Komposisi Kimia Serta Aktivitas Antioksidan Ekstrak Hidrofilik Bekatul Beberapa Varietas Padi

Abstract

The study was aimed to investigate chemical composition, dietary fiber content and the antioxidant activity of the hydrophilic extract of varieties of rice bran IR-64, Sintanur, Rajalele and Menthikwangi. Rice bran from each sample was analyzed proximate and fiber content. Hydrophilic extract was obtained by extracting each sample of bran with methanol solvent. Total phenolic content was tested by Folin Ciocalteu reagent and antioxidant activity of the extract was tested by DPPH (2,2-diphenyl-1-picrylhydrazyl) method. The results showed that all the four samples had differences amount of their moisture, ash, protein and fat contents. Fat content varies from 16.80±0.05 % - 23.75±0.04 %db, which the highest level of fat content was possessed by Sintanur bran (23.75±0.04 %db) and IR-64 bran (16.80±0.05 %db) was the lowest level. The levels of soluble fiber from four varieties of rice bran were not significantly different, between 4.07 – 4.14 %db but there was a difference in the content of insoluble fiber, which had effect on the total of fiber content. The insoluble fiber content of the rice bran varieties of Menthikwangi, Rajalele, IR-64 and Sintanur were 27.64±0.46, 28.04±0,25, 29.15±0.26 dan 30.44±0.60 %db respectively. The content of total phenols and the highest antioxidant activity of the hydrophilic extract was owned by Menthikwangi ie. 2794.28±181.83 μg galic acid equivalen (GAE)/g bran for total phenol and 41,28±0,60 % for antioxidant activity. 

ABSTRAK

Penelitian bertujuan untuk mengetahui komposisi kimia, kadar serat pangan serta aktivitas antioksidan ekstrak hidrofilik bekatul dari empat varietas padi yaitu IR-64, Sintanur, Rajalele dan Menthikwangi. Masing-masing sampel bekatul dianalisis proksimat dan kadar serat pangannya. Ekstrak hidrofilik diperoleh dengan cara mengekstrak masingmasing sampel bekatul dengan pelarut metanol. Ekstrak diuji kandungan total fenol dengan reagen Folin Ciocalteu dan aktivitas antioksidannya dengan metode DPPH (2,2-diphenyl-1-picrylhydrazyl). Hasil penelitian menunjukkan bahwa keempat sampel memiliki kadar air, kadar abu, kadar protein dan kadar lemak yang bervariasi. Kadar lemak bervariasi dari 16,80±0,05 % - 23,75±0,04%db, dengan kadar tertinggi dimiliki bekatul varietas Sintanur (23,75±0,04 %db) dan terendah bekatul varietas IR-64 (16,80±0,05 %db). Kadar serat larut (soluble fiber, SF) bekatul dari keempat varietas padi tidak berbeda secara signifikan yaitu antara 4,07 - 4,14 %db namun terdapat perbedaan pada kandungan serat tak larut (insoluble fiber, IF) yang berpengaruh pada kadar serat total. Kandungan serat tak larut bekatul dari varietas Menthikwangi, Rajalele, IR-64 dan Sintanur berturut-turut adalah 27,64±0,46, 28,04±0,25, 29,15±0,26 dan 30,44±0,60 %db. Kandungan total fenol dan aktivitas antioksidan tertinggi dimiliki oleh ekstrak hidrofilik dari bekatul verietas Menthikwangi, masing-masing 2794,28±181,83 μg ekivalen asam galat (EAG)/g bekatul untuk total fenol dan aktivitas antioksidan menangkal (scavenging) radikal bebas (DPPH) sebesar 41,28±0,60 %.