Relationship Between Protein And Eating And Cooking Qualities Of Grains Of Japonica Rice

Proceeding from protein content, protein fractions content and distribution, total amino acid content and other cooking and eating quality properties of rice, the relationship between protein and cooking and eating quality of grains of japonica rice was studied. 2 experiments were designed. In field experiment, 7 varieties with different cooking and eating quality properties, Ludao 1, Dongnong 415, Dongnong 416, Fushiguang, Dongnong V7, Dongnong V10 and Tengxi 180 were grown at high and low nitrogenous nutrition levels. In pots culturing experiment, 3 varieties, Dongnong 415, Fushiguang, Dongnong V10 were grown at different temperature treament during grain filling period. The results were showed as follows.Protein content was negatively correlated with taste value of rice (r=-0.843). Peak visicosity, breakdown and setback of amylograph properties of rice was significantly correlated with protein content (r=-0.460, -0.609, 0.630 respectively) .Total amino acid content was positively correlated with taste value of rice. Although amylose content was negatively correlated with taste value of rice, the correlation did not come to significant level. In japonica rice, protein content took more effect on cooking and eating quality than amylose content.Protein content of rice increased with the temperature during grain filling period or the nitrogenous nutrition arising. A good palatability cultivar, Fushiguang was more sensitive with the temperature during grain filling period than a inferior palatability cultivar, Dongnong 415.The glutelin content of rice increased with the arising of temperature during grain filling period which indicated that higher temperature during grain filling period could raise the glutein content of japonica rice. Both prolamin content and glutelin content of japonica rice increased with the increasing of nitrogenous nutrition. The glutelin content of Fushiguang increased with a bigger margin than that of Dongnong 415, while the prolamin content of Fushiguang increased with a smaller margin than that of Dongnong 415. The albumin content and globulin content of japonica rice decreased with the deepening of degree of milling. Theglutelin content was higher at the surface layer of rice grain with 80% ratio of milled rice.Albumin content, globulin content and prolamin content of japonica rice was negatively Correlated with taste value (r=-0.702, -0.570 and -0.533, respectively). Globulin content was negtively correlated with breakdown of amylograph properties (r=-0.445). Prolamin content was negtively correlated with breakdown and peak viscosty of amylograph properties (r=-0.430 and -0.628, respectively). It fully proved that the content of albumin, globulin and prolamin played an important role on cooking and eating quality properties of rice.Luo Qiuxiang, Crop Genetics and Breeding Prof. Li Rongtian...