Comparison of sensory properties of freshly harvested and 1-year storage Thai rice

Abstract

Thailand is a major producer and world supplier of rice, both aromatic and non-aromatic varieties. Rice sold as “new crop” shortly after it is harvested generally commands higher prices. The study compared differences in sensory properties of various aromatic (Khao Dawk Mali 105, RD 15, Pathum Thani 1) and non-aromatic (Chai Nat 1, Phitsanulok 2, Suphan Buri 1) rice varieties and differences in fresh rice and rice stored for 1 year. Floral, popcorn, and sewer/animal flavors were found in both rice samples but jasmine rice had higher intense of floral aroma and was the only aroma that decreased overtime. The texture of jasmine rice samples were more adhere to lips, grain to grain, softer and more intense of cohesiveness of mass than non-aromatic rice. There were three attributes; residual, toothpacking, sweet, from nineteen attributes were not different between jasmine and non-aromatic rice and not changed overtime. Most of the texture attributes were not changed after one year of storage except cohesiveness of mass and starchy mouthcoating that reduced after storage. There were not a significantly differences for most of the flavor attributes except musty flavor between jasmine and non-aromatic rice samples within the same testing year such as grain, straw-like, starch, popcorn flavor, sweet, overall sweet, bitter and metallic. The changes of the flavor like grain and straw-like were decreased from their original intense; while, musty flavor and bitter taste were increased.