dua-Acetyl-1-pirrolin and Hexanal Content in Some Aromatic Rice (Oryza Sativa. L) During Storage with Variety of Milling Degree and Packaging

Abstract

Scented rice or aromatic rice varieties is popular because of their flavor and texture. 2-Acetyl-1-pyrroline (2AP) contribute to pandan-leaves-like aroma, and hexanal is used as indicator of rancidity. Three aromatic cultivars (Mentik Wangi, Pandan Wangi, and Sintanur) with 100, 90, and 0% (brown rice) milling degree were stored in two types of packaging, i.e., plastic bag and hermetic bag for 4 months in room temperature. 2-Acetyl- 1-pyrroline and hexanal were determinded every 2 month during storage using gas chromatography mass spectrophotometer. Prescribed nutrient content with proximate analysis including moisture, ash, fat, protein, and amylose content, were done at the begining and at the end of storage time. Preference of rices was done by hedonic test. 2- Acetyl-1-pyrroline concentration decreasing during storage and as increasing with the milling degree. Brown rice have a highest hexanal than 90% and 100% of milling degree. Hexanal increased during 2 month storage, and decreased in 4 month storage. During storage, moisture, ash content, protein, and fat were still in standard range according to several references. Based on the amylose content, the texture all of rice before storage was sticky category and after four months of storage fell into smooth until hard texture. however ash and fat content were increasing. From preference test, Mentik Wangi 100% milling degree before storage is the most prefered rice than others. Both of hermetic bag and plastic bag gives no different influence in this case.