Standardization of Recipe for the Preparation of Prawn Gravy (Iral Kootu) and Thermal Processing in Retort Pouch

This study was conducted to standardize the preparation of Iral Kootu, a traditional delicacy of Southern districts of Tamil Nadu, India and to extend the shelf life of the product by retort processing. Three types of prawns like White Prawn (Penaeus indicus), Tiger Prawn (Penaeus mondon) and Flower Prawn (Penaeus semisulcatus) were used to make Iral Kootu. It was then packaged in a 15 x 20 cm retort pouch with a three-layer structure made of 15.60 µm polyester, 29.20 µm aluminium foil and 97.20 µm polypropylene. The pouch's suitability for thermal processing was demonstrated by the results of the physico-chemical and barrier tests. The form of the ingredients, the shape of the prawns and the sautéing method were established in the initial testing. Based on sensory evaluation, precooked prawns with sautéed ingredients and gravy in paste form were chosen for additional research. All other ingredients were kept in a fixed proportion while the gravy was made by altering the composition of the condiments and spice mixture. Condiments were applied at 15%, 20% and 25%, respectively, and spice mixes at 5%, 7.5% and 10%. All pouches had a prawn to gravy ratio of 64:36, and thermal processing was done for 15 minutes at 121°C in a pilot-scale horizontal stationary water-spray retorting system. For all three prawn kinds, the sample with the greatest score in all sensory attributes was the one with a 7.5% spice mix and 20% condiments.