| Day-lily flower (Hemerocallis citrina Baroni) is also known as "Jinzhencai" .Our country has a long history of several thound years in planting Day-lily flower which is a kind of speciality possessing highly economic worth.Hunan provience is a big one for its product of Day-lily flower occupies nearly 70 per cent market quota across the country.The kind of product,however,is very simple,for example,there is just one kind of product-dehydrated Day-lily flower at the moment.Therefore the efficiency is very low.The average price of dehydrated Day-lily flower comes to 10-12 yuan per kilogram in the market.while the price of fresh Day-lily flower reaches to 20-30 yuan per kilogram in Guangzhou city market,what's more,the product cann't meet the demands of customers'.The difference of price between dehydrated Day-lily flower and fresh one is obvious.The storibility of fresh Day-lily flower,however,is very poor at normal temperature.If we pack them up by commen material made out of polyethene,they flower in the second day and decay in the fouth day.So it is significant to study the way of fresh-keeping Day-lily flower under low temperature above zero degree and by modified atmosphere packaging. At the same time,we also want to study the effects of modified atmosphere packaging and 6-BA on post-harvesting physicology of Day-lily flower in order to investigate the principle of senescence which could provide theoretical evidence to industrialized production of modified atmosphere packaging of Day-lily flower.The storing term of fresh Day-lily flower is limited under low temperature above zero degree.Such method of fresh-keeping Day-lily flower can just meet the customers' demands in a short term,nearly one month,but it cann't do around a year.Recently the quick-frozen vegetable which was required by more and more customers in international market was developed very quickly since it adopted advanced technical conditions,which could keep original color, flavour.as well as nutrints,and made eat conveniently.So it has a strong realistic meaning to research the technical conditions of pre-processing of quick-frozen Day-lily flower.In order to investigate the way of fresh-keeping of fresh Day-lily,orthogonal test was adopted in the experiment to study the best storing temperature,ripe degree and dealing way of modified atmosphere package of fresh Day-lily flower.Weight loss,good flower ratio,Vitamin C,total sugar and RI were measured during storage.The results proved that using 6-BA as fresh-keeping agent and choosing the fourth grade flower,at 2 ℃,was the best measure.The Day-lily flower still remained commercial quality over 28 days.In order to investigate the principle of senescence of Day-lily flower,effects of modified atmosphere packaging and 6-BA treatment on physiology of post-harvesting of Day-lily flower were studied at 2 ℃ .The activity of Superoxide Dismutase Peroxidase and Catalase,the producing speed of Superoxide free radical and the contents of Malondialdehyde was tested in the experiment.The results proved that both treatments not only could improve the activity of Superoxide Dismutase andinhibit the activity of Peroxidase and Catalase,the producing velocity of Superoxide free radical and yielding of Malondialdehyde but also postpone the senescence of Day-lily flower.The effect of combining 6-BA treatment with modified atmosphere packaging treatment was better than the latter alone.The technical conditions of pre-processing of quick-frozen Day-lily flower was also studied in the experiment.In the course of experiment,blanching time,temperature,as well as the way of color-preserving was studied especialy.The optimal blanching time and temperature,using clear water as blanching liquid,was pinned down,through testing the contents of vitamin C,the activity of Peroxidase,the ratio of brown-head after being defronzen and assessing the texture of Day-lily flower under different blanching time and temperature.The best color-preserving agent,using different color-preserving agent,was confirmed,throug...
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