Mucoadhesive chitosan microcapsules for controlled gastrointestinal delivery and oral bioavailability enhancement of low molecular weight peptides.

A bioactive compound, collagen peptide (CP), is widely used for biological activities such as anti-photoaging and antioxidant effects, with increased oral bioavailability because of its low molecular weight and high hydrophilicity. However, controlling release time and increasing retention time in the digestive tract for a more convenient oral administration is still a challenge. We developed CP-loaded chitosan (CS) microcapsules via strong and rapid ionic gelation using a highly negative phytic acid (PA) crosslinker. The platform enhanced the oral bioavailability of CP with controlled gastrointestinal delivery by utilizing the mucoadhesiveness and tight junction-opening properties of CS. CS and CP concentrations varied from 1.5 to 3.5% and 0-30%, respectively, for optimal and stable microcapsule synthesis. The physicochemical properties, in vitro release profile with intestinal permeability, in vivo oral bioavailability, in vivo biodistribution, anti-photoaging effect, and antioxidant effect of optimized CS microcapsules were analyzed to investigate the impact of controlling parameters. The structure of CS microcapsules was tuned by PA diffused gradient ionic cross-linking degree, resulting in a controlled CP release region in the gastrointestinal tract. The optimized microcapsules increased Cmax, AUC, and tmax by 1.5-, 3.4-, and 8.0-fold, respectively. Furthermore, CP in microcapsules showed anti-photoaging effects by downregulating matrix metalloproteinases-1 via antioxidant effects. According to our knowledge, this is the first study to microencapsulate CP for oral bioavailability enhancement. The peptide delivery method employed is simple, economical, and can be applied to customize bioactive compound administration.

Thermoresponsive semi-interpenetrating gelatin-alginate networks for encapsulation and controlled release of scent molecules.

Plant-based meats, which are nutritious foods from non-animal sources, provide clues for addressing the negative externalities associated with conventional meat production. Interest in plant-based meat has increased and is driving the rapid growth of its market. Plant-based meat should be equipped with a temperature-dependent scent release system similar to the scent release mechanism of conventional meat, to deliver a desirable meat-like flavor to consumers and obtain higher market acceptance. In this study, we prepared thermoresponsive gelatin-alginate hybrid hydrogels to control the release of scent molecules. The polymer network of gelatin-alginate hydrogels was reinforced by a semi-interpenetrating network (sIPN). sIPN formation conferred resistance to external stimuli, such as shear force, swelling, and temperature, resulting in a sustained release of the meat scent. In addition, controlled size microcapsules fabricated from the same composition via an electrostatic extrusion process showed a sustained release pattern of the loaded scent at 70 °C, and the scent release rate was precisely controlled within an approximately 2-fold range by adjusting the alginate concentration. These observations suggest the potential use of edible biological macromolecules as food additives that can control the release of scent molecules from the plant-based meat during cooking.

Determination of Required HLB Values for Citrus unshiu Fruit Oil, Citrus unshiu Peel Oil, Horse Fat and Camellia japonica Seed Oil.

In the present study, the required hydrophilic lipophilic balance (HLB) values of Citrus unshiu fruit oil (CUFO), Citrus unshiu peel oil (CUPO), horse fat (HF), and Camellia japonica seed oil were determined empirically by preparing oil-in-water (o/w) emulsions. Lipophilic and hydrophilic surfactants were prepared in various ratios in o/w emulsion. The droplet size of the emulsion was measured using a particle size analyzer, and the turbidity was measured using a turbidity meter and a ultraviolet (UV)-vis spectrophotometer. According to the Orafidiya-Oladimeji method, the HLB value of the emulsion having the minimum dispersion ratio, the minimum droplet size, and the maximum turbidity degree was determined as the required HLB value for each essential oil. Based on these methods, the required HLB values of CUFO, CUPO, HF, and Camellia japonica seed oil were determined as 14.75-14.90, 15.35-15.40, 6.30-7.06, and 5.94-6.30, respectively.