Study and optimization of high hydrostatic pressure (HHP) to improve mass transfer and quality characteristics of candied green plums (Prunus mume)

Osmotic dehydration (OD) is the most important procedure for producing candied green plums. This study investigated high hydrostatic pressure treatment (HHP) to improve OD process. Central composite design was applied to optimize HHP parameters with pressure ranging from 50 to 400 MPa and time from 1 to 30 min. Innovative HPP procedure was compared with traditional heating treatments on the acceleration efficiency by Peleg’s model. The physico-chemical and sensorial properties were compared. The results showed that HHP was effective to accelerate the OD process, but was not as efficient as heating methods. HHP promoted higher titratable acid content, firmness and greener color than heating on the obtained product. Sensory results revealed that HHP allowed to better preserve the typical odor and flavor of the final products. Generally, HHP treatments show high potentiality to improve the OD performances of candied green plums, together with the overall quality of the final product. Practical applications: Candied green plum is a popular snack in Eastern Asian countries. The traditional process includes a heating assisted treatment in order to accelerate the candying progress, which may induce decrease to the quality of the final product. Non-thermal high hydrostatic pressure could improve the osmotic dehydration process performances, minimizing the thermal damages on the final products, promoting the improvement of its overall quality.