Effect of hydrocolloids on rheological, physico-chemical and sensory properties of carrot-tomato blended sauce.

摘要

Carrot-tomato blended sauce was prepared with different levels (0.1, 0.2, 0.3, 0.4, 0.5%) of xanthan and guar gum (1.0, 1.5, 2.0, 2.5, 3.0%). The sauce was packed and stored up to 90 days at room temperature (25+or-2 degrees C) and analyzed for physico-chemical (pH, total soluble solid, ascorbic acid, beta -carotene, and lycopene) and sensory characteristics. Rheological properties (yield stress, apparent viscosity, consistency index and flow behaviour index) of sauce were measured at selected temperatures. The flow behaviour of the sauce was adequately described by the Herschel Bulkley model over the shear rate range of 1-400 s-1. Sauce samples exhibited pseudoplastic behaviour and apparent viscosity and consistency index decreased with increase in temperature and followed Arrhenius relationship. Consistency index of sauce increased with gum concentration. Activation energy due to flow of sauce using selected hydrocolloids for different combination of gum concentration levels varied from 5.08 to 27.25 kJ/mol. Carrot-tomato blended sauce using 0.1% xanthan gum was the most acceptable on the basis of sensory attributes.