Production of snack foods from mungbean by using laboratory twin screw extruder

Research on production of mungbean snack by using Hermann Berstorff Laboratory Co-rotating Twin Screw Extruder ZE25*33D was carried out. Mungbean flour, was used as the main ingredient in a varying quantities from 50 to 100 percent. The proportion of mixture giving the highest acceptability score which was obtained by Analysis of Variance and Duncan's Multiple Range Test consisted of 91.5 percent flour mix (mungbean flour: rice flour 70:30). 7.5 percent full fat soyflour and 1.0 percent mixed vitamins. Study on the optimum condition, Response Surface Methodology was conducted by selecting three independent variables with in three different levels (14, 16 and 18 percent initial moisture content of feed ingredient 250, 300 and 350 rpm screw rotation speed and 120, 130 and 140 deg C temperature at the 7th barrel) The condition of 16 percent initial moisture of feed ingredient, employing 300 rpm screw speed, 135 deg C temperature at the 7th barrel, 16.8 kilograms per hour feed rate and 3.0 mm die was the optimum. The mungbean snack was flavored for sensory evaluation, amino acid and biological analysis. Nutritionally, the snack contained 2.07 PER which was in comparable with 83 percent casein in milk. Protein content analysed in the unflavored snack was 22.36 percent while expansion ratio was 4.03, apparent density was 0.059 gm/cubic cm, breaking strength was 0.9 kg/square cm. In further to shelf life study, the flavored mungbean snack were packed in OPP/PP, OPP/Metallized PP and OPP/Metallized PET plastic bags and stored at room temperature for 3 months. Every 2 weeks the samples were analysed for organoleptic evaluation, moisture content determination, texture and rancidity measurement. It was shown in the sensory analysis than the product gained overall acceptability score in the range of medium to good. The product was also found suitably packed in OPP/Metallized PP or OPP/Metallized PET plastic bags which could be stored at room temperature for more three months.