Investigation of chemical, rheological and sensory properties of curry-spices blend

Abstract

In this study, blends of curry leaves and spices were processed into a paste in the following ratios: 100:0; 65:35; 50:50; 35:65; 0:100 and were investigated in terms of chemical, sensory and rheological properties. The viscosity, consistency index, and flow behavior index were measured using a modular compact Rheometer MCR 102. The paste was standardized and characterized by evaluating sensory characteristics by a 9-hedonic scale. The sensory analysis had revealed that as spice mix percentage increased the acceptability of curry-spice blends were reduced. With respect to the physical and sensory properties of paste, the 50 g of spice mix had better acceptability than that of 35, 65, and 100g spices in curry-spice blends. The flow behavior index (n) of the paste containing 35% spices was higher than 100% spice mix with respect to temperatures (278 & 358K). As the temperature increased the viscosity and the consistency coefficient (K) decreased. The consistency coefficient increased from 1.160-3.970Pa s n to 2.12–6.687Pa s n as the spices percentage increased from 35% to 100%. The rheological data fitted with the Herschel Buckley model revealed that the recipe exhibited Non-Newtonian, shear-thinning behavior with thixotropic effects, at all tested combination of curry leaves puree, spices puree, and temperatures. The combined effect of the concentration, temperature, and shear rate on the viscosity of Curry-spice blends was described successfully by a simple mathematical model. • Increase in temperature decreases the viscosity and the consistency coefficient (K) of the blend. • Apparent viscosity was more sensitive to changes such as increased temperature and different blends of sample. • CSB behaves as a pseudo-plastic fluid in the range of 278–358K temperature and 35–100% spice mix concentration. • Increasing the spice mix concentration up to 100% decreased the flow behavior index (n value) of the blend. • A tri-parametric mathematical model combining temperature, concentration, and the shear rate was proposed in the research.