Effect of roasting on the sensory and quality attributes of the peanut sauce consumed in Uganda

Abstract

Groundnut sauce is fondly known for the poor yet it contributes to increased intake of some essential nutrients and health promoting phytochemicals since it is highly rich in them, and roasted groundnuts as a raw material; have a better flavour, aroma and colour which are important attributes affecting the consumer preference. However, the consumption of the roasted groundnut sauce is poorly done and under-utilized despite of all the quality attributes it has. This study was to the enhance consumption of quality sauce prepared from roasted groundnuts in Uganda. Some of the groundnuts were not roasted, some partially roasted and some groundnuts were fully roasted at different temperature time combinations. The partially roasted groundnuts were roasted at half the time of those fully roasted but at the same temperatures. The temperature time combinations included 1800C for 10 minutes, 1600C for 15 minutes and 1700C for 12 minutes for the fully roasted groundnuts; and 1800C for 5 minutes, 1600C for 7.5 minutes and 1700C for 6 minutes for the partially roasted groundnuts. The sauces were as well cooked at different temperatures that is to say 700C, 800C and 900C. The viscosity, quality and sensory properties were determined. The viscosity of peanut sauce decreased as the rate of roasting increased, fully roasted groundnuts had the lowest viscosity followed by the sauce from partially roasted groundnuts while the sauce from non-roasted groundnuts had the highest viscosity. The sauce from the partially roasted groundnuts had the least sensory attributes in aroma, taste, and overall acceptability. The sauce from the fully roasted groundnuts had the highest acceptability and best sensory attributes. It was concluded that roasting had an effect on the viscosity properties, quality and sensory attributes of the groundnut sauces. Sauce from fully roasted groundnuts emerged as the best sauce. Further study on the nutrients lost during roasting of the groundnuts as compared to those retained in the non-roasted, research on the roasting extent of the groundnuts that would develop the characteristic flavours and aroma but do not negatively affect the thickness of the resultant sauce; and research on shelf life and storage stability of those different groundnut paste/flours should be carried out.