Research On Fruit Quality And Metabolism Characteristics Of Actindia Eriantha Benth Cv.’White’ During Storage

’White’is the promising cultivar breeded from wild Actinidia eriantha Benth with good storability, satisfying taste and high content of AsA.The effects of different temperatures (20℃and1℃) on nutritional quality, AsA biosynthesis and cycle as well as sugar metabolism in ’White’were investigated during storage in this paper. The main results were as follows:1. Low temperature significantly reduced respiration and weight loss rate as well as improved the colour of the fruit flesh. Moreover, compared with20℃, the decrease rates in organic acid and other nutrients were slower and the level of membrane lipid peroxidation was lower during low temperature storage. Thus, the ripening process of postharvest ’White’was delayed.2. Synthesis and regeneration abilities were important for maintaining high AsA content in postharvest’White’. GalLDH was a key enzyme in synthesis of AsA and played an important role in both flesh and core. DHAR was the main enzyme of As A regeneration in flesh, while MDHAR and DHAR might be key enzymes in maintaining balance of AsA redox state in core. Compared with core, the flesh had much higher activities of GalLDH and DHAR, which might be the main factors of higher AsA content in flesh. The content of TA in postharvest’White’ was significantly negatively related to T-AsA, and TA was considered as the degradation products of AsA in’White’needed further research.In AsA-GSH cycle, low temperature maintained the activities of APX, MDHAR, DHAR and GR as well as the contents of AsA and GSH. Meanwhile, low temperature also kept the ratios of AsA/DHA and GSH/GSSG. However, the activity of GalLDH was decreased. It was suggested that AsA-GSH cycle played an important role in alleviating the loss of AsA during low temperature storage.3. Hexose was the predominant sugar and total sugar contents were almost equal in amount both in the flesh and the core of’white’. But the distribution of sugar in fruit was different, especially, the sugar content in the core was most significantly higher than that in the flesh. In addition, a potential change in starch and sugar contents of the flesh and the core were similar. The rapid degradation of starch content coincided with both of the increase of amylase activity and the dramatical increase in hexose content, and the content of sucrose decreased gradually. The differences and changes of sugar contents in flesh and core were the synergetic results of sucrose-metabolizing enzymes. And the activities in decomposition direction were chief during the whole storage both in flesh and core. That is to say, the activities of acid invertase (AI) and neutral invertase (NI) were much higher than sucrose phosphate synthase (SPS) and sucrose synthase (SS), which wasn’t benefit for sucrose accumulation. Moreover, compared to core, the flesh had higher enzyme activities of invertases and lower SPS, which might be the important factors causing the lower level of sucrose content.Enzyme activities of amylase, AI, NI, SPS as well as SS were showed lower activities during low temperature storage, which resulted in delaying fructose and glucose accumulation, and alleviating sucrose and starch degradation.