Comparison between microwave hydrodiffusion and pressing for plum juice extraction

Microwave (MW) hydrodiffusion and gravity, a process initially developed for extraction ofphytonutrients, can be adapted for production of an organoleptically pleasant juice, which iscompared here with classicaly extracted juice.Clear and cloudy juices were produced from plums cv. ‘Najbolia’ by enzymatic treatment andpressing. Juice yield were 550 g•kg-1 for clear juice, from 670 to 684 g•kg-1 for cloudy juicewith or without ascorbic acid (AA), and from 344 to 461 g•kg-1 for MW juice.MW juice was richest in procyanidins (334 mg•kg-1) while the cloudy juice and clear juicewith AA were richest in anthocyans (80 and 90 mg•kg-1 respectively), and phenolic acids(from 450 and 510 mg•kg-1 respectively).The MW process was clearly more rapid and simpler, though yields were lower. This processcould be an alternative to produce fruit juice where professionals of juice are confronted toextraction problem.