Study on rapid drying and spoilage prevention of potato pulp using solid-state fermentation with Aspergillus aculeatus

Effects of solid-state fermentation on rapid drying and spoilage prevention of potato pulp were evaluated. Pectin hydrolyzing and antibacterial ability of pectinase-secreting Aspergillus aculeatus and Bacillus subtilis were compared. A. aculeatus grew better in potato pulp, with highest pectinase yield of 342.71 +/- 5.09 U/mL and rapid pH reduction to 3.76 +/- 0.01. Next generation sequencing showed that the abundance of genera Candida and Enterobacter, which probably caused undesirable fermentation and spoilage, were significantly reduced after inoculation with A. aculeatus. In addition, fermentation with A. aculeatus significantly reduced water holding capacity from 16.63 +/- 0.36 g/g to 7.78 +/- 0.12 g/g, which resulted in lower viscosity and water binding capacity, and concomitantly significantly decreased moisture content from 76.05 +/- 0.24% to 12.95 +/- 0.19% after filtration and airflow drying. These results suggested that solid-state fermentation might be a promising technology for efficient processing and utilization of potato pulp.