Continuous hydrolysis of mango peel pectin for the production of antibacterial pectic oligosaccharides in packed-bed reactor using immobilized polygalacturonase

Abstract

The aim of this study was to continuously hydrolyze mango peel pectin, an agricultural waste, into pectic oligosaccharides (POS) with antibacterial activity. A packed-bed reactor (PBR) with immobilized polygalacturonase was designed, and the effects of the process conditions (flow rate, substrate concentration, and enzyme amount) were evaluated. The optimal conditions were obtained using response surface analysis, and a stable POS production with a yield of 94.56% was achieved. The PBR retained 82% of its initial activity after continuous operation for 72 h. The POS products exhibited good antibacterial activity against E. coli, S. aureus, B. subtilis, and S. typhimurium. The destructive effects of POS on the membrane system integrity were observed via scanning electron microscopy and the leakage of intracellular nucleic acids. Thus, the PBR is a powerful tool for continuous POS production, and hence, it can be applied as an alternative to chemical preservatives in the food industry.