Processing Technology of Lanzhou Lily

Lanzhou lily is a perennial herb of Liliaceae, which has a long history of planting in Lanzhou. Because its underground stem is embraced by dozens of scales, it has the characteristics of a hundred pieces of synthesis, which contains the meaning of "Pepsi" and "hundred years of good harmony". And it has the effects of invigorating stomach, tonifying deficiency, eliminating phlegm, nourishing yin and so on, so it is deeply loved by the majority of consumers. Lanzhou lily is resistant to drought and is suitable for planting in high and cold mountain areas above 2000m above sea level. The producing area with cool climate, large temperature difference between day and night, few diseases and insect pests, lily has more dry matter accumulation, white color, thick and delicate meat, delicious taste and rich nutrition.

1. Harvest period

The harvest time of Lanzhou lilies has a great influence on the processing quality of lilies. Generally, from November 15 to March 15 of the following year, the lilies are simply collected and put into baskets, transported to the market or refrigerated, and listed on the market one after another. The lilies dug in advance before the mining period are generally poor in taste and incomplete in nutrients, which are called "green seedling" lilies by the local people. Because the lily has a short time, it should be processed to extend the sales time and expand the sales area to achieve year-round supply. At present, the common lily processing products are vacuum packed fresh lily, dried Lanzhou lily and lily powder.

two。 Processing Technology of fresh Lily in vacuum Packaging

The fresh lily processed by vacuum packaging technology will have better color, aroma, taste and shape. It can be stored in 0 ℃ ~ 4 ℃ cold storage, and the shelf life can be up to 60 days, which is convenient for long-distance trafficking, storage and sale. The main production processes are as follows:

The main results are as follows: (1) according to the Lanzhou Lily quality Classification Standard issued and implemented by Gansu Provincial Bureau of quality and Technical Supervision DB62/412-95, fresh lilies are divided into super grade, first grade, second grade and third grade according to the horizontal diameter, number of split heads and uniformity of the products, as shown in Table 1.

Table 1 quality grading index of Lanzhou lily

Project super level 1, level 2, level 3

Horizontal diameter cm ≥ 9.0 ≥ 9.08.0 8.98.0 8.97.0 7.96.0 6.9

Several split heads 1 "23" 41 "23" 41 "21" 2

Uniformity% ≥ 98 ≥ 95 ≥ 95 ≥ 95

(2) remove the soil by using a brush to remove the soil and peel off the outer skin. After treatment, the lily is fresh and white, no rot spot, no injury spot, no insect spot, no scab spot, no soil on the fleshy whisker root, and the length of the whisker root does not exceed 1cm.

(3) the fresh lilies that meet the standards of each grade shall be weighed and bagged.

(4) sampling inspection randomly take out the lily bagged, observe the changes of its color, tissue shape and taste, eliminate the unqualified products, and make up the bagged quantity.

(5) packing storage: put the bagged lilies into vacuum packaging machine for vacuum packaging, and then store them in 0 ℃ ~ 40 ℃ cold storage to avoid light. The goods should be stacked off the ground 10cm, leaving enough 10cm ventilation between the goods.

3. Processing Technology of dried Lily and Lily Powder

The main results are as follows: (1) the raw materials for processing dried lilies and lily powder are: lilies whose transverse diameter is less than 6cm or whose number of lilies is more than 5 after vacuum packaging by ①; scales peeled off by ② when vacuum packaging fresh lilies; and finished fresh lilies that need to be processed by ③.

(2) peel off the scale from the selected large bulb of fresh lily to keep the scale intact. Soak the stripped and graded lily scales in water to soften the attachment, and then wash it once or twice with clean water to remove the soil, dust, residues and microorganisms attached to the surface and ensure the cleanliness and hygiene of the raw materials.

(3) blanching treatment the washed lily lobes are graded and boiled in a boiling water pot, the ratio of water consumption to the mass of lilies is 10:3, the water should submerge the lily slices, stir slowly with boards (sticks) in the pot, so that the lilies are boiled evenly. The suitable blanching time for first-class tablets, second-grade tablets and third-grade tablets was 60s, 40s and 10s, respectively. The hot-boiled lily is beige, the tissue is transparent, loses fresh hardness, but is not ripe. The sensory performance is that the skin is powdered by scraping the nails, the scales are not brittle with the mouth, the color of the broken section is uniform, and there is no white heart. Under normal circumstances, when turbidity occurs after a pot of water is boiled continuously for 2 ~ 3 times, clean water should be replaced. Remove the hot-boiled lily slices from the pot and quickly bleach them in cold water, then pour them into bamboo or porcelain plates to dry, and spread them evenly without overlap.

(4) the drying and fumigation drying methods include natural drying, artificial baking room drying and mechanical drying. At present, the artificial drying method is mostly used, which includes three steps: heating, ventilation and dehumidification, and the placement of raw materials. Drying is usually carried out at the same time as fumigated sulfur bleaching. The method of fumigating sulfur is to select pure sulfur powder with arsenic content less than 0.015% to fumigate lily tablets; the dosage is 0.2%-0.5% of the quality of raw materials, or sulfur can be fumigated according to the size of the drying room according to the amount of 150g/ cubic meters. The specific method is to put the iron container containing sulfur powder on the stove to make it heated and burned. Fumigated sulfur bleaching can destroy the biological enzyme system of lily, prevent enzymatic browning, kill various microbial pathogens attached to scales, accelerate water evaporation, shorten drying and dehydration time, and make lily dry color white. When fumigating sulfur, the hygienic Standard for the use of Food Additives issued by the Ministry of Health must be strictly implemented, and the content of sulfur dioxide should not be higher than 100mg/kg.

(5) the technical key point of baking in the drying room is to adjust the indoor temperature and humidity. When the raw materials are sent into the baking room, close the doors, windows and ventilation facilities. After the baking starts, the temperature in the baking room rises, and the temperature should be controlled at 70 ℃ ~ 75 ℃. When the indoor relative humidity exceeds 70%, the ventilation is 10 min and 15 min. When the relative humidity in the baking room drops to about 55%, turn off the ventilation facility, and then ventilation and dehumidification 4 ~ 5 times according to the humidity meter. When the hot air drying method is adopted, the steam is ventilated first and then the fan is turned on. When the temperature in the baking room rises to 70 ℃, the exhaust fan should be turned on to drain moisture once every 20min~30min. After 2 hours, the degree of dryness and humidity of the lily was appropriately prolonged. In the later stage of baking, most of the moisture of the scale is lost, and the surface is soft, so it should continue to be dried until it fully meets the requirements. The dried finished lilies are easy to shake in the baking pan, feel hard and crisp, do not soften in the middle when they are broken, and make a sound when they are broken. The whole baking process should be checked and turned frequently, so that the baked lily scales are heated evenly. After baking, the dry pieces should be spread out in time to dissipate heat, and finally stacked together to return to soft ventilation, so that the dried lily slices are dry and wet evenly, and the moisture content is less than 11%.

(6) after the baked lily is dried and cooled, the graded packaging should be selected and baked again if the moisture content is too high. Remove the old skin, lily core, scar and discolored scales, and then pack them by grade.

(7) the dried lily powder can be produced by feeding the remaining dried lily after baked or graded packaging into the mill.