Instantaneous interaction of mucin with pectin- and carrageenan-coated nanoemulsions.

The efficiency of drug delivery and sensory perception is intertwined with mucoadhesive systems. The physiochemical characteristics of mucus induce flocculation of emulsion droplets, which could significantly influence their sensory perception. In this study, we investigated the interactions between pectin- and carrageenan-coated nanoemulsions with mucin. The size and ζ-potential changes in the nanoemulsions were investigated at pHs 3.0-5.0. The results showed no significant differences (p > 0.05) in size without the addition of gums; however, the ζ-potential decreases from 2.92 mV to -2.51 mV as pH increased. The stability of nanoemulsions over the extended time (15 days) and at elevated temperature (60 °C) resulted in minimal degree of phase separation observed. The mucin particle size method was employed to characterize mucin-nanoemulsion interactions. Results confirmed that mucin-emulsion complexes were formed instantaneously mostly due to electrostatic interactions. The contact angle analysis and UV-Vis spectroscopy confirmed contribution of wetting and absorption mechanisms in the mucin interactions.

Quantitative comparison of adsorption and desorption of commonly used sweeteners in the oral cavity.

Adsorption-desorption properties of different sweeteners in the oral cavity were evaluated using high performance liquid chromatography-based methodology. Three low calorie artificial sweeteners (aspartame, acesulfame potassium and sucralose), one steviol glycoside (rebaudioside A), and high fructose corn syrup (HFCS) were examined and compared with sucrose at pH 3 and 7 in a model beverage matrix. Results indicated that HFCS had the highest adsorption in the oral cavity, followed by rebaudioside A and the artificial sweeteners. The physicochemical interaction between sweeteners and salivary proteins did not affect the adsorption properties significantly as validated from a series of characterization techniques.

Solvent-mediated pressure-treated bixin-casein complexation for targeted color delivery.

Carryover color in the whey fluid is one of the major challenges faced by the cheese manufacturing industry. In this study, we describe a solvent-mediated high-pressure process to complexate bixin and casein micelles as a novel strategy for color delivery. High pressures (120 and 240 MPa) and added ethanol resulted in change in casein hydrophobicity by exposure of tryptophan residues, as confirmed by spectroscopic methods. The incorporation of bixin resulted in a marked quenching of the fluorescence peak associated with tryptophan. A simulated coagulation study has shown that pressure-treated complexes resulted in whey powder with significantly lower a* values than unbleached whey, whereas no significant differences were observed for b* values. The results suggest that complexes can produce curds with a color similar to that using commercial annatto powder and whey powder with equal or superior color quality than obtained with chemical bleaching.

Catechin modulates the copigmentation and encapsulation of anthocyanins in polyelectrolyte complexes (PECs) for natural colorant stabilization.

Our objective was to develop a robust system for anthocyanin-based color intensification, with high-encapsulation capacity and improved stability of the encapsulated natural colorant. Catechin was used to modulate the copigmentation and encapsulation of anthocyanins in counter-ionic polyelectrolyte complexes (PECs) composed of chondroitin sulfate and chitosan. Results showed that catechin copigmentation significantly intensified red color of formulations both with and without encapsulation in PECs and improved the anthocyanin encapsulation efficiency by forming additional dense network through hydrogen bonding. A series of stability assays revealed that anthocyanin stabilizing effect of system depended on the formulated pH and adding order of catechin. The strongest retaining capacity of anthocyanin was observed when catechin was copigmented with anthocyanin directly in PECs at pH 3.3, while the coated layer of catechin covered on PECs would be more effective at pH 4.0 and 5.0. Furthermore, we demonstrated that this delivery system works for anthocyanins from different sources.

Annatto-entrapped casein-chitosan complexes improve whey color quality after acid coagulation of milk.

A fraction of annatto is often transferred to the whey fluid during Cheddar cheese processing, which negatively impacts the visual and sensory attributes of the resultant whey powder. Alternatives to reduce the color in the powder are still needed. In this study, casein-chitosan complexes were prepared to deliver annatto preferentially to the curd and reduce the amount of carryover colorant in whey powder. These complexes were relatively spherical, with a mean complex diameter of 8.3 ±â€¯1.9 µm, zeta-potential of +39.4 ±â€¯1.3 mV, and entrapment efficiency of 38.2 ±â€¯3.1%. FT-IR spectroscopy confirmed the electrostatic interaction between casein and chitosan. Complexes and commercial annatto powder were incorporated into homogenized, reduced-fat, and fat-free milk, and subjected to acid coagulation. Whey powder produced from casein-chitosan-complex-treated samples exhibited better color quality than that prepared with annatto powder, indicating that the approach considered in this study was efficient in preventing the migration of colorant to the whey.

Development and evaluation of floating alginate microspheres for oral delivery of anthocyanins - A preliminary investigation.

The goal of this study was to develop floating microspheres that could be used as gastroretentive systems for the delivery of anthocyanins (ACNs). These compounds are absorbed in the stomach and small intestine, and insufficient residence time in these organs could result in limited absorption and contribute to degradation. The microparticles containing freeze-dried haskap berry extract (321.96 ± 8.35 mg cyanidin 3-glucoside equivalents per g) were prepared by ionotropic gelation of alginate (9%, w/w) with calcium ions (CaCl2 at 2%, w/v) in the gelation bath, with calcium carbonate as the gas-generating compound (added at different ratios in the alginate/extract mixture). The effect of acetic acid concentration (2 and 10%, v/v) in the gelation medium was investigated. Increasing the carbonate : alginate weigh ratio from 0 to 3:4 resulted in different degrees of floatability, larger particles, higher encapsulation efficiency, and lower amount of ACN released. The power law equation fitted the experimental data well, indicating that release occurred mainly by diffusion. This is the first time floating microspheres are proposed as gastroretentive platforms for the delivery of ACNs.