Shear and extensional rheological characterization of thickened fluid for dysphagia management

Rheological properties and effects of in vitro gastrointestinal digestion on functional components and antioxidant activities of cooked yam flour

There is dearth of documented information on rheological behavior, bioaccessibility and antioxidant potential of cooked yam flour (CY). This study was carried out to evaluate rheological properties and effects of in vitro gastrointestinal digestion (GID) on functional compositions and antioxidant activities of CY. CY displayed enhanced pseudoplastic and ''gel-like" characteristics with incremental concentration (4.5-9.0%). After GID, contents of total polyphenols, flavonoids, sugar (TS), acidic polysaccharides (AP) and free amino acids (FAAs) significantly increased with maximal increment of 3.51-fold for TS followed by AP (3.05-fold), and DPPH, ABTS, FRAP and FIC assays pointed to a significant increase in antioxidant activity. Sixteen FAAs including 7 essential amino acids were detected with highest content of 9.81 mg/g for arginine. Large block remnants with a micro-porous structure were confirmed by scanning electron microscopy. Results indicate that CY with favourable swallowing performance can serve as a reliable source of bioaccessible and bioactive compounds with antioxidation.