Encapsulation of tributyrin by gamma-cyclodextrin: Complexation, spray drying, and in vitro fermentation

Butyrate is a short-chain fatty acid (SCFA) known for support in gastrointestinal (GI) health. Tributyrin (TB) could be used as an alternate source of butyrate. The objectives of this study were to encapsulate TB using gamma-cyclodextrin (CD) by spray-drying and to investigate the physicochemical and the fermentation properties of TB/CD complex. The TB/CD complex precipitated in water with an average stoichiometry of 1:1.3 of TB:CD. At a 1:2 molar ratio of TB:CD, TB was fully retained in the spray-dried TB/CD complex. The spray-dried TB/CD complex showed crystalline structure, supported by both X-ray diffraction spectra and scanning electron microscopy images. The TB/CD complex at 1:2 molar ratio was fermented and several SCFAs, including butyrate, were produced in an in vitro test using piglets' ileal and colonic contents. A dose-dependent increase in the butyrate concentration in both ileum and ascending colon was observed. Approximately, 426 and 1189 μmole butyrate was produced per gram of TB/CD powder at 9 mM treatment in ileum and ascending colon, respectively. Thus, the production of the TB/CD complex using spray drying is feasible and the complex has the potential for food applications to improve intestinal health. PRACTICAL APPLICATION: The findings in this study can be applied to produce encapsulated tributyrin with gamma-cyclodextrin efficiently using spray-drying. The TB/CD complex was highly fermentable and caused an increase in the butyrate concentration in both ileum and ascending colon, which can be incorporated in foods to enhance butyrate delivery to the GI tract to assist gut health.