Formulation and characterization of astaxanthin-enriched nanoemulsions stabilized using ginseng saponins as natural emulsifiers

Gaofeng Shu; Nauman Khalid; Zhang Chen; Marcos A Neves; Colin J Barrow; Mitsutoshi Nakajima

doi:10.1016/j.foodchem.2018.02.062

Formulation and characterization of astaxanthin-enriched nanoemulsions stabilized using ginseng saponins as natural emulsifiers

Food Chem. 2018 Jul 30:255:67-74. doi: 10.1016/j.foodchem.2018.02.062. Epub 2018 Feb 13.

Authors

Gaofeng Shu¹, Nauman Khalid², Zhang Chen¹, Marcos A Neves³, Colin J Barrow⁴, Mitsutoshi Nakajima³

Affiliations

¹ Tsukuba Life Science Innovation Program (T-LSI), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
² Centre for Chemistry and Biotechnology, Deakin University, Waurn Ponds, Victoria 3217, Australia; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan; School of Food and Agricultural Sciences, University of Management and Technology, Lahore 54000, Pakistan. Electronic address: n.khalid@deakin.edu.au.
³ Tsukuba Life Science Innovation Program (T-LSI), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
⁴ Centre for Chemistry and Biotechnology, Deakin University, Waurn Ponds, Victoria 3217, Australia.

PMID: 29571499
DOI: 10.1016/j.foodchem.2018.02.062

Abstract

In this study ginseng saponins (GS) were used as natural emulsifiers to formulate and stabilize O/W nanoemulsions loaded with astaxanthin (AST). GS were found to be highly effective at reducing the interfacial tension at the soybean oil-water interfaces, and were capable of producing nano-scaled droplets (d_4,3 ≈ 125 nm) using a high-pressure homogenizer. The droplet size of the nanoemulsions decreased with increasing emulsifier concentration and homogenization pressure. The nanoemulsions were stable without droplet coalescence against thermal treatment (30-90 °C, 30 min), and over a narrow range of pH values (7-9). GS-coated droplets were unstable in acidic conditions (pH 3-6) and in the presence of salt (>25 mM NaCl). The formulated nanoemulsions showed slight change in d_4,3 during 15 days of storage at 5, 25 and 40 °C. However, the chemical stability strongly depended on the storage temperature, with the lowest level of AST retained in nanoemulsions stored at higher temperature.

Keywords: Astaxanthin; Characterization; Ginseng saponins; Nanoemulsions; Stability.

MeSH terms

Dietary Supplements / analysis
Drug Stability
Emulsifying Agents / chemistry*
Emulsions / chemistry*
Hydrogen-Ion Concentration
Nanotechnology / methods*
Panax / chemistry*
Particle Size
Saponins / chemistry*
Soybean Oil
Surface Tension
Temperature
Water
Xanthophylls / analysis

Substances

Emulsifying Agents
Emulsions
Saponins
Xanthophylls
Water
Soybean Oil
astaxanthine