Physico-chemical changes in high pressure treated Indian white prawn (Fenneropenaeus indicus) during chill storage

Abstract

Changes in physico-chemical characteristics of Indian white prawn (Fenneropenaeus indicus) subjected to different high pressures and kept in chilled (2±1 °C) condition were analysed for a period of one month. Headless shell-on prawns were vacuum packed in EVOH multilayer pouches and subjected to high pressure treatment of 100, 270, 435 and 600 MPa and untreated prawns were kept as control. Biochemical parameters like pH, TMA, TVB-N, and TBA and physical parameters like colour and texture were periodically determined. pH and TBA values increased after HP treatment and significantly increased on storage. Significant reduction of TMA and TVB-N values after high pressure treatment was observed and during storage there was a gradual increase in all samples. Hardness, whiteness (L* value) and yellowness (b* value) increased with increasing pressure and redness (a* value) was found to decrease. Industrial relevance: Prawns are an important commodity of international trade. Prawns are fished from the oceans and also form an important aquaculture species. They are utilized as food and demand a high price in the market. Due to the highly perishable nature of the commodity the shelf life during chill storage is limited. Being bottom dwellers the harvested prawns contain a higher bacterial load and hence high pressure processing will help in the reduction of bacterial load and thereby extension of shelf life. High pressure processing will also help in easy removal of the shell from the flesh.