Encapsulation of Polymethoxyflavones in Citrus Oil Emulsion-Based Delivery Systems

Abstract

The purpose of this work was to elucidate the effects of citrus oil type on polymethoxyflavone (PMF) solubility and on the physicochemical properties of PMF-loaded emulsion-based delivery systems. Citrus oils were extracted from mandarin, orange, sweet orange, and bergamot. The major constituents were determined by GC/MS: sweet orange oil (97.4% d-limonene); mandarin oil (72.4% d-limonene); orange oil (67.2% d-limonene); and bergamot oil (34.6% linalyl acetate and 25.3% d-limonene). PMF-loaded emulsions were fabricated using 10% oil phase (containing 0.1% w/v nobiletin or tangeretin) and 90% aqueous phase (containing 1% w/v Tween 80) using high-pressure homogenization. Delivery systems prepared using mandarin oil had the largest mean droplet diameters (386 or 400 nm), followed by orange oil (338 or 390 nm), bergamot oil (129 or 133 nm), and sweet orange oil (122 or 126 nm) for nobiletin- or tangeretin-loaded emulsions, respectively. The optical clarity of the emulsions increased with decreasing droplet size due to reduced light scattering. The viscosities of the emulsions (with or without PMFs) were similar (1.3 to 1.4 mPa·s), despite appreciable differences in oil phase viscosity. The loading capacity and encapsulation efficiency of the emulsions depended on carrier oil type, with bergamot oil giving the highest loading capacity. In summary, differences in the composition and physical characteristics of citrus oils led to PMF-loaded emulsions with different encapsulation and physicochemical characteristics. These results will facilitate the rational design of emulsion-based delivery systems for encapsulation of PMFs and other nutraceuticals in functional foods and beverages.

Chemical Mapping of Essential Oils, Flavonoids and Carotenoids in Citrus Peels by Raman Microscopy

“…The result also indicated that flavonoids, a group of lipophilic compounds, might exist in 2 physical formats of being solution in essential oil or crystal in citrus peel. Essential oil could be used as a good natural solvent for flavonoids to deal with poor solubility in accordance with our previous study, in which different citrus essential oils were successfully used to improve citrus peels derived flavonoids (Yang and others ).…”

Improved bioaccessibility of polymethoxyflavones loaded into high internal phase emulsions stabilized by biopolymeric complexes: A dynamic digestion study via TNO's gastrointestinal model

“…A relatively low ratio of PMFs to MCT oil as the dissolution medium was important to prevent the crystallization of PMFs which may affect their rate and extent of absorption. It is notable that when a high content of PMFs is dissolved in bulk oil at high temperature, some PMFs will recrystallize rapidly if the temperature returns to room temperature ( Li et al., 2012a , Yang et al., 2017 ). It has also been previously reported that the absorption of crystalline compounds in the GI tract is typically dissolution rate-limited ( Wang et al., 2014 , Xia et al., 2015 ).…”

Effect of Preparation Parameters on Microparticles with High Loading Capacity and Adsorption Property Adsorbed on Functional Paper

“…The effect of the sweet orange oil was analyzed and evaluated by GC-MS in three samples: untreated paper, PLGA microparticles functional paper, and chitosan-PLGA microparticles functional paper. The main characteristic aroma substances of the orange essential oil were determined from NIST spectra combined with related literature [41,42]. There were 72, 52 and 59 aroma components in the three samples as detected separately by GC-MS.…”