Effect of adding superolein and sunflower oil on reheological properties chocolate syrup

Abstract

This study was carried out to determine the effect of adding superolein (POo) and sunflower oil (SFO) on rheological properties of chocolate syrup. The formulation of chocolate syrup modified from a preliminary study consisting of49.1% water, 30% sugar, 15% cocoa powder, 5% vegetable fats (POo and SFO), 0.5% lecithin and 0.4% vanilla flavor. Rheology of chocolate syrup was measured at a shear rate of O. 01-60s-1 by using rotational rheometer equipped with parallel plate at 4??C and 25??C. Data obtained in terms of shear stress and shear rate were applied into the Power Law model to determine the apparent viscosity, flow behavior index (n) and consistency index (K) of chocolate syrup. 1n this study, apparent viscosity of chocolate syrup was determined at a shear rate qf ??:'. it was found that the apparent viscosity of POo chocolate syrup was the highest; 14.62 ?? 1.97 Pa.s (4??C) and 3.91 ?? 0.21 Pa.s (25??C), followed by SFO chocolate syrup with its apparent viscosity 5.42 ?? 0.40 Pa.s (4??C) and 1.203 ?? 0.076 Pa.s (25??C), respectively. Apparent viscosity of Hershey's chocolate syrup was the lowest which was 2.15 ?? 0.070 Pa.s (4??C) and 0.6734 ?? 0.027 Pa.s (25??C). All the chocolate syrups exhibited shear-thinning behaviors with n<l at 4??C and 25??C. The consistency index of chocolate syrup increased in order ofKHershey<KSFO<Kpoo at 4??C and 25??C. For sensory evaluation, it was found that POo and SFO chocolate syrups were most preferred by the panelists compared to Hershey (p<0.05). There was no significant difference between POo and SFO chocolate syrups. In conclusion, POo and SFO can be potentiaily utilized in making of chocolate syrup compared with the existingformulation without oil.