Bioactive properties and chemical composition of six walnut (Juglans regia L.) cultivars

Screening and Characterization of Antioxidant Film Applicable to Walnut Kernels from Juglans sigillata

Walnuts play a positive role in human health due to their large amounts of unsaturated fatty acids, whereas lipid oxidation can easily occur during storage. Herein, three natural antioxidants (epicatechin, sesamol, and myricetin) were added to the composite film cross-linked with chitosan and soy protein peptide, and the antioxidant film appropriate for the preservation of walnut kernels from Juglans sigillata was screened to improve the storage quality of walnuts. The results showed that three antioxidant films could all enhance the storage performance of walnut kernels, with sesamol being the best. The characterization of antioxidant film cross-linked with chitosan and soy protein peptide containing sesamol (C/S-ses film) revealed that the composite film improved the slow release and stability of sesamol; in addition, the presence of sesamol could effectively reduce the light transmittance and water vapor permeability of the composite film, together with significantly enhancing the antioxidant and antimicrobial activities, resulting in an effective prolongation of the storage period of walnut kernels. These findings indicated that C/S-ses possess excellent potential for retarding the oxidative rancidity of unsaturated fatty acids and will provide an effective strategy for the preservation of walnut kernels.

Exploring the Ecological Implications, Gastronomic Applications, and Nutritional and Therapeutic Potential of Juglans regia L. (Green Walnut): A Comprehensive Review

The green walnut, which is frequently overlooked in favor of its more mature sibling, is becoming a topic of great significance because of its unique ecological role, culinary flexibility, and therapeutic richness. The investigation of the bioactive substances found in green walnuts and their possible effects on human health has therapeutic potential. Juglans regia L. is an important ecological component that affects soil health, biodiversity, and the overall ecological dynamic in habitats. Comprehending and recording these consequences are essential for environmental management and sustainable land-use strategies. Regarding cuisine, while black walnuts are frequently the main attraction, green walnuts have distinct tastes and textures that are used in a variety of dishes. Culinary innovation and the preservation of cultural food heritage depend on the understanding and exploration of these gastronomic characteristics. Omega-3 fatty acids, antioxidants, vitamins, and minerals are abundant in green walnuts, which have a comprehensive nutritional profile. Walnuts possess a wide range of pharmacological properties, including antioxidant, antibacterial, antiviral, anticancer, anti-inflammatory, and cognitive-function-enhancing properties. Consuming green walnuts as part of one's diet helps with antioxidant defense, cardiovascular health, and general well-being. Juglans regia L., with its distinctive flavor and texture combination, is not only a delicious food but also supports sustainable nutrition practices. This review explores the nutritional and pharmacological properties of green walnuts, which can be further used for studies in various food and pharmaceutical applications.

Specific Antimicrobial Activities Revealed by Comparative Evaluation of Selected Gemmotherapy Extracts

Nowadays, unprecedented health challenges are urging novel solutions to address antimicrobial resistance as multidrug-resistant strains of bacteria, yeasts and moulds are emerging. Such microorganisms can cause food and feed spoilage, food poisoning and even more severe diseases, resulting in human death. In order to overcome this phenomenon, it is essential to identify novel antimicrobials that are naturally occurring, biologically effective and increasingly safe for human use. The development of gemmotherapy extracts (GTEs) using plant parts such as buds and young shoots has emerged as a novel approach to treat/prevent human conditions due to their associated antidiabetic, anti-inflammatory and/or antimicrobial properties that all require careful evaluations. Seven GTEs obtained from plant species like the olive (Olea europaea L.), almond (Prunus amygdalus L.), black mulberry (Morus nigra L.), walnut (Juglans regia L.), blackberry (Rubus fruticosus L.), blackcurrant (Ribes nigrum L.) and bilberry (Vaccinium myrtillus L.) were tested for their antimicrobial efficiency via agar diffusion and microbroth dilution methods. The antimicrobial activity was assessed for eight bacterial (Bacillus cereus, Staphylococcus aureus, Salmonella enterica subsp. enterica, Proteus vulgaris, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Listeria monocytogenes), five moulds (Aspergillus flavus, Aspergillus niger, Aspergillus ochraceus, Penicillium citrinum, Penicillium expansum) and one yeast strain (Saccharomyces cerevisiae). The agar diffusion method revealed the blackberry GTE as the most effective since it inhibited the growth of three bacterial, four moulds and one yeast species, having considered the total number of affected microorganism species. Next to the blackberry, the olive GTE appeared to be the second most efficient, suppressing five bacterial strains but no moulds or yeasts. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were then determined for each GTE and the microorganisms tested. Noticeably, the olive GTE appeared to feature the strongest bacteriostatic and bactericidal outcome, displaying specificity for S. aureus, E. faecalis and L. monocytogenes. The other GTEs, such as blueberry, walnut, black mulberry and almond (the list indicates relative strength), were more effective at suppressing microbial growth than inducing microbial death. However, some species specificities were also evident, while the blackcurrant GTE had no significant antimicrobial activity. Having seen the antimicrobial properties of the analysed GTEs, especially the olive and black mulberry GTEs, these could be envisioned as potential antimicrobials that might enhance antibiotic therapies efficiency, while the blackberry GTE would act as an antifungal agent. Some of the GTE mixtures analysed have shown interesting antimicrobial synergies, and all the antimicrobial effects observed argue for extending these studies to include pathological microorganisms.

Maternal diet supplemented with African walnuts enhances cortico-hippocampal gene expression and histomorphology in rat offspring

BACKGROUND

The brain is built up during pregnancy. How it functions afterwards depends on how the expectant mother's diet nourishes it. Walnuts contain significant quantities of polyunsaturated fatty acids (PUFAs) and bioactive phytochemicals, which enhance brain health and function even with advancing age. This study examined the effects of a walnut-enriched diet (WED) on corticohippocampal histoarchitecture and gene expression in rat offspring.

MATERIALS AND METHODS

Twenty-eight female adult Wistar rats (n= 7) averaging about 185 g in weight were used for this study. After mating, pregnant dams were split randomly into four groups: A (standard rat chow/control), B (WED from GD 0 - PND 21), C (WED from GD 0 - PND 1), D (WED from PND 1 - PND 21). Offspring of dams were sacrificed at adolescence (PND 35), with brain tissues of interest harvested for subsequent analyses.

RESULTS

We observed no significant correlates in litter size, body, and brain weights across the experimental groups. Histomorphology revealed no distortion in cellular layering and delineation of cells in the PFC and dentate gyrus of both control and WED groups. Nissl staining intensity was enhanced in the offspring of dams exposed to WED versus the control, indicating improved proteostasis. Upregulated mRNA expression of DNMT3a, H2Ax, OPA1, and BDNF was observed in cortical and hippocampal tissues of WEDexposed offspring compared with the control group.

CONCLUSION

A diet enriched with African walnuts during early development induced changes predictive of cognitive improvements and enhanced stress-response signalling, plasticity, and neural resilience in rat offspring.

Walnut By-Products and Elderberry Extracts-Sustainable Alternatives for Human and Plant Health

A current alternative for sustainable development through green chemistry is the replacement of synthetic compounds with natural ones through the superior capitalization of natural resources, with numerous applications in different fields. The benefits of walnuts (Juglans regia L.) and elderberries (Sambucus nigra L.) have been known since ancient times, due to the presence of phytochemicals such as flavonoids, polyphenols, carotenoids, alkaloids, nitrogen-containing compounds, tannins, steroids, anthocyanins, etc. These active compounds have multiple biological activities for human health, including benefits that are antibacterial, antioxidant, anti-inflammatory, antidiabetic, hepatoprotective, antihypertensive, neuroprotective, etc. Like other medicinal plants, the walnut and the elderberry possess important phytosanitary properties (antibacterial, antifungal, and insecticidal) and their extracts can also be used as environmentally safe biopesticides, with the result that they constitute a viable and cheap alternative to environmentally harmful synthetic products. During recent years, walnut by-products and elderberries have attracted the attention of researchers, and investigations have focused on the species' valuable constituents and active properties. Comparing the information from the literature regarding the phytochemical profile and biological activities, it is highlighted that, apart from the predominant specific compounds, the walnut and the elderberry have common bioactive compounds, which come from six classes (phenols and derivatives, flavonoids, hydroxycinnamic acids, tannins, triterpenoids, and phytosteroids), and act on the same microorganisms. From this perspective, the aim of this review is to provide an overview of the bioactive compounds present in the different constitutive parts of walnut by-products and elderberries, which present a specific or common activity related to human health and the protection of agricultural crops in the context of sustainable development.

Avicenna's pharmacopeia for the treatment of animal bites

Envenomation is a common medical problem. The Canon of Medicine written by Avicenna is one of the reliable sources of Persian medicine. The present study aims to identify Avicenna's clinical pharmacology approach and the pharmacopeia used for the treatment of animal envenomations and also to evaluate the related data in light of the current medicine. The Canon of Medicine was searched using related Arabic keywords for the contents about the treatment of animal bites. A literature search was conducted in scientific databases including PubMed, Scopus, Google Scholar, and Web of Science to obtain relevant data. Avicenna recommended one hundred and eleven medicinal plants for the treatment of bites of vertebrate and invertebrate venomous animals including snakes, scorpions, spiders, wasps, and centipedes. He mentioned different methods of administrating these drugs including oral drugs, lotions, sprayed drugs, slow-dissolving tablets in the mouth, and enemas. Moreover, he paid special attention to pain relief in addition to specific treatments for animal bites. In the Canon of Medicine, Avicenna recommended several medicinal plants alongside analgesics for the management and treatment of animal envenomations. The current research elucidates the clinical pharmacology and pharmacopeia of Avicenna for the treatment of animal envenomations. Further research is encouraged to evaluate the efficacy of these therapeutic agents for the treatment of animal bites.

Is apomixis occurring in walnut (Juglans regia L.)? New data from progeny molecular tests and cytological investigations shed light on its reproductive system

Introduction

Persian walnut (Juglans regia) is an economically important nut fruit species cultivated worldwide for its nutritious kernel and timber quality wood. Walnut trees are mostly hetero-dichogamous and, depending on the genotype, some cultivars are protogynous, while others are protandrous. Although selfing is possible when male and female blooms overlap, the dichogamy of the species promotes outcrossing. In addition to sexual reproduction, some reports indicate that elements of apomixis may occur in commercial orchards of walnut varieties and in the last two decades, nut production by apomixis has been reported in walnut. However, there are no reliable studies on the occurrence of apomictic reproduction based on cytoembryological observations and/or molecular marker-progeny tests. This study addresses the combined use of molecular and cytological analyses to gain new insights into the population genetics and reproduction systems of J. regia.

Methods

We systematically analyzed the reproductive origin of individual progeny plants from 8 different cultivated walnut genotypes using microsatellite genotyping and carried out cytohistological investigations of 5 cultivated walnut genotypes arising seed sets from isolated flowers, to shed light on the mode of reproduction.

Results and discussion

These cytometric and genotyping analyses did not support any asexual mode of reproduction or asexual propagation by seed and all individuals studied were identified as zygotic plants produced by crossing. Likewise, the cytological findings did not confirm completely the first component of apomixis, namely apomeiosis. On the other hand, according to histological evidence, adventitious embryony seems to take place at low frequency. Overall, our findings suggest that the occurrence of gametophytic apomixis is unlikely in J. regia, but sporophytic apomixis cannot be completely ruled out.

Influence of Hazelnut and Walnut Oil Cakes Powder on Thermal and Rheological Properties of Wheat Flour

The aim of the study was to assess the influence of the addition of powdery hazelnut oil cakes (HOC) or walnut oil cakes (WOC) to wheat flour (WF) on its selected thermal and rheological properties. In the research material, part of the wheat flour (5%, 10%, 15%) was substituted with powdery oil cakes based on hazelnuts and walnuts. The control sample was wheat flour (100% WF). In the tested systems with the addition of hazelnut oil cakes (WFHOC) and walnuts (WFWOC), the characteristics of the gelatinization and retrogradation processes were determined using the DSC method, the gelatinization characteristics of 10% pastes using the RVA method, flow curves and viscosity curves, as well as mechanical spectra. Based on the results obtained, it was found that the type of oil cakes and the level of their addition significantly influenced the thermal and rheological properties of the tested systems. Partial replacement of wheat flour with HOC or WOC significantly influenced most DSC parameters. The highest values of gelatinization enthalpy ∆HG and retrogradation ∆HR were characteristic of the WFWOC5% sample (5.9 J/g) and the control sample (1.3 J/g), respectively. All tested systems showed the properties of shear-thinning non-Newtonian fluids, and the partial replacement of wheat flour with HOC or WOC resulted in a significant reduction in the maximum viscosity of pastes, increasing with the increase in the proportion of oil cakes. WFHOC-based pastes were characterized by higher values of the G' and G″ modulus, while their values and the values of the K' and K″ parameters decreased as the share of oil cakes increased. Gels based on all tested systems showed the nature of weak gels (tan δ = G″/G' > 0.1). Replacing part of the wheat flour with nut oil cakes modified the thermal and rheological properties of pastes and gels, and the observed changes were influenced by both the origin and the level of addition of powdered oil cakes. It was found that WFHOC/WFWOC15% systems had reduced viscosity and weakened viscoelastic properties compared to systems with a lower OC content, which is not a favorable feature from the technological point of view. However, these systems were the most stable, which is an advantageous feature. However, for baking purposes, research should be carried out on the rheological properties of dough made from these mixtures.

Exploring the phenolic profile, antibacterial, and antioxidant properties of walnut leaves (Juglans regia L.)

The aim of this study was to identify phenolic compounds in walnut leaves from northern Iraq and evaluate their ability to act as antibacterial and antioxidant agents. Phenolic compounds were determined by reversed-phase HPLC. Antibacterial activity was tested against various bacteria. Antioxidant properties were evaluated by various assays, including reducing power and DPPH radical scavenging activity. The HPLC profiles of walnut leaf fractions revealed quercetin, hydroquinone, 4-hydroxybenzoic acid, and caffeic acid in three fractions. The inhibitory activity of DPPH was determined as 47.66, 32.41, and 51.90 μg/mL for fractions I, II, and III, respectively. For ferric reducing power activity, fraction II > fraction III > fraction I and the FRAP activity was observed as 64.43, 73.19, and 68.18 μg/mL for fractions I, II, and III, respectively. All extracted fractions had antibacterial properties against all bacterial strains tested. Observations showed that fraction I was able to produce similar zones of inhibition as streptomycin in most cases. These results suggest that the fractions of this plant extract are plausible natural antioxidants that could be used as prime candidates for the synthesis of antioxidant drugs that can be used for the treatment of many oxidative stress-related diseases.

Research Progress on the Preparation and Function of Antioxidant Peptides from Walnuts

Food-derived peptides have good antioxidant activity and are highly safe for humans; consequently, there has been continuous growth in research on antioxidants, with potential applications in food, medicine, cosmetics, and other fields. Among food-derived peptides, walnut-derived peptides have attracted increasing attention as food-derived peptides rich in eight essential amino acids. This review summarizes the progress made in the development and identification of antioxidant peptides in walnut proteins. This article mainly describes the interaction between reactive oxygen species and cellular antioxidant products, modulation of enzyme content and activity, and regulation of the redox signaling pathways and analyzes the mechanisms of reduction in oxidative stress. Finally, the complex structure-activity relationships of walnut-derived peptides are analyzed based on their amino acid composition and secondary structure of the polypeptides. This review provides a theoretical basis for the production of walnut-derived antioxidant peptides and could help promote the development of the walnut industry.

Medicinal Plants of the Flora of Kazakhstan Used in the Treatment of Skin Diseases

The skin shows the physiological condition of the body's organs and systems that prevent infections and physical damage. Throughout the ages, in folk medicine, phytotherapy was considered a primary form of treatment in all countries, including Kazakhstan, due to the abundance and availability of plant-based remedies. This paper discusses several medicinal plants that are traditionally used in the treatment of skin diseases in the Republic of Kazakhstan. The chemical composition of these plants was analyzed, with a particular focus on the biologically active basic compounds responsible for their therapeutic efficiency in treating skin ailments.

Natural antioxidants from some fruits, seeds, foods, natural products, and associated health benefits: An update

Antioxidants are compounds that inhibit the oxidation of other molecules and protect the body from the effects of free radicals, produced either by normal cell metabolism or as an effect of pollution and exposure to other external factors and are responsible for premature aging and play a role in cardiovascular disease. degenerative diseases such as cataracts, Alzheimer's disease, and cancer. While many antioxidants are found in nature, others are obtained in synthetic form and reduce oxidative stress in organisms. This review highlights the pharmacological relevance of antioxidants in fruits, plants, and other natural sources and their beneficial effect on human health through the analysis and in-depth discussion of studies that included phytochemistry and their pharmacological effects. The information obtained for this review was collected from several scientific databases (ScienceDirect, TRIP database, PubMed/Medline, Scopus, Web of Science), professional websites, and traditional medicine books. Current pharmacological studies and evidence have shown that the various natural antioxidants present in some fruits, seeds, foods, and natural products have different health-promoting effects. Adopting functional foods with high antioxidant potential will improve the effective and affordable management of free radical diseases while avoiding the toxicities and unwanted side effects caused by conventional medication.

Composition of Nuts and Their Potential Health Benefits-An Overview

The possibility that nut intake may defend human health is an interesting point of view and has been investigated worldwide. Consequently, nuts are commonly promoted as healthy. In recent decades, the number of investigations proposing a correlation between nut consumption and a decrease in the risk of key chronic diseases has continued to increase. Nuts are a source of intake of fiber, and dietary fiber is associated with a reduced occurrence of obesity and cardiovascular diseases. Nuts likewise provide minerals and vitamins to the diet and supply phytochemicals that function as antioxidant, anti-inflammatory, and phytoestrogens agents and other protective mechanisms. Therefore, the main goal of this overview is to summarize current information and to describe the utmost new investigation concerning the health benefits of certain nuts.

Chemical Profiling, Bioactive Properties, and Anticancer and Antimicrobial Potential of Juglans regia L. Leaves

The aim of this study was to assess the biological potential of the polyphenolic fraction isolated from J. regia leaves, collected in the Subcarpathian region (Poland). The phenolic profile was determined using the UPLC-PDA-MS/MS method. Biological activity was determined by evaluating the antioxidant, anticancer, antibacterial, and antifungal effects. Prior to this study, the purified polyphenolic fraction was not been tested in this regard. A total of 40 phenolic compounds (104.28 mg/g dw) were identified, with quercetin 3-O-glucoside and quercetin pentosides dominating. The preparation was characterized by a high ability to chelate iron ions and capture O₂^•- and OH^• radicals (reaching IC₅₀ values of 388.61, 67.78 and 193.29 µg/mL, respectively). As for the anticancer activity, among the six tested cell lines, the preparation reduced the viability of the DLD-1, Caco-2, and MCF-7 lines the most, while in the antibacterial activity, among the seven tested strains, the highest susceptibility has been demonstrated against K. pneumoniae, S. pyogenes, and S. aureus. Depending on the needs, such a preparation can be widely used in the design of functional food and/or the cosmetics industry.

Juglans regia Linn.: A Natural Repository of Vital Phytochemical and Pharmacological Compounds

Juglans regia Linn. is a valuable medicinal plant that possesses the therapeutic potential to treat a wide range of diseases in humans. It has been known to have significant nutritional and curative properties since ancient times, and almost all parts of this plant have been utilized to cure numerous fungal and bacterial disorders. The separation and identification of the active ingredients in J. regia as well as the testing of those active compounds for pharmacological properties are currently of great interest. Recently, the naphthoquinones extracted from walnut have been observed to inhibit the enzymes essential for viral protein synthesis in the SARS-CoV-2. Anticancer characteristics have been observed in the synthetic triazole analogue derivatives of juglone, and the unique modifications in the parent derivative of juglone have paved the way for further synthetic research in this area. Though there are some research articles available on the pharmacological importance of J. regia, a comprehensive review article to summarize these findings is still required. The current review, therefore, abridges the most recent scientific findings about antimicrobial, antioxidant, anti-fungal, and anticancer properties of various discovered and separated chemical compounds from different solvents and different parts of J. regia.

Roasting treatments affect oil extraction rate, fatty acids, oxidative stability, antioxidant activity, and flavor of walnut oil

Introduction

The quality of pressed walnut oil can be improved by moderate roasting treatment.

Methods

This study compared physicochemical characteristics and antioxidant ability of walnut oils pressed from differently roasted pretreated walnuts, analyzed the correlation among these indicators by using Pearson correlation coefficient and correlation coefficient heatmap, and evaluated the volatile organic compounds (VOCs) of walnut oil under optimal pretreatment roasting conditions using headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS).

Results

Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were able to remarkably distinguish walnut oil produced by different roasting processes. In addition, correlation analysis showed that there was a significant impact among indicators. There were 73 VOCs were identified in the optimum roasted treated walnut oil, consisting of 30 aldehydes, 13 alcohols, 11 ketones, 10 esters, 5 acids, 2 oxygen-containing heterocycles, 1 nitrogen-containing heterocycle and 1 other compound. GC-IMS results showed that aldehydes contributed significantly to the volatile flavor profile of walnut oil, especially (E)-2-heptenal, (E)-2-pentenal and hexenal.

Discussion

The properties of walnut oil based on varying roasting pretreatment of walnut kernels were significantly differentiated. Roasting at 120°C for 20 min is a suitable pretreatment roasting condition for pressing walnut oil. Roasting at 120°C for 20 min is a suitable pretreatment roasting condition for pressing walnut oil.

Fate of foodborne pathogens during soaking and drying of walnuts

Walnuts are among the most popular tree nuts that are soaked at home. Recipes for preparing soaked walnut kernels from online blogs (n = 71) and YouTube videos (n = 29) were reviewed to identify typical consumer handling practices that were then used to determine the fate of foodborne pathogens during soaking and subsequent drying of walnut kernels. Individual five-strain cocktails of rifampin-resistant Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella, grown on agar plates and diluted in water, were inoculated onto walnuts and then dried. Inoculated walnuts were added to sterile water at a ratio of 1:4 (w/v), held at 15, 18, or 22°C for up to 24 h, and then dried at 64°C for up to 24 h (for Salmonella-inoculated walnuts). Pathogen populations during soaking and drying were enumerated on tryptic soy agar with rifampin and on CHROM agar. Initial walnut moisture was ∼4%, increased to ∼30% at 8 and 24 h of soaking and then decreased during drying to ∼4% at 6 h and <1% after 24 h. Initial E. coli, L. monocytogenes, and Salmonella populations were ∼1.0, ∼1.5, and 1.0-2.5 log CFU/g, respectively, after inoculation and drying. No significant (P > 0.05) increase in populations was observed after 24 h at 15 and 18°C or after 12 h at 22°C. Significant increases of 1.9-3.0, 1.2-2.1, and 1.8 log CFU/g for E. coli, L. monocytogenes, and Salmonella, respectively, were observed after 24 h of soaking at 22°C. Growth rates of 0.19, 0.093, and 0.16 log CFU/sample per h, respectively, were observed. Lag times of 8.8 and 11 h at 22°C were determined for E. coli and Salmonella, respectively. Populations of Salmonella declined by 1.04 log CFU/g over 12 h of drying; further significant (P < 0.05) decreases were not observed at 24 h. To limit food safety risks in soaked walnuts, educational materials should emphasize sourcing treated walnuts, kitchen sanitation, hygiene measures, and soaking at cooler temperatures or for shorter times at ambient temperatures.

THE WALNUT - CONSTRAINTS AND ADVANTAGES FOR A SUSTAINABLE DEVELOPMENT

The Persian walnut or English walnut (Juglans regia L.) is a commonly grown species for nut production and noble wood. The nut is one of the oldest food and traditional medicine sources. The native and commercial walnut genotypes present a large diversity that differ widely in nut productivity and quality. However, genetic erosion poses a serious threat to this tree. Several researches of walnut genetic diversity are being carried out utilizing morphological, biochemical, and molecular approaches in order to select superior walnut cultivars of different agroclimatic areas to increase nut production and quality. Genetic resource evaluation and agrodiversity conservation have a major role in ensuring food security for future generations through a continuous supply of new rootstocks and improved cultivars.

Quality Aspects of Designing Prohealth Liver Sausages Enriched with Walnut Paste

The aim of the study was to determine the influence of enriching liver sausages with different levels of walnut paste on the quality properties of this product. Sausages were produced with 5, 10, 15, 20, and 25% amount additions of walnut paste and without the addition of nuts (control product). It was found that walnut paste, especially when introduced at an amount >15%, was a component that limited thermal losses and significantly modified the characteristics of liver sausages. The addition of walnut paste also increased the fat content of liver sausages by two−three times, which was one of the factors that weakened their structure, including lowering their compression, shear, and penetration force but increasing their spreadability. Moreover, the addition of walnut paste at an amount of ≥20% resulted in the products having a slightly different color, with lower values for the a* color parameter. Such changes were assessed as a favorable modification to the product, increasing its overall desirability, especially with the addition of walnut paste at the level of 20%. Walnut paste can therefore be a valuable ingredient that allows for the development of a health-promoting product with improved quality features. However, with the addition of a walnut paste at an amount of 25%, it is necessary to take into account the more rapid and unfavorable fat changes that occur during the storage of the liver sausages, as indicated by about 50% higher TBARS values (compared to the control product).

Research progress on Walnut oil: Bioactive compounds, health benefits, extraction methods, and medicinal uses

Walnut oil is extracted from walnut kernels (Juglans regia Linne) or iron walnut kernels (Juhlans sigillata Dode). The percentage of oil in walnuts is 52%-70%. The main constituents in oil are fatty acids, phenols, sterols, squalene, melatonin, vitamins, and minerals. Many extraction methods such as supercritical carbon dioxide extraction, maceration, modified "bligh and dyer extraction," aqueous enzymatic extraction, ultrasonic extraction, soxhlet extraction, and cold-press extraction methods are reported in the literature. Walnut oil showed anti-inflammatory, antitumor, antioxidant, immunomodulatory, neuroprotective, cardioprotective, antidiabetic, and antihyperlipidemic activities. The reported data in the literature suggest that walnut oil has many health benefits. This review summarizes the extraction methods, bioactive constituents, health benefits, and pharmacological actions of walnut oil. PRACTICAL APPLICATIONS: Walnut oil is a natural vegetable oil of significant importance due to their nutritional, and intelligence-boosting benefits. Several factors, including the processing parameters and the phytochemical profile, affect walnut oil products' flavor and color. In addition, storage environment of walnut oil can also affect walnut oil quality. Apart from the predominant ingredient fatty acids, the chemical composition of walnut oil comprises phenols, sterols, squalene, melatonin, vitamins, and minerals. These bioactive compounds are of potential value owing to their health-promoting benefits, including antioxidant, antitumor, and cholesterol-lowering effects. Many chemical constituents were isolated from walnut oil; however, all the compounds are not explored for their possible medicinal value. Thus, clinical studies, exploration of the therapeutic potential and the molecular mechanisms of all the compounds, and development of convenient dosage forms either for therapeutic or functional food purposes are warranted.

Twin-Screw Extrusion as Hydrothermal Technology for the Development of Gluten-Free Teff Flours: Effect on Antioxidant, Glycaemic Index and Techno-Functional Properties

Gluten-free products (GFP) currently are the fastest-growing category of baked goods probably due to the high worldwide incidence of celiac disease (CD). Refined rice is one of the most used cereal flour for GFP development, due to its high content in starch and good technological aptitude. However, its low content in fibre, protein and minerals has awakened a recent interest as alternative to balance the GF flour formulas. Teff is a cereal with high levels in fibre and antioxidants compounds but the lack of gluten results in very limited techno-functional properties. Extrusion is a thermal technology that allows to combine flours, overcoming negative impacts on quality characteristics. This study evaluated the effect of twin-screw extruder on rice-teff (white and brown) mixtures with different teff concentrations (25, 50 and 75%) on their antioxidant, glycaemic index and techno-functional properties. The results showed than the high shear−temperature process produced important modifications on the flour, which were confirmed using scanning electron microscopy (SEM). Significant increases in total dietary fibre (16 to 100% increase) were observed in teff containing flours, due to carbohydrate−lipid−protein complexes, which lead to resistant starch, with no significant increase in rice flour. Hydration and pasting properties were significantly (p > 0.05) affected by extrusion, and the effect was related to the concentration of teff used. The thermal process showed a decrease in total phenol (TP) content for rice; however, extrusion enhanced the release of total phenol in rice-teff blends, which was reflected on the antioxidant activities of blend flours, especially those prepared with brown teff.

Variations in Antioxidant Capacity, Oxidative Stability, and Physicochemical Quality Parameters of Walnut (Juglans regia) Oil with Roasting and Accelerated Storage Conditions

Walnut oil, like all vegetable oils, is chemically unstable because of the sensitivity of its unsaturated fatty acids to the oxidation phenomenon. This phenomenon is based on a succession of chemical reactions, under the influence of temperature or storage conditions, that always lead to a considerable change in the quality of the oil by promoting the oxidation of unsaturated fatty acids through the degradation of their C-C double bonds, leading to the formation of secondary oxidation products that reduce the nutritional values of the oil. This research examines the oxidative stability of roasted and unroasted cold-pressed walnut oils under accelerated storage conditions. The oxidative stability of both oils was evaluated using physicochemical parameters: chemical composition (fatty acids, phytosterols, and tocopherols), pigment content (chlorophyll and carotenoids), specific extinction coefficients (K₂₃₂ and K₂₇₀), and quality indicators (acid and peroxide value) as well as the evaluation of radical scavenging activity by the DPPH method. The changes in these parameters were evaluated within 60 days at 60 ± 2 °C. The results showed that the levels of total phytosterols, the parameters of the acid and peroxide value, K₂₃₂ and K₂₇₀, increased slightly for both oils as well as the total tocopherol content and the antioxidant activity affected by the roasting process. In contrast, the fatty acid profiles did not change considerably during the 60 days of our study. After two months of oil treatment at 60 °C, the studied oils still showed an excellent physicochemical profile, which allows us to conclude that these oils are stable and can withstand such conditions. This may be due to the considerable content of tocopherols (vitamin E), which acts as an antioxidant.

Topical administration of Juglans regia L. leaf extract accelerates diabetic wound healing

Background

Diabetic wounds are one of the most important issues in diabetic patients. It seems that Juglans regia L. leaf with antioxidant and anti-inflammatory potentials can be profitable for healing of diabetic wounds. The aim of present study was to investigate the topical administration of Juglans regia L. leaf extract in diabetic wound healing.

Methods

Seventy-five diabetic male rats were randomly divided into 5 groups (n = 15), including: untreated (Control) group, Eucerin group, 2% Juglans regia L. ointment (JRL 2%) group, 5% Juglans regia L. ointment (JRL 5%) group, and Phenytoin group as a reference drug. Sampling was performed at days 7, 14, and 21 after surgery. Evaluation tests included stereology, immunohistochemistry, molecular, and biomechanical.

Results

Our results showed that the wound closure rate, volumes of newly formed of epidermis and dermis, density of fibroblasts and blood vessels, collagen deposition, density of proliferation cells, expression levels of TGF-β and VEGF genes, and biomechanical characteristics were significantly higher in extract groups compared to control and eucerin groups, however, these changes were considerable in the JRL 5% group (P < 0.05). This is while that the density of neutrophils and expression levels of TNF-α and IL-1β genes in the extract groups, especially in the JRL 5% group, were significantly reduced compared to control and eucerin groups (P < 0.05).

Conclusion

Topical administration of Juglans regia L. leaf extract, especially in 5% concentration, considerably accelerates diabetic wound healing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03735-6.

Nuts as functional foods: Variation of nutritional and phytochemical profiles and their in vitro bioactive properties

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Nutritional, biological and in vitro anti-diabetic, -obesity, -cholinergic of nuts.

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Polymeric procyanidins dominant polyphenols.

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Oleanic and pomolic acids dominant triterpenes.

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Nuts are low in Cu, Zn, Mn, Na, but rich in K and Mg.

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All nuts showed high activity in inhibiting intestinal α-glucosidase.

The aim of the present study was to examine the nutritional (fat, fatty acids, minerals, sugars) and bioactive compounds (polyphenols, tocochromanols, triterpene) and their influence on in vitro anti-diabetic (pancreatic α-amylase and intestinal α-glucosidase), anti-obesity (pancreatic lipase) and anti-cholinergic (AChE and BuChE) inhibitory activity of 8 different popular nuts—pecan, pine, hazelnuts, pistachio, almonds, cashew, walnuts, and macadamia.

The total content of phenolic compounds in nuts ranged from 432.9 (walnuts) to 5.9 (pistachio) mg/100 g. The dominant polyphenols are polymeric procyanidins (walnuts – 415.1 mg/100 g). Nuts are rich in tocochromanols (832.9–4377.5 μg/100 g), especially α- and γ-tocopherols. The highest content of α-tocopherol (vitamin E) was detected in hazelnuts and almonds (2551.0 and 2489.7 μg/100 g, respectively) while the lowest amounts were detected in macadamia, cashew and walnuts. The most abundant in nuts are oleanic and pomolic acids (35 and 22 % of total, respectively), while betulin, uvaol and erythrodiol are less characteristic triterpenes for nuts (<1%). Pine nuts are the nuts with the highest content of triterpene (690.3 mg/100 g). Pistachio and almonds are the richest in total fat (>45 %), but monounsaturated (17.5–79.3 %; hazelnuts, almonds, cashew, macadamia, pistachio and pecan) and polyunsaturated (7.5–69.3 %; pine, walnuts) are the dominant fatty acids. Moreover, nuts are low in Cu, Zn, Mn and Na content, but rich in K (464.5–1772.3 mg/100 g) and Mg (197.0–502.5 mg/100 g). Macadamia, walnuts and cashew are good sources of Se. Pistachio, almonds and cashew were characterized by the highest content of sugars, but the dominant sugar was saccharose (58.2–2399.3 mg/100 g). All nuts showed high activity in inhibiting intestinal α-glucosidase (>90 %), but lower ability to inhibit pancreatic α-amylase and pancreatic lipase activity. The activity in inhibiting acetyl- and butylcholinesterase was up to 30 %.

As described above, all nuts contain various compounds that improve the nutritional value. Therefore they should be one of the important components of the daily human diet rich in functional foods.

Evaluation of wiping edible sesame oils in the oral cavities of hospitalised older patients who resist oral hygiene management

Context

One of the causes of aspiration pneumonia is poor oral hygiene. We need care methods that caregivers can quickly, safely and inexpensively implement for convalescents with inadequate self-care. Edible sesame oil containing sesamin or sesaminol has already been shown to inhibit bacterial and fungal growth and have a vasodilating effect.

Aims

The aim of this study is to evaluate the usefulness of using edible sesame oils for oral hygiene management.

Settings and Design

This study evaluates an oral hygiene management method using two types of sesame oils in elderly hospitalised patients resistant to oral hygiene management.

Methods and Material

The inpatients received oral care for 90 days. In the intervention groups, nurses brushed and wiped the oral cavity with roasted sesame oil (RSO) or sesame salad oil, while in the control group, care with tap water alone and brushing were done. Bacteria and Candida counts from tongue swabs, water content from the tongue's surface and cheek mucosa, oral health assessment tool (OHAT) and cytology of the cheek mucosa were assessed every 30 days before and after the intervention.

Results

RSO showed a tendency to reduce the number of bacteria and Candida. There was an improvement in the OHAT scores with both oils. The water content or cytology was not changing.

Conclusions

Sesame oils may improve oral hygiene and maintain health in older patients.

Critical overview of biorefinery approaches for valorization of protein rich tree nut oil industry by-product

This review explores reutilization opportunities of protein-rich bio-waste derived from the major tree nuts (almonds, walnuts, and cashew nuts) oil processing industries through biorefinery strategies. The mechanically pressed out oil cakes of these nuts have high protein (45-55%), carbohydrate (30-35%), and fiber that could be utilized to produce bioactive peptides, biofuels, and dietary fiber, respectively; all of which can fetch substantially greater value than its current utilization as a cattle feed. Specific attention has been given to the production, characterization, and application of nut-based de-oiled cake hydrolysates for therapeutic benefits including antioxidant, antihypertensive and neuroprotective properties. The often-neglected safety/toxicological evaluation of the hydrolysates/peptide sequences has also been described. Based on the available data, it is concluded that enzymatic hydrolysis is a preferred method than microbial fermentation for the value addition of de-oiled tree nut cakes. Further, critical insights on the existing literature as well as potential research ideas have also been proposed.

A comprehensive review on ethnobotanical, medicinal and nutritional potential of walnut (Juglans regia L.)

Juglans regia L. commonly known as walnut is used as the most extensive and economical tree in the world. This review aims to study the ethnomedicinal, phytochemical and pharmacological potential of walnut. The literature has been collected from different online sources like science Direct, Scopus, ResearchGate, Google Scholar, PubMed, etc. based on inclusion and exclusion criteria. An ethnomedicinal survey has also been conducted to document the traditional knowledge and uses of walnut among the local peoples of the Union Territory of Jammu and Kashmir. On surveying the local peoples in the different major walnut-producing areas, it has been followed that the walnut is locally used as a medicinal, nutritional, and commercial plant to treat common diseases and disorders in the locality. The survey has been conducted first time in the area and no study has been reported till now in the Jammu Division while some work has been reported in the Kashmir Division. Among the many bioactive compounds present in various plant parts, Juglone has been reported a significant anti-cancer compound in treating deadly cancer. This systematic review describes the significant knowledge and traditional information collected on ethnomedicinal uses, phytochemistry, habitat, macro-morphology, area of distribution, and pharmacological importance.

3D-Printed PCL Scaffolds Combined with Juglone for Skin Tissue Engineering

Skin diseases are commonly treated with antihistamines, antibiotics, laser therapy, topical medications, local vitamins, or steroids. Since conventional treatments for wound healing (skin allografts, amnion, xenografts, etc.) have disadvantages such as antigenicity of the donor tissue, risk of infection, or lack of basement membrane, skin tissue engineering has become a popular new approach. The current study presents the design and fabrication of a new wound-dressing material by the addition of Juglone (5-hydroxy-1,4-naphthoquinone) to a 25% Polycaprolactone (PCL) scaffold. Juglone (J) is a significant allelochemical found in walnut trees and, in this study is used as a bioactive material. The effects of different amounts of J (1.25, 2.5, 5, 7.5, and 10 mg) on the biocompatibility, mechanical, chemical, thermal, morphological, and antimicrobial properties of the 3D-printed 25% PCL scaffolds were investigated. The addition of J increased the pore diameter of the 25% PCL scaffold. The maximum pore size (290.72 ± 14 µm) was observed for the highest amount of J (10 mg). The biocompatibility tests on the scaffolds demonstrated biocompatible behavior from the first day of incubation, the 25% PCL/7.5 J scaffold having the highest viability value (118%) among all of the J-loaded scaffolds. Drug release of J into phosphate buffered saline (PBS) at pH 7.4 showed that J was completely released from all 25% PCL/J scaffolds within 7 days of incubation.

Valorization of Traditional Italian Walnut (Juglans regia L.) Production: Genetic, Nutritional and Sensory Characterization of Locally Grown Varieties in the Trentino Region

Juglans regia (L.) is cultivated worldwide for its nutrient-rich nuts. In Italy, despite the growing demand, walnut cultivation has gone through a strong decline in recent decades, which led to Italy being among the top five net importing countries. To promote the development of local high-quality Italian walnut production, we devised a multidisciplinary project to highlight the distinctive traits of three varieties grown in the mountainous region Trentino (northeast of Italy): the heirloom ‘Bleggiana’, a second local accession called local Franquette and the French cultivar ‘Lara’, recently introduced in the local production to increase yield. The genetic characterization confirmed the uniqueness of ‘Bleggiana’ and revealed local Franquette as a newly described autochthonous variety, thus named ‘Blegette’. The metabolic profiles highlighted a valuable nutritional composition of the local varieties, richer in polyphenols and with a lower ω-6/ω-3 ratio than the commercial ‘Lara’. ‘Blegette’ obtained the highest preference scores from consumers for both the visual aspect and tasting; however, the volatile organic compound profiles did not discriminate among the characterized cultivars. The described local varieties represent an interesting reservoir of walnut genetic diversity and quality properties, which deserve future investigation on agronomically useful traits (e.g., local adaptation and water usage) for a high-quality and sustainable production.

Transcriptome analysis of walnut quality formation and color change mechanism of pellicle during walnut development

Walnuts (including those covered with a pellicle) are loved for their rich nutritional value. And the popular varieties of walnut cultivation are Juglans sigillata L. The pellicle (seed coat) of these walnut cultivars has different colors and has an indispensable influence on the walnut quality formation. However, there are few reports on the pellicle color and quality formation in different developmental stages of walnut (Juglans sigillata L.). Therefore, in this study, three walnut cultivars (F, Q, and T) with different pellicle colors were selected for transcriptome sequencing and physiological index analysis of the color and quality formation mechanisms at different development stages. The results showed that with the development of walnut fruit, the starch sucrose metabolism pathway in the pellicle was activated and promoted starch hydrolysis. Meanwhile, the expression levels of genes related to the alpha-linolenic acid metabolism pathway were significantly increased during walnut maturation, especially in F2. Some physiological indicators related to lipid oxidation were also detected and analyzed in this study, such as MDA, CAT, POD and DPPH. These results were similar to the expression patterns of corresponding regulatory genes in the RNA-Seq profile. In addition, lignin synthesis genes were up-regulated in the phenylpropanoid metabolic pathway, while key genes enriched in the flavonoid and anthocyanin synthesis pathways were down-regulated. The results were consistent with the results of total anthocyanins and flavonoid content detection during walnut development. Therefore, this experiment suggested that with the maturation of walnut pellicle, the gene expression in the phenylpropanoid metabolic pathway flowed to the branch of lignin synthesis, especially in the Q variety, resulting in lower flavonoid and anthocyanin content at the maturity stage than immature. This is also the main reason for the pale pellicle of the three walnut varieties after mature. The findings of this study showed that changes in the expression levels of regulating genes for lipid, starch, sugar, and flavonoid synthesis during walnut development influenced the accumulation of the related metabolite for walnut quality formation and pellicle color. The results of this experiment provided the molecular basis and reference for the breeding of high nutritional quality walnut varieties.

Chemical Compositions of Walnut (Juglans Spp.) Oil: Combined Effects of Genetic and Climatic Factors

Walnut oil is a high-value oil product. Investigation of the variation and the main climatic factors affecting the oil’s chemical composition is vital for breeding and oil quality improvement. Therefore, the fatty acid, micronutrients, and secondary metabolites compositions and contents in walnut oil were determined in three species: Juglans regia L. (common walnut), J. sigillata Dode (iron walnut), and their hybrids (Juglans sigillata Dode × J. regia L.), which were cultivated aat different sites. The major fatty acids were linoleic (51.39–63.12%), oleic (18.40–33.56%), and linolenic acid (6.52–11.69%). High variation in the contents of fatty acids, micronutrients, and secondary metabolites was found between both species and sites. Interestingly, myristic, margaric, and margaroleic acid were only detected in the hybrids’ walnut oil, yet α-tocopherol was only detected in common and iron walnut oil. Climatic factors significantly affected the composition and content of fatty acid, whereas δ-tocopherol was mostly dependent on the genetic factors. The average relative humidity explained the most variation in the fatty acids, micronutrients, and secondary metabolites, which showed a significant positive and negative effect on the monounsaturated fatty acids and polyunsaturated fatty acids, respectively. These findings contribute to the provision of better guidance in matching sites with walnut trees, and improvement of the nutritional value of walnut oil.

Phenolic Profile and Antioxidant, Antibacterial, and Antiproliferative Activity of Juglans regia L. Male Flowers

Juglans regia L., walnut, is a large, long-living tree, cultivated in temperate climates around the world. It is highly appreciated for its nutritional kernels and high-quality timber. Its barks, leaves, and husk are used as dyes and in folk medicine as herbal remedies for several diseases. From a biological and chemical standpoint, relatively little is known about the male flowers of the tree. Therefore, the aim of the study was to evaluate the phenolic profile as well as in vitro antioxidant, antimicrobial, and antiproliferative activity of male Juglans regia L. flowers. Phenolic content was determined by UPLC/PDA/MS/MS analyses; antioxidant activity was assessed by five different methods; antimicrobial activity was evaluated against the six most common pathogenic strains of Gram-positive and Gram-negative bacteria, and antiproliferative properties were assessed against six cell lines. Most of the analyses carried out in this study were performed for the first time for this raw material. J. regia flower extract was characterized by a strong ability to scavenge DPPH˙ free radicals, hydroxyl radicals, and chelating metal ions. Among the examined bacterial strains and neoplastic lines, the strongest antimicrobial activity was shown against S. aureus, L. monocytogenes, and B. cereus, and cytotoxic activity against breast cancer, glioblastoma, and astrocytoma cells. Male J. regia flowers have also been found to be a rich source of phenolic compounds. The content of polyphenols in the extract was 4369.73 mg/100 g d.w., and 24 compounds from the group of flavonoids, phenolic acids, and juglunosides were identified. Additionally, a strong correlation between the content of polyphenols and the antioxidant capacity and cytotoxic activity was observed. This is why the tested J. regia flowers are an excellent source of effective natural antioxidant, antibacterial, and chemopreventive compounds that have potential to be used in the pharmaceutical or food industries.

Compositional and Morphological Characterization of ‘Sorrento’ and ‘Chandler’ Walnuts

In Italy, most of the cultivated walnuts belong to the Sorrento ecotype, and they are considered commercially valuable due to their specific organoleptic characteristics. The aim of this study is to evaluate and compare the morphological and compositional characteristics of walnuts sampled from ‘Sorrento’ trees cultivated in different locations in Campania and trees of both the ‘Chandler’ and ‘Sorrento’ varieties derived from the same location. The results demonstrated that ‘Sorrento’ and ‘Chandler’ walnuts have different biometric characteristics and a different fat content, with the highest fat content being found in the ‘Sorrento’ variety. Regarding the fatty acid (FA) composition, the content of monounsaturated and saturated fatty acids (MUFAs and SFAs) was highest in the ‘Sorrento’ variety (from 13 to 15% for MUFAs and from 11 to 13% for SFAs), while the polyunsaturated fatty acids (PUFAs) content was highest in the ‘Chandler’ variety (77%). The total phenolics content (TPC) was highest in the ‘Sorrento’ variety (from 910 to 1230 mg GAE/100 g), while no difference in γ-tocopherol content was found. Furthermore, the influence of walnut area cultivation was shown for fat content, FA composition and TPC. Therefore, both walnut varieties demonstrated good nutritional properties considering the PUFAs and γ-tocopherol content.

Development of an Extraction Method of Aflatoxins and Ochratoxin A from Oral, Gastric and Intestinal Phases of Digested Bread by In Vitro Model

Validated extraction methods from in vitro digestion phases are necessary to obtain a suitable bioaccessibility study of mycotoxins in bakery products. The bakery industry produces bread with different ingredients to enrich the nutritional properties of this product and protect it from fungal growth. This bread can be contaminated by AFB₁, AFB₂, AFG₁, AFG₂ and OTA, so an extraction method was developed to analyse these five legislated mycotoxins in digested phases of two types of bread, one with wheat and the other with wheat and also enriched with Cucurbita Maxima Pepo at 20%. The studied “in vitro” digestion model consists of oral, gastric and duodenal phases, each one with different salt solutions and enzymes, that can affect the extraction and most probably the stability of the mycotoxins. The proposed method is a liquid–liquid extraction using ethyl acetate by extract concentration. These analytes and components have an important effect on the matrix effect (MEs) in the analytical equipment, therefore, validating the method and obtaining high sensitivity will be suitable. In the proposed method, the highest MEs were observed in the oral phase of digested pumpkin bread (29 to 15.9 %). Regarding the accuracy, the recoveries were above 83% in the digested duodenal wheat bread and above 76 % in the digested duodenal pumpkin wheat bread. The developed method is a rapid, easy and optimal option to apply to oral, gastric and duodenal phases of digested bread contaminated at a level of established maximum levels by European legislation (RC. 1881/2006) for food.

Morphological and Chemical Variation of Wild Sweet Chestnut (Castanea sativa Mill.) Populations

Sweet chestnut (Castanea sativa Mill., Fagaceae) is one of the oldest cultivated tree species in the Mediterranean, providing multiple benefits, and, since it has edible seeds, it represents an interesting model species for the research of morphological and chemical variability. In this study, morphometric methods and chemical analyses were used to quantify the extent of differences in phenotypic and nutritional traits between eight natural populations of sweet chestnut from different environmental conditions, where different management types are applied, high-forest and coppice. The samples were collected from the Prealps in Italy to the western part of Bosnia and Herzegovina. In total, 31 nut and kernel morphometric and nutritional traits were studied on 160 trees, and various multivariate statistical analyses were used to study intra- and interpopulation variations. Both analyses, morphometric and chemical, revealed a similar pattern of diversity, with morphological and chemical variability not associated with geographic or environmental variables. In addition, we found significant correlations between morphometric and chemical data. High phenotypic variability was determined both among and within the studied populations, and all populations had a similar level of diversity. The results of the analysis of morphological and chemical diversity can have many practical applications for the management, production, and conservation of the sweet chestnut genetic resources for nut production.

The Effect of Walnut (Juglans regia) Leaf Extract on Glycemic Control and Lipid Profile in Patients With Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Numerous clinical trials have examined the beneficial effects of Juglans regia leaf extract (JRLE) in patients with type 2 diabetes mellitus (T2DM); however, the results of these studies are inconsistent. Therefore, we conducted the current systematic review and meta-analysis to evaluate the effect of JRLE on glycemic control and lipid profile in T2DM patients. We searched online databases including PubMed, Scopus, EMBASE, and Web of Science for randomized controlled clinical trials that examined the effect of JRLE on glycemic and lipid indices in T2DM patients. Data were pooled using both fixed and random-effect models and weighted mean difference (WMD) was considered as the overall effect size. Of the total records, 4 eligible studies, with a total sample size of 195 subjects, were included. The meta-analysis revealed that JRLE supplementation significantly reduces fasting blood glucose (WMD, −18.04; 95% confidence interval [CI], −32.88 mg/dL, −3.21 mg/dL; p = 0.017) and significantly increases fasting insulin level (WMD, 1.93; 95% CI, 0.40 U/L, 3.45 U/L; p = 0.014). Although the overall effect of JRLE supplementation on hemoglobin A1c was not significant, a significant reduction was seen in studies with an intervention duration of > 8 weeks (WMD, −0.64; 95% CI, −1.16%, −0.11%; p = 0.018). Moreover, we also found no significant change in lipid parameters. Our findings revealed a beneficial effect of JRLE supplementation on glycemic indices in T2DM patients, but no significant improvement was found for lipid profile parameters.

A Validated Ultrasound-Assisted Extraction Coupled with SPE-HPLC-DAD for the Determination of Flavonoids in By-Products of Plant Origin: An Application Study for the Valorization of the Walnut Septum Membrane

Walnut byproducts have been shown to exert functional properties, but the literature on their bioactive content is still scarce. Among walnut byproducts, walnut septum is a dry ligneous diaphragm tissue that divides the two halves of the kernel, exhibiting nutritional and medicinal properties. These functional properties are owing to its flavonoid content, and in order to explore the flavonoid fraction, an ultrasound-assisted (UAE) protocol was combined with solid phase extraction (SPE) and coupled to high-performance liquid chromatography with diode array detection (HPLC-DAD) for the determination of flavonoids in Greek walnut septa membranes belonging to Chandler, Vina, and Franquette varieties. The proposed UAE-SPE-HPLC-DAD method was validated and the relative standard deviations (RSD%) of the within-day and between-day assays were lower than 6.2 and 8.5, respectively, showing good precision, and high accuracy ranging from 90.8 (apigenin) to 97.5% (catechin) for within-day assay, and from 88.5 (myricetin) to 96.2% (catechin) for between-day assay. Overall, seven flavonoids were determined (catechin, rutin, myricetin, luteolin, quercetin, apigenin, and kaempferol) suggesting that the walnut septum is a rich source of bioactive constituents. The quantification results were further processed using ANOVA analysis to examine if there are statistically significant differences between the concentration of each flavonoid and the variety of the walnut septum.

Physicochemical, Functional, Fatty Acids Profile, Health Lipid Indices, Microstructure and Sensory Characteristics of Walnut-Processed Cheeses

In the present study, processed cheeses fortified with walnut paste (a high source of omega-3 fatty acids) were developed and characterized. In order to identify the best cheese formulation, the effects of different proportions of walnut paste (0, 5, 10, and 15%) on cheese physicochemical, functional, fatty acids profile, health lipid indices (atherogenic and thrombogenic), microstructure, and sensorial characteristics were studied. Results showed that walnut-added samples had significantly (p ≤ 0.05) higher levels of acidity, protein, fat, and ash contents with lower meltability and oil separation index compared to the control. Processed cheeses with walnuts contained significantly (p ≤ 0.05) higher percentages of MUFAs, and ω-3 PUFAs (mainly α-linolenic acid) and significantly (p ≤ 0.05) lower amounts of SFAs (mainly myristic, palmitic and stearic acids) and ω₆/ω₃ ratio. Scanning Electron Micrograph of processed cheese containing walnut paste showed uniform distribution of walnut in the protein matrix. Processed cheeses made with 5 or 10% walnut paste presented the most acceptable sensory properties. These results indicated that walnut paste supplementation can be used as a nutritional strategy to increase concentrations of human health-promoting fatty acids in processed cheeses while maintaining good sensory and technological properties.

Pulse-Cereal Blend Extrusion for Improving the Antioxidant Properties of a Gluten-Free Flour

Extrusion is an interesting technological tool that facilitates pulse formulation into flour mixtures, with tailored fibre content, total antioxidant capacity (TAC) and glycemic index (GI) among other components in final formulas. The gluten-free (GF) market has significantly grown during the last years. GF products have evolved from specialty health foods to products targeted to the general population and not only associated to celiac consumers. This study evaluates how temperature, cereal base (rice/corn) and pulse concentration affect extruded flour properties and which conditions are more efficient to develop a gluten-free flour with high TAC and low GI. Additionally, it evaluated the effect of this optimal formula after the baking process. The results showed an increase of total phenol (TP) and antioxidant activity with extrusion, with a temperature-dependent effect (130 °C ≥ 120 °C ≥ 110 °C), which may imply an enhanced bioaccessibility of phenolics compounds after extraction. Extrusion increased GI in comparison to native flour; however, a dough temperature of 130 °C resulted in a significantly (p ≤ 0.05) lower GI than that observed for 110-120 °C doughs, probably associated to the pastification that occurred at higher temperatures, which would decrease the degree of gelatinization of the starches and therefore a significant (p ≤ 0.05) GI reduction. Corn-lentil flour showed higher antioxidant properties and lower GI index in comparison with rice-lentil blends. The formulation of the optimal blend flour into a baked product (muffin) resulted in a significant loss of antioxidant properties, with the exception of the reducing power (FRAP), although the final antioxidant values of the baked product were in the range of the original native flour blend before any process.

HPLC Fingerprints for the Characterization of Walnuts and the Detection of Fraudulent Incidents

A high-pressure liquid chromatographic method coupled to diode array detector (HPLC-DAD) was developed for the determination of phenolic compounds that could be used as markers in authentication studies of walnuts belonging to the Chandler variety, originating from Bulgaria, Greece, and France. An ultrasound-assisted extraction (UAE) protocol applied in the extraction of phenolic compounds was optimized. The method was validated and the relative standard deviations (RSD%) of the within-day, and between-day assays was lower than 6.3 and 11.1, respectively, showing adequate precision, and good accuracy ranging from 86.4 (sinapic acid) to 98.4% (caffeic acid) for within-day assay, and from 90.1 (gallocatechin gallate) to 100.6% (gallic acid) for between-day assay. Eighteen phenolic compounds were determined belonging to the classes of phenolic acids and flavonoids. The quantification results were further processed with chemometrics, and a robust partial least square-discriminant analysis (PLS-DA) model was developed for the classification of the samples according to their geographical origin, proposing markers that could be used for the control of walnuts authenticity and the detection of fraudulent incidents.

Assessment of Total Fat and Fatty Acids in Walnuts Using Near-Infrared Hyperspectral Imaging

"Persian" walnut (Juglans Regia L.) is one of the most consumed tree nuts in the world. It is rich in several bioactive compounds, with polyunsaturated and monounsaturated fatty acids (PUFA and MUFA) appearing at high concentrations. Walnut consumption protects against cardiovascular, carcinogenic, and neurological disorders. The fatty acid profile has usually been determined by gas chromatography, a reliable and robust tool, but also complex, polluting, and time consuming. In this study, near infrared hyperspectral imaging has been used for the screening of total fat, MUFA, PUFA, saturated, and individual fatty acids in walnuts. Five different walnuts varieties have been considered and modified partial least square (MPLS) regressions have been performed. The SEs of prediction (SEP) in external validation (ranged from 2.12% for PUFA to 13.08% for MUFA) suggest that hyperspectral imaging can be a reliable tool for controlling these parameters in a simple, non-destructive and environmentally friendly way.

A Novel Strategy to Produce a Soluble and Bioactive Wheat Bran Ingredient Rich in Ferulic Acid

Wheat bran (WB) is a byproduct from the milling industry that contains bioactive compounds beneficial to human health. The aim of this work was on the one hand, increasing extractability of antioxidant and anti-inflammatory compounds (specifically ferulic acid, FA), through enzymatic hydrolysis combined with hydrothermal treatment (HT) and high hydrostatic pressure (HHP). On the other hand, enhancing the stability of final ingredient applying spray-drying (SPD) and microencapsulation (MEC). The use of HT increased FA, total phenolics (TP), and antioxidant capacity (AC) in WB hydrolysates, regardless the HT duration. However, the HT tested (30 min, HT30) produced a loss in anti-inflammatory activity (AIA). The combination of HT (15 min, HT15) with HHP increased AIA of the WB. SPD enhanced the TP yield in WB with no significant effect of inlet temperature (up to 140 °C) on phenolic profile mainly composed of trans-FA and smaller amounts of cis-FA and apigenin diglucosides. SPD caused a temperature-dependent increase in AC (160 °C > 140 °C > 130 °C). SPD inlet temperatures affected total solids yield (from 22 to 36%), with the highest values at 140 °C. The use of HHP in combination with HT resulted in >2-fold increase in total solids yield.

Post-harvest Industrial Processes of Almond (Prunus dulcis L. Mill) in Sicily Influence the Nutraceutical Properties of By-Products at Harvest and During Storage

Almond cultivation in Sicily is experiencing a phase of great interest which is mainly concentrated in the development of specialized orchards, with irrigation and by adopting cultivars with high qualitative and quantitative performances. These are mostly Mediterranean genotypes with high fat content and hard or semi-hard shell, extremely different from the varieties of Californian diffusion. The development of the sector comprises the primary production of almonds but also a series of secondary products which often represent a burden for the company. From these considerations several researches have been developed with the aim of giving a value to these by-products through circular economy paths. One of the by-products widely produced, besides the shell, is the skin which covers the seed and is produced during the peeling phase. It is well-known that tegument is an important component of almond because it contains important bioactive substances (phenols and aromas) which are usually dispersed during peeling. This paper examined three different Italian cultivars widely spread in Sicily, two of Apulian origin, (Genco and Tuono), and one locally cultivated variety (Vinci a tutti). These three cultivars occupy an increasingly large area and are very popular with consumers and industry. The production of secondary products, therefore, evidences significant quantities and the possibility to give them an added value becomes a need for the sector. Therefore, the content of phenols and proanthocyanins in the skin at harvest and during storage was analyzed, adopting two different separation methods, with and without water. During the analysis it was possible to observe the different behavior of the three cultivars due to genetic and industrial factors. Skin separated without using hot water showed a higher total phenolic presence with average increases of about 20%, and with even higher increases, between 28 and 32%, for proanthocyanins. Vinci a tutti evidenced the highest total phenolic content after 8 months of storing while roasting has revealed to be a more effective skin separation approach.