Effect of Temperature, pH and Concentration of Soluble Solids on the Rheological Behavior and Molecular Mass of Pectin Obtained from Mango Vallenato Shell (Mangifera indica l.)

Abstract

The aim of the study was evaluating the incidence of pectin concentration, soluble solids concentration, extraction temperature and pH in the rheological behavior and molecular mass of a mango vallenato pectin gel. Experimental design was in blocks (mango pectin and commercial) completely random, in factorial arrangement 2, for the factors, pectin concentration (0.5-0.25% w/w), temperature (50, 70°C), pH (2.22.8) and solids concentration (55, 65°Brix), with three replicates. Storage modulus (G’), loss modulus (G”) and loss tangent (tan δ), determined on the rheometer AR 1500 with parallel plate geometry, were determined. The data were adjusted to the MarkHouwink-Sakurada model to determine the molecular weight of the pectin gel. Gels with 0.25% of mango pectin showed viscous behavior with little gelling property, the gels prepared with 50% of mango pectin at 55°Brix soluble solids concentration had a structured gel behavior, similar behavior to those of commercial pectin. The molecular mass of the gel prepared with mango pectin was in the range of 583.90 to 24.17 kDa, being significantly affected by the concentration of 0.25% of pectin, the extraction temperature and soluble solids concentration.