Dry formulations of the biocontrol agent Candida sakeCPA‐1 using fluidised bed drying to control the main postharvest diseases on fruits

BACKGROUND: The biocontrol agent Candida sake CPA‐1 is effective against several diseases. Consequently, the optimisation of a dry formulation of C. sake to improve its shelf life and manipulability is essential for increasing its potential with respect to future commercial applications. The present study aimed to optimise the conditions for making a dry formulation of C. sake using a fluidised bed drying system and then to determine the shelf life of the optimised formulation and its efficacy against Penicillium expansum on apples. RESULTS: The optimal conditions for the drying process were found to be 40 °C for 45 min and the use of potato starch as the carrier significantly enhanced the viability. However, none of the protective compounds tested increased the viability of the dried cells. A temperature of 25 °C for 10 min in phosphate buffer was considered as the optimum condition to recover the dried formulations. The dried formulations should be stored at 4 °C and air‐packaged; moreover, shelf life assays indicated good results after 12 months of storage. The formulated products maintained their biocontrol efficacy. CONCLUSION: A fluidised bed drying system is a suitable process for dehydrating C. sake cells; moreover, the C. sake formulation is easy to pack, store and transport, and is a cost‐effective process.

We are grateful to the INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria) and the FEDER (Fondo Europeo de Desarrollo Regional) for financial support via national project RTA2012‐00067‐C02‐01. In addition, we are also grateful to the INIA and FSE (Fondo Social Europeo) for the PhD grant to A. Carbó and CERCA Programme/Generalitat de Catalunya.