Immunological and Proteomic Characterization of Food Allergens in Almond Hulls

ABSTRACT This study provides a systematic evaluation of the allergenic potential of almond hulls using a combination of immunoblotting and proteomic approaches. Laboratory‐prepared almond hulls from multiple Prunus dulcis cultivars were analyzed to identify intrinsic allergenic proteins and assess potential cross‐reactivity with other Prunus species. Immunoblot analysis revealed a consistently reactive ~75 kDa protein across all almond hull cultivars. Besides, additional IgE‐reactive bands were recognized by plasmas from Prunus fruit‐allergic patients, indicating cross‐reactivity mediated by conserved panallergens such as profilins and pathogenesis‐related protein type 10 (PR‐10)/Bet v 1‐like proteins. Mass spectrometric analysis of laboratory‐prepared almond hulls identified several PR‐10/Bet v 1‐like proteins sharing 25%–53% sequence similarity with homologs from peach, apricot, and cherry, confirming the presence of intrinsic almond hull proteins with potential allergenic relevance. In contrast, proteomic analysis of pilot‐scale processed Nonpareil almond hull food powder revealed a more complex allergen profile, including the detection of amandin (Pru du 6) and profilin (Pru du 4), likely introduced through mixed‐in kernel residues or cross‐contact with almond kernels during industrial hulling/shelling. The combined data demonstrate that almond hulls contain both intrinsic proteins capable of cross‐reactivity and kernel‐derived allergens introduced through processing. These findings provide foundational evidence to guide the safe utilization of almond hulls in food systems while emphasizing the need for allergen management strategies to minimize contamination and ensure consumer safety.