Pomegranate Cultivars: Identification of the New IgE-Binding Protein Pommaclein and Analysis of Antioxidant Variability

The consumption of pomegranate is increasing as it is considered a health-promoting food. Nevertheless, it can trigger allergic reactions, sometimes severe. The LTP Pun g 1 is the only pomegranate allergen so far reported. Based on preliminary clinical observations, the main aim of this study was the investigation of still unknown allergens contained in this fruit. Pommaclein, a homologue of peamaclein, the peach allergen Pru p 7, was isolated, identified by protein sequencing, and characterized as an IgE-binding protein by different test systems. RP-HPLC protein profiles revealed significant variations of LTP and pommaclein content in the red pulp of selected cultivars and accessions. Conversely, the mesocarp appeared free of proteins and much richer in antioxidants. In conclusion, a new allergen has been identified, and it could contribute to improving allergy diagnosis. The study highlights that pomegranate mesocarp could represent a rich and safe source of nutraceuticals also for allergic subjects.