Sorbets made from bilberries (Vaccinum myrtillus), raspberries (Rubus ideaus L.), and strawberries (Fragaria ananassa Duch) have been stored for 10 months, at -22 °C. The sorbet-making process involved obtaining the juice, heating the juice with added sugar and stabiliser, and, finally, freezing in an ice cream machine. After processing and during storage, the content levels of phenolic compounds, anthocyanins, and vitamin C were analyzed as was the antioxidant capacity index: a reducing power. After processing the fruits into sorbets, the highest losses of the substances analyzed were found in the case of bilberry. In all the products stored, a significant decrease was found in the content of vitamin C. Its content, after a 10 month storage period, was 43 % (raspberry sorbet) and 67 % (strawberry sorbet) of that in the freshly made product. However, the content of anthocyanin and phenolic compounds did not change much during storage. In all the cases analyzed, the reducing power was found to decrease by at least 50% compared to its initial value. Despite those losses, sorbets obtained from berry fruits may be considered an attractive source of health-promoting phenolic compounds in the diet during the seasons of the year, when fresh raw material is hardly available.
berry fruits, sorbet, storage, vitamin C, polyphenols, anthocyanins