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.