Particle-Stabilizing Effects of Flavonoids at the Oil−Water Interface

Abstract

It has been shown that some common food flavonoids can act as excellent stabilizers of oil-in-water emulsions through their adsorption as water-insoluble particles to the surface of the oil droplets, i.e., Pickering emulsions are formed. Flavonoids covering a wide range of octanol-water partition coefficients (P) were screened for emulsification behavior by low shear mixing of flavonoid+n-tetradecane in a vortex mixer. Most flavonoids with very high or very low P values were not good emulsifiers, although there were exceptions, such as tiliroside, which is very insoluble in water. When a high shear jet homogenizer was used with 20 vol% oil in the presence of 1 mM tiliroside, rutin, or naringin, much finer emulsions were produced: the average droplet sizes (d32) were 16, 6, and 5 μm, respectively. These results may be highly significant with respect to the delivery of such insoluble compounds to the gut, as well as their digestion and absorption.

Evaluation of the Wound Healing Properties of Luteolin Ointments on Excision and Incision Wound Models in Diabetic and Non-Diabetic Rats

“…(2012) by using glycol stearate:propylene glycol:liquid paraffin (3:6:1) [23] for enhancing the bioavailability of Luteolin which has poor water solubility. The ointment base increased the solubility of the tested material and were helped to get a homogeneous mixture with enhanced penetration capacity [24,25]. An appropriate amount of Luteolin (LUT) (Sigma Chemical Co. (USA)) was added in this mixture to prepare for 0.5 % and 1 % (w/w) Luteolin test ointments.…”

In vitro digestion of Pickering emulsions stabilized by soft whey protein microgel particles: influence of thermal treatment

“…Although a great many studies have been conducted on Pickering emulsions using traditional inorganic or synthetic particles, there is a relative paucity of literature on food-compatible particulate materials from natural edible sources, examples, include cellulose nanocrystals 22 , chitin nanocrystals 23 , modified starch 24 , soy protein nanoparticles 25 , flavonoid particles 26 , micellar casein coated nanoemulsion droplets 27 and whey protein microgels 28,29 . Soft solid particles such as whey protein microgels can be a particularly effective system to resist displacement by bile salts because soft solid particles deform during adsorption increasing the adsorption energies by orders of magnitude relative to rigid particles 30 .…”

Transport oftrans-tiliroside (kaempferol-3-β-D-(6″-p-coumaroyl-glucopyranoside) and related flavonoids across Caco-2 cells, as a model of absorption and metabolism in the small intestine

“…Tiliroside is a relatively hydrophobic compound, despite having a hydrophilic conjugating side chain (coumaroyl-glucoside), it has a Log P of 2.7 (Luo et al, 2011). It is therefore feasible that tiliroside can diffuse across biological membranes.…”

“…Kaempferol is more hydrophobic (log P = 3.2 (Luo et al, 2011)) than tiliroside, with a lower molecular weight (286) and, thus would be expected to diffuse passively across biological membranes. We found that 5% of kaempferol aglycone was transferred from the apical to basolateral membrane, and that no significant difference in transfers were observed in both directions, at similar constant linear rates (see Figure 2 and 3b).…”

“…p-Coumaric acid is hydrophilic (Log P -0.65 (Luo et al, 2011)) and has a relatively low molecular weight (164). It is possible that transportation occurs via paracellular tight junctions rather than by a transcellular route.…”