Study of gadung flour production technology and physicochemical characteristic evaluation

English. Study of Gadung (Dioscorea hispida Dennt.) flour production technology and physicochemical characteristic evaluation. Two activities included in processing optimation and development of Gadung flour technology. The treatments of processing optimation are shrudding size, thick of sun drying and flour size. The experimental design was Randomized Complete Design factorial, four replications, and factors A (pressing and unpressing) and factor B (soaking in water, Na bisulfit 0.2 percent and CaO 0.3 percent solutions). The data showed that the best of Gadung flour processing through peeling, shrudding (size of 3-5 cm), soaking in Na bisulfit 0.2 percent solution or in CaO 0.3 percent solution for 5 minutes, pressing, sun drying (thick of lower 5 cm), milling, sieving 80 mesh size and packaging. Pressing contains moisture content, starch, protein, ash, fiber, HCN, diosgenine, SO3, and flour recovery lower than unpeeling. Soaking in Na bisulfit 0.2 percent contains highest protein, fat, fiber and whiteness degree. Soaking in CaO 0.3 percent contains lowest moisture content, HCN, diosgenin, water absorbtion and gel consistency value, and highest starch, ash, flour recovery, peuk viscosity and solubility value

unknown. Kajian teknologi pembuatan tepung gadung dan evaluasi sifat fisikokimianya. Percobaan ini terdiri dari 2 tahap kegiatan, yaitu kegiatan optimasi proses dan pengembangan teknologi pembuatan tepung gadung. Optimasi proses dilakukan terhadap ukuran sawut (chip), tebal penjemuran dan ukuran tepung (mesh size). Sedangkan pengembangan teknologi pembuatan tepung gadung digunakan Rancangan Lengkap faktorial, 4 kali ulangan, terdiri faktor A: Cara pengepresan (A1 = pengepresan dan A2 = tanpa pengepresan), dan faktor B: Cara perendaman (B1=air biasa, B2=Larutan Na bisulfit 0,2 persen dan B3=Larutan CaO 0,3 persen). Hasil percobaan menunjukkan pada optimasi proses, kombinasi perlakuan ukuran sawut 3-5 cm, tebal penjemuran kurang atau sama dengan 5 cm dan ukuran butiran tepung 80 mesh memberikan rendemen, derajat putih dan uji organoleptik yang diterima panelis. Pengaruh pengepresan akan menurunkan kadar air, pati, protein, abu, serat, kadar HCN, racun diosgenin, residu sulfit dan rendemen tepung, namun menaikkan kadar lemak. Dengan perlakuan perendaman larutan Na bisulfit 0,2 persen menunjukkan kadar protein, lemak, serat, derajat putih tepung tertinggi, sedangkan perendaman CaO 0,3 persen menunjukkan kadar air, HCN, diosgenin, NPA dan konsistensi gel terendah, namun kadar pati, abu, rendemen, viskositas puncak dan NKA tertinggi. Teknologi pembuatan tepung gadung dengan proses pengepresan dan perendaman larutan Na bisulfit 0.2 persen atau CaO 0,3 persen mutu tepung disukai panelis