How to make the luffa not change color

Silk gourd is prone to oxidation and discoloration after being cut open. It can be maintained in color by soaking in water, cooking quickly, and avoiding contact with metal utensils. There are mainly methods such as rapid processing, air isolation, acidic environment treatment, low-temperature storage, and selection of fresh ingredients.

1. Quick processing

After peeling or cutting the luffa, it needs to be cooked or soaked immediately. After plant cell damage, polyphenol oxidase is released, which comes into contact with oxygen and causes browning. When processing, the action should be fast to reduce exposure time to air. After cutting, cooking within 10 minutes can effectively delay discoloration.

2. Isolation from Air

Immersing the sliced loofah completely in clean water can block oxygen. A small amount of salt or a few drops of white vinegar can be added to water. Salt can inhibit enzyme activity, while vinegar can create a weak acid environment. Pay attention to soaking for no more than 30 minutes to avoid nutrient loss.

3. Acidic environment treatment

Acidic substances in lemon juice or white vinegar can lower the pH value and inhibit polyphenol oxidase activity. Mix 5 milliliters of lemon juice with every 500 grams of luffa, or soak it in a 1:10 vinegar solution to maintain its color for a longer period of time.

4. Low temperature storage

Uncooked luffa chunks should be wrapped in plastic wrap and refrigerated to slow down enzymatic reactions. It is recommended to store at temperatures below 4 ℃ for no more than 2 hours. Prolonged refrigeration can cause cell frostbite, accelerate browning, and soften texture.

5. Choose fresh ingredients

Fresh green skin and pressed hard, tender luffa are more resistant to oxidation. Mature loofah has increased cellulose content, making the cut surface more prone to blackening. When purchasing, observe whether the stem is moist to avoid fruits with scratches or dents on the skin.

In addition to the above methods, it is recommended to use ceramic or stainless steel knives when cooking, as iron knives can accelerate oxidation. Quick stir frying over high heat can better maintain the emerald green color than slow stewing, and the steaming time should be controlled within 5 minutes. Cold mixed luffa can be blanched in boiling water for 10 seconds to destroy oxidase, and then quickly supercooled. When storing whole loofah in daily life, wrap it in newspaper and place it in a cool place to avoid direct sunlight that can cause chlorophyll decomposition. If the color has slightly changed, it can still be consumed after removing the surface oxide layer, but its nutritional value and taste may decrease.