Linking Mutations in Pea (Pisum sativum L.) to Changes in Nutrient Bioaccessibility and Allergenic Potential

Ng’ang’a, Rispah Nyambura (2025) Linking Mutations in Pea (Pisum sativum L.) to Changes in Nutrient Bioaccessibility and Allergenic Potential. Doctoral thesis, University of East Anglia.

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Abstract

Background: Pea (Pisum sativum L.) is a promising legume for sustainable protein transitions; however, its nutritional value is often constrained by certain seed proteins with undesirable properties. Pre-breeding pea lines carrying null mutations in lectin (LecA), trypsin inhibitors (TI) and pea albumin 2 (PA2) were developed as a potential strategy to enhance seed quality. This thesis evaluated the impact of these mutations on starch and protein bioaccessibility, protein nutritional quality, and predicted allergenicity.

Methods: In vitro digestion models were used to evaluate starch and protein digestibility of wild-type and mutant flours under raw and hydrothermally processed conditions. Protein nutritional quality was determined using the in vitro Digestible Indispensable Amino Acid Score (DIAAS). Quantitative proteomics characterised mutation-induced changes in seed protein composition, and a novel, in silico multi-tool was used to assess predicted allergenicity. A systematic review synthesised scientific evidence on immune-mediated adverse reactions to pea and pea-derived ingredients and identified causative allergens.

Results: Null mutations did not significantly affect total starch or protein content or their digestibility under raw or cooked conditions. Raw flours exhibited low starch digestibility and high protein digestibility, but boiling produced the opposite pattern. Cooked mutant flour had a lower in vitro DIAAS than wild-type flour, indicating reduced protein nutritional quality. Proteomic profiling revealed extensive shifts in protein abundance, and in silico analyses flagged several putative allergens, the majority of which were upregulated in the mutant. The first integrated synthesis of IgE- and non-IgE-mediated reactions to pea was produced, highlighting limited molecular characterisation of pea allergens and other substantial knowledge gaps.

Conclusion: Null mutations in LecA, TI, and PA2 did not improve nutrient bioaccessibility, reduced protein nutritional quality, and increased predicted allergenicity. This thesis provides novel insights into the unintentional nutritional trade-offs in legume breeding and underscores the need for holistic evaluation strategies to guide the development of safe and nutritious plant-based foods.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Science > School of Biological Sciences
Depositing User:	Chris White
Date Deposited:	10 Feb 2026 18:36
Last Modified:	10 Feb 2026 18:36
URI:	https://ueaeprints.uea.ac.uk/id/eprint/101904
DOI:

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