To elucidate the mechanism underlying the inhibition of beef protein oxidation by lotus seedpod proanthocyanidin (LSPC), epicatechin gallate (ECG) at a final concentration of 10 to 40 μmol/L, was investigated using a combination of nanoparticle size analysis, two-dimensional infrared correlation spectroscopy (2D-IR COS), and fluorescence spectroscopy. This study focused on how ECG affected the oxidative aggregation of beef myosin as well as the interaction mode, dominant binding forces, action sites, involved functional groups, and fluorescence quenching mechanism between ECG and myosin. The results indicated that, relative to native myosin, ECG treatment at final concentrations of 10~30 μmol/L resulted in a narrowed 250 kDa band in the sodium dodecyl sulfate–polyacrylamide gel electrophoresis profiles of the ECG-Myosin complex, an increased absolute value of Zeta potential, and reduced turbidity. These observations suggested that ECG inhibited oxidative myosin cross-linking with non-covalent interactions between ECG (acting as a hydrogen donor) and myosin. Fluorescence spectroscopy and chemical probing analyses revealed that ECG binding to myosin was an entropy-driven, thermodynamically favorable endothermic process, with hydrogen bonds and hydrophobic interactions serving as the dominant forces. This interaction induced the static fluorescence quenching of myosin. Furthermore, 2D-IR COS demonstrated that the hydroxyl (-OH) groups on the D-ring of ECG, as hydrogen donors, preferentially formed hydrogen bonds and hydrophobic interactions with carbonyl (C=O), amide (N-H), and alkyl (C-H) groups within the α-helical domains of myosin. These interactions inhibited protein oxidation and intermolecular cross-linking aggregation. This study provides a theoretical basis and experimental support for LSPC development as a natural plant-derived antioxidant for meat and meat products industry-related applications.

Fresh channel catfish (Ictalurus punctatus) exhibit heightened susceptibility to microbial contamination, leading to an extremely limited shelf life. Consequently, this study evaluated the synergistic effects of high-voltage electric field (HVEF) treatment combined with Lotus seedpod procyanidins (LSPC) on microbial community dynamics and quality retention of fish fillets during refrigerated storage at 4 degrees C. The results showed that the combination of HVEF and LSPC significantly delayed quality deterioration of the fillets during storage. Specifically, compared to the control group (CK), the levels of drip loss and total volatile basic nitrogen were significantly decreased (p < 0.05) by 33.34 %, and 37.28 %, respectively, on day 12. Additionally, the combined treatment inhibited the accumulation of biogenic amines and prevented texture softening in the fillets. Microbial counts in the combined treatment group also decreased by 2.01 lg CFU/g on day 8 compared to the CK group. High throughput sequencing analysis further showed that HVEF combined with LSPC effectively suppressed the growth of spoilage bacteria such as Pseudomonas and unclassified Enterobacteriaceae. Based on these findings, the combination of HVEF and LSPC extended the shelf life of channel catfish fillets by 4 days, suggesting that this combined treatment could be an effective method for prolonging the shelf life of fresh fish fillets.

Innovative non-thermal treatments, such as high hydrostatic pressure (HHP) pretreatment, have proven effective in enhancing the release of bioactive peptides from animal proteins, particularly angiotensin-converting enzyme (ACE) inhibitory peptides. This study applied HHP at 200 MPa for 5 min, significantly disrupting protein structures and increasing enzyme cleavage sites, leading to enhanced protein-enzyme interactions. Under these conditions, ACE inhibitory activity increased by 59.5 % compared to untreated samples. Peptidomics analysis revealed a notable rise in peptide abundance, primarily in peptides under 3 kDa, while molecular weight distributions remained stable, indicating improved enzymatic efficiency. A total of 9632 peptides were identified, with peptide SFSQYPPLGRF demonstrating the highest ACE inhibitory potential through molecular docking. GO and KEGG analyses indicated that HHP treatment impacts proteins involved in metabolic pathways and energy production, promoting enzymatic hydrolysis and the release of bioactive peptides. Industrial relevance: This study highlights the potential of HHP pretreatment as a scalable, non-thermal processing method for enhancing the production of ACE inhibitory peptides. The significant increase in peptide abundance and bioactivity underscores its industrial applicability in functional food and nutraceutical development. The approach aligns with growing consumer demand for natural, health-promoting ingredients and offers a sustainable, efficient solution for peptide production.

This study investigated the preparation and application of ultra-micro crayfish shell powder to enhance the quality of surimi gels. A combination of ball milling and irradiation techniques produced an innovative powder (MID) with reduced particle size and enhanced zeta potential, dispersibility, Ca2+ release, and hydrogen bonding energy (p < 0.05), while maintaining its composition. Adding 0.50 % MID to surimi gels resulted in optimal improvements, enhancing gel strength and texture as well as elasticity. MID also increased the water holding capacity (WHC), decreased water mobility, and resulted in a dense and ordered microstructure. Fourier transform infrared spectroscopy indicated improvements were due to increased intermolecular non-covalent bonding interactions. Electronic nose analysis showed MID reduced aromatic compounds and organosulphides, preserving flavor and reducing the fishy taste. Electronic tongue analysis revealed an increase in fresh flavor response. The preparation method significantly enhanced the quality and sensory properties of surimi gels.

Oil bodies (OBs), as natural oil storage organelles, can be obtained and utilized directly by simple extraction, thereby satisfying consumer demand for plant-derived green foods. The unique topological structure of the phospholipid-protein membrane renders OBs controllable and resistant to environmental stres, demonstrating their promising prospects for applications. As natural self-assemblies, the nutrient distribution, composition, and structural characteristics of OBs can be modified in multiple ways, including the genetic improvement and various processing techniques, to meet diverse application requirements. Generally, the utilization of OBs (e.g., processing stability, emulsifying, digestion, etc.) is closely related to their interfacial properties, but the associated studies have not been systematically reviewed. In this paper, we systematically review the structural and interfacial characteristics of OBs for the first time, encompassing their biosynthetic pathways and the structure-function relationship critical to their processability and bioavailability In particular, targeted improvement methods were also discussed. The underlying mechanisms of the physicochemical stability of OBs were primarily related to the interfacial modulation, including linkages between density, charge, and the number of protein-phospholipid salt bridges, as well as the quantity and structure of extrinsic proteins. The membrane compactness, enzyme binding sites, and aggregation of OBs in gastrointestinal tract significantly impact their digestion and subsequent metabolic fate. In summary, moderate interfacial modification, by altering the interactions between membrane components and retaining some extrinsic proteins, may be a promising approach to boost the stability and functionality of OBs.

This study examined the effects of ball-milled crayfish shell powder (MD) and ball milling combined with irradiation crayfish shell powder (MID) on the digestion behaviors of silver carp surimi. During simulated digestion, surimi supplemented with crayfish shell powder exhibited reduced protein digestibility and hydrolysis. Furthermore, compared to surimi without crayfish shell powder, these samples showed larger digestate particle size, enhanced cholesterol-lowering activity, and increased release of essential amino acids. These changes were most significant (p < 0.05) in the MID-supplemented surimi. Peptidomics analysis revealed that crayfish shell powder reduced peptide release by inhibiting structural protein hydrolysis and enriching lipid-regulatory pathways. These effects were linked to the dense gel network formed by the crayfish shell powder, limiting enzyme accessibility. In conclusion, crayfish shell powder reduced protein digestibility, thereby potentially influencing the satiating effect of surimi while improving its nutritional profile, positioning it as a promising functional additive for health-promoting surimi food applications.

Flaxseed oil bodies (FOBs) are being explored as natural plant-based delivery systems for the encapsulation and delivery of nutrients. However, there is currently a relatively poor understanding of their interfacial interaction and how this impacts delivery systems. In this study, β-carotene and lutein with far different molecular polarity were used to provide insights into their impacts on properties of FOB. In addition to the carotenoids (>93%) embedded and dissolved in the lipid core, they also interacted with the interfacial membrane components to impact the FOB properties. Raman showed the proportion of random coil and β-sheet in FOB-L (hydrophilic domain of interfacial protein) increased by 8% and 5% respectively, but remained almost unchanged in FOB-β, indicating lutein could interact with the polar exterior of interfacial membranes. Consistently, molecular dynamic simulations and spectroscopy analysis showed that lutein containing hydroxyl in β, ε-ionone ring was more likely to approach the outer hydrophilic regions of interfacial protein, while fatty soluble β-carotene interacted with hydrophobic region of inner membrane protein and phospholipid alkyl chain (close to oil). This difference in interfacial interactions induced significant discrepancies in the lipid oxidation, rheological behavior of carotenoid-FOB assemblies. Lutein was located at the outer edge where oxidation begins, making it more effective than β-carotene in improving the lipid oxidation stability of the FOB. Moreover, lutein therefore modulated interactions between oil droplets and altered the rheological properties of the FOB, whereas β-carotene had little effect. This study may facilitate the design of oil bodies-based delivery systems that have improved functional properties.

In this study, litchi polysaccharides were obtained from unfermented or fermented pulp by Lactobacillus fermentum (denoted as LP and LPF, respectively). The differences between LP and LPF in the colonic fermentation characteristics and modulatory of gut microbiota growth and metabolism were investigated with an in vitro fecal fermentation model. Results revealed that the strategies of gut bacteria metabolizing LP and LPF were different and LPF with lower molecular weight (Mw) was readily utilized by bacteria. The monosaccharide utilization sequence of each polysaccharide was Ara > Gla > GalA > GlcA ≈ Glu ≈ Man. Moreover, LPF promoted stronger proliferation of Bifidobacterium, Megamonas, Prevotella, and Bacteroides and higher SCFAs production (especially acetic and butyric acids) than LP. Correlation analysis further revealed that Mw could represent an essential structural feature of polysaccharides associated with its microbiota-regulating effect. Overall, Lactobacillus fermentation pre-treatment of litchi pulp promoted the fermentation characteristics and prebiotic activities of its polysaccharide.

Aeromonas veronii is associated with food spoilage and some human diseases, such as diarrhea, gastroenteritis, hemorrhagic septicemia or asymptomatic and even death. This research investigated the mechanism of the growth, biofilm formation, virulence, stress resistance, and spoilage potential of Bacillus subtilis lipopeptide against Aeromonas veronii. Lipopeptides suppressed the transmembrane transport of Aeromonas veronii by changing the cell membrane's permeability, the structure of membrane proteins, and Na+/K+-ATPase. Lipopeptide significantly reduced the activities of succinate dehydrogenase (SDH) and malate dehydrogenase (MDH) by 86.03% and 56.12%, respectively, ultimately slowing Aeromonas veronii growth. Lipopeptides also restrained biofilm formation by inhibiting Aeromonas veronii motivation and extracellular polysaccharide secretion. Lipopeptides downregulated gene transcriptional levels related to the virulence and stress tolerance of Aeromonas veronii. Furthermore, lipopeptides treatment resulted in a considerable decrease in the extracellular protease activity of Aeromonas veronii, which restrained the decomposing of channel catfish flesh. This research provides new insights into lipopeptides for controlling Aeromonas veronii and improving food safety.

Black rice bran is a superior dietary fiber (DF) resource. However, the lack of specific distribution and functionality of DF in black rice bran has constrained its refined processing. This study divided black rice bran into five equal bran fractions (BF) by stepwise milling to obtain BF1(outermost layer) to BF5 (the innermost layer). The contents, structure, physicochemical and functional properties of DF in each bran fractions were investigated. The results revealed that the insoluble, soluble and total dietary fiber (IDF, SDF and TDF) contents were 17.52 +/- 0.48 to 31.14 +/- 0.96, 2.03 +/- 0.20 to 3.86 +/- 0.01 and 19.57 +/- 0.28 to 34.61 +/- 1.10 g/100 g dry basis, respectively. Compared to BF1, the TDF content of BF2-BF5 was reduced by 3.90, 3.20, 21.74 and 43.46%, respectively. The main monosaccharides in both IDF and SDF were xylose, glucose, arabinose and galactose. The molecular weight of SDF samples ranged from 17.19 +/- 1.95 to 36.32 +/- 0.80 kDa. The outer bran fractions (BF1-BF3) IDF exhibited higher water swelling, water retention, oil adsorption capacity, together with cholesterol and sodium nitrite adsorption capacity than those of inner bran fractions (BF4-BF5), owing to their lower crystallinity and well -developed porous structure. These results provide essential data for the development of black rice DF-based food processing with enhanced functional benefits.

Enterotoxigenic Escherichia coli (ETEC) adhesion to gut epithelial cells is a prerequisite for diarrhea. Here, we studied the synergistic effect and potential mechanism of B-type lotus seedpod oligomeric procyanidin (LSPC) combined with probiotics against adhesion of ETEC. The results indicated that LSPC exhibited an effective anti-ETEC adhesion effect. LSPC showed signally synergistic effects with probiotics, e.g., Streptococcus thermophilus (ST) and Lactobacillus rhamnosus (LGG) in response to ETEC adhesion, with the combination of LSPC and LGG being the most efficacious. This may be attributed to the restoration of transmembrane resistance of cells, the increased expression of anti-inflammatory factors (IL-10, 1.89-fold), and the reduction of cellular inflammatory factor levels (TNF-α and IL-8), regulated by LGG-LSPC, resulting in a better enhancement of cellular immune defense and barrier function. In addition, the results of gas chromatography showed that LSPC, as a prebiotic, could significantly increase the total amount of short-chain fatty acids (especially, butyric acid) produced by probiotics (e.g., LGG), thus better maintaining intestinal health against ETEC infection. In conclusion, the synergistic effect of LSPC and probiotics (represented by LGG) against ETEC adhesion in epithelial cells may be achieved through the enhancement of cellular immune defense, cellular barrier function, and maintenance of homeostasis in the gut.

Red guava, distinguished by its elevated lycopene content, emerges as a promising natural source of carotenoids. This study systematically evaluates the impact of diverse processing techniques on the efficient release of carotenoids. The primary objective is to facilitate the transfer of carotenoids into the juice fraction, yielding carotenoid-enriched juice seamlessly integrable into aqueous-based food matrices. The untreated guava puree exhibited a modest release of carotenoids, with only 66.26% of β-carotene and 57.08% of lycopene reaching the juice. Contrastly, both high-pressure homogenization (HPH) at 25 MPa and enzyme (EM) treatment significantly enhanced carotenoid release efficiency (p < 0.05), while high hydrostatic pressure (HHP) at 400 MPa and pulsed electric field (PEF) of 4 kV/cm did not (p > 0.05). Notably, HPH demonstrated the most substantial release effect, with β-carotene and lycopene reaching 90.78% and 73.85%, respectively. However, the stability of EM-treated samples was relatively poor, evident in a zeta-potential value of −6.51 mV observed in the juice. Correlation analysis highlighted the interactions between pectin and carotenoids likely a key factor influencing the stable dissolution or dispersion of carotenoids in the aqueous phase. The findings underscore HPH as a potent tool for obtaining carotenoid-enriched guava juice, positioning it as a desirable ingredient for clean-label foods.

Food protein-derived peptides have garnered considerable attention due to their potential bioactivities and functional properties. However, the limited activity poses a challenge in effective utilization aspects. To overcome this hurdle, various methods have been explored to enhance the activity of these peptides. This comprehensive review offers an extensive overview of pretreatment, preparation methods, and modification strategies employed to augment the activity of food protein-derived peptides. Additionally, it encompasses a discussion on the current status and future prospects of bioactive peptide applications. The review also addresses the standardization of mass production processes and safety considerations for bioactive peptides while examining the future challenges and opportunities associated with these compounds. This comprehensive review serves as a valuable guide for researchers in the food industry, offering insights and recommendations to optimize the production process of bioactive peptides.

As a natural plant-derived oil-in-water emulsion, oil bodies (OBs) with fine membrane structure have a great potential to be a typical green entrapping system. The dense membrane of OBs protects the interior readily oxidizable substance, but also severely blocks the passage of biologically active substances. Given full considerations of both the mobility and rigidity of the OBs membrane, in this work, tepidity-ultrasonic (TU) method was firstly applied to incorporate β-carotene within flaxseed oil bodies (FOB). Laser Scanning Confocal Microscopy (LSCM), Atomic force microscopy (AFM) and Cryo-Scanning Electron Microscope (Cryo-SEM) measurements demonstrated that TU could induce the transformation of FOB membrane and greatly promoted β-carotene encapsulation into FOB interior. In consistent with rheology, the infrared, ultraviolet and fluorescence spectra of the membrane protein, as well as force-deformation curves confirmed that the inserted β-carotene weaken the interaction of components in the membrane to a sharp reduction in membrane stiffness. The subsequent ultrasonic triggered interfacial membrane remodeling and particle size reduction, causing a significant improvement of interfacial membrane stiffness nearly back its original state and ultimately improving the stability of the system. The optimal encapsulation rate of β-carotene (96.88%) could be obtained at optimized ultrasonic condition. After 30-day storage, the relative encapsulation efficiency of β-carotene in FOB-β-TU remained at 84.06%. Thus, this paper reveals that the synergistic effect of tepidity-stirring and ultrasonic provides the possibility for solvent-free assisted encapsulation of hydrophobic bioactive substances in natural OBs. This easily applicable method is also conducive to fulfill its application in multiple food processing.

High hydrostatic pressure (HHP) and high-pressure homogenization (HPH) were applied to mango juice to explore their effects on gastric retention rate (G-CRR), bioaccessibility (BAC) of total and individual carotenoids, and the corresponding mechanisms from macroscopic to microscopic scales. Compared to the control, both HHP and HPH at 50 MPa had no significant effect on BAC and G-CRR, whereas HPH at 100 MPa significantly increased BAC by 44.33% and G-CRR by 11.84%. Further HHP treatments (particularly at 400 MPa) on the 100 MPa-HPH-pretreated samples significantly increased BAC by 71.37% and G-CRR by 24.24%. Violaxanthins/esters were less stable than carotenes in the stomach, resulting in lower bioaccessibility of violaxanthins/esters. G-CRR and BAC were negatively correlated with the viscosity and particle size of juice, whereas they were positively correlated with the solubility/dispersibility of carotenoids. In addition, pectin-carotenoid interactions may also be an important factor affecting the digestive fate of carotenoids in juice.Industrial relevance: High pressure processing (High hydrostatic pressure, HHP, and high pressure homogeniza-tion, HPH) is a non-thermal technique and its effect on the bioaccessibility of carotenoids in fruits and vegetables have attracted attention from researchers. Our research found that HPH and HHP combined treatment could decrease the particle size of mango juice, and increase the viscosity and turbidity as well as the bioaccessibility of carotenoids therein. This technology can be used to preserve the physical stability of mango juice and improve the nutritional value.

The ACE inhibitory peptides have been characterized from the enzymatic digestion product of bighead carp protein and bioconjugated with graphene oxide (GO) to enhance its activity. The results showed that aspartic acid and glutamic acid had the highest levels in ultrafiltration fractions (<5 kDa), where eight potential ACE inhibitory peptides were also identified (ADSNHKAF, KLWHHTF, LLRLHF, PPSEPTKL, VEKFPLF, YLRLHF, YYKLKPLL, YYKLKPML). Among the eight peptides, YLRLHF showed the best ACE inhibitory activity (IC50 = 121.90 mu M) and was a competitive inhibitor. Molecular docking experiments showed that YLRLHF formed four hydrogen bond interactions in the ACE protein pocket, coordination bonding with Zn2+, and 7C-7C conjugation interactions to His421. GO elevated the ACE inhibitory activity of YLRLHF (at 0.1 mg/mL) from 43.36% to 51.72%. The structural characterization results obtained from FI-IR, XPS, SEM, and TEM demonstrated the successful combination of GO and YLRLHF. Additionally, biocouples of ACE inhibitory peptides from bighead carp proteins with GO might be potential candidates for future functional foods and antihypertensive drugs.

High hydrostatic pressure (HHP) (300/400/500 MPa for 5 min) and high pressure homogenization (HPH) (50/ 100 MPa for 1 pass) were applied to mango beverage to explore their effects on water soluble pectin (WSP) and bioaccessibility of total carotenoids (BAC), and the relationship between BAC and modified WSP. Compared to untreated sample, HPH at 50 and 100 MPa combined with/without HHP pronouncedly increased the WSP and galacturonic acid (GalA) concentrations in mango beverage and the molecular weight (Mw) of WSP, decreased the degree of methylesterification (DM) of WSP, and affected other structural indicators of WSP to various extent, while alone HHP slightly increased the GalA concentration in mango beverage and the Mw of WSP. These changes induced by high pressure processing were mainly due to mechanical release and solubilization of the pectin embedded in cell wall with higher Mw, shorter/fewer side chains, and lower DM. HPH had more pro-nounced effects on WSP than HHP due to stronger mechanical force. Compared to untreated sample, HPH at 50 MPa and HHP had no significant effect on BAC, while HPH at 100 MPa significantly increased the BAC by 32.22% and HPH (100 MPa) +HHP increased the BAC by 38.65%-76.32%. The BAC showed positive binomial correlations with GalA and WSP, and upwards binomial correlations with the Mw of WSP and viscosity of mango beverage. Moreover, a statistical negative correlation was found between the BAC and DM. Results highlighted the potential of high pressure processing to regulate the BAC by modifying WSP and affecting WSP-carotenoids interactions.

Whole flaxseed (flour) as a good source of omega-3 fatty acid and phytochemicals with excellent nutritional and functional attributes has been used to enrich foods for health promotion and disease prevention. However, several limitations and contemporary challenges still impact the development of whole flaxseed (flour)-enriched products on the global market, such as naturally occurring antinutritional factors and entrapment of nutrients within food matrix. Whole flaxseed (flour) with different existing forms could variably alter the techno-functional performance of food matrix, and ultimately affect the edible qualities of fortified food products. The potential interaction mechanism between the subject and object components in fortified products has not been elucidated yet. Hence, in this paper, the physical structure and component changes of flaxseed (flour) by pretreatments coupled with their potential influences on the edible qualities of multiple fortified food products were summarized and analyzed. In addition, several typical food products, including baked, noodle, and dairy products were preferentially selected to investigate the potential influencing mechanisms of flaxseed (flour) on different substrate components. In particular, the altered balance between water absorption of flaxseed protein/gum polysaccharides and the interruption of gluten network, lipid lubrication, lipid-amylose complexes, syneresis, and so forth, were thoroughly elucidated. The overall impact of incorporating whole flaxseed (flour) on the quality and nutritional attributes of fortified food products, coupled with the possible solutions against negative influences are aimed. This paper could provide useful information for expanding the application of whole flaxseed (flour) based on the optimal edible and nutritional properties of fortified food products.

生物活性肽可以从植物、动物、海洋资源中获得,其具有多种生物活性,如抗高血压、抗氧化、抗血栓、降胆固醇、降血压、抗菌、免疫调节、细胞调节、结合矿物质等.提高蛋白质向多肽的转化率一直以来是多肽研究的难点之一,超高压技术是一种适合于规模化生产的新型非热加工物理技术,近年来被广泛地应用于蛋白质工程,超高压技术的应用改善了蛋白质的结构和功能特性,提高了生物活性肽提取、生产的效率.本文重点综述超高压技术在蛋白质改性和肽制备方面的应用,概述超高压制备生物活性肽的类型、来源和生物活性,以期为深入应用超高压技术辅助蛋白质改性和活性肽制备提供参考.

Black rice (Oryza sativa L.) is a great source of anthocyanins and dietary fiber and possesses various health-promoting properties. The modulating effect of insoluble dietary fiber (IDF) from black rice on the fermentation of cyanidin-3-O-glucoside (Cy3G) in an in vitro human colonic model, together with the possible microbiota-mediated mechanisms, was investigated. The combined Cy3G and IDF fermentation can promote the biotransformation of Cy3G into phenolic compounds such as cyanidin and protocatechuic acid with stronger antioxidant activities and increase the total production of SCFAs during the fermentation of Cy3G. 16S rRNA sequencing analysis revealed that the addition of IDF modulated the microbiota structure and bloomed Bacteroidota and Prevotellaceae-related genera, which were positively correlated with metabolites of Cy3G, thus potentially regulating the microbial metabolism of Cy3G. The work is of great significance for elucidating the material basis of the health benefits of black rice.