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The physicochemical properties of coix seed oil (CSO) liposomes prepared by five different methods were evaluated for morphology, encapsulating efficiency, particle size, storage stability, and in vitro release. The different preparation methods resulted in several types of vesicles with different properties. The type of vesicles was closely related to leakage pattern, which affected the storage stability and in vitro release profiles. Ethanol injection method was the best choice for preparing safe and stable liposomes with controlled release. The release mechanisms might account for the diffusion of CSO, and Higuchi was the most suitable model for liposomes stored at high temperature or released in simulated intestinal fluid (SIF).

BACKGROUND: Rice dreg is an underutilized source of cereal protein with good potential for application in the food industry. Glutelin represents about 850 g kg−1 of total storage protein in rice dreg. The objective of this study was to characterize the physicochemical properties and emulsion stabilization of the Maillard type conjugate formed with rice dreg glutelin (RDG) and κ-carrageenan (1:2 weight ratio) dry-heated at 60 °C and 79% relative humidity for 24 h. RESULTS: Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Fourier transform-infrared analysis provided evidence on the formation of the Maillard type conjugation. Amino acid analysis suggested that the major locus during the Maillard reaction were lysine and arginine. Circular dichroism spectra showed decreasing amounts of α-helix and β-strand in the products with increment in the amount of turns and random coil. Conjugation with κ-carrageenan could significantly improve solubility of RDG (P < 0.05). Measurements of mean droplet size and creaming stability in oil-in-water emulsions showed that the conjugate was more effective at stabilizing emulsions at low pH or in the presence of high ionic strength. CONCLUSION: The Maillard reaction can be successfully used as a coupling method for RDG and κ-carrageenan to form the conjugate with improved solubility and emulsion stabilization. Copyright © 2012 Society of Chemical Industry

In this research, carboxymethylchitosan (CMCS)-coated proliposomes (CM-PL) were prepared in an attempt to deliver coix seed oil (CSO) using conventional ethanol injection followed by surface modification and spray drying. Conventional uncoated liposomes (un-L), CMCS-coated liposomes (CM-L) and uncoated proliposomes (un-PL) were also prepared for comparison. The morphology, encapsulation efficiency (EE), particle size, zeta potential, stability, and CSO release performance were investigated for all samples. The results indicated that CM-PL possessed smoother surface, better heterogeneous size distribution, higher EE and improved stability compared with other samples. Transmission electron microscopy (TEM) showed that rehydrated CM-PL were spherical particles with CMCS layers surrounding the surface of conventional liposomes. The coating mechanism was probably due to H-bonding interactions between CMCS and the interfacial regions of the phosphatidylcholine bilayer. In addition, controlled release of CSO from coated proliposomes was obtained with more sustained release in simulated intestinal fluid (SIF) than in simulated gastric fluid (SGF).

Polyethylene glycol (PEG)-coated vitamin E (VE) lyophilized proliposomes was produced by thin-film ultrasonic dispersion and lyophilization and then evaluated by encapsulation efficiency (EE), distribution of particle size, storage stability, and release behavior in the simulated physiological media. The results showed that the conventional liposomes (CL) were successfully coated by PEG layer, and the hydrogen bond interaction between PEG and the Soybean phosphatidylcholine (SPC) headgroups in the bilayers is regarded as the coated mechanism. The mean diameter and EE were 164.2 nm and 83.87% for PEG-coated lyophilized proliposomes (PLP), respectively. VE contained within PLP exhibited a better stability comparing to the CL, and the retention percentage of PLP was 89.81% at 4 °C after 15 days storage. In addition, VE within the PLP could be controlled release in different pH of simulated media. It is proven that PLP could employ to protect VE for extending shelf life and to provide convenience for commercial usage.