| Lily is a perennial herb which belongs to the genus of Liliaceae Lilium. It is widely distributed in Central Asia continent, and it has the highest production in China, which has high edible, medicinal, health and ornamental value. The bulbs is rich in carbohydrates, fats and proteins, and also contains a variety of medicinal ingredients such as glycosides and colchicine and other nutrients such as amino acids, vitamins and mineral elements. Lily has the effects of expelling phlegm, strengthening stomach, reinforcing deficiency and nourishing yin. In this paper, the changes of the main nourishment components and antioxidant activity during storage were studied, which will provide some references for preservation of lily and comprehensive development and utilization of lily. The major findings are as follows:1. According to the results of single factor experiment, the orthogonal experient with aqueous two-phase system was designed. The results showed that the optimum conditions of lily polysaccharide extraction were as follows: extraction time of 3 h, extraction temperature of 70 ℃, ratio of water to material of 1:12, p H of 5.5. Under these conditions the extraction yield could be up to 10.16%.2. The dynamic changes of the contents of moisture, vitamin C, polyphenol,polysaccharide, flavonoid and polyphenol oxidase activity and antioxidant activity of the fresh lily which were storaged under different conditions were determined. The results showed that the contents of moisture, vitamin C, polyphenol and flavonoid were getting lower and lower, polysaccharide content and polyphenol oxidase activity increased first and then decreased, and antioxidant activity decreased with the extension of storage time under the conditions of room temperature, low temperature and room temperature vacuum. These indexes changed obviously at room temperature, which changed slowly at low temperature.Fresh lily which were storaged at room temperature started to rot after 10 days, and started to rot after 20 days at low temperature and room temperature vacuum. The main nourishment components and antioxidant activity of fresh lily which were storaged at low temperature changed slowly. Fresh lily storage test showed that low temperature condition can maintain the appearance and color and other sensory quality of fresh lily, reduce the loss of nutritional components, slowdown the quality decrease of fresh lily effectively, and extend the shelf life,so it can be used as optimum storage condition for fresh lily.3. Fresh lily were smoked by using different amount of sulfur. The results showed that when the amount of sulfur was less than 1/100(the quality of sulfur account for 1/100 of the quality of fresh lily), the dried lily showed brown basically and the sensory quality was poor,when the amount of sulfur was 1/100, the dried lily showed brown, when the amount of sulfur was 1/50, the dried lily was light yellow basically and slightly white, and the appearance and color were good, when the amount of sulfur was 1/20, the dried lily was too white. SO2 residues in the sulfur smoked dried lily was determined by iodine absorbing titration. The results showed that when the amount of sulfur was 1/50 and 1/100, SO2 residues were 307mg/kg and 141 mg/kg respectively, which were less than 400 mg/kg and accord with national standard. Combined with the results of appearance evaluation of dried lily, it was concluded that the optimum amount of sulfur for preparation of dried lily was 1/50, and the effect of sulfitation was the best.4. The dynamic changes of the contents of vitamin C, polyphenol, polysaccharide,flavonoid, SO2 residue and polyphenol oxidase activity and antioxidant activity of the dried lily which were storaged under different conditions were determined. The results showed thatthe contents of vitamin C, polyphenol, flavonoid and SO2 residue were getting lower and lower, polysaccharide content and polyphenol oxidase activity increased first and then decreased, and antioxidant activity decreased with the extension of storage time under the conditions of room temperature and low temperature. These indexes changed obviously at room temperature, which changed slowly at low temperature. The main nourishment components and antioxidant activity of dried lily which were storaged at low temperature changed slowly. Dried lily storage test showed that low temperature condition can maintain the appearance and color and other sensory quality of dried lily, reduce the loss of nutritional components, slowdown the quality decrease of dried lily effectively, and extend the shelf life,so it can be used as optimum storage condition for dried lily. |
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