There is fast increasing interest in the development of food-grade high internal phase emulsions (HIPEs). In the work, we reported that native soy β-conglycinin (β-CG; a major 7S globulin in ...soybeans) could perform as an outstanding Pickering-type stabilizer for oil-in-water HIPEs. The protein concentration in the continuous phase (c) for the formation of homogenous and gel-like HIPEs could be as low as 0.2 wt%; and increasing the c from 0.2 to 1.0 wt% led to a progressive decrease in droplet size, but a progressive increase in stiffness of the HIPEs. The fabricated HIPEs at low c values (e.g., 0.2–0.5 wt%) were a kind of HIPE gels in essence with a gel network that could not be disrupted by 6 M urea, while the HIPE at c = 1.0 wt% was a highly concentrated emulsion that could be diluted by water. All the HIPEs at c values of 0.2–1.0 wt% were extremely stable against heating (at 100 °C for 15 min), or an elongated storage up to 60 days, but they were very prone to a freeze-thawing treatment. The freeze-thawed HIPEs could be repeatedly recovered back to a similar state to the untreated ones, when subject to another emulsification, indicating an extraordinary temperature-responsiveness. The β-CG molecules suffered a structural dissociation at the quaternary conformational level into separate subunits when adsorbed at the oil-water interface. The dissociated subunits from adsorbed β-CG showed a similar tertiary and secondary conformation to that of native β-CG, confirming the Pickering-nature of these subunits. All the HIPEs exhibited a surface coverage of around 60% in regard to the subunits of β-CG. The findings would be of importance not only for extending the knowledge about the Pickering stabilization of HIPEs by native oligomeric globulins, but also for the development of novel, eco-friendly and sustainable HIPEs for food, cosmetic and medicine formulations.
Display omitted
•Native β-conglycinin (β-CG) was demonstrated to be an outstanding Pickering nanostabilizer for HIPEs.•A kind of HIPE gels could be facilely formed at low concentrations (0.2–0.5 wt%).•The HIPEs or HIPE gels exhibited extraordinary stability against heating and storage.•The HIPEs were susceptibile to freeze-thawing, but could be recovered by another homogenization.•Dissociated subunits of β-CG at the interface were the factual stabilizers for the HIPEs.
The development of biocompatible Pickering stabilizers for oil-in-water emulsions has attracted fast increasing interests, due to their potential applications in food and pharmaceutical formulations. ...This work reports that a kind of novel nanoparticles to perform as outstanding Pickering stabilizers can be facilely fabricated from insoluble soybean polysaccharides (ISP) of Okara (a byproduct of soybean processing) by a high power ultrasonication. The ultrasonication resulted in breakdown of polysaccharide-based fibres in the ISP, and subsequently, formation of nanoparticles with sizes of 127–221 nm. The nanoparticles were mainly composed of polysaccharides and proteins, possessing a lower crystallinity of cellulose (relative to ISP) and good interfacial adsorption at oil-water interface. They were demonstrated to exhibit an excellent emulsification performance and a high tendency to form a gel-like network in the Pickering emulsions. Increasing the particle concentration and/or oil volume fraction was favorable for the creaming stability of the emulsions. Most of the droplets in the emulsions at higher particle-to-oil ratios were present in a more flocculated state, which was maintained by the hydrophobic interactions, as well as a bridging particle monolayer (with two droplets sharing the same monolayer). Interestingly, a portion of fine oil droplets with sizes <0.1 μm were entrapped within the flocculated structure consisting of large droplets with sizes at around 8 μm, which might largely account for the excellent emulsification performance of these nanoparticles. The findings would be of importance not only for the development of a kind of food grade nanoparticles to perform as outstanding Pickering stabilizers for the emulsions, but also for providing a strategy for the highly-added-value utilization of Okara.
Display omitted
•Nanoparticles from insoluble polysaccharides of Okara were facilely fabricated by ultrasonication.•The nanoparticles were mainly composed of polysaccharides and proteins.•The nanoparticles exhibited an excellent emulsification performance and Pickering stabilization.•Increasing the particle concentration and/or oil fraction favored the emulsion creaming stability.•A new emulsion stabilization mechanism was proposed.
Food-grade nanoemulsions fabricated using plant proteins as emulsifiers have attracted increasing interests, owing to their promising applications in food and drug sectors. However, a limitation to ...form nanosized droplets exists when plant proteins that usually exhibit poor emulsification performance due to their high tendency to aggregate are used as the sole emulsifier. In the current work, a facile process to form nanoemulsions using soy protein isolate (SPI) as the sole emulsifier was reported, through a strategy to inhibit protein aggregation by the addition of trehalose, as well as to improve emulsification performance of the protein. Using the microfludization as the emulsification process, the as-prepared nanoemulsions displayed extremely high stability against flocculation and coalescence during or after emulsification. Further analyses indicated that the presence of trehalose greatly inhibited protein spontaneous aggregation and prevented protein denaturation and re-aggregation of SPI during microfluidization, thus improving its emulsification performance. A kind of well-dispersed and less flocculated nanoemulsions with fine droplet sizes could be facilely fabricated using SPI as the sole emulsifier, without the occurrence of any over-processing. The findings are of value for providing a strategy to facilely prepare stable plant protein-based nanoemulsions by simply inhibiting protein aggregation with the addition of appropriate concentrations of polyols.
Display omitted
•Introducing trehalose favors nanoemulsion fabrication and stability.•The presence of trehalose greatly improves protein emulsifying performance.•Protein aggregation can be greatly inhibited in trehalose-rich system.•Protein denaturation during microfluidization is avoided in trehalose-rich system.
Knowledge distillation (KD) is a learning paradigm for boosting resource-efficient graph neural networks (GNNs) using more expressive yet cumbersome teacher models. Past work on distillation for GNNs ...proposed the local structure preserving (LSP) loss, which matches local structural relationships defined over edges across the student and teacher's node embeddings. This article studies whether preserving the global topology of how the teacher embeds graph data can be a more effective distillation objective for GNNs, as real-world graphs often contain latent interactions and noisy edges. We propose graph contrastive representation distillation (G-CRD), which uses contrastive learning to implicitly preserve global topology by aligning the student node embeddings to those of the teacher in a shared representation space. Additionally, we introduce an expanded set of benchmarks on large-scale real-world datasets where the performance gap between teacher and student GNNs is non-negligible. Experiments across four datasets and 14 heterogeneous GNN architectures show that G-CRD consistently boosts the performance and robustness of lightweight GNNs, outperforming LSP (and a global structure preserving (GSP) variant of LSP) as well as baselines from 2-D computer vision. An analysis of the representational similarity among teacher and student embedding spaces reveals that G-CRD balances preserving local and global relationships, while structure preserving approaches are best at preserving one or the other.
Oral administration of the peptide alamandine has antihypertensive and anti-fibrotic effects in rats. This work aimed to determine whether subcutaneous alamandine injection would attenuate ...hypertension and cardiac hypertrophy, and improve the function of a major target of hypertension-related damage, the left ventricle (LV), in spontaneously hypertensive rats (SHRs). This was examined in vivo in SHRs and normotensive rats subjected to 6-week subcutaneous infusion of alamandine or saline control, and in vitro in H9C2-derived and primary neonatal rat cardiomyocytes treated with angiotensin (Ang) II to model cardiac hypertrophy. Tail artery blood pressure measurement and transthoracic echocardiography showed that hypertension and impaired LV function in SHRs were ameliorated upon alamandine infusion. Alamandine administration also decreased the mass gains of heart and lung in SHRs, suppressed cardiomyocyte cross-sectional area expansion, and inhibited the mRNA levels of atrial natriuretic peptide and brain natriuretic peptide. The expression of alamandine receptor Mas-related G protein-coupled receptor, member D was increased in SHR hearts and in cardiomyocytes treated with Ang II. Alamandine inhibited the increases of protein kinase A (PKA) levels in the heart in SHRs and in cardiomyocytes treated with Ang II. In conclusion, the present study showed that alamandine administration attenuates hypertension, alleviates cardiac hypertrophy, and improves LV function. PKA signaling may be involved in the mechanisms underlying these effects.
Food-grade nanoemulsions using plant proteins as the sole emulsifier has attracted increasing interest in the food field. However, plant proteins present limitations in emulsification performance ...owing to their extensive aggregation and unfavorable adsorption behavior, when applied to stabilize emulsions. In the current work, a novel strategy to efficiently form nanoemulsions using plant oligomeric globulins (soy β-conglycinin and glycinin) as the sole emulsifier was proposed through the introduction of trehalose prior to emulsification, in order to overcome the above-mentioned limitations. The formed nanoemulsions were small-sized and well-dispersed, and displayed high stability against flocculation and coalescence. The underlying mechanism for this was largely associated with the enhanced structural stability of protein which contributes to improved interfacial adsorption behavior. Results indicated that the proteins were highly stable during microfluidization and adsorption at the interface in the presence of trehalose. Further research on protein adsorption behavior revealed more rapid diffusion rate, as well as less structural unfolding and rearrangement at oil-water interface of protein particles in trehalose-rich system, than in the trehalose-poor system. Through trehalose coating, oligomeric globulins could perform as outstanding Pickering particles with a strong structural integrity at oil-water interface.
Display omitted
•A strategy to efficiently produce small and stable nanoemulsion is proposed.•Introducing trehalose improves oligomeric globulins structural stability.•Protein aggregation and denaturation can be inhibited in trehalose-rich system.•Trehalose-coated protein show rapid diffusion and less interfacial unfolding.•Trehalose coating transforms plant oligomeric globulins into Pickering particles.
Monomeric globulins have been widely employed in food-grade nanoemulsion preparation owing to their outstanding emulsification performance. However, a limitation to stabilize nanoemulsions during ...storage exists when using monomeric globulin as sole emulsifier, mainly due to the low structural stability of protein during emulsification and at water-oil interface. In the current work, an efficient strategy to fabricate ultra-stable protein-based nanoemulsions was proposed through the incorporation of trehalose to enhance the structural stability of bovine serum albumin (as a model monomeric globulin) in the aqueous phase. The as-prepared nanoemulsions exhibited a high stability against droplet flocculation and coalescence during emulsification and upon long-term storage. Further analyses indicated that the presence of trehalose could form a “shell” structure around protein particles to protect protein against denaturation, unfolding and aggregation during microfluidization. The globulins in trehalose-rich system could behave as a kind of soft nanoparticles with a strong structural integrity and were unaffected by adsorption at the interface. Moreover, the existence of abundant aggregated trehalose greatly favored protein diffusion and adsorption and contributed to more balanced protein wettability, thus allowing monomeric globulins to stabilize more interfaces with Pickering effect. The findings are of value for providing a strategy to prepare stable nanoemulsion using monomeric globulins as the sole emulsifier by simply transforming monomeric globulins into Pickering nanoparticles with the addition of trehalose.
Display omitted
•Introducing trehalose favors protein nanoemulsion formation and stability.•Protein aggregation and denaturation can be inhibited in trehalose-rich system.•Trehalose coated proteins show strong structural integrity at interface.•Aggregated trehalose contribute to protein fast diffusion and balanced wettability.•Monomeric globulins can act as Pickering-type stabilizers for nanoemulsions.
Display omitted
•Cellulose nanocrystals were demonstrated to effectively stabilize fine emulsions by microfluidization.•The droplet size and stability of the emulsions could be well tuned by the oil ...fraction (ϕ) and particle concentration (c).•Bridging flocculation was more favorable at lower ϕ or higher c values.•The finer Pickering emulsions exhibited a better coalescence stability.•This is the first observation for the fabrication of fine emulsions stabilized by cellulose nanocrystals.
Cellulose nanocrystals (CNCs) as Pickering emulsion stabilizers have attracted fast increasing interests in the food, pharmaceutical and cosmetic fields, due to their sustainability and biocompatibility. However, it still remains a debate for unmodified CNCs to act as a kind of effective Pickering stabilizers, due to their high hydrophilic nature. This work for the first time reported that CNCs were compatible with using microfluidization as the emulsification process to produce a kind of fine Pickering emulsions, with surface-average droplet sizes as low as 0.22 μm. As compared with other emulsification processes, the Pickering emulsions by the microfluidization were more stable against coalescence but readily prone to droplet flocculation and creaming. The droplet flocculation in these emulsions was mainly associated with the formation of bridging droplets with two different droplets sharing a same monolayer. The droplet size, microstructure and stability (against creaming and coalescence) of these emulsions by the microfluidization could be well tuned by varying the particle concentration (c; 0.3–1.2 wt%) and/or oil fraction (ø; 0.1-0.4). In general, the finer Pickering emulsions with more serious bridging flocculation were formed at lower ø and/or higher c values, while the emulsions at lower ø and c values were more prone to creaming. The Pickering emulsions with smaller droplet sizes exhibited a much better coalescence stability. Interestingly, the amount of adsorbed CNCs at the interface was relatively high, and the percentage of surface coverage at interface was low (ranging from 11.3 to 50.0%). The results confirmed that using the microfluidization as the emulsification technique, CNCs exhibit a good ability to stabilize the Pickering emulsions, with the microstructure and stability well-modulated by varying the c and/or ø. The findings would be of great relevance for the development of nanoscale CNC Pickering emulsions suitable for food and pharmaceutical formulations.
Glycation with carbohydrates has been considered to be an effective strategy to improve the emulsifying properties of plant storage globulins, but the knowledge is inconsistent and even ...contradictory. This work reported that the glycation with soy soluble polysaccharide (SSPS) progressively improved the emulsification efficiency of soy glycinin (SG) in a degree-of-glycation (DG)-dependent manner. The glycation occurred in both the acidic (A) and basic (B) polypeptides to a similar extent. The physicochemical and structural properties of glycated SG samples with different DG values of 0–35% were characterized. The emulsifying properties of unglycated and glycated SG were performed on the emulsions at an oil fraction of 0.3 and a protein concentration in the aqueous phase, produced using microfluidization as the emusification process. The glycation with increasing the DG led to a progressive decrease in solubility and surface hydrophobicity but remarkably increased the magnitude of ζ-potential. Dynamic latter scattering and spectroscopic results showed that the glycation resulted in a gradual dissociation of the 11S-form SG at the quaternary level (into different AB subunits), in a DG-dependent way, while their tertiary (AB subunits) and secondary structure were slightly affected. Besides the emulsification efficiency, the glycation progressively accelerated the droplet flocculation and facilitated the adsorption of the proteins at the interface and formation of bridged emulsions. The results demonstrated that the improvement of the emulsification efficiency of SG by the glycation with SSPS was largely attributed to the enhanced conformation flexibility at the AB subunit level as well as facilitated formation of bridged emulsions. It was also confirmed that once the glycated SG adsorbed at the interface, it would readily dissociated into subunits; the dissociated AB subunits exhibited an outstanding Pickering stabilization. The findings would be of importance for providing new knowledge about the molecular mechanism for the modification of emulsifying properties of oligomeric globulins by the glycation with polysaccharides.
Hepatitis B virus (HBV) can integrate into the human genome, contributing to genomic instability and hepatocarcinogenesis. Here by conducting high-throughput viral integration detection and RNA ...sequencing, we identify 4,225 HBV integration events in tumour and adjacent non-tumour samples from 426 patients with HCC. We show that HBV is prone to integrate into rare fragile sites and functional genomic regions including CpG islands. We observe a distinct pattern in the preferential sites of HBV integration between tumour and non-tumour tissues. HBV insertional sites are significantly enriched in the proximity of telomeres in tumours. Recurrent HBV target genes are identified with few that overlap. The overall HBV integration frequency is much higher in tumour genomes of males than in females, with a significant enrichment of integration into chromosome 17. Furthermore, a cirrhosis-dependent HBV integration pattern is observed, affecting distinct targeted genes. Our data suggest that HBV integration has a high potential to drive oncogenic transformation.
PDF
