Value addition and storage characteristics of product prepared from prawn waste using twin screw extruder

A value-added extruded prawn product was prepared with prawn flavour powder and corn flour using a twin-screw extruder. The effect of different parameters like moisture, temperature, prawn powder concentration, speed of the extruder and diediameter on expansion ratio and crisp texture were studied. As the moisture content increased upto 20%, the expansion ratio also increased, but at low moisture, the surface was dry and split. Surface appearance improved with the increase in moisture and at 20% moisture, the surface became very smooth. Moisture content higher than 21% yielded product with tough centre core. Higher moisture yielded moist product, which needed to be dried in a drier before packing. So, it was found that with 20% feed moisture, the extrudate had soft and crisp texture, maximum expansion ratio and dry smooth surface with yellow colour and prawn flavour. The storage characteristics of the final product were studied using three different types of packaging under nitrogen flushing. The study revealed that aluminum foil is the best packaging material to keep the product acceptable for more than three months.