Nutraceutical nanoemulsions: influence of physical states of β‐carotene (crystalized versus dissolved) on bioaccessibility (645.13)

Abstract

β‐Carotene has a poor oral bioaccessibility in the gastrointestinal tract (GIT) because of its high hydrophobicity and melting point. We investigated the bioaccessibilities of solubilized and crystalline forms of β‐carotene using a simulated GIT model. Three systems were compared: (1) soluble β‐carotene in digestible nanoemulsion (d< 200nm); (2) crystalline β‐carotene added to digestible nanoemulsion (d< 200nm); (3) crystalline β‐carotene added to phosphate buffer saline (pH=7.0). Oil‐in‐water nanoemulsions were formed by high‐pressure homogenization using Tween 20 as emulsifier and corn oil as digestible carrier oil. They were then subject to simulated mouth, stomach and small intestine digestion. The rate and extent of free fatty acid production in the small intestine decreased in the order (2)>(1)>(3); whereas the β‐carotene bioaccessibility decreased in the order (1)>>(2)>(3). The low bioaccessibility (1.3%) of system (3) was attributed to the fact that there were few free fatty acids produced to form mixed micelles to solubilize β‐carotene. The bioaccessibility of system (2) was also relatively low (3.6%) compared to system (1) (42%), which suggests that crystalline β‐carotene is less bioaccessible than soluble β‐carotene. This study provides important information for choosing a better delivery condition for lipophilic bioactive components to achieve higher bioaccessibility.Grant Funding Source: Supported by USDA