Peanut allergen reduction and functional property improvement by means of enzymatic hydrolysis and transglutaminase crosslinking.

Enzymatic processing could reduce the allergenicity of peanut proteins while may lose the functional properties. Transglutaminase (TGase) is an enzyme for improving the functional properties of proteins/hydrolysates. No studies have been conducted on peanut hydrolysates that are crosslinked with TGase. In this study, allergenicity and functional properties of peanut protein hydrolysate cross-linked by TGase were tested. Papain, ficin and bromelain were selected out of eight food-grade enzymes for the kinetic analysis of peanut protein hydrolysis that lead to high reduction rate (K) of the IgE-binding property. Peanuts hydrolyzed by the three selected enzymes (200 AzU/g) were used for IgE binding, TGase-crosslinking and functional property characterization. After hydrolysis, the IgE-binding properties of the peanut soluble extracts were decreased (by 85%-95%); and functional properties were also decreased as compared to intact peanut protein extracts. The TGase crosslinked hydrolysates had similar IgE-binding properties to the un-crosslinked hydrolysates, but with higher functional properties.

Quantitative and kinetic analyses of peanut allergens as affected by food processing.

Peanuts contain four major allergens with differences in allergenic potency. Thermal processing can influence the allergenic properties of peanuts. Until now, a kinetic model has not been reported to assess the changes of soluble allergen (extracted from processed peanuts) content as affected by various thermal processing methods. Our objective is to characterize the reaction kinetics of the thermal processing methods, including wet processing (boiling with/without high-pressure, steaming with/without high-pressure), deep-frying and dry processing (microwaving and roasting) using five time intervals. The relationships between processing time and extractable major allergen content could be explained by a simple linear regression kinetic model (except high-pressure steaming). Among all the methods with optimal processing point, frying for 6 min had a relatively lower IgE binding (linear epitopes) ratio, possibly due to the processing conditions, which caused break down, cross-linking and aggregation of Ara h 2, and a relatively lower solubility.