Evaluation of the best cooking method for some of improved rice varieties.

Cooking quality is very important for Iranian rice consumers. Some of factors such as Amylose content, Gelatinization temperature and gel consistency effect on cooking quality indirectly. Breeders adjust these factors in normal range as consumers gustatory. But after harvest, information about cooking method is very important for each variety because the appearance of cooked rice is important for selection a variety. In this research for evaluating of cooking quality, some of improved varieties (Dorfak, Kadoos, Khazar and Hybrid) were selected and evaluated. In this project for finding best cooking method , time of soaking in 8 levels and the ratio of water to rice in 2 levels (maximum and optimum of water) were established and then cooking properties such as increasing length(elongation) and width after cooking, time cooking, volume expansion, water absorption and solid loss were measured in 3 replicates. In this research we find that the best method for cooking also can be used besides of other traits for introducing a variety. In the end, correlations between chemical traits with cooking properties were evaluated for predicting of cooking quality for other varieties. For this reason fifty Iranian varieties were selected and then the correlation between physicochemical traits and cooking properties was evaluated with Spss software. In this research, elongation showed a positive correlation with protein content and a negative correlation with amylose content Since Iranian consumers cook rice with extra amount of water, because of nutrition value, solid loss is an important trait. Solid loss was mainly influenced by the L/W ratio and amylose content. Solid loss showed a negative correlation with amylose content and positive correlation with Chalkiness. Water uptake is fewer in improved varieties with low gelatinization temperature (7). . Key words: Rice, Physicochemical properties, Elongation, Time cooking, Volume expansion, Water absorption, Solid loss ٤٢