The transport and absorption of antioxidant peptides are critical for their biological activity. The walnut mealderived peptide YWSPNDEQFR (YR-10) has been shown to alleviate oxidative stress-induced liver injury, but its absorption mechanisms remain unclear. In this study, we employed a Caco-2 monolayer, DPPC liposomes, and molecular docking to characterize the transepithelial transport of YR-10 across the intestinal epithelium. YR-10 was absorbed through clathrin-mediated endocytosis and paracellular pathway, with significantly promotes the restoration of ZO-1 and closure protein gene expression, indicating its ability to restore the integrity of the epithelial barrier. Further research revealed that YR-10 binding to lipid bilayers was predominantly entropydriven, involving electrostatic, hydrogen-bonding, and hydrophobic interactions that regulated membrane fluidity and order. These findings collectively elucidate the intestinal absorption mechanism of YR-10 and provide a theoretical basis for improving the bioavailability of walnut powder-derived bioactive peptides in functional food applications.

The effects of low (4 °C) versus ambient (25 °C) temperature on cell wall turnover, and redox homeostasis in 'Jin'Aofen' figs were investigated. Compared with 25 °C, storage at 4 °C reduced decay and respiration rates, delayed firmness loss and color deterioration. It also suppressed PG, PME and CEL activities, maintained higher contents of protopectin and cellulose; and slowed soluble pectin accumulation. Storage at 4 °C maintained higher activities of SOD, CAT, POD, APX and GR. It also preserved the levels of non-enzymatic antioxidants, including TPC, TFC, ASA GSH. Meanwhile, it reduced H2O2 and O2- production and inhibited MDA. In addition, storage at 4 °C suppressed PPO, thereby alleviating enzymatic browning. Overall, storage at 4 °C maintained postharvest quality of figs by coordinately inhibiting cell wall degradation and regulating antioxidant metabolism.

ETHNOPHARMACOLOGICAL RELEVANCE:Moringa oleifera Lam. is a classic food-medicine plant long used in Ayurvedic practice and widely adopted in modern nutrition. Polysaccharides from M. oleifera (MOPs) are increasingly recognized as key macromolecules underpinning many of its health effects and are being explored for applications in pharmaceuticals, functional foods, and biomaterials. AIM OF THE STUDY:The study aims to provide an updated and comprehensive overview of the extraction, purification, structural characteristics, and biological activities of MOPs. It also seeks to address the gaps in the current knowledge surrounding their structure-activity relationships, safety evaluation, and potential applications in pharmaceutical and nutraceutical fields. MATERIALS AND METHODS:This review systematically evaluates the various extraction techniques for MOPs, including conventional and modern methods, and the impact of purification on the bioactivity of the polysaccharides. Additionally, bibliometric analysis is utilized to identify trends and hotspots in the MOPs research field. RESULTS:The study highlights the diverse extraction strategies, with modern methods like enzyme-assisted extraction showing higher yields and better bioactivity. The polysaccharides are primarily composed of monosaccharides like galactose and arabinose, with molecular weights ranging from 103 to 108 Da. Biological activities including regulation of gut microbiota, anti-inflammatory, antioxidant, and anti-diabetic effects are well-documented. MOPs also show potential for use in drug delivery, animal husbandry, and agricultural applications. Notably, the relationship between the polysaccharides' structural features and their bioactivities is underexplored, offering opportunities for further research. CONCLUSION:The review provides a critical update on the state of MOPs, particularly in relation to their biological properties and potential applications. It emphasizes the need for more research into the structure-activity relationships and safety of these compounds. The review contributes significantly by offering insights into new extraction methods, structural characteristics, and the broad range of applications of MOPs, thus laying the foundation for their future use in functional foods and medicine.

This study integrated deep learning with in vitro and in vivo experiment to optimize the production of antihypertensive peptides from walnut protein. A novel multi-enzyme combination method was developed using large language models (LLMs) for enzyme screening, resulting in walnut protein hydrolysates with superior angiotensin-converting enzyme (ACE) inhibitory activity. The optimized combination (W1) exhibited 77.96 % ACE inhibition rate (0.5 mg/mL), and maintained 74.93 % of its activity after simulated digestion, demonstrating gastrointestinal stability and bioavailability. Additionally, W1 showed excellent antioxidant properties with strong ABTS and DPPH free radical scavenging capabilities. In spontaneously hypertensive rats (SHRs), W1 significantly reduced systolic and diastolic blood pressure, with effects comparable to captopril but demonstrating superior long-term efficacy. W1 also induced significant changes in serum biomarkers, including marked reductions in ACE activity and Angiotensin II (Ang II) levels, increases in bradykinin (BK) and renin levels, enhanced SOD activity, and decreased MDA content, reflecting improvements in antioxidant and vascular protective effects. Moreover, molecular docking analysis identified key peptides (VIRGNARL, PSYQPTPSL, and PQYSNAPQL) that exhibited strong binding affinity with ACE through multiple hydrogen bonds. These findings provide valuable insights into the application of deep learning for optimizing functional peptide production and offer a promising dietary approach for hypertension management.

BACKGROUND:Accurate evaluation of pumpkin seed oxidation is essential for its effective utilization; however, conventional rancidity indicators have limitations during storage. RESULTS:This study employed headspace-solid-phase microextraction-gas chromatography-olfactometry-mass spectrometry and lipidomics to analyze lipids and volatile compounds associated with oxidative rancidity. The results identified 23 differential volatiles, with hexanal (62.61 → 279.49 ng g-1) and pentanol (29.66 → 135.3 ng g-1) showing the most significant changes (variable importance projection > 1). Additionally, 19 lipids related to glycerophospholipid metabolism were significantly down-regulated. Partial least squares regression confirmed a significant correlation between these lipids and peroxide value (P < 0.05), establishing them as markers of rancidity. CONCLUSION:These findings provide new, reliable criteria for the preservation and quality control of pumpkin seeds. © 2025 Society of Chemical Industry.

Using 'Wen 185' paper skin walnuts as the raw material, walnut albumin, globulin, prolamin, and glutelin were separated using a solubility gradient method. The study investigates the effect of oil extraction temperature on their structural characteristics. Infrared spectroscopy was employed to analyze the changes in the secondary structure of proteins, while fluorescence and ultraviolet spectroscopy were used to examine the changes in the tertiary structure. The results from infrared. spectroscopy showed that the secondary structure of albumin was minimally affected by the oil extraction temperature. However. the secondary structure of globulin, prolamin, and gluten underwent significant changes when the extraction temperature reached 130 C-omicron. Additionally, the total content of alpha helix and beta-sheet structures in gluten was lower than in the other three protein components, indicating that its secondary structure stability is weaker than that of the other proteins, Fluorescence spectroscopy results revealed that the maximum fluorescence peak of albumin and globulin shifted to a longer wavelength (red shift) after the oil extraction temperature exceeded 130 C-omicron indicating that their tertiary structure unfolded, exposing more hydrophobic amino acids on the protein surface. The fluorescence peak of prolamin shifted slightly to a shorter wavelength (blue shift) after the extraction temperature exceeded 100 C, suggesting that the hydrophobic amino acids on its surface were buried within the protein molecule. However, when the extraction temperature exceeded 130 (omicron) C , a noticeable red shift occurred, indicating an increase in hydrophobic amino acids on the protein surface. The maximum fluorescence peak of gluten exhibited a red shift within the oil extraction temperature range of 40 to 70(omicron) C indicating that changes in its tertiary structure led to increased exposure of hydrophobic groups. However, when the temperature exceeded 130(omicron)C a blue shift in the fluorescence peak was observed. suggesting a reduction in the exposure of surface hydrophobic groups. This indicates that the tertiary structure of gluten is relatively more unstable compared to the other three types of proteins, Furthermore, the overall fluorescence intensity of albumin and globulin was higher than that of prolamin and gluten, suggesting that albumin and globulin contain more hydrophobic groups than prolamin and gluten. Ultraviolet spectroscopy results showed that all four protein components exhibited a significant UV absorption around 275 nm. As the oil extraction temperature increased, there was little change in the peak intensity of albumin, globulin, prolamin, and gluten, However, the number of UV absorption peaks in albumin and globulin was greater than in prolamin and gluten, suggesting that albumin and globulin contain more exposed hydrophobic amino acid groups, which is consistent with the conclusion drawn from fluorescence spectroscopy that albumin and globulin have more hydrophobic groups on their surfaces. In conclusion, when the oil extraction temperature reaches 130 C-omicron , it significantly affects the structure of albumin, globulin, and prolamin. The structural stability of gluten is relatively low, and at an oil extraction temperature of 70 C, its structure is already noticeably impacted. This study provides useful insights for understanding the effect of oil extraction temperature on walnut protein structure and for the development of walnut cake protein component products.

The oxidative stability of walnut kernels during storage has a significant impact on their industrial development. However, the effect of storage conditions on the oxidation of walnut kernel lipids and its mechanism have not been systematically elucidated. Therefore, in this study, the lipid oxidation process in walnut kernels under different storage conditions (room temperature-air, room temperature-vacuum, low temperature-air, and low temperature-vacuum) was systematically studied from the perspective of phenomena, substances, and mechanisms using HPLC–MS and GC–MS methods. Experimental results found the walnut kernels stored at room temperature in air showed the highest PV (7.78 mmol/kg), conjugated diene (1.29), and hexanal (848.65 ng/g) after a 9-month storage. A total of 597 lipid substances were detected in walnut kernels under the four storage conditions, including 5 classes and 26 subclasses, of which 115 were significantly different. Differential lipid metabolite analyses indicated that storage conditions mainly affected the glycerophospholipid and glycerolipid metabolic pathways of walnut kernels, followed by linoleic acid metabolism. It revealed that temperature, rather than air conditions, played a dominant role in the lipid oxidation of walnut kernels during storage. This experiment could provide a comprehensive understanding of the lipid oxidation of stored walnut kernels and technical support for quality control.

Walnut meal is a large quantity and high-quality resource with great exploitation value. Ultrasonic-assisted enzymolysis (UAE) was utilized in the preparation of peptides from walnut meal protein. Results indicated that by optimizing the UAE process with neutral protease, an ultrasound power of 180 W, a 4.3 h duration and an enzyme dosage of 10 KU/g, the walnut peptides exhibited the most potent antioxidant activity. In comparison to the control group, the WPI treated with ultrasound and neutral enzymes in combination (UNWPI) demonstrated a significant enhancement in their DPPH, ABTS, and & sdot;OH scavenging capabilities, with increases of 234.23 %, 240.22 %, and 69.52 %, respectively. By analyzing the structure of walnut antioxidant peptides with or without ultrasound, it was observed that the underlying mechanism for the increased antioxidant activity was that UAE not only formed more small peptides, but also produced more peptides with hydrophobic amino acids at their terminal ends. Subsequently, six peptides were identified and screened from UNWPI, namely IFW, IIPF, IVAF, IIFY, ILAFF, and IFIP, which exhibited high antioxidant activity and could bind to Keap1 protein through hydrogen bonding, it-alkyl interactions, and it-it stacking interactions. The research results provided theoretical basis and technical support for the preparation of walnut antioxidant peptides and the high-value utilization of walnut meal.

This study investigates the roles of grapevine berry inner necrosis virus (GINV) and grapevine yellow speckle viroid 1 (GYSVd1) in regulating the soluble sugar and organic acid metabolism of grape berries and wine. The contents of soluble sugar and organic acid components and the activity and expression levels of critical enzymes of the soluble sugar acid metabolism pathway were measured in ‘Welschriesling’ grape berries and wine carrying the virus GINV, the viroid GYSVd1, and a mixed infection of both GINV and GYSVd1 (GINV + GYSVd1), respectively. The results show that the virus GINV and the viroid GYSVd1 decreased the soluble sugar and increased the organic acid in berries and wine. GINV decreased glucose content and increased malic acid content by regulating AI, NADP-IDH, PEPC, and NAD-MDH activity, as well as VvHT4, VvSWEET10, VvPEPC, and VvMDH expression levels. GYSVd1 decreased glucose content and increased malic acid content by regulating AI and CS activity and VvHT4, VvSWEET15, and VvPEPC expression. The results suggest that the viroid GYSVd1 negatively impacts berries and wine more than the virus GINV. Moreover, in the mixed infection with GINV + GYSVd1, the negative effects of GINV and GYSVd1 on soluble sugars do not seem to be observed.

Walnut (Juglans regia L.) meal, being the primary by-product of walnut oil processing, is rich in high-quality proteins and of significant potential for development and utilization. The study used multi-stage gradient purification, liquid-quantity chromatography, and computerized virtual screening to isolate and characterize antioxidant peptides from walnut meal. Active sites and mechanism actions of antioxidant peptides were examined using oxidative damage model of HepG2 cells. Five novel peptides exhibiting high antioxidant activity were identified, among which YR-10 significantly increased the cell viability of HepG2 oxidatively damaged cells to 20.64 %. Meanwhile, YR-10 significantly reduced the ROS content to 42.54 % and apoptosis level to 11.80 % in HepG2 oxidatively damaged cells. In addition, YR-10 competed with Nrf2 for Keap1 binding site, inhibited Keap1 (13.83 %) expression, and promoted Nrf2 (27.15 %), HO-1 (34.59 %), and SOD1 (42.67 %) expression, which ultimately activated the Keap1/Nrf2/HO-1 pathway and alleviated oxidative damage.

This study investigated the potential regulatory mechanisms influencing chilling injury in peach fruit under various storage temperatures (0 degrees C and 5 degrees C) and calcium treatments (calcium chloride (CaCl 2 ) and trifluoperazine (TFP)). The results showed that 0 degrees C storage and CaCl 2 treatment activated the expression of PpCAMTA5 , while repressed the expression of PpNAC25 , PpPAO , PpRBOHA , PpRBOHC , and PpRBOHD , and reduced hydrogen peroxide (H 2 O 2 ) content. This concerted regulation effectively suppressed chilling-induced browning in peach fruit during cold storage. However, the opposite effects were presented in TFP-treated fruit. Additionally, the interaction between PpCaM7 and PpCAMTA5 inhibited PpNAC25-mediated transcriptional activation of PpPAO , PpRBOHA , PpRBOHC , and PpRBOHD . Thus, these results suggested that the PpCaM7-PpCAMTA5 complex mitigates chilling injury in peach fruit via inhibiting reactive oxygen species (ROS) production.

The study investigated the lipid oxidation of pumpkin seed kernels (PSK) under different storage conditions (room temperature, vacuum-room temperature, refrigeration, and vacuum-refrigeration) using HPLC-MS and GC-MS. Experimental results found the vacuum-refrigeration group showed the lowest PV (0.24 g/100 g), diene (8.68), hexanal (356.64 ± 16.06 ng/g), and nonanal (132.05 ± 8.38 ng/g) after a 9-month storage. A total of 586 lipids, including 6 classes and 27 subclasses, were detected, 46 of which showed significant differences. Refrigeration samples had the highest diacylglycerol content, while room temperature samples demonstrated the highest triacylglycerol and phosphatidylcholine content. Differential lipid metabolite analyses indicated that storage conditions mainly affected glycerolipid metabolism, glycerophospholipid metabolism, and sphingolipid metabolism pathways in PSK, while glycerolipid and glycerophospholipid metabolism were still dominant. It revealed that refrigeration was more effective than vacuum in inhibiting the oxidation of PSK. These findings could offer valuable references for the storage, transportation, preservation, and the development and utilization of PSK.

Walnut kernels are prone to oxidation and rancidity due to their rich lipid composition, but the existing evaluation indicators are not sensitive enough to promote their industrial development. This study aims to investigate the potential markers in oxidative rancidity walnut kernels using lipidomics and volatolomics. The results showed that the antioxidant capacity of walnut kernels significantly decreased after oxidation, with the decreasing of total phenolic content from 36276.34 mg GAE/kg to 31281.53 mg GAE/kg, the DPPH and ABTS free radical scavenging activity from 89.25% to 73.54%, and 61.69% to 43.73%, respectively. The activities of lipoxygenase (LOX) and lipase (LPS) increased by 6.08-fold and 0.33-fold, respectively. By combining volatolomics and chemometrics methods, it was found that significant differences existed in the content of hexanal, caproic acid, 1-pentanol, (E)-2-octenal, and 2-heptanenal before and after walnut kernel oxidation (VIP > 1). Based on the results of lipidomics, it can be concluded that the above five compounds can serve as characteristic markers for walnut kernel oxidative rancidity, mainly produced through glycerol phospholipid (GPL), glyceride, linoleic acid (LA), and α-linolenic acid (ALA) metabolism pathways. Possible mechanisms of lipid degradation in oxidized walnut kernels were also proposed, providing technical support for the storage, preservation, and high-value utilization of walnut kernels.

The demand for plant protein is increasing significantly due to the shortage of protein resources. Walnut protein, the main by-product of preparing walnut oil, has limited application in the food industry due to its poor solubility. It was found that the soy protein isolate (SPI) concentration had significant effects on the gel properties of the walnut protein isolate (WNPI)-kappa-Carrageenan (KC) composite system treated with 15 mmol/L NaCl. The results showed that the gel strength of the composite system increased first and then decreased with the increased concentration of SPI from 0 to 2.5%. The best rheological properties, texture properties, water holding capacity ((92.03 +/- 1.05)%), swelling ratio ((2.04 +/- 0.19)%), freeze-thaw stability and thermal stability (85.53 degrees C) of the composite gel were found at an SPI concentration of 1%. In the meantime, the secondary structure of protein had the least alpha-helix content of 10.17% and the highest beta-sheet content of 39.64%, the fluorescence intensity and free sulfhydryl content reached the highest value. 1% SPI could also act as a filler for WNPI to enhance the intermolecular forces such as hydrophobic interaction between the two substances, thus forming a stable gel network structure. This study can provide technical support for improving the gel properties of walnut protein and producing new plant protein gel products.

Sesquiterpene valencene is dominant in flavedo tissues of sweet oranges and imparts a unique woody aroma. However, the interaction between the biosynthetic pathways of valencene and other nutritional compounds is less studied. Sesquiterpenoids were significantly accumulated in a previously reported glossy mutant of orange (MT) than the wild type (WT), especially valencene and caryophyllene. In addition, we identified several other pathways with variations at both the transcriptional and metabolic levels in MT. It's interesting to found those up-regulated metabolites in MT, such as eukaryotic lipids, kaempferol and proline also showed strong positive correlation with valencene along with fruit maturation while those down-regulated metabolites, such as phenylpropanoid coumarins and most of the modified flavonoids exhibited negative correlation. We then categorized these shifted pathways into the 'sesquitepenoid-identical shunt' and the sesquitepenoid-opposite shunt' and confirmed the classification result at transcriptional level. Our results provide important insights into the connections between various fruit quality-related properties.

Fresh walnut kernel (FW) and dry walnut kernel (DW) are significantly different in antioxidant activity. However, the metabolomic mechanism underlying these differences remains to be explored. Here, we evaluated the antioxidant activities of FW and DW of four walnut varieties, and characterized their metabolites by GC-MS and LC-MS/MS. The influence of different metabolites on antioxidant activity of walnut kernel was investigated through a multivariate analysis. DW showed significantly higher antioxidant activities than FW. A total of 144 metabolites were detected in all samples. Pearson correlation analysis demonstrated that phenolic metabolites and polyunsaturated fatty acids significantly affect the antioxidant activity. A further network analysis of 21 target differential metabolites indicated that the higher antioxidant activity of DW may be mainly attributed to the higher content of phenolic acid polymers. This study reveals the potential mechanism for improving of antioxidant activity of walnut kernels by drying.

Walnut is considered as a good source of antioxidants. However, the molecular mechanism for the composition and accumulation of antioxidant-related metabolites in walnut remains elusive. In this study, a comprehensive transcriptomic and metabolomic analysis was carried to reveal the metabolic dynamics, antioxidant activity variations and underlying regulatory networks during the development of walnut kernel. The results demonstrated that walnut kernel goes through the stages of cell division and proliferation, nutrient accumulation, and nutrient stabilization and maintenance, and the antioxidant activity first decreases and then increases during development. Metabolomic analysis identified a total of 176 metabolites in walnut. Hydrolyzed tannins (HT), coumarins and their derivatives (COA) are significantly positively correlated with the antioxidant activity. Phenylpropane metabolism is the key pathway for HT and COA synthesis, and CHI, CHS, F3H and UGT are the key regulatory enzymes. Sugars and organic acids provide energy and precursor for the accumulation of nutrients in walnut kernel through sugar metabolism and the tricarboxylic acid cycle (TCA). Large amounts of amino acids are accumulated at the nutrient accumulation stage, providing precursors for the formation of proteins and flavonoids during the ripening of walnut. Our results provide new insights into the metabolic regulation of antioxidant activity during walnut ripening.