Effect of Different Cold Storage Temperatures on the Evolution of Shucking Yield and Quality Properties of Offshore Cultured Japanese Oyster (<i>Magallana gigas</i>) Treated by High Pressure Processing (HPP)

Abstract

High pressure processing (HPP) can improve oyster shucking yield immediately after the treatment and increase the microbiological and sensory shelf life of oysters stored at 0-4 degrees C. However, the evolution of shucking yield during storage has not been previously examined and there are no studies focusing on shelf life at higher storage temperatures. To elucidate both aspects, control and HPP (300 MPa; 2 min) offshore cultivated oysters (Magallana gigas) were stored at 4 and 10 degrees C for 14 days, analyzing shucking yield, color, texture, microbiological and sensory characteristics. HPP samples showed a higher shucking yield (17\% on average) than controls with minimal impact in texture and color, regardless of storage time and temperature. At 10 degrees C, HPP delayed microbial growth and sensory deterioration, increasing the estimated shelf life of oysters by 3 to 4 days (aerobic plate count < 6 log cycles; overall sensory acceptability > 2). Compared to controls stored at 4 degrees C, HPP oysters stored at 10 degrees C presented the same shelf life (5 to 9 days) but with higher shucking yield (up to 25\%). In conclusion, HPP is an excellent tool to increase the shucking yield and delay sensory deterioration of oysters stored at 10 degrees C.