Optimization of process parameters of manna bar, a kind of nougat, production

Abstract

Manna bar, a kind of nougat, is a typical Iraqi-Iranian confectionary that is made by manna, glucose syrup, table sugar, egg white, cardamom and nuts (pistachio, walnuts, or almond). Manna bar is a similar confectionary with French nougat, Italian torrone, and Spanish turrón, but produced from different raw materials and different process. The aim of this research was to determine influence of cooking temperature, cooking time and mixing time on the quality of manna bars during the production. The analyses made in this study were moisture content, pH value, color and textural properties. It was found that increasing cooking temperature from 100°C to 120°C, cooking time from 5 min. to 15 min., and mixing time from 10 min to 30 min. decreased moisture content from 15.58 to 8.50 %, but increased (p<0.05) hardness from 131.56 to 856.16 g. Browning index and pH value decreased (p<0.05) by increasing mixing time. Response surface analysis was carried out to optimize the production of manna bar. It’s results showed that cooking at 120°C for 10.10 min and mixing of 21.26 min was the best condition as desirability = 0.682. This study showed that high temperature at 120°C and long cooking for 15 min., and mixing for 30 min. improved the physical and chemical properties of manna bars.