Black plum peel torshak: physicochemical properties, sensory attributes, and antioxidant capacity

Plum peel is a by-product of plum processing. It is a rich source of antioxidant and phenolic compounds. The aim of this study was to investigate the chemical composition, sensory attributes, time-independent rheological properties, texture characteristics (Back extrusion test), and antioxidant activity of black plum peel torshak as a function of prune (10%, 20%, and 30%) and apple (20%, 30%, and 40%) purees. Increasing the prune and apple puree concentrations rose consistency coefficient and apparent viscosity of the power-law model and all texture parameters (firmness, cohesiveness, consistency, and index of viscosity). Sensory evaluations showed that total acceptance dropped gradually by increasing the level of prune and apple purees. The sample with 20% prune puree and 20% apple puree was determined as the best formulation among samples. The antioxidant activity of black plum peel torshak improved dramatically with increasing the prune and apple puree concentrations. PLS analysis showed that the results of sensory and instrumental properties were in agreement with each other.