Mold in, mold out: harvest bins harbor viable inoculum that can be reduced using novel sanitation methods to manage blue mold decay of apples

Authors: LUCIANO-ROSARIO, DIANIRIS - Orise Fellow; CASTRO, JOHANNY - Pennsylvania State University; PETER, KARI - Pennsylvania State University; COX, KERIK - Cornell University; Gaskins, Verneta; Fonseca, Jorge; Jurick Ii, Wayne

Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/13/2024
Publication Date: 11/22/2024
Citation: Luciano-Rosario, D., Castro, J., Peter, K., Cox, K., Gaskins, V.L., Fonseca, J.M., Jurick Ii, W.M. 2024. Mold in, mold out: Storage bins harbor viable inoculum that can be reduced using novel sanitation methods to manage blue mold decay of apples. Postharvest Biology and Technology. 221. Article e113323. https://doi.org/10.1016/j.postharvbio.2024.113323.
DOI: https://doi.org/10.1016/j.postharvbio.2024.113323

Interpretive Summary: The apple industry faces many challenges that result in food waste and loss. One of these concerns is the prevalence of postharvest diseases. One of the most common postharvest pathogens of apples is the fungus that causes blue mold. In addition, fungicide resistance to this and other pathogens adds to management difficulties. Therefore, there is a need to develop innovative methods to achieve better postharvest pathogen control for the apple industry. In this study we show that apple picking/storage bins can be a reservoir for blue mold decay and tested novel treatments live UV-C irradiation, sodium hypochlorite application, and 2-phenylethanol to sanitize these. The tested treatments are effective in reducing spore viability in apple picking/storage bin materials (wood and plastic). This work contributes towards the continuous development and implementation of additional postharvest pathogen control strategies for the apple and other fruit and vegetable industries.

Technical Abstract: Postharvest diseases account for major economic losses worldwide, while also contributing to food waste and loss. Blue mold decay of apples, caused by Penicillium expansum, is one of the most prevalent postharvest diseases of pome fruits. This necrotrophic fungal pathogen is mycotoxigenic and presents a danger to food safety via the production of patulin, a detrimental mycotoxin. In addition, fungicide resistance threatens blue mold management strategies, creating a need towards the development of novel control strategies. The apple storage/processing industry uses wood and plastic bins to harvest and store apples for weeks, months, and even up to 1 year. Although it has been hypothesized that apple storage bins can serve as a viable inoculum source to incite decay, there is no experimental evidence that has conclusively demonstrated this concept. In this study we report the presence of Penicillium spp. in apple storage bins (plastic) in the mid-Atlantic USA and developed small scale methods to test 1) if storage bins can serve as a source of inoculum for blue mold decay and 2) evaluate novel bin sanitation methods as preventative and curative applications. We demonstrated that apple picking bin materials can serve as a source of inoculum when in direct contact with wounded apples. Additionally, it was shown that UV-C irradiation, sodium hypochlorite, and 2-phenylethanol are effective at reducing inoculum viability in plastic materials in a curative fashion. These findings are envisioned to aid the development of large-scale bin sanitation strategies and its applications have great potential to impact a broader range of postharvest pathogens and stored commodities.