Study On The Physilolgicalbasis Of Vitaminc In Kumquat CV. Huapi And CV. Rongan

Kumquat was native to China.The fruit was sweet and edible.It has a long history of cultivating in southern China.It has become a pillar industry of county economy in Yangshuo and Rongan of Guangxi.Its main cultivars were 'Rong'an kumquat'and its oil small-scale variation of the 'Hua'pi kumquat'.In this study,Hua'pi kumquat and Rong'an kumquat were used as the experimental object,studied the following aspects of the content:The first,the contents of total AsA(T-AsA),L-ascorbic acid(AsA),The reduced form)and dehydroascorbate(DHA,the oxidized form)in peel and flesh of two kumquat fruits were analyzed dynamically,and the differences in the accumulation of ascorbic acid;The second,In the process of fruit development,the soluble solids,organic acids,reducing sugar,sucrose and soluble sugar were dynamically compared,and the relationship between them and the corresponding ascorbic acid content was analyzed;Thirdly,the key enzymes related to AsA biosynthesis,decomposition and recycle metabolism were L-galactono-1,4-lactone dehydrogenase(GalLDH),ascorbate acid oxidase(AAO),ascorbate peroxidase(APX)onodehydroascorbate reductase(MDHAR)and dehydroascorbate reductase(DHAR)were significantly correlated with AsA content,and the biochemical and enzymatic mechanisms of fruit peel were compared and analyzed.Fourthly,the activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)and the content of reduced glutathione(GSH)in the antioxidant system were studied.The synergistic relationship between enzymatic antioxidant system and nonenzymatic antioxidant system in the fruit of two kumquat fruits during fruit development was explored.The results showed as follows:1.The changes of T-AsA and AsA in the two kumquat fruits were similar,and the contents of T-AsA and AsA were significant Hua'pi kumquat and Rong'an kumqua.While the cumulative trend of DHA consistent,Hua'pi kumquat DHA content is higher than Rong'an kumquat.2.The contents of soluble solids,reducing sugar,sucrose and soluble sugar in the flesh of two kinds of kumquat were increased with the development of fruit,and the contents of Hua'pi kumquat were significantly higher than those of Rong'an kumquat.In addition to the flesh of Rong'an kumquat,There was a significant positive correlation between the fruit of the AsA and the peel of two kumquat and the pulp of Hua'pi.3.There was a significant positive correlation between the change of GalLDH activity and the content of AsA in the peel,but there was no regular change in the activity of GalLDH in the whole fruit during the fruit development.And whether it is in the peel or pulp,Rong'an kumquat GalLDH activity is greater than Hua'pi kumquat.4.The AAO and APX activity in the peel of the Hua'pi kumquat and Rong'an kumquat.In addition to individual periods,Hua'pi kumquat were significantly higher than those of Rong'an kumquat.There was a positive correlation between the activity of AAO and APX in the two kumquat flesh and the accumulation of corresponding DHA,which indicated that the two enzymes in flesh had a certain effect on the content of AsA by affecting DHA.5.For the same breed,DHAR activity was significantly higher in both peel and flesh MDHAR activity;In addition,the activity of the two enzymes in the peel at the same time was higher than that of the two enzymes high.The results showed that the activity of DHAR in the peel was higher than that in the peel,and the content of MDHAR in two kumquats pulp was similar.The activity of MDHAR in the pulp of two kumquat was different,and the DHAR activity of the two kumquat flesh was positively correlated with the accumulation of the corresponding AsA.On the MDHAR activity,there was a positive correlation between the pulp of Huapi and the corresponding AsA content..6.Compared with SOD,POD and CAT in the fruit flesh of the same kumquat,the changes of the three kinds of enzyme activity of peel and pulp were different in the fruit development,and the peel was bigger than the pulp.The results showed that GSH could be detected during the whole development period,and the development of GSH in the two pulp showed a tendency to fluctuate during the fruit development.Non-enzymatic system of AsA-GSH cycle and SOD,POD and CAT in the enzymatic system plays a leading role in the antioxidant process of kumquat fruit.