Products and processes related to the use of ICRISAT mandate cereals in the food industry

Abstract

Dehulling of sorghum and pearl millet grains was found to reduce the hardness and resulted in crunchier extrudates in case of both  sorghum and pearl millet. Composite flours were prepared using whole sorghum and whole pearl millet as well as dehulled sorghum and dehulled pearl millet along with the other crops of the semi-arid tropics, namely; chick pea, pigeon pea and groundnut. Other than control (100% whole/dehulled sorghum flour and 100% whole/dehulled pearl millet flour), the composite flours had chickpea flour (30%), pigeon pea flour (30%) or a blend (30%) of equal combination of chick pea-groundnut flour or pigeon peagroundnut flour. Nutritional properties of the composite flour blends were analyzed and extrusion cooking was carried out using a twin screw extruder (temperature: 115 °C and 90 °C for two different heating zones, die diameter: 3 mm and screw speed:
400 rpm). Texture analysis of the extrudates was carried out and data compared across formulations to find the most acceptable product. Sensory analysis results indicate that in case of sorghum blends, extrudates prepared from the composition of dehulled sorghum, chick pea and ground nut (70:15:15) was most acceptable organoleptically. This correlates well with its high expansion ratio (2.80 0.11) and low bulk density (0.16 0.01 g ml-1) as well as with the texture analysis data (peak force = 18.12 N and Slope = 0.09 N mm-1). In case of pearl millet blends, extrudates prepared from dehulled pearl millet and pigeon pea (70:30) was found to be most acceptable by the sensory panel. The sensory data is further supported by the low values obtained for peak force(16.81 N) and slope (0.01 N mm-1). The expansion ratio was 2.81 0.09 and the bulk density 0.22 0.01 g mL-1. The nutritional profiles of the blends were also superior when compared to that of the control. A number of healthy snacks have been developed based on this study and are ready for commercialisation. In addition, the work also focussed on other opportunities to exploit the nutritional and functional properties of dryland cereals in the food processing industry for developing various value-added food products.