Abstract
This study was carried out to investigate the properties of pectin extracted from Vietnamese mango peels that have been discarded as waste. Three different mango cultivars named Hoa Loc, Ghep and Cat Chu at three different maturities were studied. Pectin extracted from immature, ripe and overripe stages ranged from 18.4 to 31.7 g/100 g dry weight (DW); the highest yields were obtained from the ripe fruits. Ghep peels contained the highest pectin amounts which ranged from 24.2 to 31.7 g/100 g DW, followed by Cat Chu (19.2 to 26.5 g/100 g DW) and Hoa Loc peels (18.4 to 24.1 g/100 g DW). Except for degree of esterification and emulsion capacity, other properties of the extracted pectin including water holding capacity, solubility and emulsion stability were significantly affected by the fruit maturation. Varieties, solubility, degree of esterification, emulsion activity and emulsion stability of the pectin isolated from the three cultivars ranged from 77.4% to 86.0%; 50.3% to 55.8%; 11.8% to 34.3% and 28.5% to 94.5%, respectively. Fourier-transform infrared results showed that almost all collected pectin samples could be classified as the high methoxyl pectin. Rheology data indicated viscosity of the isolated pectin was strongly dependent on temperatures.