Milled rice Quality Preservatio through Packaging Develoment

Abstract

A survey study from 14 rice exporters indicated that, present of insect and quality deterioration were the significant problems of the consumer packaged rice in foreign maket. The high cost due to increase in labor wage and packaging material were also indicated. To preserve miled rice quality through packaging, two experiments were studied during 6 month period. Milled rice obtained from dry season crop was used in the first experiment. It contained 28% apparent amylose. The rice was stored in bags made of 4 different types of material, such as polypropylene (PP0, poolyethylene (PE), laminated nylon (NY 15/PE17/PE70 : NY) and laminated aluminum foil (OPP20/PE20/AL/PE20/PE40 : AL). the rice in the NY and the AL bags might be sealed either under normal or vacuum presure at -0.9 bar (NY-V or AL-V) or with a bag of oxygen absorber inside. The treatment of the rice in the AL with the oxygen absorber and stored at 15 c (AL-V15) was also tested for comparison. Milled grain derived from an aromatic rice through polishing and whitening wee studied in teh second experiment. The samples were stored in the bags made of PP, PE, NY or AL. The rice in the NY bag might be sealed under normal or vacuun pressure or with the oxygen absorber substance inside. The results from both trials verified that all types of packaging material could not provide an protective effect from insect infestation. Contamination of the store pests was found more abundant in the rice kept in the PP and the PE bags. The number of the insects increased in accordance with the storage period. The insect infestation brought into the present of bad smell in the cooked product. This rice also contained higher level of free fatty acid and peroxide value of its extracted fat. Sealing the NY and the AL bags under vacuum pressure or adding the oxygen absorber could provide a protective effect tothe pest development. This gave a benefit in slow down the deterioration of the rice quality and the loss of aromatic flavor of its cooked product. Milled aromatic rice obtained from polishing process tended to have a superior aromatic flavor than that of whitened grain.