EFFECT OF FERMENTATION TIME ON QUALITY OF MODIFIED GADUNG FLOUR FROM GADUNG TUBER (Dioscore hispida Dennst.)
Brilian Prima Anindita, Atika Tri Antari, Hakun Wirawasista Aparamarta, Setiyo Gunawan*
Department of Chemical Engineering, Institut Teknologi Sepuluh Nopember (ITS), Surabaya 60111, Indonesia
*Corresponding author:
Email: gunawan[at]chem-eng.its.ac.id
Tel: +62-31-5946240; Fax: +62-31-5999282
Abstract
Gadung (Dioscorea hispida Dennst.) is one of tubers which is available in almost all regions in Indonesia. However, due to the high content of cyanide acid, these tubers cannot be consumed directly. Therefore, proper processing techniques are needed to improve the nutritional value in gadung tubers. The aim of this study was to investigate the effects of fermentation time and initial bacteria cells number on improving the quality of modified gadung flour. Before fermentation process, gadung tubers were soaked in water at a ratio of 1:50 for 120 minutes to reduce levels of cyanide acid (161.83 ppm to 53.21 ppm). The fermentation time was performed for different periods of time (12, 24, and 36 hours) with intitial bacteria cell number of 1,21 x 1011 cells of Lactobacillus plantarum. The result showed that swelling power of modified gadung flour (6.75 g/g) was greater than wheat flour (4.57 g/g) but water solubility and flour whiteness degree of gadung flour (0.56% and 71.43%) were close to wheat flour (1.06% and 74,94% - 76.38%), for fermentation time of 36 hours.
Keywords: modified gadung flour, swelling power, water solubility, whiteness degree
Topic: Chemical Engineering