Design of Maize Starch-Based Pickering Emulsions: Effects on Lipid Digestion, Absorption, and Duodenal Transcriptomics

Designing food microstructures to elicit specific physiological responses is crucial for advancing functional food innovation. Pickering emulsions were fabricated using starch nanoparticles with tailored amylose/amylopectin ratios, prepared by blending modified high-amylose (HAMG) and waxy maize (WMG) starch granules. Increasing amylopectin content progressively reduced droplet size, shifting from a unimodal distribution centered at 13.76 μm in pure HAMG systems to predominantly smaller droplets (~1.72 μm) in pure WMG emulsions. In vitro digestion demonstrated that amylose-rich emulsions preserved higher structural integrity and suppressed lipid hydrolysis via a more rigid interfacial barrier, whereas amylopectin-rich emulsions enhanced enzyme accessibility and free fatty acid release. In vivo murine studies further demonstrated that high-amylose Pickering emulsions delayed gastric emptying and reduced postprandial plasma triglyceride levels. Duodenal transcriptomic analysis revealed that rapid lipid flux in WMG-treated mice induced pronounced metabolic reprogramming, including upregulation of genes involved in fatty acid transport (fabp1/2), chylomicron assembly (apoa4), peroxisomal β-oxidation (acox2), mitochondrial oxidative phosphorylation, and immune-related pathways. Overall, these results demonstrate that interfacial engineering using starch particles enables precise regulation of lipid digestion and intestinal metabolic responses, providing a rational strategy for targeted functional and medical food design.