Cooking green beans without discoloration method

Adding a small amount of salt or baking soda when cooking green beans can prevent discoloration. The discoloration of green beans is mainly related to factors such as chlorophyll decomposition, acidic environment, and high-temperature oxidation. By adjusting the pH value, controlling the heating time, and rapid cooling, the emerald green color can be effectively maintained.

When boiling green beans, the water should be boiled before adding to the pot, and the amount of water should completely cover the beans. High temperature rapid blanching for 1-2 minutes can inactivate oxidase. At this time, adding 1 gram of salt or 0.5 grams of baking soda can neutralize organic acids and help stabilize chlorophyll structure. Use stainless steel cookware to avoid discoloration catalyzed by iron ions. After blanching, immediately supercool to stop the residual heat. After draining, mix in a small amount of edible oil to form a protective film on the surface. If frozen green beans are used and cooked directly without thawing, refrigerated fresh beans need to be soaked 2 hours in advance. Avoid using copper and iron cookware and acidic seasonings. Lemon juice or vinegar should be added after cooking. Steaming is more conducive to color retention than boiling water. After steaming in a steamer, keep it on medium heat for 6-8 minutes, and lay gauze to isolate condensed water to reduce pigment loss.

For fresh green beans, it is recommended to choose varieties with plump pods and a bright green color. Peeling and boiling them fresh can maximize the retention of chlorophyll. Put it in a fresh-keeping bag for daily storage, remove the air and refrigerate, and consume it within 3 days. In addition to salt and bicarbonate of soda, adding a little edible oil or sugar when blanching can also help protect the color, but it should be noted that diabetes patients should be careful with sugar. Long term storage can be blanched and frozen, and the color can still be maintained at over 80% after thawing.