Effect Of Processing Degree On Rice Nutritional And Eating Quality

Rice is one of the most important grain rations in our country.With the improvement of life situation,people's excessive pursuit of its appearance and eating quality lead to the phenomenon of excessive processing of rice,resulting in a large loss of nutrients in rice.Meanwhile,undermilled rice is not accepted by customers for its bad taste.The appropriate processing of rice has been taken more and more attention by the relevant state departments.Hubei Ezhou,Hunan Linli,Jiangxi Xingan late long-grain nonglutinous rice and Yunnan Kunming japonica rice are used as the research object.On the basis of the determination of processing degree of four kinds of rice with different processing links,the nutritional quality and eating quality of rice with different processing precision were studied.The research results show that:(1)The processing degree and the milling rate of different varieties of rice were different in the same process.With the deepening of the processing,the processing degree of rice was higher,and the rice milling rate decreased gradually.The processing degree of four kinds of finished rice was the first level,and the rice milling rate was 89.2%,88.3%,88.6% and 87.2% respectively.(2)In the processing of all links,the moisture content of Hubei Ezhou,Hunan Linli late long-grain nonglutinous rice and Yunnan Kunming japonica rice changed little,the moisture content of Jiangxi Xingan late long-grain nonglutinous rice increased with the improvement of processing degree;The crude fat,crude protein,crude fiber and ash content of four kinds of rice decreased with the increase of processing degree.In the early stage of rice processing,the content of four kinds of nutrients decreased rapidly,when the milling rate reached approximately 90%,when the rice processing precision reached the national level of the standard,the content of the four nutrients remained unchanged.The content of four kinds of rice starch increased with the increase of the milling degree,and the content of rice starch increased rapidly when the milling rate was from 100% to 90%.(3)The peak viscosity,the minimum viscosity,breakdown and the final viscosity of the four kinds of rice increased with the decrease of milling rate of rice.The setback showed a decrease with the decrease of milling rate of rice.The appearance,taste and comprehensive score of the four kinds of rice showed an increasing trend,and the scores of the three indexes increased rapidly before reaching a certain degree.After that,the indexes are basically stable;the hardness of rice decreased with the decrease of the milling rate,when the viscosity increased.In the early stage,the change of hardness and viscosity was bigger,and the change of the two values was decreased after reaching a certain degree of milling.The sensory quality of rice increased with the increase of processing degree.In the early stage of rice milling,the sensory score of rice rose faster,and the score gradually became unchanged after the processing degree reached the national second grade rice standard.(4)The correlation analysis between the gelatinity index and the sensory characteristics of the rice,the taste index of the rice,and the sensory characteristics were analyzed.The results showed that the peak viscosity had a significant positive correlation with the odor,palatability,taste,cold rice texture and sample score in the sensory quality.The setback was negatively correlated with the rice odor,and significant negatively correlated with the palatability,taste,cold rice texture and sample score.There was a significant negative correlation between the comprehensive score of rice taste identification group and other indexes except sensory evaluation in sensory evaluation.The hardness was positively correlated with most sensory quality indexes,and the viscosity was positively correlated with the taste,when it was significant positively correlated with the rice odor,sensory evaluation score.Indicating that the gelatinization characteristics and taste identification group score can well reflect the changes in rice food quality.