Immunoanalytical method for quality control of orange juice products

The main goal of the present study is to develop an immunoanalytical method for the quality control of orange juice products. Peptides from various pa rts (juice, albedo, and flavedo) of citrus fruits (orange, mandarin, grapef ruit, and lemon) were analyzed and isolated by SDS-PAGE. Antisera were deve loped in mice against the protein pool of orange juice and peel and tested by Western blot analysis. Using these antisera, some juice- and peel-specif ic peptides were detected. One of the antibodies in the antiserum developed against peel proteins recognized a single peel-specific peptide with a mol ecular mass of 28 kDa in 10000-fold dilution. It did not give any positive reactions against the sample prepared from the juice. The 24 and 27 kDa jui ce-specific peptides were isolated in electrophoretically pure form, and po lyclonal antibodies were developed against them in mice. The anti-27 kDa an tibody reacted with a 29 kDa protein in the peel sample, and it gave a posi tive reaction against the 27 kDa peptide of the juice. The antibodies devel oped in the course of the present work seem to be useful for determining th e juice content in commercial citrus beverages and for evaluating the peel contamination in them.