河裡和海里的很多魚和蟹都有寄生蟲,如三文魚和藍蟹等。
生魚蟹蝦,一定要經過處理,才能生食。如何處理,實際上就是通過低溫冷凍殺死寄生蟲。
FDA對於零售商的要求是,必須滿足以下三項之一,才能出售供食客生食的魚蟹蝦。
1.海鮮冷凍貯藏在 -4°F (-20°C) 或以下7 天。
2.海鮮冷凍在 -31°F (-35°C) 或以下冷凍成硬塊后,貯藏在 -31°F (-35°C) 或以下達 15 小時。
3.海鮮冷凍在 -31°F (-35°C) 或以下冷凍成硬塊后,貯藏在 -4°F (-20°C) 或以下達24 小時。
家用的冰箱根本達不到這麼低的溫度,一般店裡出售的魚蝦蟹也沒法達到這個要求。
如果要吃生魚蟹蝦,可以去日本店或韓國店或 美國 wholefood market,買用來生食的或做壽絲的經過處理的生魚蟹蝦,稱sushi grade的魚蝦蟹。
有關資料見:
http://www.sushifaq.com/sushi-grade-fish.htm
What is sushi grade fish and where do I buy it?
The only concern any inspectors have is referred to as the parasite destruction guarantee, which is accomplished by 'freezing and storing seafood at -4°F (-20°C) or below for 7 days (total time), or freezing at -31°F (-35°C) or below until solid and storing at -31°F (-35°C) or below for 15 hours, or freezing at -31°F (-35°C) or below until solid and storing at -4°F (-20°C) or below for 24 hours' which is sufficient to kill parasites. The FDA's Food Code recommends these freezing conditions to retailers who provide fish intended for raw consumption (for further information, please visit the FDA website).