PROJECT-SNACK AND BREAKFAST FOODS

Technology of the Month

Low cost collet extrusion for expanded/puffed snacks

Snack foods now comprise an important part of the daily nutrient and calorie intake of manyconsumers. Expanded products like snacks and breakfast cereals are very popular todaybecause of their crunchy texture, which arises from the honeycomb structure imparted to thematerial during extrusion. At CIPHET, an extrusion facility with range of extruders has beenestablished during last 3 years. In particular a collet extruder of small capacity (25-35 kg/h)shows a very promising feature for the production of low cost protein enriched ready-to-eatexpanded snacks. This heavy-duty low cost collet extruder, driven by 10 hp AC motor andfeed rate is controlled with a 1 hp DC motor. The length to diameter (L/D) ratio of extruderwas 5:1. The barrel is enrobed with cold/ tap water circulation to maintain the temperature.


For the development of ready-to-eat snack foods, screw speed (500 rev/min), feed rate (25kg/h) and feed moisture(14%, wb), feed particle size (1.65-2.36 mm) were
found optimum and kept constant for different protein enriched extruded snack foods. It is attached with a cutter (1 hp DC motor). The feed of required particle size with predetermined formulation can be fed through feeder,which can be regulated by
screw auger. The expanded products of 14-20 mm axial diameter can be produced.

The investigation was carried out at CIPHET with this low cost collet extruder for the continuous production of protein enriched expanded snacks at optimum extrusion condition and different legumes incorporations (black gram, green gram, lentil and peas) on selected cereals and coarse cereal grit. It was found that this is suitable to process and produce legume blended cereals and coarse cereals expanded snack foods and instant flour with low moisture (<14%, wb) and low lipid content. Extrudate flour which are partially dextrinised and gelatinized during the treatment, yielding instant flour showed the scope for preparation of
higher energy density gruels. The lower viscosity profile of extrudate flour as compared to its raw composite flour and higher nutritional and sensory values expressed the usefulness and possibility of product development, especially high quality diet and weaning foods at competitive prices, which can dramatically transform the Indian cereal industry. This food extrusion facility costs about Rs. 2.0 Lakhs. This can be easily adopted by the small and cottage level entrepreneur for the production of Ready-To-Eat snacks and similar products.

This production is highly profitable (about Rs. 14/kg of product). This technology facilitates use of low cost rice and wheat brokens to be converted into high value ready to eat snack foods at rural catchments. At CIPHET we offer one week training programme for upcoming entrepreneurs on this technology for establishing rural enterprises.