Commercial whey protein concentrate (WPC) was hydrolysed with either Alcalase 2.4 FG (Novo Nordisk), or papain (Sigma) (in one-step process) or with two enzymes (in two-step process) to determine the changes in the immunoreactivity of a-lactalbumin and b-lactoglobulin. Enzymatic hydrolysis of WPC was performed by pH-stat method. Hydrolysates were analysed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis, immunoblotting and size-exclusion chromatography (SE-HPLC). Immunoreactive properties of peptide fractions separated from the hydrolysates by fast protein liquid chromatography (FPLC) were determined using dot-immunobinding and enzyme-linked immunosorbent assay (ELISA) methods. Finally the sensory analysis was used to confirm organoleptic changes resulting from the application of different enzymes. The Ôtwo-stepÕ process was observed to be the most effective however allergenic epitopes were still present, as it was found by ELISA with anti-a-la and anti-b-lg antibodies. The addition of papain as the second enzyme in the hydrolysis process contributed to the improvement of the sensory properties of WPC hydrolysate as compared with the Alcalase hydrolysate. Alcalase-papain partially hydrolysated WPC can be found a promising base for production of the tolerogenic formula.

No abstract

The seeds of pea and soybean were germinated with and without light at 20C up to 3 days. After germination, fresh sprouts were subjected to sensory evaluation using quantitative descriptive analysis and hedonic tests. Changes in the immunoreactivity of the samples were determined by competitive enzyme‐linked immunoabsorbent assay using rabbit polyclonal antisera to pea and soybean proteins. The results indicated that the sensory quality of pea sprouts was significantly better than that of soybean. The dominating attributes differentiating the soybean samples from the pea samples were rancid odor and taste, which had clearly negative effect on their overall quality. The immunoreactive properties of the samples were dependent on whether they were with or without cotyledons. Removal of the cotyledons almost completely reduced the immunoreactivity of soybean and pea. The presence or absence of light during the germination process did not affect the results. PRACTICAL APPLICATIONS The results indicated that the germination of pea and soybean seeds is a relevant processing technique for reducing their immunoreactivity. This suggests that pea and soybean sprouts could be used to develop the special products for people who suffer from food allergic disorders. Further studies in this field should be carried out to determine whether it is possible to reduce the total immunoreactivity of pea and soybean seeds by prolonging their germination time. From the sensory viewpoint, pea sprouts appear to have an advantage over soybean sprouts in food system applications. The substantial reasons for the limited use of soybean sprouts arise from their rancid odor and taste.