Wild jellyfish are transparent, and white, cyan or yellowish alum is a dehydrating agent that must be used during the processing of jellyfish alum. However, too much alum will cause excessive aluminum residue. Food standards require that the alum content of salted jellyfish should be 1.2 %-2.2%, alum with a suitable ratio can also better ensure the taste of the product, improve the quality of the product, and extend the shelf life of the product. Some producers sell incompletely treated dilum jellyfish products as finished products. The skin of this jellyfish has a translucent jelly-like appearance and a soft white hemp-like shape. If you squeeze it lightly with your hands, liquid will overflow; The appearance of the jellyfish head is brown-red, with a soft and white jelly-like substance in the center. It tastes astringent, slippery and is inedible. When processing jellyfish in areas with hot climates, in order to prevent the jellyfish from rotting, borax and boric acid are often added as preservatives. These two substances are food additives not allowed by the state. Borax can cause poisoning symptoms in people, including nausea, vomiting, Bloody diarrhea and abdominal pain. Sulfites or sulfates are used as bleaching agents by some jellyfish processing companies to remove "bloody heads" and "red coats" from jellyfish. Sulfur dioxide can cause allergic reactions such as asthma, and some people may experience headaches after ingesting this preservative. and nausea. In response to these unsafe factors, my country is implementing relevant salted jellyfish quality standards. High-quality jellyfish skin: it should be white or light yellow, shiny, naturally round, large and flat, without red, variegated, or black spots, and the flesh should be thick, uniform, and tough; no fishy odor; tough; good taste Crunchy and delicious. Inferior jellyfish skin: The skin becomes darker, has a peculiar smell, has poor toughness when pinched by hand, and is easily broken. High-quality jellyfish heads: should be white, yellowish brown or reddish amber in natural color, shiny, complete in shape, without stinging whiskers, thick and tough meat, and crispy in texture. Inferior jellyfish heads: Purple-black in color, poor toughness when pinched by hand, easily broken when picked up by hand, smelly and pus-like liquid.