The influence of composite enzymatic hydrolysis on the antigenicity of β-conglycinin in soy protein hydrolysates

Abstract

The β-conglycinin is considered one of the major soybean allergens. The effects of hydrolysis with Neutrase and Flavourzyme on the antigenicity of β-conglycinin were investigated by indirect competitive, enzyme-linked immunosorbent assay (ELISA) and western blotting analysis. The molecular weight distribution was performed by SDS-PAGE. The hydrolysate with the lowest antigenicity was further separated by ultrafiltration. The results showed that enzymatic hydrolysis significantly reduced the antigenicity of β-conglycinin in soy protein hydrolysates. Flavourzyme hydrolysis for 15 min, inactivating the enzyme and then Neutrase hydrolysis for 15 min was the optimal combination of enzymatic hydrolysis, and the antigenicity of β-conglycinin in the hydrolysates was reduced by 64.46% compared with unhydrolyzed soy protein. The molecular weight distributions of hydrolysates were 31, 26, 20, and 15 kDa or lower. The low molecular weight (<10 kDa) ultrafiltration fractions exhibited the lowest antigenicity. Practical applications Enzymatic hydrolysis could be an efficient method in the reduction of soybean protein antigenicity. Flavourzyme hydrolysis for 15 min, inactivating the enzyme and then Neutrase hydrolysis for 15 min was the optimal hydrolysis mode for the reduction of β-conglycinin antigenicity. The results suggested that less than 10 kDa ultrafiltration fractions of hydrolysates showed the lowest antigenicity, which could be useful in the development of hypoallergenic soybean peptide powder.