Characterization and stability investigation of rhein encapsulated microcapsules using different enteric biopolymers with pullulan and Jiuzao glutelin conjugates via Maillard reaction.

The poor water solubility and rhein (RH) stability limit its application in the functional food industry. In the present study, the RH-loaded water-in-oil-in-water nano emulsion and microcapsules were prepared using the conjugates of pullulan-Jiuzao glutelin (JG) (m/m, 2:1, PJC-2) obtained by Maillard reaction and enteric-soluble materials (polymethlacrylic acid, hydroxypropyl methylcellulose phthalate, cellulose acetate phthalate, and D-mannitol). The effects of different formulations on the microstructure, physicochemical properties, and storage stability of microcapsules were analyzed. The results showed that microcapsules exhibited stability against different external environments. The encapsulation efficiency of RH in the four enteric-soluble-PJC-2 double-deck microcapsules (70.03 ± 3.24%-91.08 ± 4.78%) was significantly improved than PJC-2 ones (61.84 ± 0.47%). The antioxidant activity and stability of RH in the microcapsules were improved (ABTS, 49.7%-113.93%; DPPH, 40.85%-101.82%; FRA, 62.32%-126.42%; and FCA, 70.58%-147.20%) after in vitro simulated digestion and extreme environmental conditions compared to free RH. This work provides a microcapsule based on PJC-2 with enteric-soluble materials for insoluble functional ingredients to improve solubility, stability, and bioactivity in the food industry.

Ultrasound-assisted modification of functional properties and biological activity of biopolymers: A review.

In this review, the recent applications of power ultrasound technology in improving the functional properties and biological activities of biopolymers are reviewed. The basic principles of ultrasonic technology are briefly introduced, and its main effects on gelling, structural, textural, emulsifying, rheological properties, solubility, thermal stability, foaming ability and foaming stability and biological activity are illustrated with examples reviewing the latest published research papers. Many positive effects of ultrasound treatment on these functional properties of biopolymers have been confirmed. However, the effectiveness of power ultrasound in improving biopolymers properties depends on a variety of factors, including frequency, intensity, duration, system temperature, and intrinsic properties of biopolymers such as macromolecular structure. In order to obtain the desired outcomes, it is best to apply optimized ultrasound processing parameters and use the best conditions in terms of frequency, amplitude, temperature, time, pH, concentration and ionic strength related to the inherent characteristics of each biopolymer. This will help employ the full potential of ultrasound technology for generating innovative biopolymers functionalities for various applications such as food, pharmaceuticals, and other industries.