Phenolic contents of some disease-resistant raisins (Vitis spp.)

Abstract

The evaluation of different fruit species and grapes by drying gains importance especially because of its high nutrient content and long-term preservation. In addition, due to increasing consumer and environmental awareness, consumers have more demand for raisins produced by using minimum chemical pesticides throughout the production process. In addition, due to the increasing importance of phenolic compounds for human health, the demand for high phenolic content cultivars and their products is increasing. In this study, 7 different grape cultivars (‘Mars Seedless’, ‘Campbell Early’, ‘Muscat Bleu’, ‘Kay Gray’, ‘Philipp’, ‘Kishmish Vatkana’, ‘Rhea’) which are tolerant or resistant to fungal diseases and grown with a reduced spraying program were studied. Grapes were obtained from the trial vineyard of Yalova Atatürk Horticulture Central Research Institute (Yalova, Turkey). After these cultivars were dried in an energy-saving heat pump dryer, the important phenolic compound contents were determined by HPLC method and the differences between the cultivars were revealed. As a result, the phenolic compounds of the raisins obtained by drying these grape cultivars, which can be grown in humid regions, in an energy-saving heat pump dryer were determined and the correlations between these compounds were determined. Thus, it has been determined in this study that raisins are an important source of polyphenols and that there may be significant differences between species or cultivars.