Postharvest Storage And Cold Chain Physiological Characteristics Of Baodao Banana

Bananas are the second largest fruit after citrus and the fourth largest food crop in the world after rice,wheat and corn.In recent years,China’s banana industry has developed rapidly and plays a pivotal role in international trade.However,banana is a typical respiratory climacteric type fruit,which is not resistant to storage and long-distance transportation,which seriously affects its commercial value.This article uses the Baodao banana fruits as the experimental material,and provides theoretical basis and technical reference for the postharvest storage and cold chain preservation of bananas through the study of its storage quality in postharvest pre-cooling,storage,transportation,and sales.The main research contents and results of this paper are as follows:(1)The effect of different pre-cooling methods on bananas was studied.When the average initial temperature of the bananas is 31.7℃,its internal temperature is reduced to 16℃through different pre-cooling treatments.After the pre-cooling,the respiratory intensity of bananas was significantly reduced.The time consumed by the cold storage,the differential pressure pre-cooling,and the ice-water pre-cooling was170 min,70 min,and 20 min,respectively.(2)The impact of normal temperature transportation,cold storage incubator transportation and low temperature refrigerated transportation on the transportation process of bananas is simulated.During the first 2 days of transportation in the cold storage incubator and the whole process of low-temperature refrigerated transportation,the temperature of the bananas core and the breathing intensity are kept at a low level.After 3 days of simulated transportation,the bananas MDA(malondialdehyde)content(2.89mol/g)of simulated low-temperature refrigerated transportation was lower than simulated normal temperature transportation(3.58mol/g)and simulated cold storage incubator transportation(3.59mol/g).Low-temperature refrigerated transportation is better than the other two transportation methods in both long-term and short-term transportation.In the absence of low-temperature refrigerated trucks,short-term transportation within 2d can also play a role in preservation of freshness.(3)The effect of different concentrations of 1-MCP(1-methyleyclopropene)on the bananas storage process was studied.After being treated with 100nl/L1-MCP,bananas began to turn from green to yellow after 40 days of storage,which was 20days longer than that in the CK group.During storage,treatments with different concentrations of 1-MCP inhibited the relative conductivity,soluble solid content,soluble sugar content,MDA content,CAT(Fungal catalase)activity,POD(peroxidase)activity increase and fruit firmness decrease.Before the respiratory jump,the SOD(superoxide dismutase)activity of bananas treated with 100nl/L1-MCP was higher than other treatments.100nl/L 1-MCP treatment can more effectively inhibit the initiation of respiratory jump during bananas storage,thereby prolonging the storage period of bananas.(4)The effect of different concentrations of MT(melatonin)on the storage process of bananas was studied.The bananas in the control group began to change from green to yellow after only 21 days of storage.During 21d-28d,the fruit hardness decreased rapidly,the relative conductivity of the peel,the soluble solid content,the total soluble sugar content,MDA content,CAT and POD activity all increased rapidly.(5)Increasing the temperature and ethephon concentration within a moderate range has a positive effect on the maturation process and quality of’Baodao Bananas’,which reduces the hardness of the fruit,increases the permeability of the peel membrane,decreases the total chlorophyll content,and changes the color from green to yellow.The content of soluble solids and soluble sugar in the pulp increases,and the content of starch and Vc is reduced to achieve edible quality.Compared with 18℃,a proper high temperature of 20℃can promote the increase of soluble solids and soluble sugar content.Accelerate the hydrolysis of starch and the conversion of Vc,so as to promote the ripening of Baodao Banana fruits and shorten the ripening time.(6)The influence of different sales methods on the shelf life of bananas was studied.Both the 16℃low temperature and the wrapper with plastic wrap slowed down the decrease of banana peel L~*.On the 4th day of the shelf,the relative conductivity of the peel was 25℃treatment>25℃+plastic wrap treatment>16℃treatment>16℃+plastic wrap treatment.Both treatments inhibited the changes of the total soluble sugar content and titratable acid content of bananas at 16℃.This shows that the use of low-temperature preservation cabinets and plastic wrap during the sales period is beneficial to maintain the flavor quality of bananas during the shelf life,extend the shelf life of bananas,and improve product competitiveness.