Metabolite release and rheological properties of sponge cake after in vitro digestion and the influence of a flour replacer rich in dietary fibre.

The present study aimed to better understand the metabolite release and rheological characteristics of sponge cake after in vitro digestion and the effect of Eucheuma as a fibre-rich flour replacer. Overall, 22 compounds including amino acids, saccharides, fatty acids, and other metabolites were identified based on nuclear magnetic resonance spectra. Principal component analysis and orthogonal projection to latent structures-discriminant analysis showed that Eucheuma reduced the release of amino acids and fatty acids. The released glucose from the EP20 sample (20% replacement of flour with Eucheuma) decreased by 35.4% in intestinal phases compared with the control cake. Eucheuma's in vitro effects on sponge cake digestion mainly reflected altered flow behaviour index. All samples showed solid-like behaviour and a decrease in viscoelastic moduli after digestion. This study forms the basis for future optimisation of food properties to control their digestive characteristics.