Effect of nutrient sources on bench scale vinegar production using response surface methodology

Abstract

AbstrAbstr Abstr Abstr Abstract: act: act: act: act: The present work aims to evaluate on a bench scale, the effects of nitrogen and phosphorous nutrient source concentrations in vinegar production, a process that is used by small scale industries in the State of Paraiba. The response surface methodology has been utilized for modeling and optimization of the fermentation process. Initially a 2 3 complete factorial design was used, where the effects of initial concentrations of ethyl alcohol, phosphorous and nitrogen sources were observed. After this analysis the concentration range of the nutrient variables were extended and a two level plus a star configuration factorial experimental design was performed.The experimental values are well represented by the linear and quadratic model equations obtained. The optimum concentration of ethanol was 4% in which the yield and the productivity of the acetic acid were maximized to the values of 70% and 0.87 g L -1 h -1 respectively, for a 24 hours fermentation period. The evaluation of the quadratic models showed that the yield of vinegar is maximized from 28.1 to 51.04% and the productivity from 0.69 to 1.29 g L -1 h -1 when the concentration of the nitrogen nutrient in the medium is increased from 0.2 to 2.3 g mL -1 . Thus, at the optimized nitrogen nutrient concentration both the yield and the productivity of the vinegar are increased by 1.85 times.

Utilization of residue from cassava starch processing for production of fermentable sugar by enzymatic hydrolysis

“…The experiments were performed according to the values of variable levels and the planning matrix of CCRD presented in Tables 1 and 2, respectively. For enzymatic hydrolysis, the starch was gelatinized by incubating a sufficient amount of flour to obtain a final concentration of 10% (m v -1 ) starch, in the initial presence of 40 mL distilled water, but considering the final volume of 50 mL with the further addition of buffer. The starch concentration used in this study was based on literature data, considering the maximum concentration of 10%, as higher concentrations for flour make the process unfeasible due to the high viscosity acquired mainly during gelatinization (Leonel et al, 1999;Ferreira et al, 2005;Bringhenti et al, 2007).…”

Scale Up of Sugarcane Vinegar Production by Recycling of Successive Fermentation Batches and its Organoleptic Evaluation

“…Different nutrient sources have been used in a number of studies like ammonium sulphate, yeast extract, corn steep liquor, bionyl F15, ammonia and potassium dihydrogen phosphate, sodium hydrogen phosphate as source of nitrogen and phosphorous, respectively (Berraud ; Ferreira et al . ; Kim et al . and Gullo and Giudici ).…”