High quality sweet organic cherry ingredients by osmotic dehydration before freezing: the primary importance of cultivar

Summary

Sweet organic cherry (Prunus avium) is worth processing for its important nutritional value, linked to high anthocyanin content. Osmo-dehydrofreezing, a combined process where freezing is preceded by an osmotic dehydration step in concentrated sugar solution, could be the method of choice in order to maintain the original quality of fruit. The purpose of the present work was to evaluate the influence of cultivar on solid-liquid exchanges and on colour modification during osmotic dehydration carried out for 45 min at 25°C in a 65% (wt/wt) sucrose solution. For two consecutive years (2004, 2005) nine cultivars of sweet organic cherries were processed: two grown in the South and seven in the North of Italy. Water loss and soluble solids gain values were quite low, as already cited in literature, and they were strongly influenced by the cultivar. The process modi-fied cherry colour, causing a slight lightening mainly in cultivars with higher solid-liquid exchanges. The results underlined the utmost importance of the tis-sue structure, linked to the cultivar.