Construction Of Rice Quality Index System And Verification Of Screened Characteristic Index

Rice Quality(RQ)refers to the characteristics of rice as food or commodity in the whole process from rice production to processing into direct consumer goods.Rice quality indicators are complex and diverse.The contribution of rice quality indicators with different uses to the overall quality is not equal,nor does it act independently,but influences and restricts each other.These indicators constitute the "complexus" of agricultural quality,but there is still a lack of scientific and practical evaluation methods.Based on this,this thesis take rice as the research object,combing the quality evaluation index,evaluation method and evaluation basis,building based on the different uses of rice quality index system,and analysis of different regions and main variety rice quality difference,filtering based on the characteristic of different uses rice quality indicators,to promote the quality evaluation of rice to the specification.The main research contents and results are as follows:1.Construction of quality indicatorsFirstly,the rice quality indexes were comprehensively sorted out,and then the rice users(consumers,related industry practitioners)and industry experts were surveyed by Delphi evaluation method.Then,the order relationship analysis method(G1 method)was used to process the questionnaire results,and finally,the rice quality evaluation index system based on different industrial uses was formed.The results showed that the quality evaluation index system of edible commercial rice was taste value,brown rice rate,milled rice rate,etc.Starch content,protein content and gelatinization temperature were used to evaluate rice quality.The quality evaluation index system of rice for fermentation products was starch content,protein content,amylose content,etc.The quality evaluation index system of rice used for rice flour processing products includes starch content,protein content,gelatinization temperature,etc.2.Study on rice quality difference in different producing areas and varietiesAccording to the rice quality evaluation system of different uses,representative samples and quality indexes of dominant rice producing areas and main varieties were tested.The results showed that:in the nutritional quality indicators,the average protein content of the 280 participating rice varieties was 7.31%,the coefficient of variation was 16.58%,this indicates that the protein content varies greatly between different varieties.Among them,Hunan early indica 45 is the highest,it reached 11.3%,the content of Shennong 625 is only 5.03%;in the food and taste quality indicators,the average food taste value of the tested rice varieties was 78.10 points,the coefficient of variation was 7.32%,food taste values vary little between different varieties,Jihong No.6 has the highest food taste value,it reached 90 points,Zhongzao 33 was only 63 points;in the processing quality indicators,the average roughness rate of all rice samples was 80.84%,the variation range ranged from 76.00%to 87.60%,the coefficient of variation was 2.05%,it indicates that there is little difference in the roughness rate between the different varieties,among,Nanjing 5055,Shennong 511 and Yongyou 15 varieties have a large roughness rate,this total data rate was 84.30%,84.50%,87.60%,respectively;in the commodity quality indicators,the average finishing rice rate of the tested rice varieties was 58.30%,from 39.11%to 72.54%,the coefficient of variation was 11.62%,the whole finishing rice rate varies little between different varieties.3.Selection of characteristic quality indexes and determination of superior producing areas and optimum varietiesThrough the sample collection and evaluation of the dominant producing regions and the main planting varieties,the main component analysis method(PCA)was used to determine the dominant producing regions and the optimal varieties of rice with different uses,and the characteristic quality indexes of rice with different uses were selected.The results show that the dominant producing areas of rice products are the southeast coastal areas(Guangdong and Guangxi)and the Yangtze River Basin(Jiangxi),high-quality varieties are Zhengui(Guangdong),Chun Liangyou 61,Ling Liangyou 722,and the characteristic quality indexes are the glue consistency,the highest viscosity,the resistant starch content and the protein content;the dominant producing area of rice for fermentation products is the rice advantage in the Yangtze River Basin(Anhui),high-quality varieties are Wanxiangyou,Jingliangyou,Longliangyou,and the characteristic quality indexes are the saccharification performance and the reduced sugar content;the dominant producing areas of rice for edible commercial rice are the rice dominant areas in Northeast China(Heilongjiang)and the rice dominant areas in the Yangtze River Basin(Yunnan),high quality varieties are Longjing 31,Nei 6 you 5182,Jingyou No.3,Dianheyou 918,and the characteristic quality indicators are food taste value,protein,smell;the dominant producing area of irrigated rice noodles is the rice advantage area in the southeast coast(Guangdong and Zhejiang),high quality varieties are Huanghuazhan,Yexiangsimiao,Zhejingyou 122,and the characteristic quality indexes were food taste value,alkali elimination value,protein content and amylose content.To sum up,the rice quality index system has good practical and scientific values,which can provide reference and basis for the rice quality differences of different advantageous producing areas and main varieties,screen the characteristic index system for different uses,and is helpful to realize the comprehensive evaluation and effective application of rice quality.