Characterizations and rheological study of the purified polysaccharide extracted from quince seeds.

BACKGROUND

The functional characteristics of hydrocolloids are mainly dependent on their physicochemical properties. Thus, it is essential to characterize the new sources of hydrocolloids.

RESULTS

Quince seed gum (QSG) is a high-molecular-weight polysaccharide (9.61 × 106 g mol-1 ) composed of 85.04 ± 2.87% carbohydrate (6.39% l-arabinose, 40.43% d-xylose, 5.60% d-galactose, 5.75% d-glucose and 31.11% d-mannose), 13.16 ± 1.73% uronic acid, 5.77 ± 0.83% moisture, 2.78 ± 0.21% protein, 5.64 ± 0.21% ash, and 0.75 ± 0.09% fat. Our findings indicated that this gum could be introduced as a value-added by-product in the food and pharmaceutical industries. Carbon-13 nuclear magnetic resonance and Fourier transform infrared spectroscopy suggested a highly substituted xylan structure for QSG. In the dilute regime, an increase in the ion concentration was accompanied by a decrease in intrinsic viscosity of QSG. When the salt concentration increased from 0 to 50 mmol L-1 , the consistency coefficient (as a measure of apparent viscosity) declined. On the other hand, with further increasing of salt concentration, the consistency coefficient (as a measure of apparent viscosity) values increased. Similarly, the G' and G″ values for 10 and 50 mmol L-1 calcium chloride concentrations were less than in control samples.

CONCLUSIONS

The rheological behavior of the QSG studied in this paper can provide insight into its potential application in food and pharmaceutical industries. © 2018 Society of Chemical Industry.