Effect of In Vitro Digestion on Water-in-Oil-in-Water Emulsions Containing Anthocyanins from Grape Skin Powder.

Weili Xu,Sophia Xue,Bio Bamba,John Shi,Charles Forney,Yang Yang,Guihua Xu,Loong-Tak Lim

doi:10.3390/molecules23112808

Abstract

The effects of in vitro batch digestion on water-in-oil-in-water (W/O/W) double emulsions encapsulated with anthocyanins (ACNs) from grape skin were investigated. The double emulsions exhibited the monomodal distribution (d = 686 ± 25 nm) showing relatively high encapsulation efficiency (87.74 ± 3.12%). After in vitro mouth digestion, the droplet size (d = 771 ± 26 nm) was significantly increased (p < 0.05). The double W1/O/W2 emulsions became a single W1/O emulsion due to proteolysis, which were coalesced together to form big particles with significant increases (p < 0.01) of average droplet sizes (d > 5 µm) after gastric digestion. During intestinal digestion, W1/O droplets were broken to give empty oil droplets and released ACNs in inner water phase, and the average droplet sizes (d < 260 nm) decreased significantly (p < 0.05). Our results indicated that ACNs were effectively protected by W/O/W double emulsions against in vitro mouth digestion and gastric, and were delivered in the simulated small intestine phase.

Highlights

Anthocyanins (ACNs) extracted from grape/berry are a group of water-soluble pigments belonging to the flavonoids classes [1]
Microscopic analysis revealed that numerous small droplets were in the internal phase of the large globules (Figure 2A), indicating a Type-B W/O/W multiple emulsions according to the Florence and Whitehill classification [31]
The results indicated that all double-emulsion different stages of in vitro digestion (Figure 5)

Summary

Introduction

Anthocyanins (ACNs) extracted from grape/berry are a group of water-soluble pigments belonging to the flavonoids classes [1]. The bioactivity of ACN extracts makes them one of the most effective ingredients used in functional foods. Extracted ACNs are degraded during processing and storage in the presence of light, high temperature, alkaline conditions, oxygen or enzymes [8]. Their bioactivity could be lost when processing through the human digestive system [9,10]

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Conclusion