Optimisation and Evaluation of Ricebean (Vigna Umbellata) Extrusion Process for Downstream Food Processability

Abstract

Ricebean(Vigna umbellata), a native bean of North-Eastern part of India has not been explored fully for development of convenience foods although it is loaded with various vitamins, minerals, dietary fiber, phytochemicals and bioactive compounds. The effect of extrusion parameters namely moisture content, barrel temperature and screw speed on expansion ratio, extrudate density, and breaking strength was investigated by using response surface methodology. It was observed that moisture content of flour had significant (p<0.05) affect on expansion ratio, extrudate density, and breaking strength of extrudates. The optimal combination of process parameters which resulted in extrudates with maximum expansion ratio but minimum extrudate density and breaking strength were 15 per cent moisture content, 110°C barrel temperature and 350 rpm screw speed. The value of water absorption index, water solubility index, swelling power, oil absorption index, bulk density, true density and colour for optimally extruded ricebean flour (OEF) was found significantly different (p<0.05) whereas value of proximate parameters were insignificant (P>0.05) than the native flour. The OEF was used for different downstream processings such as papadability, friability, steamability, cakeability, gravyability and porridgability and compared with that of native flour for their process quality parameters. The cake prepared with OEF had significantly (p<0.05) less baking time (25 min) than the cake of native ricebean flour (35 min). However, consistency and over all acceptability (OAA) of porridge from OEF was found significantly (p<0.05) higher than porridge of native ricebean flour. Hierarchical cluster analysis on OAA showed that porridgability and cakeability were most influential downstream processes.

Effect of different processing conditions to obtain expanded extruded based on cowpea

“…Lira Filho ( 2002) and Jakkanwar et al (2018) extruding WCF in a single screw also found negative effects of temperature on the SEI, but Marques (2013) obtained a positive correlation. Bepary et al (2019) also found negative effects of temperature when using ricebean (Vigna umbellata (Thunb.) Ohwi & H. Ohashi) flour and a twin screw extruder.…”

“…Strauta & Muizniece-Brasava (2016) found harder extrudates as well as higher moisture content. Bepary et al (2019) using the same analytical procedure, and the same independent extrusion variables, but in different ranges, obtained ricebean whole flour extrudates with hardness from 9.61 to 27.95 N, with positive effects of rotation speed and moisture, and negative for temperature.…”

“…The applied test simulates a bite as if the incisor teeth were aligned; representing a blade, cutting perpendicularly to the longitudinal axis of the extrudate until complete breakage, and the peak force obtained is the measure of the cutting force, indicative of the product's hardness. This is one of the parameters of mechanical characteristics, defined as the force required to achieve a given deformation, or the force required to break the extrudate (Bepary et al, 2019).…”