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BACKGROUND: Food marketers desire residue‐free fresh grapes although grapes have a short postharvest life. This study was performed to determine the influences of pre‐ and/or postharvest chitosan (Ch) coatings on postharvest quality of minimally processed (stem‐detached) organic 'Crimson Seedless' berries. Berries were sorted as: (a) control (untreated berries); (b) preharvest Ch (dipping the clusters on the vine into 1% Ch 10 days before harvest at 20% soluble solid content (SSC)); (c) postharvest Ch (dipping the stem‐detached berries into 1% Ch); and (d) pre + postharvest Ch. Berries were stored in 12 × 15 cm rigid polypropylene cups for up to 42 days at 1.0 ± 0.5 °C. RESULTS: Pre‐ and/or postharvest Ch coating reduced weight loss during storage. Pre‐ + postharvest Ch was the best treatment for restricting polygalacturonase (PG) activity, extending the visual quality, color features (L*, C and h°), skin rupture force, biochemical (SSC, titratable acidity, maturity index and pH) and bioactive (total phenol content, antioxidant activity) features. Pre‐ or postharvest Ch was also significantly effective in maintaining many quality features. CONCLUSION: Pre‐ and/or postharvest 1% Ch coatings effectively maintained the quality of minimally processed grape berries of organically produced 'Crimson Seedless' grapes by delaying weight loss and PG activity and keeping the postharvest physical, biochemical and bioactive features for 42‐day cold storage at 1.0 ± 0.5 °C. The combined use of pre‐ and postharvest Ch found to be more effective than single treatment. Thus, pre‐ + postharvest 1% Ch coating could be recommended as an ecofriendly sustainable methodology for extending the postharvest quality of minimally processed fresh grapes. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Berry quality, total phenol, sensory characteristics and decay incidence of grapes ( V. vinifera cvs. Müşküle and Red Globe) as affected by prestorage hot water immersion with or without cap stem excision treatments were investigated with 7-day interval during storage at 1 °C for 21 days. Weight loss occurred mainly up to the second week and was more pronounced for the untreated control samples subjected to the stem excision. In Müşküle, the least weight loss value was obtained from hot water-treated grapes (0.62%), while the highest loss occurred in control grapes of stem-excised berries (0.96%). Immersion of stem-retained grapes in hot water was the best applications for maintenance of overall storage quality for both cultivars. According to panellist scores, it is evident that hot water has positive effect on maintaining the minimally processed table grapes without altering the flavour and taste of the commodity. Stem-retained berries of hot water treatment had the highest score for both Müşküle and Red Globe, with their values 3.8 and 4.2, respectively, while the least values were obtained from stem-excised berries of untreated control group of both the cultivars (1.9 and 3.0, respectively). At the end of three-week storage, the least decay rates were determined in stem-retained berries that received hot water treatment (5.3% for Müşküle and 1.1% for Red Globe). Attenuate influence of brief high temperature exposure on ripening parameters (SSC, TA, MI, pH) was also observed. Postharvest hot water treatment may be used as a nonchemical means to extent storage life of minimally processed grapes with its alleviating effect on physiological disorders. Cap stem retaining in minimal processing can be recommended to maintain the quality of grapes. [ABSTRACT FROM AUTHOR]