Citrus Orange Peel Residue Fermented Feed Protein Studied

Orange residue is byproduct of fruit process. It takes heavy contamination for the reason of not fully used. In this paper, feed-protein production was studied in solid state fermentation of orange residue with stains fermentation, including Aspergillus ficuun (A), Aspergillus oryzae (B), Endomycopsis fibuligera (C). After that, soluble protein, activities of cellulose, xylanase,β-glucosidase and acidic protease were studied in the products of solid state fermentation to identify its value.First we analyzed the main composition of orange residue, the results demonstrated that the total protein, crude fattiness, crude cellulose and crude ash, in the orange residue, are 6.25%, 6.4~8.1%, 2.3~2.6%, 9.5~10.6%, 3.1~3.6%, respectively. After that, we analyzed the effect of different stains on the ferment products, including Aspergillus ficuun (A), Aspergillus oryzae (B), Endomycopsis fibuligera (C). The results showed that the best ferment conditions were mixing of the three stains in the orange residue medium complemented with 15% (w/w) bran. Based on the level of total protein, we identified that the best process parameters were inoculation volume 40%, cultivate temperature 28℃, substrate moisture 70 % and cultivate time 4 d. Furthermore, with the results of determination of soluble protein, we make certain that the inoculants ratio of combined A, B and C is 2:3:1.With the Response Surface Methodology (RSM) and the Face-Centered Central Composite Design (FCCCD), we optimized the experiments parameters for more soluble proteins in the fermentation of orange residue. The results showed that combination of A ,B and C in the inoculants ratio is 1.357:1.447:0.661, and inoculation volume, cultivate temperature, substrate moisture and cultivate time are 31.3%, 26.7℃, 71.2 % and 62.7 h respectively.Moreover, we also the effect of materials for the fermentation of orange residue on the activities of cellulose, xylanase,β-glucosidase and acidic protease, the results demonstrated that mixing with different stains is helpful for the output of soluble proteins in this process. In general, we found the best condition for the fermentation of orange residue, analyzed the impact of all kinds of factors time, ferment temperature, the sorts of stains, etc in this study. All the data maybe useful to increase the efficiency of orange residue fermentation.