Hypobaric treatments of strawberries: A step towards commercial application

The application rate, length and timing of any physical treatment influence its effectiveness. In developing a treatment for commercial application, delays prior to, and caused by the physical treatment may play an important role to find product outcomes. Previously, hypobaric treatment has been identified as a potential decay reduction treatment. The aims of this study were to investigate the impact of application speed, length and delay prior to and caused by hypobaric treatment on the subsequent efficacy to reduce decay development in strawberry. Hypobaric treatment for 6 h and repeated application of 50 kPa mitigated effectiveness. Delaying application by 8 h continued to result in reducing strawberry decay without affecting weight loss and firmness in subsequent storage. However, hypobaric treated (50 kPa for 4 h at 20 °C) strawberries were no different from non-treated fruit shifted directly to 5 °C, suggesting that application at 20 °C is inappropriate. Alternatively, hypobaric treatment (50 kPa, 4 h) at 5 °C reduced fungal decay in comparison to control fruit transferred directly to 5 °C, indicating that hypobaric treatment after cooling may be the best approach to minimize decay development. Results of this work demonstrate the potential to combine hypobaric treatment with cold storage to extend storage life of strawberries. However, for more effective application, perhaps hypobaric treatment should be tested as a hurdle technology to be used in conjunction with other physical treatments (UV-C, heat and ultrasound) and/or volatile chemical treatments.