Preparation of crosslinked starches with enhanced and tunable gel properties by the cooperative crosslinking-extrusion combined modification

Due to its safety and palatability, the citric acid crosslinking modification is an excellent way to modify the properties of starch gels. However, the application of this method is restricted by the low degree of crosslinking of gels produced by this method in the hydrogel system. To produce citric acid-crosslinked starch with improved strength and tunable gel characteristics, a novel ion-esterification cooperative crosslinking-extrusion combined (CCEC) modification approach is presented in this study. The linear and nonlinear rheological characteristics of the samples were measured to evaluate the effectiveness of CCEC modification. Findings disclosed that at 0.1 % strain, the elastic modulus of the CCEC-modified starch (SC-0.5Zn2+, G' = 1522.29 ± 36.31) exhibited a significant rise of 387.27 % as compared to the elastic modulus of citric acid-crosslinked starch (SC, G' = 318.29 ± 11.62). Furthermore, changing the cation concentration allowed for efficient control of the gel's rheological characteristics. The samples were characterized by SEM, FTIR, XRD, and XPS. The CCEC-modified gels had a smaller pore size distribution and a denser honeycomb porous structure. The CCEC modification reaction involves ester bonds and electrostatic attraction. This research is essential to elucidate how coupled physicochemical modification techniques affect the manipulation of starch gel characteristics.

Preparation and Characterization of Sustained Released Zinc Citrate Encapsulated in Whey Protein Nanoparticles

BACKGROUND AND OBJECTIVES

The use of milk proteins for drug delivery is a new trend in functional foods and pharmaceutical. Recently, researchers have focused on the utilization of whey proteins in the preparation of nanoparticle and carrier for drugs and micronutrients. The objectives of this paper were to use whey proteins isolate (WPI) nanoparticles for the encapsulation of zinc citrate micronutrients and characterization of the prepared nanoparticles.

MATERIALS AND METHODS

Nanoparticles were prepared from WPI with pH cycling and used for the encapsulation and sustained release of zinc citrate with three ratios (7, 14 and 28 mM) of zinc citrate per gram WPI. The particle size of the prepared nanoparticles was characterization and examined by transmission electron microscopy. The release of Zinc from the prepared nanoparticles was carried out using simulated gastric fluid at pH 1.2 using dialysis membranes, the amount of zinc citrate loaded whey protein (14.36 mg Zinc in 1 g WPI) within range of daily dose of zinc for healthy adults.

RESULTS

The WPI nanoparticles were able to encapsulate efficiently zinc, with encapsulation efficiency that ranged between 99.79 and 96.31%. Zinc was highly released from the prepared nanoparticles in acidic media (pH 1.2).

CONCLUSION

It can be concluded that WPI can be used as an effective vehicle for the protection and sustained release of zinc in food and pharmaceutical preparations.