The influence of the storage temperature on the stability of lipid microparticles containing ginger oleoresin

Abstract

Ginger oleoresin (GO) can be encapsulated within a protective lipid matrix in order to facilitate handling, provide protection against the external environment or promote the stability of GO compounds. The aim of this study was to verify the ability of solid lipid microparticles (SLMs) containing GO (10-20% w/w) to maintain or improve the stability of ginger compounds, by monitoring SLMs' characteristics during storage at different temperatures (25 and 40 °C). The lipids matrix of SLMs were composed by stearic acid (90, 80, 75, 65% w/w) and oleic acid (15% w/w), The crystalline structure of the particles after 84 days of storage did not present any polymorphic alterations, while presenting spherical form upon scanning by electron microscopy. SLMs containing oleic acid showed degradation of 6-gingerol when stored at 40 °C. Major volatile compounds had better stability in particles containing oleic acid. Kinetics of volatiles release resulted in a diffusion mechanism. SLMs showed better stability of GO compounds during storage at 25 °C than un-encapsulated GO and could, therefore, improve its distribution in foods due to its conversion to powder.

Keywords: Lipid compatibility; Pungent compound; Release; Spray chilling; Volatile oil.