HARDNESS OF COOKED RICE AS AFFECTED BY VARIETIES, COOLING METHODS AND CHILL STORAGE
Rice is an important carbohydrate source in daily catering, and also one of the main components in some ready meals. Ready meals containing cooked rice should be cooled quickly for storage. In this research, air blast cooling and cold room cooling were used to cool cooked rice. The effect of cooling condition, rice variety and chill storage on the textural property, especially hardness, of cooked rice was investigated. Results show that air blast cooling can significantly reduce the cooling time and weight loss as compared with cold room cooling for the three varieties (Thai jasmine rice, long grain rice and Japanese rice). The cooling methods can also significantly affect the hardness of cooked rice depending on the rice variety. Thai jasmine rice has lower amylose content; therefore, hardness was generally lower than that of the other two varieties. During the chill storage at 4C, the hardness was increased for all samples except for cooked Thai jasmine rice cooled by air blast cooling, indicating that fast cooling time can inhibit or slow down the starch retrogradation during chill storage for low-amylose-content rice. PRACTICAL APPLICATIONS
In the food industry, ready meals are usually kept at 4 or −18C for longer shelf life. However, the retrogradation of rice starch takes place very easily during the storage, and storage temperature can significantly affect the behavior of cooked rice. In both domestic and international markets, the end-use quality of rice has significant impact on its market value and acceptability to consumers. Therefore, the behavior of cooked rice is interesting to food scientists and technologists because it profoundly affects the quality, acceptability and shelf life of the rice-containing dishes. The current research will provide further information for the food industry on the effect of cooling condition, rice variety and chill storage on the textural property, especially hardness, of cooked rice.
Document Type: Research Article
Affiliations: College of Food Science and EngineeringHarbin Institute of TechnologyHarbin, China
Publication date: April 1, 2009