Study of Antioxidant Potential of Red Rice and Their Utilization in “Beras Kencur” Drink

Abstract

The objective of this research is to evaluate potential antioxidant of indigenous red rice and its application as ingredient of “beras kencur” drink. Eleven local varieties of red rice obtained from various places in Indonesia have been elaborated for their antioxidant activities by using established in vitro systems, including 2,2’-diphenyl-1-picahydrazyl free radical-scavenging (DPPH) and ferric reducing antioxidant power (FRAP). Their total phenolic and flavonoid contents were determined by colorimetric assay. The methanolic red rice extract showed various DPPH free radical scavenging activities ranging between IC50 108.9 to 320 μg/ml and the FRAP ranging between 477.9 to 1371.1 μmol Fe(II)/g. Total phenolic and flavonoid contents were in range of 27.6 – 82.1 TEA/g and 119.8 – 215.6 QE/g. Red rice from Jatiluwih exhibited the best quality among 11 samples being analyzed in term of total phenolic and flavonoid content as well as its antioxidant activity. Therefore, it was selected for further research as the main ingredient in “beras kencur” drink formulation. Formulation of “beras merah kencur” drink has been optimized by using mixture design experiment software. The optimization results indicated that the composition of 60% red rice, 20% galingale and 20% ginger had the higest desirability value. The comparative test on the “beras merah kencur“ drink, obtained from optimal formula drink (BMKOFD), with three commercial “beras kencur” drinks showed that the BMKOFD showed higher antioxidant activity (significanly different at =0.05). Morover, BMKOFD also had higher consumer acceptences in sensory aspect, e.g colour, aroma, taste and after taste (5.5, 7.4, 4.5 and 4.4 at 1-7 scale). In conclusion, the use of red rice could increase antioxidant activity of “beras kencur’ drink without lowering consumer acceptences

Fenomena saat ini menunjukkan bahwa semakin banyak konsumen yang cenderung kembali ke alam, back to nature, termasuk dalam memilih makanan dan minuman. Salah satu minuman tradisional khas Indonesia adalah jamu beras kencur yang digemari oleh anak-anak hingga orang dewasa dikarenakan rasanya yang manis dan menyegarkan serta bermanfaat bagi kesehatan. Beras merah memiliki beberapa keunggulan antara lain memiliki senyawa flavonoid fungsional, elemen mikronutrisi essensial, lemak fungsional dan penangkap radikal bebas sehingga diharapkan dapat berperan sebagai bahan pangan fungsional. Beberapa daerah di Indonesia memiliki berbagai varietas beras merah baik lokal maupun hasil rakitan. Namun informasi kandungan senyawa atau kelompok senyawa yang memiliki aktivitas antioksidan pada beras merah lokal dari berbagai tempat di Indonesia masih belum banyak diketahui. Penelitian yang memanfaatkan makanan dan minuman tradisional khas Indonesia sebagai bahan penelitian masih sangat terbatas. Tidak terstandarnya formula minuman tradisional yang diturunkan secara turun temurun mengakibatkan kualitas citarasa, aroma, dan terutama khasiat minuman tradisional tidak konsisten, sehingga sulit dalam pengendalian mutunya. Oleh karena itu, perlu dilakukan penelitian makanan dan minuman tradisional khas Indonesia guna mendapatkan formula dan mengetahui khasiatnya, agar mutu dapat terjamin.