甜高粱籽粒与秸秆混合酒醅理化指标特征变化的研究

Study on the Physicochemical Index Variation of the Sweet Sorghum Fermented Grains Mixed with Stalks

【目的】明确甜高粱籽粒与秸秆固态发酵过程中混合酒醅温湿度变化特征,理化指标的变化规律及各因素之间的相关性。【方法】以甜高粱籽粒与秸秆为原料进行固态发酵,利用自动温湿度计对发酵温度进行实时监测,定时取样分析酒醅中酒精度、水分、总糖、还原糖、蛋白质、酸度的变化,并利用SPSS软件对酒精度与各理化指标的相关性进行分析。【结果】窖池内各个部位的酒醅温度存在差异,酒醅温度上层>中层>下层,上层酒醅升温及降温过程比中层和下层更为平缓。同一发酵层中心区域与周围区域酒醅温度变化特征不同,中心区域酒醅温度变化相对缓慢。发酵过程中酒醅湿度变化幅度为10%rh左右,酒醅湿度下层>中层>上层;酒醅湿度中心区域比周围区域变化缓慢。发酵时酒醅理化指标变化规律为:(1)酒精度先增加后降低,于156 h时达到最高值12.5%;(2)总糖、还原糖含量快速降低,于第6 d后逐渐趋于稳定;(3)发酵后酒醅蛋白质含量由5.1%增加到了8.6%,提高了68.5%。【结论】依据甜高粱籽粒与秸秆发酵过程理化指标的变化规律,选择合适的出窖蒸馏时间,可有效提高乙醇产率。利用甜高粱籽粒与秸秆固态发酵生产乙醇,不仅实现了甜高粱的能源化,还可提高甜高粱发酵残渣作为饲料的营养价值。

【Objective】The purpose of this study is to make clear the temperature,humidity change characteristics and the physical and chemical index of the sweet sorghum fermented grains and understand the correlation between the factors.【Method】Using the whole plant（ including spike） of sweet sorghum as raw materials for solid state fermentation,timing sampling and analysis the fermented grains temperature,moisture content,alcohol,total sugar,reducing sugar,protein,acidity. The correlation between alcohol and physical and chemical indexes was analyzed by SPSS software.【Result】The temperature of all parts of pits were different,the fermented grains temperature was： upper 〉middle 〉lower,and the upper fermented grains heating and cooling process went on more smoothly than the middle and lower parts. The fermented grains humidity center area changed more slowly than the surrounding areas. Change characteristics of region and its surrounding regions with a layer of fermentation of fermented grains temperature center was different. The same layer center area and the surrounding area fermented grains temperatures were different,and changes in central area of fermented grains temperature was relatively slow. The humidity of fermentation increased by 10% rh,the fermented grains humidity was： lower 〉middle 〉upper,centre of fermented grains humidity changed more slowly than the surrounding area. Fermented grains physical and chemical index change rule was：（1） The alcohol content increased first and then decreased,and at the time of 156 h it reached the highest value12. 5%;（2） The content of total sugar and reducing sugar decreased rapidly and stabilized gradually after sixth days;（3） After fermentation,protein content increased from 5. 1% to 8. 6%,which was increased by 68. 5%.【Conclusion】Based on the variation process of fermentation of sweet sorghum grain and stalk physicochemical index,the appropriate pit distillation time is selected,which can effectively improve the yield of ethanol. The production of ethanol from sweet sorghum grain and stalk in solid state fermentation not only realizes the energy conversion of sweet sorghum,but also improves the nutritional value of sweet sorghum fermentation residue as feed.