Lactoferrin-Based Ternary Composite Nanoparticles with Enhanced Dispersibility and Stability for Curcumin Delivery.

Curcumin has been reported to exhibit free radical antioxidant, anti-inflammatory, and anticancer activities, which are beneficial for nutraceutical applications. However, its application for this purpose is limited by its poor water solubility, stability, and bioavailability. These problems can be overcome using food-grade colloidal particles that encapsulate, protect, and deliver curcumin. These colloidal particles can be assembled from structure-forming food components that may also exhibit protective effects, such as proteins, polysaccharides, and polyphenols. In this study, lactoferrin (LF), (-)-epigallocatechin gallate (EGCG), and hyaluronic acid (HA) were used to fabricate composite nanoparticles using a simple pH-shift method. We showed that curcumin could be successfully loaded into these LF-EGCG-HA nanoparticles (d = 145 nm). The encapsulation efficiency (86%) and loading capacity (5.8%) of curcumin within these nanoparticles were relatively high. Encapsulation improved the thermal, light, and storage stabilities of the curcumin. Moreover, the curcumin-loaded nanoparticles exhibited good redispersibility after dehydration. The in vitro digestion properties, cellular uptake, and anticancer effects of the curcumin-loaded nanoparticles were then explored. Compared to free curcumin, the bioaccessibility and cellular uptake of the curcumin were significantly improved after encapsulation in the nanoparticles. Furthermore, the nanoparticles significantly promoted the apoptosis of colorectal cancer cells. This study suggests that food-grade biopolymer nanoparticles can be used to improve the bioavailability and bioactivity of an important nutraceutical.

Ultrasound-assisted preparation of lactoferrin-EGCG conjugates and their application in forming and stabilizing algae oil emulsions.

The aim of this study was to prepare lactoferrin-epigallocatechin-3-gallate (LF-EGCG) conjugates and to determine their ability to protect emulsified algal oil against aggregation and oxidation. LF-EGCG conjugates were formed using an ultrasound-assisted alkaline treatment. The ultrasonic treatment significantly improved the grafting efficiency of LF and EGCG and shortened the reaction time from 24 h to 40 min. Fourier transform infrared spectroscopy and circular dichroism spectroscopy analyses showed that the covalent/non-covalent complexes could be formed between LF and EGCG, with the CO and CN groups playing an important role. The formation of the conjugates reduced the α-helix content and increased the random coil content of the LF. Moreover, the antioxidant activity of LF was significantly enhanced after conjugation with EGCG. LF-EGCG conjugates as emulsifiers were better at inhibiting oil droplet aggregation and oxidation than LF alone. This study demonstrates that ultrasound-assisted formation of protein-polyphenol conjugates can enhance the functional properties of the proteins, thereby extending their application as functional ingredients in nutritionally fortified foods.

Development of antibacterial nanoemulsions incorporating thyme oil: Layer-by-layer self-assembly of whey protein isolate and chitosan hydrochloride.

The aim of this study was to develop a thyme oil emulsion with good physicochemical properties and antibacterial activity. Initially, oil-in-water emulsions containing whey protein-coated essential oil droplets were prepared by high-pressure homogenization. The double-layer emulsions were formed around the oil droplets by electrostatic deposition of cationic chitosan hydrochloride onto the anionic protein-coated droplets. Then, the structure, physicochemical properties, and storage stability of the emulsions were determined. Emulsions formulated using 1% v/v thyme oil, 0.7 wt% whey protein, and 0.25 wt% of chitosan hydrochloride contained relatively small cationic droplets. Moreover, the emulsions containing double-layer coatings were shear-thinning fluids. Storage tests indicated that double-layer emulsions had better stability than the single-layer. Antibacterial tests indicated that the double-layer emulsions exhibited prolonged antibacterial activity against two model food pathogens: E. coli and S. aureus. These results provide a scientific basis for the rational design of antimicrobial delivery systems for use in foods.