Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk NR4 7UQ, UK.
Marlow Foods Ltd, Station Road, Stokesley, North Yorkshire TS9 7AB, UK.
Food Chem. 2020 Nov 15;330:127252. doi: 10.1016/j.foodchem.2020.127252. Epub 2020 Jun 7.
Mycoprotein is a food ingredient from filamentous fungi rich in protein and fibre. This study investigated the protein bioaccessibility from the fungal cells by colourimetric assays in different mycoprotein formulations, following extraction methods and in vitro gastrointestinal digestion. The methods effects were further analysed by static laser light scattering, SDS-PAGE and optical-fluorescence microscopy. The extraction methods released a comparable proportion of protein (30 wt%) independent of sample concentration (10 wt% and 25 wt%), whereas the simulated digestions endpoints released a higher proportion of protein from the less concentrated (46 wt%). Furthermore, mechanical/physical processing had only a minor impact. Intestinal proteases promoted the most efficient protein release but without causing any apparent damage to the cell walls when viewed by microscopy. This suggested that the enzymes can diffuse through the cell walls, due to its porosity/permeability, and are the main factors responsible for the hydrolysis and bioaccessibility of protein from mycoprotein.
真菌蛋白是一种富含蛋白质和纤维的丝状真菌食品成分。本研究通过比色法测定了不同真菌蛋白配方中真菌细胞内蛋白质的生物可及性，考察了提取方法和体外胃肠消化的影响。采用静态激光散射、SDS-PAGE 和光学荧光显微镜进一步分析了方法的效果。提取方法释放出的蛋白质比例相当（30wt%），与样品浓度无关（10wt%和 25wt%），而模拟消化终点从较低浓度（46wt%）中释放出更高比例的蛋白质。此外，机械/物理处理的影响较小。肠蛋白酶促进了蛋白质的最有效释放，但通过显微镜观察，细胞壁没有明显损伤。这表明酶可以通过细胞壁扩散，由于其多孔性/渗透性，是导致真菌蛋白中蛋白质水解和生物可及性的主要因素。
