Effects of chitosan molecular weight and mass ratio with natural blue phycocyanin on physiochemical and structural stability of protein.

Phycocyanin (PC), an algae-extracted colorant, has extensive applications for its water-solubility and fresh blue shade. When PC is added to acidified media, dispersions are prone to aggregate and decolorize into cloudy systems. For palliating this matter, chitosan with high, medium, and low molecular weights (HMC, MMC, and LMC) were adopted in PC dispersions, and their protective effects were compared based on physiochemical stabilities. The optimal mass ratio between chitosan and PC was identified as 1:5 based on preliminary evaluations and was supported by the higher ζ-potential (31.0-32.1 mV), lower turbidity (39.6-43.6 NTU), and polyacrylamide gel electrophoresis results. Through interfacial and antioxidant capacity analyses, LMC was found to display a higher affinity to PC, which was also confirmed by SEM images and the maximum increase in transition temperature of their complex (155.70 °C) in DSC measurements. The mechanism of electrostatic interaction reinforced by hydrophobic effects and hydrogen bonding was elucidated by FT-IR and Raman spectroscopy. Further comprehensive stability evaluations revealed that, without light exposure, LMC kept PC from internal secondary structure to external blueness luster to the maximum extent. While with light exposure, LMC was not so flexible as HMC, to protect chromophores from attack of free radicals.

Fabrication and characterization of whey protein isolates- lotus seedpod proanthocyanin conjugate: Its potential application in oxidizable emulsions.

Emulsified ω-3 polyunsaturated fatty acid have expanding application in different food matrix with improved water solubility while still prone to oxidation. Lotus seedpod proanthocyanidin (LSPC) was grafted to whey protein isolate (WPI) to create nature-derived antioxidant emulsifiers. 1HNMR, SDS-PAGE and multiple spectrometry showed that the structure of protein was changed after grafting. DPPH and FRAP measurements showed that WPI-LSPC conjugate (90.53 ± 1.48% of DPPH scavenging, 691.85 ± 4.54 µg/mL for FRAP assay) possessed a much better antioxidant ability than WPI (17.06 ± 3.34% of DPPH scavenging, 10.43 ± 0.26 µg/mL for FRAP assay). Ultrasonic emulsification and DSC experiments showed that WPI-LSPC conjugate were more effective at forming and stabilizing the flaxseed oil emulsions than pure WPI, with higher thermostability. Likewise, low levels of primary and secondary oxidation products were formed for the conjugate than the pure protein in O/W systems after storage, again suggesting WPI-LSPC could be used as fine antioxidant emulsifiers in oxidizing delivery systems.

Surface decoration of neohesperidin-loaded nanoliposome using chitosan and pectin for improving stability and controlled release.

The aim of this study was to improve the physicochemical stability of neohesperidin (NH) using nanoliposomal encapsulation in association with surface decoration strategy employing chitosan (CH) and pectin (P). Different nanoliposomal systems, i.e. NH-loaded nanoliposome (NH-NL), CH-coated NH-NL (CH-NH-NL), and P-coated CH-NH-NL (P-CH-NH-NL) were characterized through DLS, HPLC, TEM, and FTIR. The results confirmed good encapsulation efficiency (>90%) and successful layer formation with nano-sized and spherical carrier. Both CH-NL and P-CH-NL exhibited better physicochemical stability than NL under storage, thermal, pH, ionic, UV, oxidative, and serum conditions. In vitro mucin adsorption study revealed that CH-NL (60%) was more effective in mucoadhesion followed by P-CH-NL (46%) and NL (41%). Furthermore, P-CH-NL showed better performance in NH retention under different food simulants compared to CH-NH-NL and NH-NL, in which the release was mainly governed by the diffusion process. Thus, the P-CH conjugated nanoliposome could be a promising nano-carrier for neohesperidin.

Formation, Physicochemical Stability, and Redispersibility of Curcumin-Loaded Rhamnolipid Nanoparticles Using the pH-Driven Method.

The aim of the present work was to fabricate the curcumin-loaded rhamnolipid nanoparticles using the pH-driven method to enhance the physicochemical stability and redispersibility of curcumin. The mixture of curcumin and rhamnolipid could be spontaneously assembled into the curcumin-loaded rhamnolipid nanoparticles with a small size (107 nm) and negative charge (-45.5 mV). Curcumin molecules could bind to rhamnolipid molecules through hydrophobic effects and hydrogen bonds. The effect of different mass ratios of rhamnolipid and curcumin (1:2, 1:1, 2:1, 4:1, 6:1, and 8:1) on the functional property of the curcumin-loaded rhamnolipid nanoparticles was investigated. With the rise of rhamnolipid and curcumin mass ratio, the encapsulation efficiency of curcumin in the nanoparticles was increased from 44.59% to 81.12% and the loading capacity of curcumin was elevated from 10.14% to 31.67%. When the mass ratio of rhamnolipid and curcumin was 4:1, the curcumin-loaded rhamnolipid nanoparticles exhibited better physical stability, pH stability, and redispersibility. Moreover, the nanoparticles could effectively protect curcumin against the photodegradation and thermal degradation. Therefore, the rhamnolipid nanoparticles have the potential to be applied as a nanodelivery system for bioactive molecules in functional foods.

Effects of environmental stresses on physiochemical stability of ß-carotene in zein-carboxymethyl chitosan-tea polyphenols ternary delivery system.

ß-Carotene is a natural nutrient that serves as a natural food colorant. However, the weak physical stability restricts its development in food industrial production. Here, the influences of a variety of external environmental conditions on the stability of ß-carotene enriched zein-carboxymethyl chitosan (CMCS)-tea polyphenols (TP) ternary composite nanoparticles were investigated. Compared with zein unitary and zein-CMCS binary complexes, it was interesting to note that ternary complexes had the best stability against color fading and there was little impact on its nanoparticle size during storage with change in temperature. Besides excellent antioxidant properties, ternary complexes were extremely effective in inhibiting ß-carotene color degradation when exposed to ultraviolet light. Based on our results, the novel zein-CMCS-TP nanoparticles are expected to be an effective delivery system to encapsulate hydrophobic bioactive compounds, which is a promising approach to improve their storage stability against external environmental stresses.

Why is glycocholic acid sodium salt better than deoxycholic acid sodium salt for the preparation of mixed micelle injections?

Classical mixed micelle systems make excellent parenteral drug carriers for lipophilic or poorly soluble drugs, but many formulations details are not fully understood and need further study. Thus, we constructed mixed micelle systems with lecithin and either glycocholic acid sodium salt or deoxycholic acid sodium salt in order to investigate the differences between the bile salts. Vitamin K1, a lipid-soluble drug, was encapsulated in the mixed micelles, and the influence of bile salts on the quality and stability of the mixed micelle systems was analyzed. Both bile salts displayed similar profiles, and the amounts of bile salts used in formulating clear solutions did not differ. Mixed micelle systems formed from glycocholic acid sodium were physically stable at low pH levels (5.5), whereas those formed from deoxycholic acid required higher pH (>8.5). High pH levels hurt active pharmaceutical ingredients that are prone to hydrolytic and oxidative degradation. Hence, when mixed micelle systems formed from deoxycholic acid sodium were sterilized, unexpected chemical unstability occurred. Therefore, we conclude that glycocholic acid sodium salt is more suitable than deoxycholic acid sodium salt for the preparation of mixed micelle injections.