Advanced Proteomic and Bioinformatic Tools for Predictive Analysis of Allergens in Novel Foods

Analysis of trends and allergenicity risk assessments in novel food approvals within the European Union between 2018 and 2023

Novel food (NF) approvals in the European Union between 2018 and 2023 (n = 117) were retrieved and analysed. They consist of new NF (52.1%), modification (38.5%), and traditional food (9.4%). The average time taken for new NF applications to be approved was 38 months in 2023, with clock-stops occurring in all approvals since 2020. For new NFs, only 21.3% and 9.8% performed tests by bioinformatics homology and immunological analyses respectively, suggesting that allergenicity assessments remain a challenge. Allergenicity risks were regarded as possible for 47.5% of the new NF approvals, while 52.5% were expected to be low, very low, or unlikely. However, it was not always clear what the decision was based on. While protein intake levels were rarely mentioned in the allergenicity conclusions of approvals, new NFs with allergenicity risks typically had protein intake exceeding 1 mg/day. Establishing a dose that represents a Threshold of Allergological Concern below which a protein is unlikely to cause sensitisation in consumers, could make de novo allergenicity assessment of NFs more feasible. This approach might exempt certain proteins from testing, instead focusing on proteins of possible allergenic relevance.

Buffalo worm (Alphitobius diaperinus) proteins: Structural properties, proteomics and nutritional benefits

Biophysical methods such as circular dichroism (CD) and differential scanning calorimetry (DSC) have been minimally used to characterize insect-derived proteins. This study examines the insect Alphitobius diaperinus as a potential protein source. Techniques such as alkaline solubilization coupled to isoelectric precipitation and Osborne fractionation were used to obtain protein concentrates and fractions (albumins, globulins, prolamins, glutelins). SDS-PAGE results showed dominant protein bands at 78.3, 73.3, 49.3, 34.5, 32.0, and 10.3 kDa. All fractions had over 60 % α-helix and β-sheet structures, indicating stable conformations. Prolamins showed high surface hydrophobicity and thermal stability. Nutritionally, glutelins exhibited the highest concentration of essential amino acids (68.75 g/100 g protein), and demonstrated superior In vitro protein-digestibility (84.04 %) as well as the highest In vitro protein-digestibility corrected amino acid score (73.11 %). Therefore, this study characterized the structural-function relationship of A. diaperinus proteins and collectively assessed their suitability and safety for human consumption.

Proteomic identification of allergenic proteins in holm oak (Quercus ilex) seeds

Humans have used Quercus ilex acorns as a staple food since ancient times. Recently, their nutritional and nutraceutical value has revived interest for human consumption. Ensuring their safety as food requires assessing their allergenic potential. In this work, we predicted the allergenic profile of acorns by in silico analysis of the Q. ilex genome and transcriptome. In addition, immunoblot analysis of pooled sera from patients allergic to various dry fruits was performed, with immunoreactive bands subjected to mass spectrometry analysis. The most remarkable allergens identified belong to the Bet v 1, profilin, prolamin, Hsp70 and cyclophilin families. Acorns from different mother trees exhibited also different IgE sensitization patterns. Thus, acorns from trees showing damage symptoms, and located in declined areas, had higher allergen contents than those from healthy ones, which corresponded to higher abundance of stress-related proteins.

Novel foods in the European framework: benefits and risks

Given the rapidly increasing global demand for food, it is mandatory to consider new sources of nutrients, safe and sustainably produced protein foods to complement the current traditional and limited sources of protein in the human diet. In recent years, a wide range of nontraditional protein foods have been explored, prompting the European Union to legislate on how novel foods can be introduced and traded on the European market to ensure their safety. This review will illustrate the range of novel foods authorized in the EU and their potential impact on human health, highlighting the gaps, the potential risks, and the future research opportunities and perspectives.

Comparative Seed Proteome Profile Reveals No Alternation of Major Allergens in High-Yielding Mung Bean Cultivars

Mung bean contains up to 32.6% protein and is one of the great sources of plant-based protein. Because many allergens also function as defense-related proteins, it is important to determine their abundance levels in the high-yielding, disease-resistant cultivars. In this study, for the first time, we compared the seed proteome of high-yielding mung bean cultivars developed by a conventional breeding approach. Using a label-free quantitative proteomic platform, we successfully identified and quantified a total of 1373 proteins. Comparative analysis between the high-yielding disease-resistant cultivar (MC5) and the other three cultivars showed that a total of 69 common proteins were significantly altered in their abundances across all cultivars. Bioinformatic analysis of these altered proteins demonstrated that PDF1 (a defensin-like protein) exhibited high sequence similarity and epitope matching with the established peanut allergens, indicating a potential mung bean allergen that showed a cultivar-specific response. Conversely, known mung bean allergen proteins such as PR-2/PR-10 (Vig r 1), Vig r 2, Vig r 4, LTP1, β-conglycinin, and glycinin G4 showed no alternation in the MC5 compared to other cultivars. Taken together, our findings suggest that the known allergen profiles may not be impacted by the conventional plant breeding method to develop improved mung bean cultivars.

Food allergen detection by mass spectrometry: From common to novel protein ingredients

Food allergens are molecules, mainly proteins, that trigger immune responses in susceptible individuals upon consumption even when they would otherwise be harmless. Symptoms of a food allergy can range from mild to acute; this last effect is a severe and potentially life-threatening reaction. The European Union (EU) has identified 14 common food allergens, but new allergens are likely to emerge with constantly changing food habits. Mass spectrometry (MS) is a promising alternative to traditional antibody-based assays for quantifying multiple allergenic proteins in complex matrices with high sensitivity and selectivity. Here, the main allergenic proteins and the advantages and drawbacks of some MS acquisition protocols, such as multiple reaction monitoring (MRM) and data-dependent analysis (DDA) for identifying and quantifying common allergenic proteins in processed foodstuffs are summarized. Sections dedicated to novel foods like microalgae and insects as new sources of allergenic proteins are included, emphasizing the significance of establishing stable marker peptides and validated methods using database searches. The discussion involves the in-silico digestion of allergenic proteins, providing insights into their potential impact on immunogenicity. Finally, case studies focussing on microalgae highlight the value of MS as an effective analytical tool for ensuring regulatory compliance throughout the food control chain.

Unveiling the potential of proteomics in addressing food and feed safety challenges

The food and feed sector in Europe is rapidly evolving to address contemporary challenges, striving for fairer, safer, greener and more sustainable food systems. This includes the exploration of new protein sources for human consumption and animal feed such as protein derived from insects, algae or novel plant-derived proteins, and the re-evaluation of existing sources like processed animal protein (PAP). To generate reliable data on the diverse array of emerging protein sources for future food and feed safety assessments, a growing demand for the development and implementation of advanced analytical techniques exists. New approach methodologies (NAMs) including, mass spectrometry (MS)-based proteomics methods have been emerging as valuable techniques which potentially can be implemented in regulatory laboratory settings to complement conventional approaches in this realm. These MS-driven strategies have already proven their utility in diverse applications, including the detection of prohibited substances in feed, identification of allergens, differentiation of fish species in complex mixtures for fraud detection and the verification of novel foods and alternative protein sources. This EU-FORA programme was focused on three core objectives namely: (i) the training of the fellow in utilising MS-based proteomics for food and feed safety analyses, (ii) the involvement of the fellow in the development of standardised operating procedures (SOP) for targeted and non-targeted proteomic MS-based workflows for species and tissues specific PAP identification in a national reference laboratory (NRL) and (iii) the transfer and implementation of MS-based approaches and standardised protocols for PAP analysis at the fellow's home institution. Altogether, this programme facilitates the broadening and diversification of use of MS-based proteomic methodologies for reinforcing their significance within the domains of food and feed safety research and regulatory science applications.