Technological processes to decrease the allergenicity of peach juice and nectar

Among vegetable foods peach (Prunus persica) has been recognized as a signi ficant cause of allergy. The protein, which is considered to be the major p each allergen, has been named Pru p 1. Because peaches are consumed both as fresh fruits and after processing to obtain peach juice, nectar, jam, syru py peach, etc., research was carried out to identify a technological proces s for production of hypo- or nonallergenic peach-based products. SDS-PAGE a nd immunoblotting analysis of extracts prepared from four commercial peach nectars showed that the Pru p 1 was not removed, and neither was its allerg enic activity decreased by technological treatments carried out for nectar production. Some treatments oriented toward a removal of or, at least, a de crease in the allergenic power were assumed and verified at laboratory scal e. A variable considered was heat treatment at 121 degrees C for 10 and 30 min: this treatment was not able to decrease the allergenicity of the Pru p 1 protein. Furthermore, the protein band was still present even after 60-m in reaction with two different acidic proteases. The two technological trea tments that were found to decrease the major allergen of peach were chemica l lye peeling of fruits and ultrafiltration of juice through membranes with suitable cutoff. On the basis of the results obtained from this research, a processing flow sheet was defined to obtain hypoallergenic or probably no nallergenic limpid juices and nectars. These products may represent, beside s finished foods, intermediates to obtain various products after addition o f further ingredients such as pectins, sugars, and fiber.