Rheological, textural, micro-structural and sensory properties of mango jam

Mango jam behaved as pseudoplastic fluid exhibiting yield stress. The Herschel-Bulkley (HB) model described adequately the steady-state rheological behavior of jam. Temperature dependence of the consistency index followed Arrhenius relationship. Time dependent structural breakdown characteristics of mango jam followed Hahn model. Hardness of mango jam increased with pectin concentration and acidity. Hardness increased up to 60% sugar concentration but decreased with further increase in sugar concentration at all pH and pectin levels. Stickiness, work of shear, and adhesion did not show any systematic trend with pH, pectin, and sugar concentration. The overall acceptability was rated highest for mango jam prepared with 65% sugar, 1% pectin at pH 3.4. Principal component analysis (PCA) revealed that hardness and work of shear are the most relevant among all the characteristics (physicochemical, sensory, textural, rheological, and compositional) studied for mango jam. Microstructure of mango jam was found to be composed of network regions with large pores as well as dense, compact regions with small pores. (C) 2010 Elsevier Ltd. All rights reserved.