Characterization of a novel starch-based foam with a tunable release of oxygen.

Here, we used techniques of extrusion and coating to produce starch-based foams with a combined function of buffering and controlled release of oxygen. The foams presented open-cell structures and showed a compression recovery ratio of 94%. After coating with poly(vinyl alcohol) solution, in which calcium peroxides were loaded, the developed functional foams showed a behavior of controllable oxygen release under a wet condition, as well as a high compression strength (≥2.2 MPa). Also, these foams showed an improved moisture resistance with a reduction in maximum moisture absorption from 25 to 14%. Under a vibrated storage condition to simulate food transportation, guavas packaged with functional foams showed a reduced physical damage, and browning index from 5.00 to 2.97, owing to the foams' superior buffering ability and self-regulation of storage atmosphere. The functional packaging system of the starch-based foams developed in our work is promising for fruit and vegetable preservations.

Changes of digestive and fermentation properties of Sargassum pallidum polysaccharide after ultrasonic degradation and its impacts on gut microbiota.

The in vitro digestive and fermentation properties of Sargassum pallidum polysaccharide (SPP) after ultrasound degradation were investigated. The results showed that SPP and its degraded fractions were not affected by human saliva, but slightly degraded by breaking glycosidic bonds under simulated gastrointestinal digestion. The DPPH radical scavenging activity, α-glucosidase inhibitory activity, and bile acid-binding capacity of SPP and its degraded fractions were decreased after digestion, which was attributed to the reduction of molecular weights (MWs) and viscosity. Furthermore, in vitro fermentation assay indicated that SPP and its degraded fractions showed good fermentability. The predominant compositional monosaccharides including arabinose, galactose, glucose, xylose, and uronic acid were significantly decreased, and the degraded SPP fractions were more easily fermented and utilized by gut bacteria. SPP and its degraded fractions could modulate gut health by decreasing the Firmicutes/Bacteroidetes ratio and increasing the relative abundances of some beneficial genera, such as Prevotella, Dialister, Phascolarctobacterium, Ruminococcus, and Bacteroides. These findings suggested that SPP and its degraded fractions exhibited similar influence on gut microbiota community, but appropriate degraded SPP fractions were more easily fermented by gut microbiota.

Preparation and Characterization of Microemulsions of Myricetin for Improving Its Antiproliferative and Antioxidative Activities and Oral Bioavailability.

To improve the bioactivity and oral bioavailability of myricetin, a microemulsion formulation was successfully developed, which consisted of Cremophor RH40 (12%), Tween 80 (6%), Transcutol HP (9%), WL 1349 (18%), and distilled water (55%). With lower content of surfactants and higher stability after dilution and storage for 6 months, the optimized myricetin microemulsion (MYR-ME) could dramatically enhance the solubility of myricetin 1225 times that in water. MYR-ME significantly increased antiproliferative activity against human cancer cell HepG2 without influence on normal cell LO2. It also notably improved the cellular antioxidative activity of myricetin. Furthermore, the oral bioavailability of myricetin was remarkably enhanced by MYR-ME in Sprague-Dawley rats after oral administration, which was 14.43-fold that with myricetin suspension. Therefore, the MYR-ME developed here could be used as a potential carrier for myricetin with substantially enhanced bioactivities and bioavailability and might promote myricetin's future utilization in functional foods and cosmetics.

Preparation and characterization of debranched-starch/phosphatidylcholine inclusion complexes.

In this study, debranched-starch/phosphatidylcholine inclusion complexes were prepared. The effect of reaction parameters such as reaction temperature, reaction time, and addition amount of phosphatidylcholine on the phosphatidylcholine payload and inclusion rate was investigated. The phosphatidylcholine payload and inclusion rate prepared under the optimal conditions were 106 mg/g and 84.8%, respectively. The formation of debranched-starch/phosphatidylcholine inclusion complexes was confirmed by the results of XRD and FT-IR. Furthermore, the molecular, cluster, and fractal structures of the complexes were investigated using (13)C CP/MAS NMR and SAXS. The results indicated that the inclusion complexes were formed by hydrophobic interactions between alkyl chain of phosphatidylcholine and debranched-starch helix cavity. The complexes possessed a mass fractal structure, and a semicrystalline structure with a Bragg distance of 19.04 nm formed. After complexation, the stability of phosphatidylcholine was significantly improved, and phosphatidylcholine of the complexes can be gradually released with pancreatin treatment. This study revealed that debranched-starch can be used as an effective carrier of phosphatidylcholine for the purpose of improving its stability.

Preparation of starch nanoparticles in a water-in-ionic liquid microemulsion system and their drug loading and releasing properties.

An ionic liquid microemulsion consisting of 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6), surfactant TX-100, 1-butanol, and water was prepared. The water-in-[Bmim]PF6 (W/IL), bicontinuous, and [Bmim]PF6-in-water (IL/W) microregions of the microemulsion were identified by conductivity measurements. Starch nanoparticles with a mean diameter of 91.4 nm were synthesized with epichlorohydrin as cross-linker through W/IL microemulsion cross-linking reaction at 50 °C for 4 h. Fourier transform infrared spectroscopy (FTIR) data demonstrated the formation of cross-linking bonds in starch molecules. Scanning electron microscopy (SEM) revealed that starch nanoparticles were spherical and that some particles showed aggregation formation. Furthermore, drug loading and releasing properties of starch nanoparticles were investigated with mitoxantrone hydrochloride as a drug model. This work provides an efficient and environmentally friendly approach for the preparation of starch nanoparticles, which is beneficial to their further application.