.The dynamic of physicochemical properties, volatile compounds and microbial community during the fermentation of Chinese rice wine with diverse cereals[J].Food Research International, 2024, 198:115319.
[17] Liang Z C, Lin X Z, He Z G, et al.Dynamic changes of total acid and bacterial communities during the traditional fermentation of Hong Qu glutinous rice wine[J].Electronic Journal of Biotechnology, 2020, 43:23-31.
[18] Peng Q, Li L Y, Xie G F.Impact of glutinous rice varieties from different regions on microbial community structure, metabolic profiles, and flavor characteristics of Chinese rice wine (Huangjiu)[J].Foods, 2025, 14(7):1261.
[19] Xia G H, Wu C R, Zhang M Z, et al.The metabolome and bacterial composition of high-moisture Italian ryegrass silage inoculated with lactic acid bacteria during ensiling[J].Biotechnology for Biofuels and Bioproducts, 2023, 16(1):91.
[20] Hu Y L, Lei X Y, Zhang X M, et al.Characteristics of the microbial community in the production of Chinese rice-flavor Baijiu and comparisons with the microflora of other flavors of Baijiu[J].Frontiers in Microbiology, 2021, 12:673670.
[21] Li C.Recent progress in understanding starch gelatinization - An important property determining food quality[J].Carbohydrate Polymers, 2022, 293:119735.
[22] Gabelle J C, Jourdier E, Licht R B, et al.Impact of rheology on the mass transfer coefficient during the growth phase of Trichoderma reesei in stirred bioreactors[J].Chemical Engineering Science, 2012, 75:408-417.
[23] Yin X, Yoshizaki Y, Kurazono S, et al.Characterization of flavor compounds in rice-flavor Baijiu, a traditional Chinese distilled liquor, compared with Japanese distilled liquors, awamori and kome-shochu[J].Food Science and Technology Research, 2020, 26(3):411-422.
[24] Walker G M, Stewart G G.Saccharomyces cerevisiae in the production of fermented beverages[J].Beverages, 2016, 2(4):30.
[25] 余洁瑜, 刘功良, 白卫东,等.米香型白酒的研究进展[J].中国酿造, 2021, 40(1):29-32.
Yu J Y, Liu G L, Bai W D, et al.Research progress on rice-flavor Baijiu[J].China Brewing, 2021, 40(1):29-32.
