Isolation and chemoenzymatic treatment of glycoalkaloids from green, sprouting and rotting Solanum tuberosum potatoes for solanidine recovery

•Determination of the glycoalkaloid content in the flesh of different types of turned green, germinated and rotting potatoes.•Post-harvest contributes to a several-fold increase of glycoalkaloid level.•A simple chemo-enzymatic protocol is proposed to convert α-chaconine to solanidine. The estimation of glycoalkaloids in the flesh of different types of decayed potatoes was evaluated. The results showed that turned green and also sprouting or rotting potato flesh contain high amounts of toxic solanine and chaconine, exceeding by 2–5-fold the recommended limit, and ranging from 2578±86mg/kg to 5063±230mg/kg of dry weight potato flesh. For safety consideration, these decayed potatoes should be systematically set aside. To avoid a net economic loss and encourage the removal of this hazardous food, a recycling process was investigated to generate added-value compounds from the toxic glycoalkaloids. A simple chemo-enzymatic protocol comprising a partial acidic hydrolysis followed by an enzymatic treatment with the β-glycosidase from Periplaneta americana allowed the efficient conversion of α-chaconine to solanidine.