Postharvest hot water and sodium bicarbonate treatments to maintain quality and reduce decay development of ‘Hachiya’ persimmon fruits in storage

‘Hachiya’ persimmon cultivars were grown commercially in western regions of Turkey. During storage period of persimmon fruits, many physiological and pathological disorders occur. This study was conducted for two years to determine the effects of postharvest heat and sodium bicarbonate treatments on major quality parameters and decay development of ‘Hachiya’ persimmon fruits. Persimmon fruit were dipped in hot water at 50 and 55°C for 2 min or immersed in 2% sodium bicarbonate solution for 2 min. As control treatment, fruits were dipped into water at 20°C for 2 min. Treated fruits were air-dried, placed in commercial plastic boxes, stored at 0.5±0.5°C and 90-95% RH for 60 days. Hot water was the most effective treatment on prevention of decay development compared to the other tested treatments. Especially when the fruits were dipped into 50°C hot water for 2 min, the decay incidence was quite low. Fruit flesh firmness, total phenolic content and antioxidant activity of fruit treated with hot water were higher than the control fruit after 60 days of storage. The effects of treatments on total soluble solids, L-ascorbic acid, tannin content, respiration rate and ethylene production were not statistically significant. Results showed that, hot water and sodium bicarbonate treatments exert positive effects on preservation of quality and reduction of decay development of persimmon fruits in cold storage. © 2020 International Society for Horticultural Science. All rights reserved.This study was supported by Ege University Research Foundation ( ? ? -Z? RF? - ? ? ?)

Effects of sulphur dioxide and chlorine dioxide treatments on quality of ‘Sultana Seedless’ table grapes in storage

Sulphur dioxide fumigation is one of the most important factors that determine storability of table grapes. Despite its beneficial effects, there is a risk of having sulphite residues in grapes. In this study, the effects of sulphur dioxide (SO2) pads and chlorine dioxide (ClO2) generators on storability of table grapes ‘Sultana Seedless’ packed in modified atmosphere packages (MAP) was investigated. Grape samples were subjected to 6 different treatments as a) MAP1, b) MAP1+ClO2, c) MAP2, d) MAP2+ClO2, e) MAP2+SO2 and f) Polyethylene (PE)+SO2 (commercial) after pre-cooling and packages sealed with plastic clips. Grapes in all treatments were stored at -0.5°C and 90% relative humidity for 3 months. SO2 concentrations of grapes in MAP’s and PE packages were determined as 0.53 and 8.30 ppm, respectively. Decay rates increased significantly (26%) in ClO2 treatment after 3 months of storage. Sensory evaluation scores also decreased due to increases in stem browning and decrease in texture. ClO2 treated grapes lost their marketability due to high decay development and loss of sensory properties after 3 months. Effects of different treatments on color, berry removal force, berry firmness and chemical attributes of table grapes were similar. The results showed that table grapes could be successfully stored up to 2 months with ClO2 generators and 3 months with SO2 pads. © 2020 International Society for Horticultural Science. All rights reserved