Processing steps of day lily
The harvest flowers should be processed in time. Firstly, steam the day lily in high heat to denature the enzymes and inhibit their activity. If they are placed for too long, the buds will convert nutrients and gradually open the flower under the action of enzymes, which will affect the drying quality. Thermal steaming is the key link in the drying process of day lily.
Before steaming, the raw materials should be selected. You should remove impurities and pick out the flowers that have opened. Put the selected flowers on the cage. After boiling the water with high fire, you should quickly put the day lily in the cage. After the steam emerges, switch to slow heat and steam for about 10 minutes. When steaming, the cage should be kept a certain distance away from the water surface because if the distance is too close, the flower buds that come into contact with the boiling water will crack and spread out, which means the drying value will be lost.
The degree of thermal steaming is generally controlled at the time when the flower buds are “raw inside and ripe outside”. The artificial drying process can be slightly more mature than natural drying process. The flower buds released from the cage are in yellow and bright color, which is light yellow but not green, and the flower buds are covered with small water droplets. After being released from the cage, the stacking thickness is reduced by 1/3 compared to fresh day lily. It is slightly soft and flexible when pinched by hand. When picking up the middle of the bud with chopsticks, the two ends are slightly bent downwards. After steaming, the yellow flowers should be quickly picked out and placed in a container to be tightly sealed, and the residual heat should be used to make them meet the requirements. If the day lily are still raw, you can pick them out and then steamed again. After steaming, it can be placed in a ventilated and shady place to cool down naturally. If conditions permit, the yellow flowers can be cooled and dried for about 4 hours.
Daylily drying process
Put the baking tray (which could load 5 kg/square meter day lily) into the drying room at 80℃. As the daylily absorbs a lot of heat, the temperature of the drying room will drop to 60℃–65℃. Keep this temperature for 10-12 hours, then naturally cool down to 50 ℃ until the drying process complete. During the drying process, pay attention to dehumidification condition and keep the relative humidity level below 65%. The dehydrated day lily should be held tightly without becoming brittle, and can be spread out naturally and not stick to each other after loosing the grip. Afterwards, you can dry it by sunshine for a while, then the color can be improved.
The dehydrated and dried day lily also needs traditional sulfur fumigation treatment to prevent mold and insects. Meanwhile, it can improve color and improve the preservation rate of vitamins.
Before sulfur fumigation, a comprehensive selection should be made according to the product quality requirements. You should pick the unqualified flower and spray some water on their surface, afterwards, place it on the drying plate and then put it on the bracket in the sulphur fumigation chamber. Put the red-hot iron plate or charcoal in the center of the sulfur fumigation chamber, then sprinkle sulfur powder to make it fully burn and generate smoke, and then close the doors and windows. 30-40 grams of sulfur is prepared for sulfur fumigation of 10 kg day lily, and the sulfur fumigation time is 3-5 hours.