Konjac glucomannan decreases metabolite release of a plant-based fishball analogue during in vitro digestion by affecting amino acid and carbohydrate metabolic pathways

Konjac glucomannan (KGM) provides a sense of fullness by delaying physiological processes related to food digestion, which helps weight management and cholesterol maintenance. This study assessed the influence of KGM on the digestive performance of a plant-based fishball (PFB) analogue during in vitro digestion via nuclear magnetic resonance (NMR) spectroscopy and rheological measurements. A total of 27 metabolites were identified, such as amino acids, sterols, saccharides, and fatty acids. Moreover, KGM generally decreased the released amino acids, glucose, and fatty acids. It is possible because KGM affected the metabolic pathways of amino acids and carbohydrates, based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Furthermore, PFB6.5 (PFB with 6.5% of KGM) digesta exhibited significantly higher yield stress τ0 (28.0 Pa), consistency coefficient K (46.25 Pa·Sn), and viscoelasticity G0* (749 Pa) than PFB3.5 (9.2 Pa, 14.66 Pa·Sn, 188 Pa). Besides, surface morphology indicated that fishball digesta became more porous, dissociative, and fragmented than PFB, revealing KGM reduced the breakdown of proteins. In conclusion, KGM prolonged the digestion and decreased metabolite release of PFB, which may help control appetite and reduce postprandial blood glucose levels.