Construction Of Rice-specific Evaluation System For Brewing Huangjiu

Huangjiu was called as the national wine of our country,which has a long history;it is a good health preserving wine.The quality of raw rice is closely related to the quality of Huangjiu.With the improvement of people's living standard and the continuous development of Huangjiu industry,the market competition of Huangjiu is becoming more and more fierce.The traditional brewing model has been unable to meet the people's demand for high-quality consumption,and the traditional artificial sensory evaluation of Huangjiu has a large subjective and human disturbance factors,so it is of great significance for enterprises to explore new analysis methods to control the taste and quality of Huangjiu Generally,glutinous rice and japonica rice are used as the main raw materials for Huangjiu brewing.The existing national rice standards can not effectively evaluate the quality of Huangjiu raw materials.Generally,companies will follow the past experience to select glutinous rice and japonica rice as the main raw materials for Huangjiu brewing.There is no targeted study on the correlation between Huangjiu quality and rice,which is not conducive to improving the quality of Huangjiu rice raw materials and Huangjiu,so it is necessary to explore the index of rice that affects the quality of Huangjiu.Pattern recognition methods such as principal component analysis and cluster analysis can effectively find the physical and chemical indicators of raw rice that affect the quality of Huangjiu,and plays a certain guiding role in finding the suitable rice for Huangjiu brew.As a new artificial intelligence taste analysis instrument,electronic tongue has the advantages of objective results,simple operation,high efficiency and strong practicality.It is widely used in soy sauce,meat products,beverages and alcoholic foods.Whether Huangjiu electronic tongue taste signals can predict the basic physicochemical indexes of Huangjiu is worth discussing.Therefore,this paper takes Huangjiu rice raw materials as the research object,combines multiple linear regression analysis and other pattern recognition methods to explore the key indicators of raw rice that affect the quality of Huangjiu,and analyzes the range of key indicators of raw materials suitable for Huangjiu processing;based on electronic tongue technology,the equation model of Huangjiu taste score and basic physical and chemical indexes of Huangjiu was analyzed,and the correlation between electronic tongue signal score and basic physical and chemical indexes of Huangjiu was analyzed.The main research results are as follows:(1)Compared with the traditional brewing technology,the liquefying method has the characteristics of high utilization rate of raw materials,more complete fermentation,energy saving and emission reduction,and clean production.The specific process is:raw rice?grinding?screening?liquefaction?saccharification?inoculation?fermentation?filtration?centrifugation?finished product.(2)32 kinds of rice were selected to make Huangjiu,and 32 kinds of rice basic nutrients and gelatinization characteristics were detected by chemical analysis.The results showed that the water content,protein content,fat content,crude starch content and amylose content were 11.52?16%,5.91?9.29%,0.73?1.50%,78.84?89.95%and 0.9-23.4%respectively.Among 32 gelatinization indexes,peak viscosity distribution ranges from959.67 to 3763.50 Pa·s,minimum viscosity distribution was 449.70?1957.00 Pa·s,final viscosity distribution was 581.33?3505.5 Pa·s,the breakdown value was 109.00?1807.00Pa·s,the setback value was 131.67?1549.00 Pa·s,the gelatinization temperature was69.15-87.57 Pa·s,the relative standard deviation of all indexes is more than 5%,which shows that there are significant differences in the basic nutrients and gelatinization characteristics of different rice standards,and the selection of samples is representative.(3)Through correlation analysis,the relationship between nutritional components and gelatinization characteristics of rice,the relationship between nutritional components of raw rice and basic components of Huangjiu,and the relationship between gelatinization characteristics of rice flour and the basic components of Huangjiu were explored.The results showed that there was a significant positive correlation between water content and p H,a significant positive correlation between protein and fat and non sugar solids,and a significant negative correlation between crude starch and amylose content and non sugar solids.The peak viscosity of the gelatinization index of rice flour has a significant positive correlation with total sugar content and alcohol content of Huangjiu,a significant negative correlation with total acid and non sugar solid content of Huangjiu,a significant positive correlation with the minimum viscosity and alcohol content,a significant negative correlation with the final viscosity and the non sugar solid,a significant negative correlation with breakdown and the non sugar solid,and a significant negative correlation with setback,in addition,there was a significant negative correlation between non sugar solids and gelatinization temperature.(4)Based on regression analysis and cluster analysis,from the comprehensive score of brewed Huangjiu,the selection of suitable Huangjiu brewing rice and the selection of rice correlation indexes that affect the quality of Huangjiu,the comprehensive score of Huangjiu was obtained,and the relevant indicators and factors affecting Huangjiu brewing were determined.The related equations of rice physical and chemical indicators,and the feasibility and application scope of the method are analyzed.Among the comprehensive scores of Huangjiu,Sample 1,Sample 2,Sample 9,Sample 16,Sample 19 and Sample 21have the highest scores,respectively 2.17,1.71,1.56,1.40,1.32 and 1.18,which is suitable for Huangjiu brewing;sample 8 of rice samples,Sample 13,Sample 14 and Sample 15brewed Huangjiu had the lowest comprehensive score,with scores of-1.19,-1.57,-1.96and-2.08,respectively.(5)The relevant indexes affecting the brewing of Huangjiu were determined as the moisture content,crude starch content and fat content,as well as peak viscosity,breakdown,setback and gelatinization temperature.The correlation model between Huangjiu comprehensive score and rice index was established,the decision coefficient R~2of obtained model was 0.77,which was higher than 0.75,indicating that the model had good performance and could effectively and quickly predict Huangjiu quality by detecting rice index.When water content is less than 11.86%,crude starch content is more than34.15%,fat content is less than 1.40%,peak viscosity is more than 2319 Pa·s,breakdown is less than 684.33 Pa·s,setback is less than 343.33 and gelatinization temperature is less than 78.72?,the quality of Huangjiu is better.The correlation model between Huangjiu comprehensive score and rice was established.The decision coefficient R~2of the model was 0.771,higher than 0.750,which indicated that the model had good performance and could effectively and rapidly predict the quality of Huangjiu by detecting rice index.(6)The method for measuring the electronic tongue of Huangjiu has been optimized.The best conditions are as follows:selecting six indicators for sourness,bitterness,astringency,umami,salty taste,bitterness and aftertaste for measurement can simplify the testing process and improve the analysis efficiency.The data screening method of the Huangjiu sample is 6 parallel tests performed by the electronic tongue,and the data from the 4th to 6th parallel determination is selected for analysis,which can achieve good test results and ensure the high efficiency of the test.(7)Through correlation analysis,the relationship between basic physical and chemical indexes of Huangjiu and electronic tongue taste score of Huangjiu was explored.The results showed that total sugar content of Huangjiu had a very significant negative correlation with acidity,saltiness and astringency of Huangjiu.It has a very significant positive correlation with umami;the p H of Huangjiu has a very significant negative correlation with acidity.There is a positive correlation between total acid and Huangjiu acidity and astringency,and it is negatively correlated with umami and salty taste of Huangjiu;Alcohol content is associated with acidity,astringency and freshness of Huangjiu.There is a very significant positive correlation between taste and a very significant negative correlation with the salty taste of Huangjiu;the content of non-sugar solids in Huangjiu has a very significant negative correlation with the acidity of Huangjiu;the content of amino acid nitrogen in Huangjiu has a significant relationship with the bitterness of Huangjiu Negative correlation.The relationship between physicochemical properties and electronic tongue taste of Huangjiu was explored by correlation analysis.The results showed that total sugar content had a significant negative correlation with acidity and saltiness of Huangjiu,and a significant positive correlation with the astringency and freshness of Huangjiu;p H value of Huangjiu had a significant negative correlation with acidity of Huangjiu,and a significant correlation with astringency,freshness and saltiness of Huangjiu.There was a significant positive correlation with astringency and the bitter aftertaste of Huangjiu;there was a significant positive correlation between total acid,sour taste and astringency of Huangjiu,and a significant negative correlation with fresh taste and salty taste of Huangjiu;there was a significant positive correlation with sour taste,astringency and salty taste of Huangjiu,and a significant negative correlation with salty taste of Huangjiu.There was a significant negative correlation between the content of solid substance and sour taste of Huangjiu,and a significant negative correlation between amino acid nitrogen content and bitter taste of Huangjiu.(8)When establishing the correlation model between the electronic tongue signal scores of the six taste indicators and the basic physical and chemical indicators of Huangjiu,the partial least squares method has a high fitting accuracy and the determination coefficients of the obtained models are all higher than 0.75,and the model performance good,can effectively and quickly predict the basic physical and chemical indicators of Huangjiu.