Stabilisasi Tepung Bekatul Melalui Metode Pengukusan Dan Pengeringan Rak Serta Pendugaan Umur Simpannya
Abstract
Bran is side product from rice milling. According to BPS (2008), bran production reach at 4,8 million tons. Bran can be processed to be various product, one of them is bran powder. Bran powder can be used as brade substitution agent, cookies, and dietary drink. The decreasing of quality of bran can occure through hydroliytic and oxidation processes. The problem can be solved trough bran stabilization. It can be processed by steaming of the material in certain time. The purposes of this research are to get condition of stabilization and bran drying, bran characterization and stabilized bran, also to predict the packaging time. Constant condition of drying of the fresh bran reached in 4 hours with the drying rate about 1 x 10-4 g/second untill the water level at 5 %. Steaming of the bran was carried out in 3 level of time; 5, 10, and 15 minutes. The next step was characterizing the bran and stabilized bran. The characterization of fresh bran include water level 6,86 %, fat 16,84 % (db), ash 7,43 % (db), protein 13,72 % (db), crude fiber 7,25 % (db), carbohydrate by different 47,9 % (db), and TBA 0,68 mg malonaldehid/kg sample, solubility 11,95 %, swelling power 5,96 %, cyneresis 95,50 %, total colony number 1,65 x 106, and was not found E. Coli colony. Based on tested parameter water level, fat, and TBA were choosen bran with steaming at 5 minutes. The stabilized bran characterization include water level 5,61 %, fat 14,23 % (db), and TBA 0,23 mg malonaldehid/kg sample. The bran that was stabilized at 5 minutes was used as the material to predict the storage and shelf life. The product packed in metalizzed and was storaged at tempeature 35, 45, and 50oC during 8 weeks. The quality parameter that was used in were water level, TBA, and brightness level. During the storage, it occured decreasing of water level and brightness level, also the increasing of TBA value. The critical value of the quality parameter that was used in packaging time of stabilized bran was TBA. Based on organoleptic test at the 4th week at storage 50oC, the critical point was 0,51 mg malonaldehid/kg sample. Arrhenius equation of stabilized bran during the packaging was k = 0,074 e -176 (1/T). Packaging time of stabilized bran at 30oC was predicted in 39 days, at temperature 25oC was in 40 days, and at temprature at 15oC was in 50 days.