EVALUATION OF WASHING IN CHLORINATED SEAWATER TO ASSESS THE MICROBIOLOGICAL AND SENSORIAL CONDITION OF “IN NATURA” OYSTERS (Crassostrea gigas) CULTIVATED IN FLORIANOPOLIS-SC (BRAZIL)

Abstract

Raw oysters were washed with chlorinated seawater and analyzed concerning microbiological and sensorial qualities. The oysters were acquired at a growing area from Santa Catarina Federal University, Brazil. After removing the shells, the oyster-flesh was dipped into cold seawater containing 100 ppm of sodium hydrochloride during periods of 3, 5 and 7 minutes. One sample remained in natura as the control. Aerobic mesophilic flora, aerobic psychrophilic flora, coliform bacterias and E. coli were counted by Petríülm™ methods. Sensorial evalualion of the samples was performed by a team of seven judges using a 9-point hedonic scale, observinq the characteristics of color, odor and taste. Five­minute and seven-minute washing treatments reduced 69% of mesophilic flora and 94% and 97% of the total coliform contamination, respectively. E. coli was absent in all samples. As concerns to the sensorial evalualion, there was no difference at a significance level of 5% among the samples of washing treatments of 3 and 5 minutes and the control sample.