K. Wignyanto Sri, Suprayogi
A combined substrat consisting of solid and liquid waste produced during the course of pineapple and fermented soybean processing was used for the production of instant dry yeast. Two stages of experiment were conducted. The first experiment aimed to find out the best proportion beween solid pinneaple and liquid waste released from fermented soybean industry (1:0 ; 1:1.5 ; 1:1 ; 1:1.5; 0:1) as substrate for the growth of Saccharomyces cerevisiae and the second stage of experiment was to find out the optimum concentration of dextrin as filler and lecithin for the production of instant dry yeast. A central composit design with two factor was used to carry out the second stage experiment. Dextrin concentration (50%; 60%; 70%) as the first factor and lecithin concentration (0.5%:1.0% 1.5%) as the second factor. The response analysed are the water content, solubity, cell viliability and ethanol content. Results obtained from the first stage shows that the best substrate for the growth of S. cerevisiae was the ratio of pineapple waste and liquid soybean waste (1 : 0.5), incubation time 12 hours, temperature incubation 30oC, and agitation rate 150 rpm. The production of S. cerevisiae is 4.35 x 108 cell/ml. The shortest adaptation time is 4 hours. Results obtained from the second stage experiment are computed with Design Expert 7.1.3. The optimum condition obtained were dextrin concentration of 63.59 % (w/v) and lecithin concentration of 1.57 % (w/v), producing product having water content 6.25%, solubility 77.56%, cell viliability is 62.6%, and ethanol concentration is 4.21 %.
Department of Agro Industrial Technology, Faculty of Agricultural Technology, University of Brawijaya, Jalan Veteran, Malang, Jawa Timur, 65145, Indonesia
