Cellular uptake of carotenoid-loaded oil-in-water emulsions in colon carcinoma cells in vitro

Antiallergic effect of Picholine olive oil-in-water emulsions through β-hexosaminidase release inhibition and characterization of their physicochemical properties

The inhibitory effect of Picholine olive oil from Montpellier in Southern France on the chemical mediator release in type I allergy, using rat basophilic leukemia (RBL-2H3) cells, was investigated. Oil-in-water (O/W) emulsions prepared using Picholine olive oil showed an inhibitory effect on the chemical mediator release and decreased expressions of genes related to type I allergy in RBL-2H3 cells. We then measured the phenolic compounds present in Picholine olive oil using high-performance liquid chromatography and investigated some physical properties, such as droplet size, size distribution, viscosity, and surface tension of the resulting olive O/W emulsions. Our findings indicate that Picholine olive oil has high flavonoids content, especially apigenin, and the prepared emulsion of Picholine olive oil resulted in a considerable small size distribution, with an average droplet size of 170 nm.

Nanoemulsion delivery systems: influence of carrier oil on β-carotene bioaccessibility

Consumption of carotenoids may reduce the incidences of certain chronic diseases, but their use in foods is currently limited because of their poor water-solubility, low bioavailability and chemical instability. We examined the impact of carrier oil type on the bioaccessibility of β-carotene encapsulated within nanoemulsion-based delivery systems. Oil-in-water nanoemulsions (d<200nm) were formed using a non-ionic surfactant (Tween 20) as emulsifier and long chain triglycerides (LCT), medium chain triglycerides (MCT) or orange oil as carrier oils. The influence of carrier oil type on β-carotene bioaccessibility was established using an in vitro model to simulate the oral, gastric and small intestinal phases of the gastrointestinal tract. The rate and extent of free fatty acid production in the intestine decreased in the order LCT≈MCT≫orange oil; whereas β-carotene bioaccessibility decreased in the order LCT≫MCT>orange oil. The bioaccessibility of β-carotene was negligible (≈0%) in orange oil nanoemulsions because no mixed micelles were formed to solubilise β-carotene, and was relatively low (≈2%) in MCT nanoemulsions because the mixed micelles formed were too small to solubilise β-carotene. In contrast, β-carotene bioaccessibility was relatively high (≈66%) in LCT nanoemulsions. Our results have important implications for the design of effective delivery systems for encapsulation of carotenoids and other lipophilic bioactive components.

Effect of organic-phase solvents on physicochemical properties and cellular uptake of astaxanthin nanodispersions

A simplex centroid mixture design was used to study the interactions between two chosen solvents, dichloromethane (DCM) and acetone (ACT), as organic-phase components in the formation and physicochemical characterization and cellular uptake of astaxanthin nanodispersions produced using precipitation and condensation processes. Full cubic or quadratic regression models with acceptable determination coefficients were obtained for all of the studied responses. Multiple-response optimization predicted that the organic phase with 38% (w/w) DCM and 62% (w/w) ACT yielded astaxanthin nanodispersions with the minimum particle size (106 nm), polydispersity index (0.191), and total astaxanthin loss (12.7%, w/w) and the maximum cellular uptake (2981 fmol/cell). Astaxanthin cellular uptake from the produced nanodispersions also showed a good correlation with their particle size distributions and astaxanthin trans/cis isomerization ratios. The absence of significant (p > 0.05) differences between the experimental and predicted values of the response variables confirmed the adequacy of the fitted models.

Microcapsules with a pH responsive polymer: influence of the encapsulated oil on the capsule morphology

Microcapsules were prepared by microsieve membrane cross flow emulsification of Eudragit FS 30D/dichloromethane/edible oil mixtures in water, and subsequent phase separation induced by extraction of the dichloromethane through an aqueous phase. For long-chain triglycerides and jojoba oil, core-shell particles were obtained with the oil as core, surrounded by a shell of Eudragit. Medium chain triglyceride (MCT oil) was encapsulated as relatively small droplets in the Eudragit matrix. The morphology of the formed capsules was investigated with optical and SEM microscopy. Extraction of the oil from the core-shell capsules with hexane resulted in hollow Eudragit capsules with porous shells. It was shown that the differences are related to the compatibility of the oils with the shell-forming Eudragit. An oil with poor compatibility yields microcapsules with a dense Eudragit shell on a single oil droplet as the core; oils having better compatibility yield porous Eudragit spheres with several oil droplets trapped inside.

Carotenoids: actual knowledge on food sources, intakes, stability and bioavailability and their protective role in humans

Carotenoids are one of the major food micronutrients in human diets and the overall objective of this review is to re-examine the role of carotenoids in human nutrition. We have emphasized the attention on the following carotenoids present in food and human tissues: beta-carotene, beta-cryptoxanthin, alpha-carotene, lycopene, lutein and zeaxanthin; we have reported the major food sources and dietary intake of these compounds. We have tried to summarize positive and negative effects of food processing, storage, cooking on carotenoid content and carotenoid bioavailability. In particular, we have evidenced the possibility to improve carotenoids bioavailability in accordance with changes and variations of technology procedures.

Emulsion-based delivery systems for lipophilic bioactive components

There is a pressing need for edible delivery systems to encapsulate, protect, and release bioactive lipids within the food, medical, and pharmaceutical industries. The fact that these delivery systems must be edible puts constraints on the type of ingredients and processing operations that can be used to create them. Emulsion technology is particularly suited for the design and fabrication of delivery systems for encapsulating bioactive lipids. This review provides a brief overview of the major bioactive lipids that need to be delivered within the food industry (for example, omega-3 fatty acids, carotenoids, and phytosterols), highlighting the main challenges to their current incorporation into foods. We then provide an overview of a number of emulsion-based technologies that could be used as edible delivery systems by the food and other industries, including conventional emulsions, multiple emulsions, multilayer emulsions, solid lipid particles, and filled hydrogel particles. Each of these delivery systems could be produced from food-grade (GRAS) ingredients (for example, lipids, proteins, polysaccharides, surfactants, and minerals) using simple processing operations (for example, mixing, homogenizing, and thermal processing). For each type of delivery system, we describe its structure, preparation, advantages, limitations, and potential applications. This knowledge can be used to facilitate the selection of the most appropriate emulsion-based delivery system for specific applications.