Physiochemical changes in tissue of edible oyster Crossostrea glomerata at refrigerated temperature

Oysters are bivalve molluscs in the family Osteridae of the order Ostereoida and are found throughout the world. Quality of stored muscle of oyster, Crossostrea glomerata depends on the temperature and storage time. Investigation on factors responsible for spoilage of oyster meat in refrigerator (۷±۲°C); in term of biochemical indices, indicated that in ۱-۲ days the following changes will accur: oyster tissue total protein from ۷.۶±۰.۴۴g% to ۷.۰۶±۰.۶۴g%, salt soluble protein from ۳A۶±۰.۵۲mg% to ۲.۵۳±۰.۱۴g%.Totallipid from ۳.۰±۰.۳۸g% to ۲.۵±۰.۲۹g%, TMA from ۱.۱±۰.۱۱ mg% to ۱.۴۶±۰.۰۹ and TVB, from ۹۴۶±۰.۲۹mg% to ۱۹.۳۳±۰.۰۶ and on ۷th day of storage, total protein to ۴.۵±۰.۳۲g%, salt soluble protein to ۱.۱±۰.۲۱g%, total lipid to ۱.۴±۰.۱۹g%, TMA, to ۴.۳±۰.۴۱ mg% and TVB to ۸۳.۳±۳.۵ changed. Amount of Glycogen in fresh meat was ۵.۳g% which decreased to ۳.۲g% during ۷ days storage. Water content in fresh tissue was ۷۹.۰±۰.۵۷g% and increased at ۷±۲°C gradually with the increase of storage time. After ۷ days it reached to the highly significant (p<۰.۰۰۱) value of ۸۹.۱±۰.۵۴g%.pH in fresh tissue was also noted ۶.۶۰±۰.۱۷and slightly non significant change was observed during ۷ days of storage. On the ۷th day it decreased to ۶.۳±۰.۰۵ from its fresh tissue value significantly (p£۰.۰۰۱) with storage time. Results concluded that oyster meat could be preserved for ۴ days up to acceptable refrigeration temperature.

Keywords:

Physiochemical , Edible oyster , Refrigerated temperature , Refrigeration period