变黑的虾还能吃吗？这种“黑虾”千万别吃

Core Viewpoint - The discoloration of shrimp is primarily due to oxidation rather than contamination or spoilage, and such shrimp are generally safe to eat [3][4]. Group 1: Oxidation Process - The blackening of shrimp occurs when polyphenols and polyphenol oxidase are released from damaged cells after the shrimp die, leading to a chemical reaction with oxygen that produces melanin [4]. - The shrimp's head, legs, and shell are particularly prone to blackening due to higher exposure to air and physical damage during handling [4]. Group 2: Prevention Methods - To prevent shrimp from turning black, it is essential to thoroughly cook them to destroy the oxidase, with longer heating times resulting in less discoloration during storage [6][7]. - Storing shrimp in water can help isolate them from oxygen, thus preventing oxidation; placing shrimp in a container submerged in water before refrigeration is recommended [8]. - It is advised to cook thawed shrimp promptly to avoid accelerated blackening due to temperature increases and cell structure breakdown [9]. Group 3: Black Gill Disease - A different condition known as black gill disease can cause shrimp to appear black while alive, characterized by internal blackening of the gills and often accompanied by an unpleasant odor and sliminess; such shrimp should not be consumed [10][12].