Effect Of 1-methylcyclopropene Combined With Carbon Dioxide On Postharvest Softening Of Blueberries

Blueberry belongs to the genus Vaccinium of Rhododendron family.Harvested in summer,it has higher respiration metabolism,after harvest,it becomes mature and senescence due to the blocking of nutrient transport.The blueberry is high value of nutrition,but its commodity value is seriously affected due to its incapacity for storage and unfavorable transportation.The main problem with blueberries after harvest is decay and softening.In this study,it was found that post-harvest 1-MCP combined with CO₂ treatment could greatly delay the ripening and senescence of blueberries,inhibit the softening and maintain the flavor of blueberries in a large extent.This study analyzed the improvement of 1-MCP combined with CO₂ treatment during the storage period of blueberries.The decay rate,hardness,titratable acid,soluble solid and malondialdehyde content;The polygalacturonase(PG),?-galactosidase(?-Gal);The genes expression of the enzymes involved in softening;The expression of related to ethylene transduction gene were monitored.The flavor quality of blueberry was determined by electronic tongue.The spontaneous air conditioning treatment method is designed and is intended to be applied in production practice.The main results are as follows:1.Post-harvest blueberry use 1-MCP combined with short-term high concentration of CO₂treatment at room temperature can reduce the occurrence of blueberry decay in some extent,The decay rate of 2-4 d was significantly reduced,and maintain the hardness of blueberry.It inhibited the decrease of titratable acid content,decreased the peak value of soluble solids,delayed the increase of PG and?-Gal,down-regulated the expression of softening related genes(Vc PG?Vc PE?Vc PL?Vc?-Gal?Vc?-Glu),and inhibited the expression of ethylene transduction related genes(VcETR?VcEIN),The contents of total phenols,flavonoids and anthocyanins were maintained.Compared with 1-MCP treatment,the taste of blueberries was improved.During the storage period,a significant correlation was found between sweet taste and sour taste through electronic tongue detection.In the control group,the value of sour taste decreased significantly at the later stage,and blueberries in the treatment group maintained sour taste without increasing sweetness.2.This experiment designed a spontaneous gas regulation mode combining CO₂ with 1-MCP.There was no significant difference in the preservation of blueberries between the carbon dioxide directly passed through the spontaneous gas regulation and the carbon dioxide directly passed through the carbon dioxide cylinder,The final concentration of carbon dioxide released in this experiment could reach 50%.The method of 1-MCP combined with CO₂ to treat blueberries can be applied in post-harvest logistics transportation,can solve the problem of limited sales market of blueberries and extend the freshness retention period of blueberries.