Digestibility and allergenicity of beta-lactoglobulin following laccase-mediated cross-linking in the presence of sour cherry phenolics

Abstract

beta-Lactoglobulin (BLG) is an important nutrient of dairy products, but it represents a serious health risk in patients allergic to milk. Sour cherry (Prunus cerasus L) extract (SCE) is frequently added as a natural food colour in composite foods, such as fruit yogurt, ice creams, frappes and milkshakes. The aim of this study was to investigate the potential of laccase to cross-link BLG in the presence of an SCE and to characterise the obtained products for their bioactivity. Laccase cross-linked BLG in the presence of sour cherry phenolics. In a basophil-activation assay, the allergenicity of the cross-linked protein was shown to decrease in all nine cow's milk-allergic patients, while digestibility of the remaining monomeric BLG in simulated conditions of the gastrointestinal tract increased. Tryptic peptides became immediately available in BLG treated by laccase and laccase/SCE. The hydrolysates obtained by trypsin digestion of BLG/laccase/SCE showed an increase of 57% in radical-scavenging activity, compared to the control BLG. Enzymatic processing and usage of natural phenolic extracts as mediators of enzymatic reaction may improve BLG safety and the availability of peptides following digestion, while conserving its bioactivity.