In-vitro investigation of mycoprotein: opportunities for older adult nutrition

Dietary intake is a major determinant of later life course outcomes, with poor dietary intake linked with increased incidence of non-communicable diseases. Protein under-nutrition is a contributing factor to declining health in community dwelling older adults. Mycoprotein is a food ingredient produced from the fermentation of Fusarium venenatum , that is high in protein and fibre, has a complete amino acid profile as well as being low in fat (1) . The aim of this study was to utilise in-vitro gastrointestinal digestion models to determine the extent of variability in the digestibility profile of mycoprotein when comparing a standard adult model, to the older adult model. Freezed dried Mycoprotein paste was subjected to in-vitro gastrointestinal digestion, using a computer controlled bioreactor system (2) , utilising optimised conditions which simulated both adult and older adult gastrointestinal conditions (3) . Following digestion, absorbable and non-absorbable protein fractions were separated and the protein content determined determined using total nitrogen analysis (Rapid Max N exceed, Elementar UK) and total amino acid analysis via ion exchange chromatography with post-column ninhydrin derivitisation (Hitachi LA8080, Avantor UK). All values were corrected using blank (protein free) digestions containing only digestive enzymes. After mass balance correction (for protein content of digestive enzymes and non-protein nitrogen), total in-vitro protein digestibility of mycoprotein was 65.0 % (SD 0.03 %) using standard digestion conditions in triplicate. For conditions that simulated older adult digestion, total protein digestibility was reduced by 3.4 %. Digestibility of indispensable amino acids between the two models, were non-significant (p > 0.05). Previously published trials have shown that for plant based feedstocks, protein digestibility reduced by up to 20 % using older adult conditions. As the global food system evolves to meet the nutritional needs of a growing population and challenges of Net Zero, there is potential for high protein plant based alternatives to meet the nutritional needs of an ageing population. This work has demonstrated that the digestion of mycoprotein is largely unaffected by the changing gastrointestinal conditions of older adults and therefore could play an important role in future nutritional support strategies for older adults.