The effect of post-harvest technologies on selected metabolites in persimmon (Diospyros kaki Thunb.) fruit

Tannins are frequently a main focus in the investigation of de-astringency treatments of persimmon, and the effect of a controlled atmosphere on other phytochemicals is often overlooked. In the present study, changes in the content of total soluble and insoluble phenolics, soluble tannins, saponins, and carotenoids, as well as changes in primary metabolites, were monitored.

Generally, treatment with ethylene induced a decrease in total phenolic content, whereas, when treated with CO₂ , the content of total phenolics remained unchanged compared to the level of total phenolics before treatment. Treatment with apple-sourced ethylene did not significantly affect the level of total phenolics. Additionally, for both varieties, 'Kaki Tipo' and 'Rojo Brillante', the share of insoluble phenolics strongly increased when treated with CO₂ , whereas, when treated with ethylene, the same change applied for the ratio of soluble phenolics. The content of carotenoids varied markedly among treatments and varieties, whereas the content of total saponins remained unchanged, regardless of the treatment and variety.

The results obtained in the present study show that the content of metabolites in persimmon was affected markedly and variedly using post-harvest technology. Apart from the treatment used, changes in the content of metabolites are also affected markedly by the persimmon variety. © 2018 Society of Chemical Industry.