Influence of particle size distribution of orange-fleshed sweet potato flour on dough rheology and simulated gastrointestinal digestion of sweet potato-wheat bread

Influence of particle size distribution (45-355 mu m) of orange-fleshed sweet potato flour (SPF) on dough rheological properties and changes of beta-carotene and polyphenols during simulated gastrointestinal digestion of sweet potato-wheat bread (SPWB) were investigated. Dough prepared from SPF with particle size 45 mu m showed improved network structure with fused starch granules and branched proteins, presented higher maximum height during fermentation (H-m, 19.70 mm), and exhibited the optimal elastic and viscous modulus values. SPWB from SPF with particle size 45 mu m showed higher specific volume (1.81 ml/g) and lower hardness (8612.3 N) as compared to other particle sizes. SPWB from SPF with particle size 106 and 75 mu m exhibited higher beta-carotene content in intestinal phases during simulated gastrointestinal digestion, followed by 45 mu m, whereas that from SPF with particle size 45 mu m showed more polyphenols content. Thus, SPF with particle size 45 mu m shows greater application potential for producing novel bread.