Effects of industrial and home-made spread processing on bilberry phenolics

Abstract

Bilberries processed into spreads represent an important source of anthocyanins if these remain rich in the final product. The effects of thermal processing were studied with non-ground and ground bilberries processed into spreads according to industrial and home-made procedures. Samples were analysed by LC-DAD-MS/MS and LC-MS. The spreads had 28-60% less total phenolics, 4-62% less anthocyanins, and 1-fold to 2-fold more phenolic acids and total flavonols than the bilberries, but approximately equal flavanols. The home-made spread from ground bilberries had ca. 26% higher antioxidant activity. Delphinidin 3-glucoside and cyanidin 3-glucoside were taken through the two spread procedures, with their degradation to gallic acid (38-57%), protocatechuic acid (1-2%) and 2,4,6-trihydroxybenzaldehyde determined. The amounts of gallic and protocatechuic acids did not reflect well for anthocyanin degradation. The industrial spread procedure with non-ground bilberries is a more suitable procedure to maintain the final content of anthocyanins.

Keywords: (+/−)-Catechin (PubChem CID: 107957); (−)-Epicatechin (PubChem CID: 72276); 2,4,6-Trihydroybenzaldehyde; Bilberries; Caffeic acid (PubChem CID: 689043); Chlorogenic acid (PubChem CID: 1794427); Cyanidin 3-glucoside (PubChem CID: 197081); Delphinidin 3-glucoside (PubChem CID: 443650); Gallic acid (PubChem CID: 370); Home-made; Industrial; Liquid chromatography–mass spectrometry; Myricetin (PubChem CID: 5281672); Phenolics; Protocatechuic acid (PubChem CID: 72 and 8468); Quercetin (PubChem CID: 5280343); Spreads.