A predictive approach to reducing strawberry post-harvest waste: Impact of storage conditions and water activity on Botrytis cinerea germination

Abstract

Botrytis cinerea is the primary fungus responsible for strawberry post-harvest decay. Understanding the factors affecting its germination is crucial to controlling its growth and reducing fruit waste. This study aimed to evaluate and model the effects of storage temperature (5, 10, 15, 20 and 25 °C) and water activity (aw) (0.920 to 0.998) on B. cinerea germination. Germination was monitored microscopically for up to 30 days using a strawberry model medium. An asymmetric model was fitted to the percentage of germinated spores (Pt) over time to estimate the maximum percentage of viable spores (Pmax, %), the germination rate (μ, %/h), and the germination time required to reach Pmax/2 (τ, h). Secondary models were then developed to relate the asymmetric model parameters with temperature and aw. The results showed that B. cinerea germination was significantly affected by both temperature and aw under all conditions tested. Cardinal models effectively described the relationships between μ and τ with aw. The optimum germination rate (μopt) and time (τopt) at 20 °C were estimated as 6.643 ± 0.484 %/h and 9.15 ± 0.32 h, while the minimal (aw min) and optimal (aw opt) aw values for germination were estimated as 0.858 and 0.993, respectively. At 5 °C, aw min increased to 0.905 and τopt nearly doubled, indicating delayed germination. The optimal storage temperatures to reduce strawberries waste were estimated as lower than 10 °C for aw values around 0.97. The models developed in this study assist in managing strawberry storage temperature based on aw to delay B. cinerea germination, thereby contributing to the reduction of post-harvest waste.