The lipid type affects the in vitro digestibility and β-carotene bioaccessibility of liquid or solid lipid nanoparticles

Abstract

olid lipid nanoparticles (SLNs) are emulsion-based carriers of lipophilic bioactive compounds. However, their digestibility may be affected by the solid lipid phase composition. Hence, the aim of this work was to study the in vitro lipolysis kinetics as well as the relationship between the lipid digestion, micelle fraction composition and β-carotene bioaccessibility of SLNs with different solid lipids, being blends of medium chain triglyceride (MCT) oil, glyceryl stearate (GS) or hydrogenated palm oil (HPO) as compared to liquid lipid nanoparticles (LLNs) with pure MCT. SLNs formulated with GS were fully digested, similarly to LLNs. However, HPO-containing SLNs presented slower lipolysis kinetics during the intestinal phase at increasing HPO concentration. Despite this, HPO-SLNs showed higher β-carotene bioaccessibility, which was related to the higher amount of monounstaturated free fatty acids in the micelle fraction. Thus, this work provides valuable insight for designing delivery systems of bioactive compounds with optimal functionality.

This study was funded by the Ministry of Economy, Industry and Competitiveness (MINECO/FEDER, UE) throughout projects RTI2018-094268-B-C21 and AGL2015-65975-R. Heloísa Martins thanks for the scholarship financed by “Coordenação de Aperfeiçoamento de Pessoal de Nível Superior” (CAPES) – Brazil - Finance Code 001. María Artiga-Artigas thanks the University of Lleida for her pre-doctoral fellowship. Laura Salvia-Trujillo thanks the “Secretaria d’Universitats i Recerca del Departament d’Empresa i Coneixement de la Generalitat de Catalunya” for the Beatriu de Pinós post-doctoral grant (BdP2016-00336).