The effects of cooking time and sugar on total phenols, hydroxymethylfurfural and acrylamide content of mulberry leather (pestil)

Abstract

The effects of glucose syrup (0, 20, and 40%), sucrose syrup (0, 20, and 40%) and cooking time (10 and 20 min) on the chemical characteristics of mulberry pestil were investigated by replacing glucose syrup and sucrose syrup with mulberry syrup. Changes in glucose and sucrose syrup concentrations significantly affected invert sugar, sucrose and total soluble solids content of mulberry pestils. The invert sugar values of mulberry pestil increased with the addition of glucose syrup, but decreased with the addition of sucrose syrup. An increase in levels of sucrose or glucose syrup resulted in an increase of the lightness of colour values; however, an increase in cooking time reduced the lightness of colour of mulberry pestil. When sucrose and glucose syrup were added, an increase in pH values of samples but a reduction in titratable acidity was detected. Replacing glucose syrup with mulberry syrup in the formulations resulted in a decrease in the amount of hydroxymethylfurfural and acrylamide formed in mulberry pestils. The reducing effect of glucose syrup on hydroxymethylfurfural and acrylamide formation was much greater than the effect of sucrose syrup.