Physico-chemical changes during enzymatic liquefaction of mango pulp (cv. 'Keitt')

Mango pulp from Keitt variety was liquefied with 1. 1 mL/kg commercial enzyme mixture preparations for 2 h at 40C. Various physico-chemical characteristics of the mango pulp at different stages of liquefaction were investigated. Apparent viscosity of pulp and serum reduced rapidly to 78% and 93% respectively, in 30 min liquefaction. No marked changes in apparent viscosity of pulp samples and percentage cell wall hydrolysis in the subsequent 60, 90 and 120 min were observed. High correlation coefficient values (R²> 0. 99) of the linear regression analysis showed the feasibility of using a power law model for fitting the shear stress-shear rate data of the pulp. The enzymetreated pulp showed 83 % and 84 % serum Yields duping 30 and 120 min reaction times respectively against 52 % for fresh pulp. Slight increase in TSS (°Brix), acidity, reducing and total sugars, and slight decrease in pH was found in the pulp as well as serum fractions as the incubation continued. No marked change in color (yellowness) was observed in the enzyme-treated pulp, however, the corresponding serum showed less yellowness and color saturation indicating retention of yellow pigments in the pulp fraction. 4-3-carene was identified as major mono terpenic compound in mango pulp comprising more than 73 % of the total aroma compounds. About 9% loss in the total aroma components was observed duping the liquefaction process. (Résumé d'auteur