Search Results (52)

To effectively address the issues of poor ventilation, light deficiency, increased pest and disease pressure, and declining fruit quality in closed-canopy walnut orchards, this study was conducted in a standard, densely planted ‘Xinwen 185’ walnut orchard. Three treatments were established: an unthinned control (CK), a 1-year thinning treatment (T1), and a 2-year thinning treatment (T2). All parameters were uniformly investigated during the 2023 growing season to analyze the effects of thinning on orchard population structure, microenvironment, leaf physiological characteristics, fruit quality, and yield. The results demonstrated that tree thinning significantly optimized the population structure: crown width expanded by 6.22–6.76 m, light transmittance increased to 27.74–33.64%, and orchard coverage decreased from 100% to 75.94–80.51%. The microenvironment was improved: inter-row temperature increased by 2.34–4.08 °C, light intensity increased by 5.38–25.29%, and relative humidity decreased by 2.15–3.30%. Furthermore, leaf physiological functions were activated: in the T2 treatment, the chlorophyll content in outer-canopy leaves increased by 15.23% and 12.45% at the kernel-hardening and maturity stages, respectively; the leaf carbon-to-nitrogen ratio increased by 18.67%; the net photosynthetic rate (Pn) during fruit expansion increased by 34.21–46.10%; and the intercellular CO₂ concentration (Ci) decreased by 10.18–10.31%. Fruit quality and yield were synergistically enhanced: single fruit weight increased by 23.39~37.94%, and kernel weight increased by 26.79–41.13%. The total sugar content in inner-canopy fruits increased by 16.50–16.67%, while the protein and fat content in outer-canopy fruits increased by 0.69–12.50% and 0.60–2.18%, respectively. Yield exhibited a “short-term adjustment and long-term gain” pattern: the T2 treatment (after 2 years of thinning) achieved a yield of 5.26 t·ha⁻¹, which was 20.38% higher than the CK. The rates of diseased fruit and empty shells decreased by 65.71% and 93.22%, respectively, and the premium fruit rate reached 90.60%. This study confirms that tree thinning is an effective measure for improving the growing environment and enhancing overall productivity in closed-canopy walnut orchards, providing a scientific basis for sustainable orchard management and increased orchard profitability. Full article

Nuts, including tree nuts such as almonds, walnuts, cashews, and macadamias, as well as peanuts, are widely consumed for their health benefits owing to their high-quality protein content. Globally, the nut industry represents a multi-billion-dollar sector, with increasing demand driven by consumer interest in nutrition, functional foods, and plant-based diets. Recent advances in proteomic technologies have enabled comprehensive analyses of nut seed proteins, shedding light on their roles in nutrition, allergenicity, stress responses, and food functionality. Seed storage proteins such as 2S albumins, 7S vicilins, and 11S legumins, are central to nutrition and allergenicity. Their behavior during processing has important implications for food safety. Proteomic studies have also identified proteins involved in lipid and carbohydrate metabolism, stress tolerance, and defense against pathogens. Despite technical challenges such as high lipid content and limited genomic resources for many nut species, progress in both extraction methods and mass spectrometry has expanded the scope of nut proteomics. This review underscores the central role of proteomics in improving nut quality, enhancing food safety, guiding allergen risk management, and supporting breeding strategies for sustainable crop improvement. Full article

This study explores the valorization of walnut green husk, an agro-industrial by-product, through ultrasound-assisted extraction to obtain polyphenol-rich extracts with antioxidant properties. The extracts demonstrated non-cytotoxicity, regardless of the presence of pesticides, antibiotics, or the type of crop. Notably, organic walnut husk yielded higher total polyphenols and antioxidant activity, identifying 37 polyphenolic compounds compared to 22 in traditional crops. Chickpea protein was utilized as a wall material to encapsulate the extract, resulting in a sustainable, vegan antioxidant powder. Optimal results were achieved using 5% (w/v) chickpea protein and spray drying at 136 °C, yielding a light-colored powder with high antioxidant content and stability under low humidity (≤35%). The product shows promise as a natural, plant-based alternative to synthetic antioxidants in food systems. Further studies are needed to evaluate its functional and technological performance during food integration and storage. Full article

The study aimed to produce semolina pasta enriched with walnut or hazelnut oil cake and to investigate its nutritional and technological properties. The pasta was prepared by substituting 10% of semolina with walnut or hazelnut oil cakes. The chemical composition, antioxidant properties, and culinary characteristics of the pasta were determined. Additionally, the texture and color of uncooked and cooked pasta were examined using instrumental techniques. The enriched pastas showed higher protein, fat, ash, and dietary fiber contents compared to standard pasta (SP). Walnut oil cake pasta (WOCP) had the highest protein content, amounting to 15.8 g/100 g dry weight (d.w.), while hazelnut oil cake pasta (HOCP) had the highest dietary fiber content (6.75 g/100 g d.w.). Moreover, the enriched pastas showed significantly higher antioxidant potential and total phenolic content, both before and after cooking. The total phenolic content (TPC) of cooked pasta ranged from 88.85 mg GAE/100 g d.w. (SP) to 145.48 mg GAE/100 g d.w. (WOCP). Compared to SP, the developed pastas required cooking times of 2–3 min longer and showed higher water absorption, accompanied by increased cooking losses. They were characterized by a specific, dark color and showed reduced hardness and lower elasticity after cooking compared to SP. Pasting properties further suggested that starch swelling was restricted by the nut oil cakes. Overall, incorporating walnut and hazelnut oil cakes enhanced the nutritional profile and imparted notable health-promoting attributes to the pasta, underscoring the potential of these by-products as functional ingredients in pasta formulations. Full article

This study investigates the effect of walnut green husk extract (WE) on gut microbiota, metabolites, and immune-antioxidant changes in fattening pigs through gut microbiota-metabolite interactions. A total of 60 healthy fattening pigs (Duroc × Landrace × Yorkshire) with an initial body weight of 65.2 ± 3.1 kg were randomly assigned to two groups (n = 30 per group): the control group (NC), which was fed a basal diet, and the WE group, which was fed the basal diet supplemented with 0.1% walnut green husk extract (WE). Dietary supplementation with 0.1% WE significantly increased the relative abundances of beneficial bacteria (e.g., Firmicutes, Lactobacillus) and reduced pathogenic bacteria (e.g., Proteobacteria, Shigella). Untargeted metabolomics identified 170 differentially accumulated metabolites, among which propionic acid—a key short-chain fatty acid with immunomodulatory effects—was significantly upregulated by 1.09-fold (p = 0.03) and showed a positive correlation with beneficial microbial abundances. These metabolites were enriched in glycerophospholipid and α-linolenic acid metabolism pathways, where eicosadienoic acid inhibited the nuclear factor kappa-B (NF-κB) pathway for anti-inflammatory effects, and methyl cinnamate synergistically regulated mitogen-activated protein kinase (MAPK) signaling with Lactobacillus. Serum analyses showed that WE significantly enhanced IgA, IgM, and IgG levels by 3.97-fold, 4.67-fold, and 4.43-fold (p < 0.01), reduced malondialdehyde (MDA) concentration by 82.8% (p < 0.01), and trended to improve antioxidant capacity via glutamine. Mechanistically, WE promoted short-chain fatty acid production by beneficial bacteria, forming a “microbiota–metabolite–immunity” cascade to enhance lipid metabolism and alleviate intestinal inflammation. These findings highlight that WE provides multi-omics evidence for its application as a functional feed additive. Full article

MIKC-type MADS-box transcription factors constitute one of the largest gene families in plants, playing pivotal roles in regulating plant growth and development, hormone signaling transduction, and responses to biotic and abiotic stresses. However, there have been no reports on the systematic identification and characterization of MIKC-type MADS-box proteins in walnuts. In this study, we identified 52 JrMADS genes in the walnut genome and transcriptome, and categorized them into 14 subfamilies through structural domain and phylogenetic tree analysis. It was found that these genes were unevenly distributed across 16 chromosomes. Within the MIKC-type MADS-box gene family, we identified three pairs of tandem-duplicated genes and 40 pairs of segmental duplicated genes, indicating that segmental duplication was the primary mechanism of gene amplification in walnut. Ka/Ks analysis showed that the family genes have undergone purifying selection during evolutionary processes. The promoter was predicted to contain cis-acting elements related to growth, development, plant hormones, and stress response. Expression profile analysis showed that JrMADS genes have different expression patterns in various tissues and developmental stages of male and female flower buds. Notably, an ancient clade of TM8 (JrMADS43) genes was found, which is absent in Arabidopsis but present in other flowering plants. Another gene, TM6 gene (JrMADS4), belongs to the AP3 subfamily and is a clade that has diverged from tomatoes. Through qPCR analysis, we verified the differential expression of JrMADS genes at different developmental stages (MB-1/2/3 and FB-1/2/3), with JrMADS5, JrMADS8, JrMADS14, JrMADS24, JrMADS40, JrMADS46, JrMADS47, JrGA3ox1, and JrGA3ox3 showing significantly higher expression in male than in female flower buds. In summary, our results provide valuable information for further biological functions research on MIKC-type MADS-box genes in walnut, such as flower organ development, and lays a solid foundation for future studies. Full article

Walnut gluten (WGLU) is a plant-based protein rich in essential amino acids for the human body. Due to its poor water solubility and functional properties, its application in the food industry is limited. For the first time, this study looks into how different durations (0, 30, 60, 90, and 120 s) of atmospheric cold plasma (ACP) treatment affect the structure and functional properties of WGLU. ACP processing destroys the spatial structure of the WGLU and alters its functional properties. The comprehensive performance reached its best after 60 s of ACP treatment, the main manifestations included increased β-sheet content, reduced α-helix content, and unfolding of the tertiary structure, which ultimately improved the stability of emulsification and foam. Meanwhile, the solubility (86.35%), water retention rate (2.15 g/g), oil retention rate (5.31 g/g), emulsification rate (10.59 m²/g), and foaming rate (24.67%) of WGLU reached their maximum values. However, longer treatment times (90 and 120 s) induce WGLU aggregation, followed by decreased functional properties. In summary, the physicochemical and functional properties of WGLU can be significantly enhanced through ACP treatment, enhancing the bioavailability of gluten and providing an effective strategy for its application in food processing. Full article

Background: Epidemiological research has shown that regular walnut (from Juglans regia L.) consumption is associated with a reduced risk of cardiovascular disease (CVD), potentially attributable to their antioxidant and anti-inflammatory properties. The vascular cellular adhesion molecule-1 (VCAM-1), a protein upregulated in CVD, has been previously examined in relation to walnut consumption. However, the clinical findings regarding the effects of walnuts on endothelial function among middle-aged individuals susceptible to metabolic syndrome (MetS) remain inconclusive. Objective: This study examined the effects of daily walnut consumption over a four-week period on cardiometabolic parameters (lipid and glycemic profiles, as well as soluble VCAM-1 levels) and anthropometric measurements in middle-aged individuals with at least one altered MetS parameter and no medication. Methods: In a randomized controlled cross-over trial, 22 eligible Caucasian participants (48.81 ± 4.3 years) were selected and randomly assigned to receive either 45 g of walnuts per day or no walnuts within a controlled diet. There were two 28-day intervention periods, with a one-month washout period in between. Clinical and biochemical evaluations were conducted at the beginning and end of each intervention period. Results: A total of 20 participants completed the intervention and were analyzed, with walnuts being well tolerated. A significant decrease in waist circumference (p = 0.049) and a slight change in fasting blood glucose (p = 0.089) were noted following walnut intake. Conclusions: Short-term (4 weeks) dietary supplementation with walnuts resulted in a statistically significant reduction in waist circumference while not impacting the overall health status of participants. Longer-term studies are necessary to investigate the benefits of daily walnut consumption and its impact on the onset and development of MetS in this age group. Full article

This study aims to explore the effect of pH on the solubility of walnut protein isolate (WPI) across a pH range of 7.0 to 12.0. The findings reveal that WPI solubility increased with rising pH levels, reaching a maximum solubility of 61.13% (4.79 mg/mL) at pH 12.0. Building on these results, WPI was subjected to compound heating at pH 12.0, with temperatures ranging from 60 °C to 100 °C (maintained for 30 min), to evaluate its structural and functional properties. Compared to the control group, WPI solubility peaked at 80.56% when heated to 90 °C. Additionally, its foaming capacity rose to 118.22% ± 7.34, accompanied by improved foaming stability. The average particle size decreased to 151.93 nm, while the surface charge increased to −28.33 mV. The protein subunits progressively aggregated within the range of 20.0 kDa to 14.1 kDa, and the surface hydrophobicity decreased. Scanning electron microscopy revealed that the surface morphology of the WPI became increasingly smooth with rising heating temperatures. Moreover, significant changes were observed in the secondary structure of the WPI. This study underscores the potential of pH-shifted compound heating treatment as a promising processing technique for WPI, offering key insights into the optimization of walnut protein processing. Full article

The application of walnut protein isolate (WPI) and polyphenols is usually limited by low solubility. To solve the above problem, the impact of the alkaline treatment method and the ultrasound-assisted alkaline treatment method on the structural and functional properties of protein–polyphenol covalent complexes (WPI–(–)-epigallocatechin-3-gallate (EGCG), UWPI–EGCG, respectively) was explored. Fourier transform infrared spectroscopy and fluorescence spectroscopy indicated that the covalent binding of EGCG to WPI altered the secondary and tertiary structures of the protein and increased its random coil content. In addition, the UWPI–EGCG samples had the lowest particle size (153.67 nm), the largest absolute zeta potential value (25.4 mV), and the highest polyphenol binding (53.37 ± 0.33 mg/g protein). Meanwhile, WPI–EGCG covalent complexes also possessed excellent solubility and emulsification properties. These findings provide a promising approach for WPI in applications such as functional foods. Full article

Objective: This study aims to investigate the structural and functional characteristics of walnut protein hydrolysates (WPHs) with different molecular weights prepared using protease from Dregea sinensis Hemsl, as well as the anti-fatigue effects of low-molecular-weight walnut protein hydrolysates (LWPs) and their impact on the cecal microbiota and faecal metabolism of mice. Methods: The anti-fatigue activity of WPHs with different molecular weights was evaluated, and the LWPs were analyzed in a centralized manner. A 28-day gavage study was conducted to assess LWP’s anti-fatigue benefits in mice, supplemented by metabolomic analysis to explore its impact on metabolic pathways. Results: Our findings revealed that LWP significantly outperformed unhydrolyzed walnut protein (WP) in terms of water retention, lipid retention, emulsifying properties, and foaming capacity. Notably, differential protein expression associated with LWP highlighted pathways related to antioxidant activity. In vivo studies showed that LWP markedly enhanced glycogen storage in the muscles and liver of mice, while reducing serum levels of serum urea nitrogen, lactate dehydrogenase, blood lactic acid, and creatine kinase. Furthermore, the levels of Superoxide Dismutase and Glutathione were significantly elevated, alongside a reduction in Malondialdehyde, indicating that LWP’s anti-fatigue effect is closely linked to improved oxidative stress resistance. Additionally, LWP promoted beneficial increases in microbial populations such as Akkermansia, Alistipes, Eubacterium, and Muribaculum, which are associated with enhanced fatigue resistance. Metabolomic analysis indicated significant enrichment in glycerophospholipid metabolism and amino acid biosynthesis, identifying key metabolites including palmitoylethanolamide and 4-methyl-5-thiazoleethanol, both of which are integral to health maintenance. Conclusions: LWP demonstrates a robust anti-fatigue effect, supported by its accessibility, straightforward preparation, and eco-friendly characteristics. These attributes suggest that LWP has promising potential for inclusion in health products aimed at enhancing vitality and combating fatigue. Full article

Fermented walnut (FW) meal exhibits antifungal activity against Penicillium victoriae (the fungus responsible for prickly pear spoilage), which is mainly attributed to the synergistic effect of antimicrobial peptides and salicylic acid (SA). This study aimed to investigate the synergistic mechanism between YVVPW (YW-5, the peptide with the highest antifungal activity) and SA against the cell membrane of P. victoriae. Treatment enhanced prickly pear’s rot rate, polyphenol concentration, and superoxide dismutase (SOD) activity by 38.11%, 8.11%, and 48.53%, respectively, while reducing the microbial count by 19.17%. Structural analyses revealed β-sheets as YW-5′s predominant structure (41.18%), which increased to 49.0% during SA interaction. Molecular docking demonstrated YW-5′s stronger binding to β-(1,3)-glucan synthase and membrane protein amino acids via hydrogen bonds, hydrophobic forces, and π-π conjugate interactions. Spectroscopic analyses demonstrated SA’s major role in YW-5 synergy at the interface and polar head region of phospholipids, enhancing lipid chain disorder and the leakage of cell components. Malondialdehyde and SOD levels increased nearly two-fold and six-fold when treated with YW-5/SA, and YW-5 showed a more pronounced effect. Scanning electron and transmission electron microscopy confirmed that SA caused greater damage to spore morphology and cell ultrastructure. These findings support this formulation’s functions as an efficient antifungal substance in fruit storage. Full article

Effective post-exercise recovery is vital for optimizing athletic performance, focusing on muscle repair, glycogen replenishment, rehydration, and inflammation management. This review explores the evolving trend from traditional supplements, such as protein, carbohydrates, creatine, and branched-chain amino acids (BCAAs), toward functional foods rich in bioactive compounds. Evidence highlights the benefits of functional foods like tart cherry juice (anthocyanins), turmeric-seasoned foods, and sources of omega-3 fatty acids, including fish, flaxseeds, chia seeds, and walnuts, for mitigating oxidative stress and inflammation. Additionally, probiotics and prebiotics support gut health and immune function, which are integral to effective recovery. Personalized nutrition, informed by genetic and metabolic profiling, is examined as a promising approach to tailor recovery strategies. A systematic search across PubMed, Web of Science, and Google Scholar (2000–2024) identified studies with high empirical rigor and relevance to recovery outcomes. Findings underscore the need for further research into nutrient interactions, dosage optimization, and long-term effects on athletic performance. Integrating functional foods with personalized nutrition presents a comprehensive framework for enhanced recovery, greater resilience to physical stress, and sustained performance in athletes. Full article

Walnut (Juglans regia L.) possesses the ability to prevent coronary heart disease and promote cardiovascular health. This ability can be attributed to their rich content of polyphenols, particularly flavonoids. The biosynthesis of flavonoids is reliant on the catalytic activity of uridine diphosphate glycosyltransferase (UGT). However, the identification of UGTs in walnut has not been reported. In the current study, a total of 124 UGT genes containing the PSPG box were identified from the walnut genome. Based on phylogenetic analysis, the 124 UGTs could be classified into 16 distinct groups, which exhibited an uneven distribution across the 16 chromosomes. Subcellular localization prediction analysis revealed that approximately 78.23% of walnut UGT proteins were predominantly localized in the cytoplasmic compartment. Furthermore, motif annotation confirmed that motifs 1, 2, and 3 represented conserved structural features within UGT proteins, while interestingly, around 56.5% of walnut UGT members lacked introns. Through the analysis of promoter cis-regulatory elements, it was revealed that JrUGTs are involved in photoresponse, hormonal regulation, and other physiological responses. In conjunction with transcriptome analysis and quantitative expression, approximately 39% of UGT genes in walnut exhibited high expression levels during early fruit development. Correlation analysis between UGT genes’ expression and phenolic content in walnut indicated that JrUGT6, JrUGT38, JrUGT39, JrUGT58, JrUGT69, JrUGT75, and JrUGT82 might be involved in phenolic biosynthesis in walnut. This comprehensive study provides an overview of the UGT genes in walnut, serving as a valuable reference and theoretical foundation for further investigations into the biological functions of JrUGTs in flavonoid biosynthesis. Full article

To enhance the functional properties of walnut protein isolate (WalPI), hydrophilic whey protein isolate (WPI) was selected to formulate WalPI-WPI nanoparticles (nano-WalPI-WPI) via a pH cycling technique. These nano-WalPI-WPI particles were subsequently employed to stabilize high internal phase Pickering emulsions (HIPEs). By adjusting the mass ratio of WalPI to WPI from 9:1 to 1:1, the resultant nano-WalPI-WPI exhibited sizes ranging from 70.98 to 124.57 nm, with a polydispersity index of less than 0.326. When the mass ratio of WalPI to WPI was 7:3, there were significant enhancements in various functional properties: the solubility, denaturation peak temperature, emulsifying activity index, and emulsifying stability index increased by 6.09 times, 0.54 °C, 318.94 m²/g, and 552.95 min, respectively, and the surface hydrophobicity decreased by 59.23%, compared with that of WalPI nanoparticles (nano-WalPI), with the best overall performance. The nano-WalPI-WPI were held together by hydrophobic interactions, hydrogen bonding, and electrostatic forces, which preserved the intact primary structure and improved resistance to structural changes during the neutralization process. The HIPEs stabilized by nano-WalPI-WPI exhibited an average droplet size of less than 30 μm, with droplets uniformly dispersed and maintaining an intact spherical structure, demonstrating superior storage stability. All HIPEs exhibited pseudoplastic behavior with good thixotropic properties. This study provides a theoretical foundation for enhancing the functional properties of hydrophobic proteins and introduces a novel approach for constructing emulsion systems stabilized by composite proteins as emulsifiers. Full article