Perubahan Sifat Fisikokimia dan Fungsional Tepung Beras Akibat Proses Modiflkasi Ikat-Silang - S. Joni Munarso; D. Muchtadi; D. Fardiaz; R. Syarief (Balai Besar Penelitian dan Pengembangan Pascapanen Pertanian, 2004)
Penelitian ini dilakukan untuk mengevaluasi perubahan sifat fisik, kimia dan fungsional tepung beras akibat proses modifikasi ikat-silang. Sebanyak 4 jenis beras, yaitu IR64B, IR64J, IR42B, dan IR42J yang beragam dalam hal mutu dan kadar amilosanya direaksikan dengan fosfor-oksiklorida (POCI,) dengan konsentrasi yang bervariasi, yi. 0, I; 0,2 dan 0,3% pada pH 10,5. Hasil penelitian menunjukkan bahwa tepung beras terfosforilasi atau terikat-silang terbukti mengalami perubahan, yakni kenaikan derajad putih, dan berbagai perubahan sifat kimia maupun fungsional lain. Kadar pati tepung beras makin menurun akibat penggunaan POCI3 dengan konsentrasi yang makin tinggi. Akibat penurunan kadar pati ini, kadar komponen kimia lain, seperti protein, lemak, serat, abu dan fosfor mengalami peningkatan. Pada tepung beras terikat-silang juga diperoleh sifat pasta yang meningkat baik pada viskositas puncak, viskositas pasta, maupun viskositas balik. Changes of physicochemical and functional properties of rice flour as affected by cross link modification processAn experiment to evaluate the changes of physical, chemical and functional properties of rice flour as affected by cross-linked modification process has been executed. Four rice samples, namely IR64B. IR64J, IR42B. and lR42J, which differrent quality and amylose content, were reacted with phosphor-oxychloride (POCl,) at various concentrations, i.e. 0.1 ; 0.2 and 0.3%, at the pH of 10.5. The result shows that phosphorilated or cross-linked rice flour had been identified to have higher whiteness degree. and some' changes in chemical and functional properties. Starch content of rice decreased as higher concentration of POCl, is applied. Meanwhile, the content of other chemical compounds, such as protein, fat, fiber, ash and phosphorous, increased as starch content decreased. Higher peak, paste, and set back viscosities were also observed in cross-linked rice flour.