Pengaruh Pemanasan Gelombang Mikro terhadap Masa Simpan dan Kandungan
Asam Lemak Bekatul
(The Effect of Microwave Heating on Shelf Life and Fatty Acid Content of Rice
Bran)
Liem Oktaviani Putri Purnomo*, Yohanes Martono**, A. Ign Kristijanto**
*) Mahasiswa Program Studi Kimia Fakultas Sains dan Matematika
**) Dosen Program Studi Kimia Fakultas Sains dan Matematika
Universitas Kristen Satya Wacana
Jalan Diponegoro 52-60 Salatiga 50711, email:
[email protected]
ABSTRACK
Rice bran is easily rancid due to the enzymatic activity. An effort to inhibit the enzymatic activity of rice bran oil is done through rice bran stabilization at high temperature using microwaves. Therefore, the purposes of this study are: Firstly, application of rice bran stabilization method using microwave in order to preserve the quality of rice bran unsaturated fatty acid. Secondly, to compare the shelf life between stabilized and unstabilized rice bran using Accelerated Shelf Life Test (ASLT) with Arrhenius model based on the content of Free Fatty Acids (FFA). And thirdly, to identify fatty acid content of rice bran between treated and untreated of microwaves using Gas Chromatography-Mass Spectrometer (GC-MS). In this study, to accelerate the process of fatty acid hydrolysis, stabilized and unstabilized rice bran were stored at different temperatures which were: 25ºC, 35ºC, 45ºC, and 50ºC, respectively. Data of activation energy, constants rate of % FFA formation and the shelf life were determined by linear regression following Arrhenius model. The results of this study showed that stabilized rice bran had shelf life of 38.45 days at room temperature,in contrary the unstabilized rice bran showed shelf life of 11.21 days. Identification of fatty acids composition showed that the stabilized and unstabilized rice bran did not provide a major influence on the fatty acid composition. The dominan fatty acid are: oleic acid, linoleic acid and palmitic acid. The stabilization process using microwave can extend shelf life of rice bran without damaging the fatty acid content.
