Proteomic fingerprinting of apple fruit, juice, and cider via combinatorial peptide ligand libraries and MS analysis

Abstract

Combinatorial peptide ligand libraries coupled to MS was applied to extensively map the proteome of apple fruit, and to detect its presence in commercial apple juice and cider to evaluate their authenticity and genuineness. Using the Uniprot_Malus database, 96 proteins were detected in apples, among which 30 proteins were specifically captured via combinatorial peptide ligand libraries. Next, three proteins, previously recognized in fruits, were found in apple juice, which were involved in cellular metabolism of fruit maturation and in allergenic reactions. On the other hand, only one Malus allergen was identified in cider beads eluate, demonstrating that the industrial processes did not prevent any negative effects in sensitive subjects. Thus, the present study not only increases the knowledge of the apple proteome but also offers a reliable analytical method to assess quality and genuineness of commercial products, which could be also used to inform consumers about the presence of allergens.

Tiered approach for the identification of Mal d 1 reduced, well tolerated apple genotypes

“…The Mal d 1 gene expression is also depending on the ripening stage 66 , the storage time 18 and different stress conditions like pathogen or water-stress 16,67 . LC-MS based proteome analyses after tryptic digestion of fruits and detection of allergens have already been performed 68,69 . Analysis of birch pollen proteins revealed 43 peptides of 11 different Bet v 1 isoforms 70 , which were later confirmed for additional genotypes 71 but a comprehensive targeted analysis of Mal d 1 proteins has not been performed until now.…”

Identification of allergenomic signatures in allergic and well-tolerated apple genotypes using LC-MS/MS

“…Preliminary proteomic studies focused on significant changes of expressed proteins during maturation and fruit ripening to gain deeper knowledge of metabolic processes ( Shi et al, 2014 ). A proteomic approach was used to map the proteome of apple fruit, juice and cider and allowed the identification of differentially expressed proteins including Mal d3 ( Lerma-García et al, 2019 ). Recently, an exploratory proteomic study was performed to detect Mal d1 isoforms in the two apple cultivars SAN and GD, revealing different isoform patterns ( Romer et al, 2020 ).…”