Evaluasi Nilai Biologis dan Indeks Glikemik Mi Jagung Substitusi Kering dan Instan

Abstract

Tepung jagung merupakan salah satu bahan pangan yang berpontensi untuk dikembangkan, salah satunya digunakan dalam formulasi produk mi. Hasil penelitian sebelumnya menunjukkan bahwa tepung jagung dapat menyubstitusi tepung terigu hingga 30%. Karakteristik mutu fisik mi jagung substitusi kering dan instan yang dihasilkan adalah mi yang kenyal, sedikit agak keras, tidak lengket, agak elastis dan tidak mudah putus. Proses pemanasan memiliki pengaruh signifikan terhadap komposisi kimia dan nilai gizi dari produk yang kaya karbohidrat. Pengaruh pemanasan terhadap karakteristik fungsional karbohidrat berkaitan erat dengan indeks glikemik. Makanan yang memiliki indeks glikemik rendah atau tidak cepat menaikkan kadar glukosa darah dibutuhkan oleh penderita diabetes. Kajian mengenai pengaruh pemanasan terhadap evaluasi nilai biologis dan indeks glikemik pada proses produksi mi jagung substitusi ini penting bagi penderita diabetes untuk lebih selektif dalam memilih dan mengkonsumsi bahan pangan.. Tujuan penelitian ini adalah untuk (1) menentukan pengaruh pemanasan terhadap komposisi kimia dan nilai evaluasi biologis mi kering dan mi instan yang disubstitusi dengan tepung jagung dan; (2) menentukan indeks glikemik mi jagung substitusi kering dan instan dibandingkan dengan mi terigu komersial.

Corn flour is potentially used as a raw material in noodle formulation. The previous study showed that 30% of corn flour was used as a substitute of wheat flour in dried and instant noodle. The corn flour substituted noodle applied drying or frying process at a high temperature, which may affect the nutritional content and biological value of the noodle. For this reason the effect of heating process (drying or frying) during noodle processing on chemical composition and biological value of corn flour substituted noodle was studied. The wet noodle was dried in oven at 60oC for 70 minutes to produce dried noodle and fried in cooking oil at 160oC for 4 minutes to produce instant noodle. The noodles were evaluated in terms of chemical composition and glycemic index. Commercial instant noodles were also analyzed as a comparison. The amylose content of dried noodle substituted with 30% corn flour was 30.99% which was higher than that of instant noodle substituted with 30% corn flour (28.85%). The content of resistant starch of corn flour substitued dried and instant noodle corn was 14.80% and 17.25% respectively. Starch and soluble fiber digestibility of dried corn noodle was significantly different from these of instant corn noodle, which were 30.93% and 0.49%, and 25.33% and 0.68% respectively, whereas protein digestibility was relatively the same. The glycemic index of dried and instant corn noodle substitution and commercial noodle was categorized as a low glycemic index (54.18%; 51.33 and 48.65%), whereas the glycemic load of them was 26.12; 22.18 and 18.63 respectively and was categorized as a high and middle glycemic load. Drying or frying process did not significantly affect the glycemic index of both dried and instant corn noodle substituted.