Functional improvements in β-lactoglobulin by conjugation with high methoxy pectin by the Maillard reaction

beta-lactoglobulin (BLG), a major protein in whey, was conjugated with high methoxy pectin (HMP) by the Maillard reaction to improve emulsifying property and reduce allergenicity of BLG. The Maillard reaction was carried out at a weight ratio BLG: HMP = 1:4.15 and 1:6 at 60 degrees C at a relative humidity of 79% for 5 days. Crude conjugates were purified by dialysis and anion exchange chromatography. These two conjugates were named Conj. LS and Conj. HS, respectively. The results of SDS-PAGE showed that conjugates of various molecular weights were generated, and the weight ratios of protein to saccharide of Conj. LS and Conj. HS were 1:2.15 and 1:6.44 respectively, and the degree of reduction of free amino groups was 6.1 and 6.7 respectively. Emulsifying property of BLG was significantly improved by both conjugation. Both conjugates showed excellent emulsifying property in the acidic pH and in the presence of NaCl. Conjugation with HMP significantly reduced immunogenicity, which was more pronounced in conj. HS. Conjugation with HMP was considered to be an effective method to improve the functionality of BLG. Conjugation method used in this study is a safe method that is considered to be very valuable for food processing.