Synergistic effects of ultrasound pretreatment and λ-carrageenan complexation on the stability and quercetin delivery efficiency of tilapia protein emulsion gels: The role of λ-carrageenan concentration.
Aug 2026· Ultrasonics sonochemistry· Vol 133, pp.
108021
· 0 citations· 49 references
Medicine
Abstract
The application of quercetin in functional foods is severely limited by its poor aqueous solubility, chemical instability, and low oral bioaccessibility. This study investigated the synergistic effects of ultrasound pretreatment and λ-carrageenan (λ-CA) complexation on the stability and quercetin delivery efficiency of tilapia protein (TP)-based emulsion gels. The results showed that ultrasonication induced partial unfolding of the TP secondary structure and tertiary conformation, thereby exposing more hydrophobic groups and free sulfhydryl groups, which promoted the formation of UTP-λ-CA complexes with enhanced solubility. More importantly, this synergistic strategy constructed a denser, more ordered gel network, providing effective steric hindrance against droplet aggregation and significantly enhancing the viscoelasticity, environmental stability, and digestive resistance of the system. Compared with UTP-0.1%λ-CA and UTP-0.2%λ-CA complex-stabilized emulsion gels, the UTP-0.3%λ-CA emulsion gel exhibited the smallest droplet size (D4,3 = 14.95 μm, D3,2 = 2.80 μm), the highest storage modulus (G'), and superior viscoelasticity. It also demonstrated the highest quercetin retention rates after UV irradiation (77.07%) and thermal treatment (74.93%). Furthermore, this system achieved the greatest quercetin bioaccessibility (31.19%), a 2.09-fold increase compared to the TP emulsion gel (14.92%). These findings provide theoretical support for the development of high-performance aquatic protein-based delivery systems for hydrophobic bioactive compounds.
Curcumin has applications in food and medical industries, but its stability and bioaccessibility are poor. Coconut cake albumin (CCA) has potential as a component of the curcumin-loading system; however, relative data are scare.
Herein, emulsion gels were formed using coconut cake albumin modified by ultrasonication and carboxymethylation (CCA-UC) in this study.
The results evidenced that ultrasonication and carboxymethylation increased the emulsifying capacity (from 67.51 to 143.65 m
2
/g) and emulsion stability (from 70.37 to 87.18%) of CCA by improving its solubility and interface sorption capacity, enhancing the zeta potential, and reducing droplets’ size (
p
< 0.05). CCA and CCA-UC formed compact emulsion gel when concentration was more than 10 g/100 g. Compared with the CCA-emulsion gel, CCA-UC-emulsion gel had more compact and denser gel structure, higher crystallinity (38.65%), bound water content and viscosity, and lower energy storage (
G’
), loss modulus (
G”
), and loss factor. Furthermore, CCA-UC-emulsion gel showed superior thermal and oxidative stability, and higher chewiness (35.83 g), springiness (0.90), hardness (67.44 g), and cohesiveness (0.85) than CCA-emulsion gel. Additionally, CCA-UC-emulsion gel exhibited superior intestinal digestion rate, higher curcumin encapsulation (89.64%) and loading efficiency (204.01 μg/g), better photostability, and superior bioaccessibility (49.08%). However, more specific mechanisms should be investigated in the further work.
These findings revealed that ultrasonication assisted with carboxymethylation was an effective way to improve the emulsion gel properties of CCA and increase the bioaccessibility of curcumin. However, more specific mechanisms should be investigated in the further work.
Temperature is a key factor regulating the assembly and functional properties of protein-polysaccharide complexes and appropriately heat-treated QPI-κC complexes offer a synergistic plant-based platform for the encapsulation, protection, and intestinal delivery of hydrophobic bioactives.
Jiangling Zhang, Guangfan Qu, Feiyan Yang et al.· International Journal of Bio...· 0 citations
Starch nanocrystals (SNCs) derived from rice starch were complexed with soybean β-conglycinin (7S) or glycinin (11S) to develop food-grade Pickering emulsifiers for curcumin delivery. The effects of the SNC-to-protein mass ratio on particle structure, interfacial properties, emulsion stability, and gastrointestinal digestion were systematically evaluated. At an SNC-to-protein mass ratio of 1:1, the SNCs-7S and SNCs-11S complexes exhibited the smallest particle sizes of 110 ± 4 and 234 ± 6 nm, respectively. Their three-phase contact angles approached 90°, indicating favorable interfacial wettability. SNCs induced concentration-dependent fluorescence quenching of 7S and 11S, with maximum quenching efficiencies of 61.02 ± 1.41% and 37.51 ± 1.09%, respectively. Raman spectroscopy and molecular docking analyses indicated that complex formation involved rearrangements of the protein secondary structure and hydrogen bonding. All calculated binding energies were below -6.0 kcal/mol, with the lowest value of -6.5 kcal/mol observed for SNCs-11S. Pickering emulsions containing 60% soybean oil exhibited shear-thinning and predominantly elastic behavior (G' > G″). The 1:1 composite systems formed the strongest network structures and exhibited no evident creaming, flocculation, or oiling-off after storage at 4 °C for 30 days. The SNCs-7S emulsion achieved a curcumin encapsulation efficiency (EE) and loading capacity of 90% and 7.5%, respectively, exceeding the corresponding values of 86% and 6.0% obtained for the SNCs-11S emulsion. After intestinal digestion, free fatty acid release from the SNCs-7S and SNCs-11S emulsions reached 46.31 ± 2.71% and 40.68 ± 0.71%, respectively. Overall, the 1:1 SNCs-7S system exhibited the most favorable interfacial assembly, storage stability, curcumin encapsulation, and lipid digestibility.
Yuan Wang, Yang Yang, Yue Xu et al.· International Journal of Bio...· 0 citations
The objective of this study was to develop a nanoemulsion of cumin essential oil (CEO-NE) stabilized synergistically by soybean lecithin (SL) and Tween 80 (TW 80), and to investigate the effects of different cumin essential oil (CEO) concentrations (1%–5%) on its physicochemical properties, antioxidant, and antibacterial activities, with a view to further evaluating its potential for preserving sun-dried camel meat. The results showed that when the SL to TW 80 ratio was 1:1, the prepared CEO-NE exhibited the smallest particle size (119.33 ± 2.52 nm) and the highest absolute zeta potential (−56.72 ± 1.23 mV). Through hydrogen bonding and hydrophobic interactions, CEO-NE at various concentrations formed stable nanoemulsion systems, with significantly improved thermal stability. Among these, 3% CEO-NE exhibited the best encapsulation efficiency and the most uniform particle distribution. The results of the antioxidant and antibacterial activity assessments showed that all CEO-NE samples (1%–5%) exhibited concentration-dependent antioxidant and antibacterial effects. The DPPH and ABTS radical scavenging rates increased from 60.24% to 97.09% and from 58.99% to 81.52%, respectively, while the total colony counts of Escherichia coli and Staphylococcus aureus decreased by 1.1 log CFU/mL and 1.32 log CFU/mL, respectively. Furthermore, the activity of CEO-NE at all concentrations was significantly superior to that of free CEO (P < 0.05). Experiments applying CEO-NE to the preservation of air-dried camel meat indicated that, during the 12-day drying process, the CEO-NE-treated group effectively maintained meat moisture content, significantly reduced thiobarbituric acid reactant values (0.46 ± 0.07 mg/kg) and total microbial counts (4.03 ± 0.14 log CFU/g), and improved sensory quality.
Hongyan Yu, Haitao Yue, Yu-Chuan Wang et al.· Food Chemistry: X· 0 citations
This study introduces a two-step ultrasonic strategy for fabricating zein-resveratrol-pectin ternary complexes as Pickering emulsion stabilizers. The novelty lies in two aspects. First, resveratrol serves as both a structural modulator and an antioxidant. Second, ultrasonication plays a distinct dual role, with primary ultrasonication optimizing nanoparticle assembly (encapsulation efficiency 86.0%, particle size ∼180 nm) and secondary ultrasonication activating interfacial complexation with pectin to yield complexes with superior emulsifying performance (emulsifying activity index 15.94 m2/g). The resulting emulsion exhibited solid-like gel behavior (storage modulus ∼100 Pa), minimal creaming (20.01%), and exceptional stability under thermal, pH, and ionic stresses, with minimal creaming even at 85 °C. Raman spectroscopy confirmed the formation of a dense interfacial layer, which underpinned the enhanced oxidative resistance (peroxide value 0.25 mmol/L after 5 days). This work demonstrates that integrating polyphenol modification with dual-stage ultrasonication offers a green and effective approach for developing high-performance, clean-label food colloids.
Qiufang Liang, Panpan Cao, Yunxia Du et al.· Food Chemistry· 0 citations
Emulsion gels have great potential for application in fat substitutes. Sunflower oil body (SFOB)-κ-carrageenan (CG) emulsion gels were fabricated, and the synergistic effects of SFOB extraction pH, oil phase volume fraction, and CG concentration on their gelation behavior, multiscale structure, and functional properties were systematically investigated. Results showed three variables significantly regulated the interfacial protein composition of SFOB, the cross-linking density of the gel network, and the binding force between SFOB and CG. The optimal emulsion gel was formulated with 0.9% CG and 20% oil phase volume fraction (from SFOB extracted at pH 7.0), which exhibited a compact and uniform three-dimensional network structure, superior WHC and minimal cooking loss. Furthermore, FTIR and SARS revealed that disulfide and hydrogen bonds contributed to the stabilization of the gel structure. Overall, this CG/SFOB emulsion gel represents a promising fat substitute and provides a novel approach for developing low-fat food products.
A new machine-learning framework aims to improve the success rate of computational protein design while moving away from results that reproduce sequences found in nature.
