Pomelo Peel Dregs Fermentation Debitterizing Process Experimental Study

Pomelo peel residue is byproduct of fruit fresh-eating and processing. It will take heavy contamination for the reason of not fully used. There are many nutritional compositions in pomelo peel. Not only does fermenting pomelo peel to feed chang waste into valuables, but also it reduce pollution. In this paper, debittering was studied in fermentation of pomelo peel residue to remove naringin and limonin. The researches of stains screening, process conditions optimization, debittering effect of naringin were made in-depth.(1) Based on the degradation rate of naringin and content of soluble protein, we analyzed the effect of different stains on the ferment products, including aspergillus oryzae, aspergillus niger, trichoderma koningii, saccharomycopsis fibuligera, induced aspergillus niger. The results showed that the best fermention stain of removing naringin was induced aspergillus niger. By single factor experiments and orthogonal experiment, we identified that the best process parameters were substrate moisture 60 %, inoculation volume 0.4 mL?g-1, and cultivate time 4 d. At that condition, the results is the degradation rate of naringin 92.9%, the content of soluble protein 0.389 mg?g-1.(2) Based on the degradation rate of limonin and content of soluble protein, we analyzed the effect of different stains on the ferment products, including aspergillus niger, induced aspergillus niger, phanerochaete chrysosporium, saccharomycopsis fibuligera, trichoderma koningii, geotrichum candidum, pachysolen tannophilus, aspergillus oryzae, acetobacter pasteurianus, induced acetobacter pasteurianus. The results showed that the best fermention stain of removing limonin was induced acetobacter pasteurianus. By single factor experiments and face-centered central composite design experiment, we identified that the best process parameters were substrate moisture 74.866%, inoculation volume 0.385 mL?g-1, and cultivate time 3.263 d. At that condition, the results is the degradation rate of limonin 63.2%, the content of soluble protein 0.268 mg?g-1.(3) Based on the degradation rate of naringin, we also analyzed the debittering effect of naringinase on the ferment products in single factor experiments about pH, time, temperature, enzyme dosage and ratio between stuff and water. By single factor experiments and orthogonal experiment, we identified that the best process parameters of removing naringin with naringinase were pH 4, time 9 h, temperature 35℃, enzyme dosage 2%, ratio between stuff and water 1: 4. At that condition, the degradation rate of naringin is 81.9%,(4) we analyzed the debittering effect of cellulase, xylanase and them with naringinase removing naringin and limonin.