Allergenicity assessment of novel food proteins: what should be improved?

Allergenicity prediction is one of the most challenging aspects in the safety assessment of foods derived from either biotechnology or novel food proteins. Here we present a bottom-up strategy that defines a priori the specific risk assessment (RA) needs based on a database appropriately built for such purposes

Safety Assessment of Immune-Mediated Adverse Reactions to Novel Food Proteins

Transplantation and autoimmunit

Food allergens of plant origin : their molecular and evolutionary relationships

Along with other forms of allergic disease, food allergies appear to be on the increase, with childhood allergies to foods such as peanuts being of particular concern. Around 7¿10 foods are responsible for the majority of allergies, including several of plant origin, notably peanut. Allergies are usually triggered by the protein components in a food, which are also known as allergens. However, not all the proteins in an allergenic food like peanut are allergens. Why should this be? This question has been addressed by an EU-funded inter-disciplinary network of clinicians, food chemists and plant biochemists called Protall. From the groups considerations it is clear that, whilst the abundance of a protein in a food is one factor involved in determining its allergenic potential, this is not sufficient on its own to predict its allergenicity. Through an analysis of common properties of plant food allergens that trigger a reaction via the gastrointestinal tract it has become evident that they belong almost exclusively to three structurally related protein superfamilies¿¿the prolamin superfamily (which includes the prolamin storage proteins of cereals, non specific lipid transfer proteins, -amylase inhibitors, and 2S albumins), the cupin superfamily (specifically the 11S and 7S globulin storage proteins) and the cysteine proteases. Whilst we cannot as yet predict the allergenicity of a given protein, such an understanding of the structural attributes of proteins that predispose them to becoming allergens is important if we are to understand what makes some foods more allergenic than others. It is also highly relevant to developing more reliable means of assessing the allergenic risks posed by novel foods, developing effective processing strategies for reducing allergen loads in foods and developing novel therapeutic options as an alternative to dietary exclusion

FTIR imaging of wheat endosperm cell walls in situ reveals compositional and architectural heterogeneity related to grain hardness

International audienceEndosperm cell walls of cultivars of wheat (Triticum aestivum L.) selected for their endosperm texture (two soft and two hard) were analysed in situ by Fourier transform infrared (FTIR) microspectroscopy. FTIR imaging coupled with statistical analysis was used to map the compositional and structural heterogeneity within transverse sections from which cell contents had been removed by sonication. In the majority of grains analysed, two distinct populations of endosperm cells could be identified by spectral features that were related to cell morphology and age, regardless of cultivar. The main cell-wall component responsible for these differences was the polysaccharide arabinoxylan. In a few samples, this heterogeneity was absent, for reasons that are not understood, but this was not correlated to endosperm texture or growth conditions. Within the same population of endosperm cells, cell walls of hard endosperm could be distinguished from those of soft endosperm by their spectral features. Compared to hard cultivars, the peripheral endosperm of soft cultivars was characterised by a higher amount of polymer, whose spectral feature was similar to water-extractable arabinoxylan. In contrast, no specific compound has been identified in the central endosperm: structural differences within the polysaccharides probably contribute to the distinction between hard and soft cultivars. In developing grain, a clear difference in the composition of the endosperm cell walls of hard and soft wheat cultivars was observed as early as 15 days after anthesis