Microencapsulation of an anthocyanin-rich blackberry (Rubus spp.) by-product extract by freeze-drying

Abstract

One approach to improving sustainable food production is to add value to fruit by-products, which are currently used as animal feed or discarded, yet may be useful sources of natural antioxidants due to their phenolic compounds. Hence, the present work aimed to produce and evaluate two products prepared from an anthocyanin-rich extract of a blackberry by-product through freeze-drying. Maltodextrins with 10 and 20 dextrose equivalent (DE), were assessed as the carrier matrices. The maltodextrin DE did not significantly influence the mean diameter and solubility of the particles. Morphological analysis revealed that all the particles exhibited a broken glass structure and shriveled surfaces. Comparatively, better results were obtained from the maltodextrin 10 than 20DE powders, regarding anthocyanin retention in the drying process, hygroscopicity, moisture content, acidity, water activity and color indices (P < 0.05). The results suggest that blackberry by-products contain valuable biocompounds, namely anthocyanins. Therefore, the anthocyanin extraction, concentration and microencapsulation with maltodextrin 10DE, presented a potential approach to using blackberry by-products as food colorants or healthy ingredients.