Comparison of the Influence of Different Fruit Drying Methods on the Content of Selected Bioactive Substances

Abstract

The aim of the work was to evaluate the effect of hot air and infrared drying on the content of total polyphenols and anthocyanin dyes in selected types of small fruits. In the work we used chokeberry (Aronia melanocarpa Michx.) variety Nero, elderberry (Sambucus nigra L.) variety Haschberg, sour cherry (Prunus cerasus L.) variety Fanal, red currant (Ribes rubrum L.) variety Lake, black currant (Ribes nigrum L.) variety Triton, cherry elaeagnus (Elaeagnus multiflora Thunb), raspberry (Rubus idaeus L.) variety Heritage and blueberry (Vaccinium corymbosum L.) variety Bluecrop. Drying was performed in a Concept S1060 hot air dryer and a Yden CI IR D5 infrared dryer. The analysis of the content of anthocyanin dyes was performed by the pH differential method, the determination of the total content of polyphenols was performed by the Folin - Ciocalteu method. By analyzing fresh fruits, we found the highest content of anthocyanin dyes in the fruits of chokeberry (3036.97 mg.100 g-1 DM) and the lowest in the fruits of cherry elaeagnus (83.86 mg.100 g-1 DM). The total polyphenol content ranged from 726.07 mg GAE.100 g-1 dry matter (cherry elaeagnus) to 7895.61 mg GAE.100 g-1 DM (chokeberry). After drying in a hot air dryer, the content of anthocyanin dyes decreased by 62.20% (in elderberry) to 72.52% (in cherry elaeagnus) and the content of total polyphenols by 45.16% (in chokeberry) to 53.34% (in red currant). After drying in an infrared dryer, the decrease in the content of anthocyanin dyes was 50.41% (in elderberry) to 71.22% (in cherry elaeagnus) and total polyphenols 41.05% (in chokeberry) to 47.89% (in sour cherry).