After the raw oysters are fished out of the water, they are dried by removing impurities attached to the shells. Calcined oysters are calcined on the basis of raw oysters. Raw oysters are usually grayish yellow or gray with a rough surface. Calcined oysters are generally grayish white, some are bluish gray, and there is a little burnt smell.
Raw oyster shells can be divided into three layers in section; The outermost layer is a thin and transparent stratum corneum, the thickest layer is a columnar structure composed of calcium carbonate called prismatic layer, and the inner layer is a flaky structure called nacre.
The shell is formed by the secretion of the lower mantle, which extends from the top of the shell to the edge of the abdomen. It is a membrane formed by two layers of upstream dust skin cells with connective tissue in the middle. There are muscle fibers in the membrane that make it adhere to the inner surface of the shell. The edge of the mantle thickens to form three folds, and there are radial muscles and annular muscles on the inner folds to make the edge close to the shell.
There are a large number of sensory cells or organs in the folds, which have tactile and visual functions. The outer fold has a strong secretory function. The two shells are unequal, the left shell or the lower shell is large and concave, and the left shell is fixed on rocks or seabed stakes.
Generally, in the later stage of metamorphosis, the foot silk secretes mucus, which fixes the edge of the mantle on the substrate, and then the shell secreted by the mantle directly adheres to the plug. The foot completely disappeared, the degeneration of the adductor muscle disappeared, and the adductor muscle moved to the middle of the body, completely losing its mobility.
Adductor muscle and ligament have antagonistic effect. Due to permanent fixation, there are developed small tentacles or feelings at the edge of the mantle. Mantles never have healing points or water pipes, because they live on hard surfaces, where there are almost no sediments, which have been carried away by tidal movements.
Oyster selection
When purchasing high-quality oysters, we should pay attention to selecting large, fat, yellowish, uniform, dry and brownish red surface. Cooked oysters have a slightly open shell, which means they are alive before cooking. If you cook after death, the shell is closed, because the living have a reaction when cooking, so the shell is opened and the dead have no reaction.
Use chopsticks to separate the oysters from the bottom of the basin, because the position of the oysters is always in the center of the basin, and the spit sand sinks directly to the bottom, so that the water sucked in by the oysters hanging in the middle is clean.
When buying oysters, ask the boss for some sea salt and dissolve it in clear water to create the taste of sea water. Then put two chopsticks in the basin to prevent the small basket from sinking. Finally, put a basket full of oysters on it and drop a few drops of sesame oil. After 2-3 hours, you will see a lot of dirty things on the pelvic floor.