Postharvest nitric oxide fumigation delays fruit ripening and alleviates chilling injury during cold storage of Japanese plums (Prunus salicina Lindell)

Abstract

We investigated the effects of nitric oxide (NO) fumigation on fruit ripening, chilling injury, and quality of Japanese plums cv. 'Amber Jewel'. Commercially mature fruit were fumigated with 0, 5, 10, and 20 µL L-1 NO gas at 20 °C for 2 h. Post-fumigation, fruit were either allowed to ripen at 21 ± 1 °C or were stored at 0 °C for 5, 6, and 7 weeks followed by ripening for 5 d at 21 ± 1 °C. NO-fumigation, irrespective of concentration applied, significantly (P ≤ 0.5) suppressed the respiration and ethylene production rates during fruit ripening at 21 ± 1 °C. At 21 ± 1 °C, the delay in fruit ripening caused by NO-fumigation was evident from the restricted skin colour changes and retarded fruit softening in fumigated fruit. NO treatments (10 and 20 µL L-1) delayed the decrease in titratable acidity (TA) without a significant (P ≤ 0.5) effect on soluble solids concentration (SSC) during fruit ripening. During 5, 6, and 7 weeks of storage at 0 °C, NO-fumigation was effective towards restricting changes in the fruit ripening related parameters, skin colour, firmness, and TA. The individual sugars (fructose, glucose, sucrose, and sorbitol) profiles of NO-fumigated fruit were significantly different from non-fumigated fruit after cold storage and ripening at 21 ± 1 °C. CI symptoms, manifested in the form of flesh browning and translucency, were significantly lower in NO-fumigated fruit as compared to non-fumigated fruit after 5, 6, and 7 weeks storage and followed by ripening for 5 d at 21 ± 1 °C. NO-fumigation was effective in reducing the decay incidence in plum fruit during ripening without storage and after cold storage at 0 °C for 5, 6, and 7 weeks. In conclusion, the postharvest exposure of 'Amber Jewel' plums to NO gas (10 µL L-1) delayed fruit ripening by 3-4 d at 21 ± 1 °C, and also alleviated chilling injury symptoms during cold storage at 0 °C for 6 weeks.

Nitric Oxide Fumigation Delays Mango Fruit Ripening

“…The exact mode of action of NO in suppressing ethylene production during fruit ripening in mango fruit warrants to be investigated. Suppression of respiration during ripening in NO-fumigated fruit has also been reported earlier in plums (Singh et al, 2009), peaches (Grima-Calvo et al, 2008;Grima-Calvo et al, 2005) and strawberry (Zhu and Zhou, 2007).…”

“…Earlier, ethylene has been reported to be directly involved in promoting the activities of fruit softening enzymes, such as polygalacturonase (Lazan et al, 1986), galactosidases (Ali et al, 1995), pectin esterase and β-1,4-glucanase (Ali et al, 2004) in mango fruit. Similarly, the NO fumigation (5 or 10 μL.L −1 ) has been reported to delay fruit softening during storage and ripening period in plums, pears and peaches (Singh et al, 2009;Sozzi et al, 2003;Zhu and Zhou, 2006), but a higher concentration (15 μL.L -1 ) in peaches enhanced fruit softening. In our experiment, NO concentrations (20 and 40 μL.L -1 ) reduced fruit softening in mango during ripening for 8 d, thereby delaying eating fruit soft stage up to 2 days than control fruit.…”

“…Ethylene and respiration rate (carbon dioxide production) from mango fruit during ripening was determined according to the method described by Singh et al (2009). Ethylene was estimated using a gas chromatograph (6890N Network GC system; Agilent Technology, Palo Alto, CA, USA) fitted with a 2 m long stainless steel column (Porapaq-Q, 3.18 mm, 80/100 mesh size; Sepelco, Bellefonte, PA, USA) and a flame ionization detector (FID).…”

“…It was filtered through 0.2 µm nylon syringe filter [Alltech Associates (Australia) Ltd., NSW, Australia] and loaded into 1 mL glass vial. Individual sugars was determined according to the method described by Singh et al (2009) except the flow rate was kept at 0.5 mL.min -1 . The chromatographic peak of individual compound was identified by comparing retention time and spiking with standard compounds.…”

“…Short storage life limits its export to distant markets. Postharvest exogenous application of nitric oxide (NO) has been reported to delay ripening of climacteric fruits such as banana, tomato and plum (Cheng et al, 2009;Eum et al, 2009;Singh et al, 2009). No research work has been reported on the role of NO fumigation in modulating mango fruit ripening.…”