Effective Methods to Prevent Browning After Lily Harvest

During the harvesting and storage of lilies, prolonged exposure to sunlight causes the lily scales to change color from white to brown, a condition known as browning. Browning is an oxidation reaction catalyzed by biological enzymes in the lily scales. Browning reduces the quality of commercial lilies; in the case of lily seed bulbs, browned bulbs have a low germination rate and are prone to rotting. This year lilies matured early, and harvesting is expected around early July, so attention should be paid to preventing browning early.

During harvesting, care should be taken to provide shade coverage. Under strong direct sunlight, lilies dug from the soil are often prone to browning, and this is often overlooked by growers, thereby reducing lily quality. Therefore, harvesting is best done on cloudy days or on sunny afternoons, and dug lilies should not be left exposed in the open for too long. If harvesting on a sunny morning, the dug lilies should be promptly covered with straw or other covering materials to block light, preventing direct exposure to strong sunlight that causes oxidative browning. Promptly remove soil and debris, cut off the roots, and place the lilies in baskets. Once a basket is full, place covering material over it as well to block light. After harvesting, transport them back promptly, place them in a cool indoor spot, spread them out to dry slightly, and do not leave them outside in the sun.

Commercial lilies should be blanched (boiled) as early as possible. The purpose of blanching is to kill the biological enzymes in lilies that promote browning, prevent enzymatic browning, kill pathogens, and prevent rot. Some farmers do not understand the principle and function of blanching and often fail to blanch in time. Because blanching is done too late, the outer scales or even the core scales develop browning or begin to develop browning before blanching, and after processing the dried slices are not white in color, becoming yellow slices or even black slices. Therefore, lilies after harvesting should be blanched on a sunny day as early as possible. If blanching time is too long, the slices easily break apart and become mushy; if blanching time is too short, the biological enzymes are not completely killed and inactivated, leading to more severe browning and ultimately turning into black slices, seriously affecting quality. In Xinshao, farmers commonly use a lotus-leaf cauldron for blanching. The lotus-leaf cauldron holds 50 kg of water; bring it to a boil, then pour in about 15 kg of washed and drained scales while stirring with a stick. When the lilies turn from white to slightly yellow, and then from yellow back to white, when scraping the slice with a fingernail reveals a powdery surface, when tasting the slice shows it is crisp and raw, when breaking the slice shows no white core in the cross-section, and when the water in the pot has not become cloudy, this indicates the blanching time is appropriate, and the slices should be removed from the pot immediately. Generally speaking, outer scales should remain in the boiling water for 5-6 minutes, and core scales for 2-3 minutes, after which they should be removed from the pot immediately. After blanching 2-3 batches in the same pot of water, the water should be changed. After removal from the pot, cool immediately and dry in the sun.

Lily seed bulb storage. To prevent browning and rotting, the storage site should be dry, well-ventilated, cool, and protected from light. Generally, the sand-soil layering method is used for light blocking. After harvesting, place the lily bulbs in a cool room and spread them out briefly to reduce moisture in the scales, but the time should not be too long, generally about 2 days. Choose a cool room, spray the floor with 0.3% formaldehyde solution or 0.3% potassium permanganate solution, then spread a layer of clean garden soil or river sand 5-7 cm thick on the floor, place the lilies on it in neat rows. Then cover the lilies with a layer of soil or sand about 3-4 cm thick, and repeat this process, with the height not exceeding 1.5 m, and seal the surroundings tightly with soil or sand. This ensures light blocking, moisture retention, and ventilation. Check once every 20-30 days, and avoid turning them over too much. If any spoiled bulbs are found, remove them promptly.