Complex coacervation and freeze drying using whey protein concentrate, soy protein isolate and arabic gum to improve the oxidative stability of chia oil

Efficacy of almond gum for coacervation with whey protein isolate- optimization, functionality and characterization: A comparison with high-methoxyl pectin

Complex coacervates of whey protein isolate (WPI) and two polysaccharides (almond gum (AG) and high methoxyl pectin (HMP)) under the different pHs (2.5-6.0) and biopolymer mass ratios (1:1-6:1) were prepared to achieve the maximum coacervate yield (CY). The optimum pH and mixing ratio to obtain the maximum CY of WPI-AG (75.93 %) and WPI-HMP (53.0 %) coacervates were 4.3 and 2:1, and 3.5 and 3:1, respectively. Although higher serum layers in emulsions stabilized by WPI-AG/HMP coacervates were detected at the 90 °C, remarkable heat stability under processing temperatures was obtained in ex-situ emulsions with both complex coacervates. Significantly more cold-storage and ionic stabilities were observed for emulsions formulated with WPI-AG than WPI-HMP. Peak shifts in FTIR spectra in the WPI-AG coacervate compared to the individual WPI and AG biopolymers revealed strong electrostatic interactions between these biopolymers. The absence of crystalline peaks for AG and HMP in X-ray diffraction (XRD) spectra confirmed the complexation of AG and HMP with WPI. Thermogravimetric and microstructural analyses showed that porous, loose mesh-like WPI-AG coacervates had superior thermal stability and structural integrity compared to WPI-HMP coacervates and individual biopolymers, which evidenced a more gradual weight loss pattern. WPI-AG coacervates would be promising for efficient emulsion-based delivery systems.

Characterization of O/W emulgels based on whey protein-alginate-inulin coacervates: Influence of temperature and ultrasound as protein preconditioning process

Preconditioning processes in proteins play a crucial role in enhancing their functional properties as surface active agents. Whey protein isolate (WPI, 20 wt%) was preconditioned via temperature (WPIT, 90 °C) or ultrasound (WPIUS, 20 kHz, 80 % amplitude). FTIR and zeta potential analysis demonstrated the effect of the preconditioning process on the secondary structure and surface properties of WPI. WPI-Alginate:Inulin (AI) complex coacervates (CCWPI:AI) were formed at pH 3.0 using WPIT and WPIUS, and the associative electrostatic interactions between WPI-AI led to coacervation yields >90 %, influenced by the preconditioning process employed. Viscoelastic properties outlined a predominantly solid-like behavior (G´ > G"). The CCWPI:AI system based on WPIT showed enhanced strength and gel-like structure compared to the WPIUS-based system. Oil-in-water (O/W) emulgels were formed and stabilized with the CCWPI:AI complexes, exhibiting spherical droplets (93.3-292.8 μm), whereas texture and rheological properties highlighted the formation of gel-like systems. The centrifugation STEP technology was used to evaluate the physical stability of emulgels, WPIT-based emulgels displayed superior stability against creaming than untreated WPI and WPIUS-based emulgels. These findings provide a basis for developing emulgels with prolonged stability and tunable functional properties, tailoring enhanced viscoelastic and texture attributes to meet specific needs for industrial applications where gel-like properties are pursued.

Advances in protein-based microcapsules and their applications: A review

Due to their excellent emulsification, biocompatibility, and biological activity, proteins are widely used as microcapsule wall materials for encapsulating drugs, natural bioactive substances, essential oils, probiotics, etc. In this review, we summarize the protein-based microcapsules, discussing the types of proteins utilized in microcapsule wall materials, the preparation process, and the main factors that influence their properties. Additionally, we conclude with examples of the vital role of protein-based microcapsules in advancing the food industry from primary processing to deep processing and their potential applications in the biomedical, chemical, and textile industries. However, the low stability and controllability of protein wall materials lead to degraded performance and quality of microcapsules. Protein complexes with polysaccharides or modifications to proteins are often used to improve the thermal instability, pH sensitivity, encapsulation efficiency and antioxidant capacity of microcapsules. In addition, factors such as wall material composition, wall material ratio, the ratio of core to wall material, pH, and preparation method all play critical roles in the preparation and performance of microcapsules. The application area and scope of protein-based microcapsules can be further expanded by optimizing the preparation process and studying the microcapsule release mechanism and control strategy.

Utilization of gallic acid-crosslinked soy proteins as wall material for chia oil microencapsulation

BACKGROUND

Chia oil represents the vegetable source with the highest content of omega-3 fatty acids. However, the incorporation of polyunsaturated fatty acids into food is limited due to their susceptibility toward oxidation. This investigation aimed to study the microencapsulation of chia oil (CO), using gallic acid (GA) crosslinked-soy protein isolate (SPI) as a wall material and its effect on its oxidative stability.

RESULTS

Microcapsules presented a moisture content, water activity, and encapsulation efficiency of around 2.95-4.51% (wet basis); 0.17 and 59.76-71.65%, respectively. Rancimat tests showed that with higher GA content, the induction period increased up to 27.9 h. The storage test demonstrated that the microencapsulated oil with crosslinked wall material has lower values of hydroperoxides and higher induction times concerning the non-crosslinked oil. Finally, the fatty acid profile at this storage time indicated that microcapsules with GA did not have significant changes. In vitro digestion exhibited a reduction in the percentage of bioavailable oil for crosslinked microcapsules, but with no variations in its chemical quality, and an increase in the total polyphenols amount and antioxidant activity.

CONCLUSION

The results obtained demonstrated that the microencapsulation of CO using SPI crosslinked with GA as wall material exerted a very important protective effect since a synergistic effect could be described between the microencapsulation effect and the antioxidant power of GA. © 2023 Society of Chemical Industry.