Research About The Relationship Between Gannan Navel Orange Fruit Colour And Carotenoids And Environmental Regulation Storage

Citrus peel color is mainly affected by the content and proportion of chlorophyll,carotenoid,particularly the latter plays a crucial role to the change of fruit peel color.In recent years,It was reported that exogenous ethylene also plays a role in the mature aging of nonclimacteric fruit,especially in the process of peel color change.This research mainly centred on the color changes of gannan navel oranges during the postharvest storage process.First,we analyzed the physical and chemical property of gannan navel oranges and their main carotenoid components in different maturity.Second,we compared the influence of two types of ethylene regulation on gannan navel orange during the storage process,including their physical and chemical properties and the change of peel carotenoids.Then,we analyzed the results of ethylene response in different maturity oranges,especially researched on the change rule of content and types of carotenoids in peels.Trying to find out a few rules of carotenoid transformation in peel from green to yellow to red.At last,we hoped to provide some basic scientific basis for citrus fresh-keeping,faded green operation.The main contents and results are as follows:1.With the maturity of navel oranges increased,the trend of total acid,total sugar,solub le solid,and the content of vitamin C and the other intrinsic quality indicators in fruit sho wing increased first and then decreased,the types and content of peel carotenoids change significantly with the maturity.The color of the fruit began to turn from green to yellow,t he largest effect on pericarp color is the content of carotenoid pigment and chlorophyll,.With the navel orange peel turning yellow to red,the kinds and content of carotenoids pla yed the main role.Such as lutein,and б-carotene,beta – citraurin,beta-cryptoxanthin,the ir proportional relations change affects subtle color changes mainly affect the pigment in t he ripening process,together with chlorophyll ultimately affect fruit from green to yellow and red2.Ethylene had affects on peel color of Navel orange in P1-3 period,and P1> P2> P3,the less fruit mature was,the more sensitive to exogenous ethylene would be,considering factors such as fruits shrinkage in the actual production process,it was recommended using exogenous ethylene in P2 fruit maturity.P1-3 of three experiments ethylene treatment group compared the L *,a *,b * was P1> P2> P3.After the treatment,P1 fruit peel was more reddish,but it has lack of brightness,rendering soft,slight shrinkage phenomenon;P2 fruit to exogenous ethylene corresponding effect was very obvious,more excellent than P1;P3 fruit response to exogenous ethylene was not very clear.3.The effect of exogenous ethylene on the chlorophyll of different ripening fruit was dif ferent.In P1,ethylene treatment would accelerate the chlorophyll A and chlorophyll B de gradation,and carotenoid synthesis;in P2,ethylene treatment on the degradation of chlor ophyll A had no effect,slightly promoted the degradation of chlorophyll B,which could si gnificantly promote the carotenoid synthesis;in the P3 stage,the effect of chlorophyll A a nd B was not particularly evident,but it could promote the synthesis of carotenoids,and t he total content of Carotenoid was increased.4.Exogenous ethylene treatment green fruit can accelerate the chlorotic process,the tot al content of carotenoids basically unchanged,but all kinds of carrot group ratio was large r and the mutual conversion significantly,promote the generation of yellow or red caroten oids.Beta-carotene turned to the beta-cryptoxanthin leading to the content of beta-cryptox anthin increasing,and beta-cryptoxanthin and zeaxanthin turned to red Beta-citraurin con verting to beta-citraurin accumulation,violaxanthin converted to new zeaxanthin or lutein and zeaxanthin,resulting in decreased,and all of these reasons leaded to the Gannan nav el orange peel turned yellow to orange.Ethylene treated fruits has three maturity stages an d trends of five kinds of carotenoids were as following: the percent content of lutein and beta-carotene decline;the percent content of beta-cryptoxanthin increased;violaxanthin percent content had no significant change;P1,P2 beta-citraurin percent content increase d,P3 stage had no significant change;5 kinds of carotenoid pigment content and accounts for the percentage of the total decline.