Tailoring bilberry powder functionality through processing: Effects of drying and fractionation on the stability of total polyphenols and anthocyanins

Abstract

Bilberries are a rich natural source of phenolic compounds, especially anthocyanins. The press cake obtained during the processing of bilberry juice is a potential source of phytochemicals. The objective of this study was to evaluate different drying techniques and the fractionation of bilberry press cake powder toward obtaining phenolic‐rich ingredients for incorporation into value‐added food products. The derived powders were dispersed in water and dairy cream, to investigate the effects of drying and fractionation on the dispersibility and solubility of phenolic compounds. The drying techniques, hot air drying and microwave drying, applied on bilberry press cake reduced the content of total phenolics and anthocyanins. The degradation was, however, consistently small and similar for both techniques. The major anthocyanins detected in the samples were stable during drying and fractionation treatments. Fractionation of the press cake powder affected the total apparent phenolic content and composition of the different fractions. The highest phenolic content (55.33 ± 0.06 mg g −1 DW ) and highest anthocyanin content (28.15 ± 0.47 mg g −1 DW ) were found in the fractions with the smallest particle size (<500 μm), with delphinidin‐3‐O‐galactoside being the most abundant anthocyanin. Dispersibility of all dried powder samples was higher in dairy cream than water, and the highest level of anthocyanins was measured in samples from the powder with the smallest particle size (<500 μm), dispersed in cream. The application of drying, milling and fractionation was found to be a promising approach to transform bilberry press cake into stable and deliverable ingredients that can be used for fortification of food products with high levels of phenolic compounds.

Vaccinium myrtillus L. Fruits as a Novel Source of Phenolic Compounds with Health Benefits and Industrial Applications - A Review

“…This fruit is consumed not only in a fresh manner, but also in processed products (press cake) and derivatives (juice, jam and liqueur) [95,96]. Fruits drying and its transformation into powder represent a suitable alternative widely used by consumers and the food industry that allow having them available throughout the year for subsequent use as an ingredient in based foods (extruded products, bakeries, sauces, beverages, ice creams, yogurts, and confectionary) [11,97]. The by-products resulting from the production of bilberries, as well as the fruits that, due to their exterior appearance or size do not meet commercialization standards, may also be used for the preparation of polyphenols extracts and the production of novel foods, conferring them added value and reducing the environmental impact.…”

Spectroscopic studies and molecular docking on the interaction of delphinidin‐3‐O‐galactoside with tyrosinase

“…Cyanidin‐3‐sophoroside from Garcinia mangostana rind effectively reduced activity of TY 26 . Delphinidin‐3‐O‐galactoside (DG), a natural water‐soluble anthocyanidin, is widely distributed in grapes, berries, plants, vegetables, and fruits 27–32 . No study on the interaction between DG and TY has been reported so far.…”

“…26 Delphinidin-3-O-galactoside (DG), a natural watersoluble anthocyanidin, is widely distributed in grapes, berries, plants, vegetables, and fruits. [27][28][29][30][31][32] No study on the interaction between DG and TY has been reported so far. The structure of DG is shown in Figure 1.…”

Tailoring bilberry powder functionality through preprocessing and drying

“…This is the first part of a two‐step study where the bilberry powder functionality is tailored by effects from the whole production process including pretreatments, drying techniques, and post‐treatments. In the second part, Oliveira et al () describe the effects of drying and fractionation on the stability of polyphenols and anthocyanins in bilberry press cake powder.…”