Since 2000, the opportunity to eat raw oysters with shell has been increased due to the spread of oyster bars, and the safety and freshness evaluation of oyster (Crassostrea gigas) are becoming more important. However, judging the vitality and freshness of oyster is technically difficult and is still kept by the experience of skilled people in actual production. Additionally, because the heart beats continuously throughout life, the corresponding beating patterns can be used as an indicator of health and stress in various organisms. In this study, we verify the relevance of heartbeat activity and vitality of oyster during storage using image processing techniques and biochemical indicators. We also examine the application to the distribution of active aquaculture products through rapid vitality and freshness judgment on site, which is difficult to handle with conventional biochemical analysis methods.
Since 2000, the opportunity to eat raw oysters with shell has been increased due to the spread of oyster bars, and the safety and freshness evaluation of oyster (Crassostrea gigas) are becoming more important. However, judging the vitality and freshness of oyster is technically difficult and is still kept by the experience of skilled people in actual production. Additionally, because the heart beats continuously throughout life, the corresponding beating patterns can be used as an indicator of health and stress in various organisms. In this study, we verify the relevance of heartbeat activity and vitality of oyster during storage using image processing techniques and biochemical indicators. We also examine the application to the distribution of active aquaculture products through rapid vitality and freshness judgment on site, which is difficult to handle with conventional biochemical analysis methods.
The heartbeat activity tended to prolong the cardiac cycle as the stored days passed. It was suggested that the prolongation of the cardiac cycle is caused by the decline of vitality, when the A.E.C. values were 40\% or more in the early stages of storage, and the pH decreased over time from around 6.7 to around 6.3. An unusual heartbeat pattern, such as arrhythmias, was confirmed in individuals whose cardiac cycle was prolonged.