Effect of Coating Substance on Texture and Retrograded Properties of Frozen Cooked Brown Rice

Abstract

Three rice varieties : Niaw San-Pah-Tong (Br1), Khao Dawk Mali105 (Br2) and Khao Tah- Haeng17 (Br3) (6.32, 15.65 and 22.02 % amylose content) were milled to be brown rice and cooked in electric rice cooker and coated with 10 percent coating substance, freezed at –30^oC and stored at –18^oC.
The frozen cooked brown rice with coating substance was determined for texture and retrograded properties after 5 cycles of freeze–thaw compared to uncoated cooked brown rice. The results showed that the coated cooked brown rice was significantly (P>0.05) less in hardness (89.29, 125.10 and 127.83 N) than uncoated cooked brown rice (97.05, 132.92 and 190.10 N) for the three rice varieties; Br1, Br2 and Br3 after 5 cycles of freeze-thaw. Similar results were found for the retrograded properties which showed that the coated cooked brown rice was significantly (P>0.05) less in retrogradation (1.88, 2.38 and 3.02 J/g) than uncoated cooked brown rice (2.57, 2.97 and 3.64 J/g) for the three rice varieties; Br1, Br2 and
Br3 after 5 cycles of freeze-thaw.