米酸汤发酵工艺优化及贮存稳定性预测模型

Research on the optimization of fermentation technology and the prediction model of storage stability of rice acid soup

该文研究米酸汤最优发酵工艺及米酸汤稳定性动力学和热力学模型,以取代传统米酸汤自然发酵工艺并延长产品的保质期。以发酵时间、菌种接种量、发酵温度以及初始pH值为自变量,进行单因素实验,再以总酸为响应值,进行响应面分析,得到米酸汤最佳发酵工艺条件。研究不同温度(25、35、45℃)对米酸汤品质的影响,通过分析离心沉淀率、粒径、色差值、黏度、pH值和感官评分等指标,建立动力学及热力学模型。优化后工艺条件参数为发酵时间104 h、接种量为5%、发酵温度为36℃、初始pH 6.6,在此条件下,R 2=0.97,总酸(9.48±0.08)g/L,与模型预测值9.43 g/L基本一致。在贮存期间离心沉淀率、色差值与感官评分的相关性最高,R 2均>0.98。该文建立离心沉淀率、色差值与感官评分、温度之间的动力学及热力学模型,计算出离心沉淀率和色差值预测模型误差CV平均值分别为13.46%、6.07%,均<15%。响应面法优化米酸汤配方切实可行,能缩短发酵周期,提高产品质量,对于米酸汤生产具有良好的实践参考价值。该模型可以用于米酸汤贮存稳定性预测,为米酸汤提供一种贮存稳定性快速预测方法。

In order to replace the traditional fermentation process and extend the shelf life,the optimal fermentation process,stability kinetics and thermodynamics model of rice acid soup were investigated.The fermentation time,inoculum proportion,fermentation temperature and initial pH value were taken as independent variables to perform single-factor experiment.Then the total acid was used as the response value to conduct response surface analysis to obtain the optimal fermentation conditions of rice acid soup.The effects of different temperatures(25,35 and 45℃)on the quality of rice acid soup were studied.Kinetic and thermodynamic models were established by analyzing centrifugal precipitation rate,particle size,chromatic aberration,viscosity,pH value and sensory scores.The optimized process parameters were fermentation time 104 h,inoculum amount 5%,fermentation temperature 36℃,and initial pH 6.6.Under this condition,its R 2 was 0.97,and the total acid was(9.48±0.08)g/L,which was basically consistent with the model predicted value of 9.43 g/L.The centrifugal precipitation rate and chromatic aberration value during storage had a strong correlation with the sensory score,and the R 2 was higher than 0.98.Kinetic and thermodynamic model of the precipitation rate,chromatic aberration,sensory score and temperature were established.The calculated mean value of error CV of centrifugal precipitation rate and chromatic aberration prediction model were 13.46%and 6.07%,respectively,which were less than 15%.The response surface method is feasible to optimize the formula of rice acid soup,which can shorten the fermentation period and improve the product quality.The model can provide a rapid prediction method to predict the storage stability of rice acid soup.