Development and evaluation of a pneumatic extruder for production of fortified rice noodles (idiyappam)

Abstract

The traditional food products of various regions are now developing into food processing business. Marketing of these kind of culinary products will enhance the more income, jobs as well as minimizes post-harvest. Traditionally rice noodles or idiyappam is prepared by pressing the rice flour water mix through the die with holes of required diameter manually. It is a time consuming and energy intensive laborious process. There are motorized idiyappam machines are available. But such motorized extruders are complicated in design, energy intensive and lacking in precision with more moving parts and associated gear mechanisms. Pneumatic engineering is based on the compressed air or compressed inert gas. In this study a pneumatic extruder was developed for the production of fortified rice noodles, which composed of frame assembly, pneumatic cylinder, compressor, air filter regulator, double solenoid valve, pneumatic pipes/tubes, pneumatic fittings, timer, flow control valve, extruder die, dough cylinder , noodle collecting plate, plate holding section and DC motor. In order to evaluate the developed system towards extrusion fortified rice noodles, the effect of process parameters which would influence the capacity, energy and rate of extrusion such as pneumatic pressure of 600, 700 and 800 kPa, speed of the piston 0.05,0.06 and 0.07 m/s, jackfruit seed flour proportion in the blend of 5, 8 and 11% were studied. Physical properties, cooking properties, nutritional profile and sensory scores were analysed. The optimised operating condition of pneumatic pressure, speed of the piston and jackfruit seed flour proportion in the blend were found to be of 800 kPa, 0.07 m/s, 5 % respectively. From this study, it may be derived that the jackfruit seed flour fortified rice idiyappam prepared through the pneumatic extruder developed under this study at optimised operating condition of 800 kPa of pneumatic pressure, speed of the piston 0.07 m/s and 5% fortification of jackfruit seed flour in the rice powder resulted in production of higher capacity of noodles at lower energy level and higher rate of extrusion. These noodles were found to be on par with cooking and physico-chemical qualities, nutritionally rich and organoleptically superior with that of traditionally prepared rice idiyappam.