Combined Carvacrol Fumigation And Ice Temperature Storage On Postharvest Quality Of Endrobium Officinale

Dendrobium officinale is a precious traditional Chinese medicinal herb with very high nutritional value and be entitled the reputation of “a mircle material that can save our lives” in China.Since it is rich in Dendrobium polysaccharides,Dendrobium alkaloids,as well as phenolic compounds and other functional substances,so Dendrobium officinale has the benefits of stomach,anti-tumor,enhance immunity and so on.At present,Dendrobium officinale often processed into tiepifengdou provide to consumer.This processing method will evaporate most free-water of Dendrobium officinale,Although it can effectively extend the shelf life.However,the high temperature in the processing process has a great influence on the active substances such as polysaccharides and dendrobium alkaloid.So,Tiepifengdou can’t meet the requirements of the modern people well,fresh Dendrobium officinale began to get the favor of consumers.Fresh Dendrobium officinale has great medicinal value,but it is difficult to storage,with its own respiration and transpiration,the quality will became bad gradually during storage period,such as weight loss,microbial infection,germination,nutritional ingredient loss and so on.The traditional preservation methods of Dendrobium officinale is common cold storage,but is doesn’t work effectively,therefore,it is very important to find a suitable storage method for the postharvest preservation of Dendrobium officinale.In this paper,fresh Dendrobium officinale was used as experimental material,Study on ice temperature storage and carvacrol combined with the effect of ice temperature storage on postharvest quality of Dendrobium officinale.Experiments were carried out on four temperature storage treatments such as ice temperature and the different concentration of carvacrol in ice temperature storage,by measuring the changes of Dendrobium officinale polysaccharide,chlorophyll content,cellulose content,water content and the activity of PAL 、 PPO 、 POD then conduct a comprehensive analysis,we have the following conclusions:(1)The freezing point of Dendrobium officinale(annual)is-2.3±0.8℃.The freezing point of Dendrobium was negatively correlated with the water soluble polysaccharide content,and highly positive correlation with the water content.(2)Compared with cold storage and frozen storage,the storage quality of Dendrobium officinale could be better preserved by ice-temperature storage.After 49 days storage of ice-temperature,the water-soluble polysaccharide of Dendrobium was0.9% higher than that stored at 0℃.Compared with 4℃ and-4℃storage,the watersoluble polysaccharide was higher than 1.9% and 2.7%.At the same time,the lower the storage temperature was,the better the quality of Dendrobium officinale was,such as chlorophyll,cellulose and so on.But if the storage temperature is lower than that of Dendrobium,it will cause the inner freeze of Dendrobium,results in cell breakage,nutrient outflow and impact storage quality.(3)In this reseach,the difference between 98 days storage and fresh Dendrobium under the ice temperature storage and ordinary cold storage was observed by TEM.The content of cellulose in the fresh Dendrobium officinale cell wall was less,cell structure was neat,and the material exchange between cells was frequent,and now the cellular metabolism was vigorous.However,the cellulose content in the cell wall of Dendrobium was increased,which was much higher than that of-2℃ storage,after 4℃store 98 days.There are have little material exchange,cell shrinkage,the occurrence of wall separation,cell organelles have obvious dissolution.(4)Because Carvacrol has antibacterial,safe,non-toxic and no-pollution to the environment,it is gradually applied in the preservation of fruits and vegetables.The suitable concentration of carvacrol treatment combined with ice temperature storage can delay the loss of Dendrobium polysaccharides during storage,reduce cellulose synthesis,delaying Dendrobium fibrosis,also have positive effects on chlorophyll,moisture keeping dendrobium.At the same time,carvacrol also regulate internal resistance of Dendrobium and antioxidant enzyme activity,scavenging free radical accumulation of aging cells,delaying cell senescence.