<![CDATA[Proses pratanak bertekanan dapat memperbaiki kualitas dan menurunkan indeks glikemik beras. Penelitian ini bertujuan, mengkaji pengaruh tekanan pengukusan terhadap kualitas fisik dan komposisi kimia beras pratanak serta sifat organoleptik nasi pratanak, menguji indeks glikemik nasi pratanak pada berbagai tekanan pengukusan. Penelitian dilakukan menggunakan Rancangan Acak Lengkap dengan 4 perlakuan tekanan pengukusan yaitu 0,8 kg/cm2 (110oC), 1,5 kg/cm2 (122oC), 2 kg/cm2 (127oC) dan 2,5 kg/cm2 (132oC) dan 4 kali ulangan. Hasil penelitian menunjukkan bahwa proses pratanak bertekanan dapat memperbaiki kualitas fisik beras yaitu meningkatkan 20,71 persen butir utuh, menurunkan 15,11 persen butir patah, menurunkan 0,16 persen butir menir dan meningkatkan 6,43 persen rendemen, namun belum mampu meningkatkan butir kepala. Proses pratanak bertekanan juga mampu merubah komposisi kimia seperti, meningkatkan 0,38 persen lemak, meningkatkan 0,19 persen abu, meningkatkan 4,21 persen amilosa dan meningkatkan 0,95 persen pati resisten, namun menurunkan 0,01 persen karbohidrat dan menurunkan 0,55 persen protein . Panelis menyukai sifat organoleptik aroma dan tekstur beras pratanak, namun relatif agak suka terhadap warna dan rasa. Perlakuan pratanak dengan tekanan pengukusan 2,0 kg/cm2 (127oC) mampu menurunkan indek glikemik dari 48,18 menjadi 35,52 dan tekanan pengukusan 0,8 kg/cm2 (110oC) mampu menurunkan indeks glikemik dari 48,18 menjadi 44,88.kata kunci: padi, beras pratanak, tekanan pengukusan, indeks glikemikPressure parboiling process can improve the quality and reduce glycemic index of rice. The parboiled rice would be suitable to be consumed by diabetes sufferer. The research was aimed to study the effect of steaming pressure on physical quality, chemical composition and organoleptic properties and to evaluate the glycemic index of parboiled rice at various steaming pressure. The study was conducted using a completely randomized design with 4 treatments of steaming pressure i.e. 0.8 kg/cm2 (110o C), 1.5 kg/cm2 (122o C), 2.0 kg/cm2 (127o C) and 2.5 kg/cm2 (132o C) and 4 replications. The results showed that the pressure parboiling process could improve the physical quality i.e. the increase of the whole grain 20.71 percents, reduced broken 15.11 percents, reduced small broken 0.16 percents and increased yield 6.43 percents. Pressure parboiling process was also able to change chemical compositions i.e. increased fat 0.38 percents, increased ash 0.19 percents, increased amylose 4,21 percents,increased amylase resistant starch 0.95 percents, reduced carbohydrate 0.01 percents and reduced protein 0.55 percents. Organoleptic properties of parboiled rice were relatively preferred in terms of aroma and texture, but rather less preferred in the cases of color and flavor. Pressure parboiling rice with 2.0 kg/cm2 steaming pressure (127o C) could reduce the glycemic index from 48.18 to 35.52, while the steaming pressure of 0.8 kg/cm2 (110o C) could reduce the glycemic index from 48.18 to 44.88. ]]>
