In Vitro Fermentation Properties Are Determined by Starch–Lipid Complexes as an Entity Rather Than Their Constituent Mixture

Starch–lipid complexes were shown to have promising fermentation properties, but it is unclear whether the fermentation properties are determined by the starch–lipid complexes as an entity or derived from the simple mixture of constituent molecules. Accordingly, the in vitro fermentation properties of complexes formed between debranched high-amylose maize starch (DS) and myristic acid (MA) were compared with those of a simple mixture (MIX) of equal amounts of DS and MA in the complexes. Fermentation of DS–MA complexes significantly promoted the production of gases, acids, and short-chain fatty acids (SCFAs) and the proliferation of Blautia, Dialister, Megamonas, and Megasphaera relative to MIX ( p < 0.05). Untargeted metabolomics showed that key metabolites positively correlated with SCFAs and beneficial bacteria were significantly upregulated in the DS–MA complex group than in the MIX group. Our study shows that the fermentation properties of starch–lipid complexes were determined by the complexes as an entity rather than their constituent mixture.