Optimization of pectin and citric acid concentration on the physical and organoleptic characteristics of Barhi date jam using response surface methodology

Date is a tropical plant originating from Middle East. Among various types of dates in the world market, Barhi is the most famous one as its edibility during all stages of maturity. Barhi date has a short ripening stage, therefore further processing is needed to extend its shelf life. One of them is by processing the Barhi dates into a jam. The aim of this study was to determine the optimum formulation of the jam. The optimization method was using Response Surface Methodology with Centre Composite Design and two independent variables, i.e., pectin and citric acid concentration and the responses are total colour difference (?E) and spreadability. The optimum formulation of Barhi date jam was 0.52% pectin and 0.69% citric acid. It had total colour difference (?E) of 6.77 and spreadability of 9.2 cm. The results of the actual data verification and the predicted value of the software showed no significant difference (p-value> 0.05). The results of quality acceptance test showed that Barhi date jam can be accepted by consumers.