Aroma volatiles and sensory quality of organically-grown apple cultivars after dynamic controlled atmosphere (DCA) storage and comparison with CA-stored fruit with and without 1-methylcyclopropene (1-MCP)

Authors: AL SHOFFE, YOSEF - Cornell University; Rudell, David; PARK, DOSU - Cornell University; ALGUL, BURAK - Aydin Adnan Menderes University; QIN, MINGZE - Cornell University; SHI, MENGHAN - Cornell University; DANDO, ROBIN - Cornell University; WATKINS, CHRISTOPHER - Cornell University

Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/19/2024
Publication Date: 8/28/2024
Citation: Al Shoffe, Y., Rudell, D., Park, D., Algul, B.E., Qin, M., Shi, M., Dando, R., Watkins, C.B. 2024. Aroma volatiles and sensory quality of organically-grown apple cultivars after dynamic controlled atmosphere (DCA) storage and comparison with CA-stored fruit with and without 1-methylcyclopropene (1-MCP). Postharvest Biology and Technology. 218. Article 113162. https://doi.org/10.1016/j.postharvbio.2024.113162.
DOI: https://doi.org/10.1016/j.postharvbio.2024.113162

Interpretive Summary: Different technologies can be used to help suppress ripening beyond what is afforded using controlled atmosphere (CA) cold storage. These include treating apples at harvest with 1-methylcyclopropene (1-MCP), a gas that blocks the action of the natural ripening hormone ethylene. More recently, dynamic controlled atmosphere (DCA) storage technologies have been developed as means to indicate whether lower oxygen atmospheres will be tolerated by a particular batch of apples as low levels of this gas can lead to off-flavors and even storage disorders. 1-MCP treatment is not allowed for production of apples certified as organic. Consequently, DCA may replace 1-MCP as necessary. Using 6 cultivars harvested at commercial maturity, we tested whether DCA was a viable replacement for 1-MCP or if additional ripening control was actually necessary. Storage of cultivars that retain firmness and tartness while in storage, neither technology was necessary. In cultivars that did soften or lose tartness DCA storage was a viable surrogate to 1-MCP treatment. Results show that use of DCA can supplant 1-MCP treatment when necessary, but additional ripening control technologies beyond conventional CA should be considered according to cultivar.

Technical Abstract: Long-term storage of many apple cultivars can be especially challenging for organic production where use of 1-methylcyclopropene (1-MCP), a crop protectant that controls ripening is disallowed. For many cultivars, controlled atmosphere (CA) storage, alone, is inadequate for managing disorders and ripening. Dynamic controlled atmosphere (DCA), by determining the pO2 just above the anaerobic compensation point (ACP), permits the use of lower pO2 setpoints without any negative impacts of anaerobiosis. Consequently, DCA can replace 1-MCP for these purposes. In this study, we sought to determine where this held true for a selection of old and new release cultivars in the context of sensory perception. Cultivars included ‘Enterprise’ and ‘GoldRush’ harvested in 2018 (year 1), and ‘Honeycrisp’, ‘Golden Delicious’, ‘Jonagold’, and Fuji harvested in 2020 (year 2). This study also accounts for differences of objective instrumental and sensory evaluation. ACP was monitored for DCA using chlorophyll fluorescence (CF) and compared with conventional static CA with or without 1-MCP treatment at harvest. DCA storage suppressed ripening to a similar level as 1-MCP coupled with CA in both years as best indicated by reduced ester biosynthesis and, for some cultivars, softening. However, ripening suppression did not impact overall sensory preference of ‘Enterprise’, ‘Honeycrisp’, or ‘Fuji’, all cultivars that retained firmness and tartness regardless of storage regime and even negatively impacted it for ‘Goldrush’, an especially tart and firm cultivar. Sensory preference of ‘Golden Delicious’ and ‘Jonagold’ which have more typical diminishing firmness and acid profiles were most benefited by either 1-MCP treatment or DCA storage. Results highlight that use of storage technologies that suppress ripening beyond conventional CA storage are best employed on cultivars with more conventional softening and acid metabolism profiles as opposed to new cultivars that were selected primarily against these ripening phenotypes. The results also demonstrate the value of sensory evaluation compared with the more objective to reveal the influence of different storage regimes on human perception.