Physical, chemical, and biological characterization of ginsenoside F1 incorporated in nanostructured lipid carrier.

This study was aimed to determine the physical property and thermodynamic stability of nanostructured lipid carrier suspension incorporating ginsenoside F1 (GF1_NLC), and to evaluate its transport and antioxidant properties. GF1_NLC suspension possessed spherical particles with an average size of 98.9 nm, and the encapsulation efficiency reached approximately 90%. There was a good compatibility between ginsenoside F1 (GF1) and the nanostructured lipid carrier (NLC) formulation, giving no contribution to the changes in the structural organization and crystallization behavior of lipid particles. However, the incorporation of GF1 reduced the thermodynamic stability of the lipid particles. The permeability of GF1_NLC (39.2%) across Caco-2 cell monolayer was higher than that of free GF1 (26.0%); however, no significant differences were observed in the radical scavenging activity (84.1% and 85.5%, respectively). In conclusion, NLC could be a potential candidate for the delivery of GF1 into the living body due to its small particle size, high encapsulation efficiency, and improved permeability. PRACTICAL APPLICATIONS: Poor water solubility in an aqueous solution and low absorption rate of ginsenoside F1 in the intestinal track limit its practical application in food systems. In this study, ginsenoside F1 was encapsulated in nanostructured lipid carrier to enhance its water solubility and absorption rate. The results of the encapsulated ginsenoside F1 showed high encapsulation efficiency of 90% with fine particle size of 98.9 nm that could correspond to the enhancement of water solubility in an aqueous solution and permeability across Caco-2 cell monolayer. The results may encourage the food industry to utilize this encapsulation technique for the enhancement of the functional properties of poorly water-soluble bioactive compounds.

Physicochemical and in vitro digestion characteristics of size-different red ginseng powders.

The aims of the present study were to prepare different-sized red ginseng powders and investigate the particle size effect on the release property of ginsenosides in in vitro digestion conditions. Ultrafine powder showed bimodal particle size distribution with a large peak at around 100 µm and small peak at around 10 µm, differently from fine powder showing unimodal distribution at 100 µm. The specific surface areas of fine- and ultrafine powders were 48.72 ± 6.41 and 86.74 ± 5.96 m2/g, respectively. Time-dependent release property of the powders in the simulated gastrointestinal fluids was determined by quantifying ginsenoside Rg1 released. The initial and final concentrations of ginsenoside Rg1 released was higher in ultrafine powder than fine one. It is expected that particle size reduction and corresponding increase in the specific surface area have a potential to improve the release of ginsenosides in the gastrointestinal tract and enhance the chances to be absorbed in human body.

Influence of autoclave treatment and enzymatic hydrolysis on the antioxidant activity of Opuntia ficus-indica fruit extract.

The objectives of this study were to obtain Opuntia ficus-indica fruit (OFIF) extract by autoclave treatment, to convert the flavonoid glycosides in the autoclave extract (AE) to aglycones by enzymatic hydrolysis, and to compare the antioxidant activity of AE and OFIF extracts obtained by other conventional methods. It was revealed that the total polyphenol and flavonoid content and antioxidant activity of AE were higher than those of water extract but were a slightly lower than those of ethanol extract, which indicates that autoclave treatment might be an efficient extraction method for OFIF. Moreover, it was confirmed that the conversion of various flavonoid glycosides to aglycones in all the OFIF extracts does not significantly affect the antioxidant activities. Therefore, it is extrapolated that the antioxidant activity might be correlated to the intestinal absorption rates and metabolic pathway induction upon oral administration rather than the structure of compound itself.

Effect of frozen-storage period on quality of American sirloin and mackerel (Scomber japonicus).

This study aimed to study the effect of frozen-storage period on the quality of sirloin and mackerel (Scomber japonicus). The samples were evaluated after being kept in frozen storage at -17.9 °C for different periods of time (1, 8, 15, 22, and 29 days). The frozen storage resulted in increase in ice crystal formation on the surface of both sirloin and mackerel. Frozen-storage period had an effect on the increase in the drip loss of both sirloin and mackerel with a positive correlation (p < 0.05) as well as on the decrease in the hardness of sirloin with a negative correlation (p < 0.05). During the frozen-storage period, the 2-thiobarbituric acid reactive substance level was increased in mackerel while the level in sirloin was maintained; both levels were within safe limits. Consequently, a 29-day freezing period is postulated to have little effect on the quality of sirloin and mackerel.

Improving the encapsulation efficiency and sustained release behaviour of chitosan/ß-lactoglobulin double-coated microparticles by palmitic acid grafting.

Chitosan (CS) was grafted with 0.1 and 0.5% (w/v) palmitic acid (PA) to improve its encapsulation efficiency (EE) and sustained release characteristics when forming CS microparticles. Thereafter, PA-grafted CS (PA-CS) microparticles were coated with denatured ß-lactoglobulin (ßlg), which forms an outer protective layer. The possibility of hydrophobic interaction with the hydrophobic substances in the CS microparticles increased as the proportion of the grafted PA increased. EE was measured as 64.79, 83.72, and 85.00% for the non-grafted, 0.1, and 0.5% PA-CS microparticles, respectively. In simulated small intestinal conditions, 4.66 and 17.55% of the core material release in the PA-CS microparticles were sustained after 180min by 0.1, and 0.5% PA grafting, respectively. PA grafting enables the sustained release in simulated gastrointestinal fluids by enhancing the hydrophobic interaction between CS and the hydrophobic core material.

Proof of concept study for different-sized chitosan nanoparticles as carbon dioxide (CO2) indicators in food quality monitoring.

The objective of this study was to develop different-sized chitosan nanoparticles as CO2-based food quality indicators. Chitosan nanoparticles were fabricated with different sizes (small, 300nm; medium, 500nm; and large, 1000nm) by ionic gelation. To investigate the performance of chitosan nanoparticles as CO2 indicators, they were suspended in aqueous solution at pH 8.0. Changes in the pH and absorbance of the suspension were measured over time, the absorbance at the transition appearance time being calculated using the inverse-Hill function. The resultant transition appearance times were 11.23, 14.33, and 27.69min for the small, medium, and large-sized chitosan nanoparticles, respectively. Controlling the chitosan nanoparticle size enables the transition appearance time of the CO2 indicator to be adjusted in order to match the change in quality of packaged food. This study suggests that different-sized chitosan nanoparticle-based CO2indicators can be used as food quality indicators.

Positively Charged Nanostructured Lipid Carriers and Their Effect on the Dissolution of Poorly Soluble Drugs.

The objective of this study is to develop suitable formulations to improve the dissolution rate of poorly water soluble drugs. We selected lipid-based formulation as a drug carrier and modified the surface using positively charged chitosan derivative (HTCC) to increase its water solubility and bioavailability. Chitosan and HTCC-coated lipid particles had higher zeta-potential values than uncoated one over the whole pH ranges and improved encapsulation efficiency. In vitro drug release showed that all NLC formulations showed higher in vitro release efficiency than drug particle at pH 7.4. Furthermore, NLC formulation prepared with chitosan or HTCC represented good sustained release property. The results indicate that chitosan and HTCC can be excellent formulating excipients of lipid-based delivery carrier for improving poorly water soluble drug delivery.