Comparison of β-Lactoglobulin Content in Dairy Products by Inhibition ELISA and Immunoblotting

抄録

To estimate the effect of food processing on allergen content in dairy products, β-lactoglobulin (β-LG) contents of 4 milks, 5 yogurts and 6 cheeses were compared using inhibition ELISA (enzyme-linked immunosorbent assay), SDS-PAGE and immunoblotting. Results of the inhibition ELISA suggested that low temperature-pasteurized milk contained several times higher levels of β-LG than high temperature-pasteurized milk, and that yogurts contain a lower amount of β-LG than milks. On the contrary, results of SDS-PAGE and immunoblotting suggested that the degradation of milk proteins including β-LG during yogurt manufacturing was not very extensive. These results suggest that yogurts contain factor(s) which interfere some reactions of inhibition ELISA. β-LG was also detected in cheeses, though the level was lower than that of milks. Though milk proteins were degraded most extensively in Roquefort cheese, its β-LG level was the highest. Among them, processed cheese had the lowest amount of β-LG, followed by Emmental cheese. These results suggest that an appropriate application of specific bacteria is useful for the preparation of low allergenic dairy products.