Authors : Mohammadyar Hoseyini, Narmela Asefi and Mansoureh Mozaffari
Abstract: Due to increasing price of hydrocarbons and difficult access to them, process based on hydrocarbonate substrate has been shifted to design process on the base of waste agriculture carbohydrate such as apple pomace, coffee husk, wheat straw, pineapple waste, mixed fruit, bagasse to produce citric acid. Apple pomace is a suitable substrate for microbial production of citric acid, Aspergillus niger. In this study, new solid-state bioreactor (22.2 m3) was designed with heat gradients and aeration changes and has successfully been put into operation. The operation of bioreactor was optimized using simplex method of analysis. The result of the present study considering the economical and industrial aspects showed that maximum amount of citric acid was produce under the following conditions: moisture content, 80% (w/w); fermentation time, 93.9 h; aeration rate, 1.2 (L min-1); nitrogen source (ammonium sulfate), 0.19% (w/w) and plate distance, 7.4 cm. Under optimized conditions, 159.14 g citric acid was produced from 1 kg dry apple pomace.
Mohammadyar Hoseyini, Narmela Asefi and Mansoureh Mozaffari, 2011. Production of Citric Acid from Apple Pomace by Using Surface Culture Method. Agricultural Journal, 6: 226-230.