The effect of Thai glutinous rice cultivars, grain length and cultivating locations on the quality of rice cracker (arare)

Physicochemical and thermal properties of two Thai glutinous rice cultivars (RD6 and Short Grain) differing in grain length (whole grain and broken rice) and cultivating locations (the upper northeastern and the middle northeastern regions) and the quality characteristics of glutinous rice cracker produced from them were studied. RD6 cultivar was different in amylose content, gel consistency, volume expansion and hardness of rice cracker with those of Short Grain cultivar. Broken rice significantly gave greater amylose content, harder cool gel texture, less swelling, lower volume expansion and harder texture of rice cracker than whole grain rice. Furthermore, structure of starch molecule of broken rice differed from that of whole rice. The physicochemical, thermal properties and the qualities of rice crackers of RD6 cultivated from the upper northeastern and the middle northeastern regions showed no significant difference. To obtain good qualities of rice cracker, the rice should have lower amylose content, softer cool paste texture, greater breakdown value and less setback of amylogram. Amylose content and alkali gel consistency (120 mg flour) were significantly correlated with several other rice properties. The analysis of both properties is useful for the industry in controlling the quality of glutinous rice being used as raw material.