Characterization of polyphenols, lipids and dietary fibre from almond skins (Amygdalus communis L.)

Photoprotective effect of topical treatment with Lopezia racemosa extract against deleterious UVB irradiation effects in the skin of hairless mice

Lopezia racemosa is known as a "mosquito flower or perlilla." It is commonly found in corn crops. In traditional Mexican medicine, this plant is used to treat stomach cancer and urinary tract infections. Likewise, compounds and extracts isolated from plants have shown cytotoxic and anti-inflammatory effects. The objective of this study was to evaluate the photochemoprotective effect of topical treatment with the methanolic extract of L. racemosa (MELR) as a photochemoprotective agent against the harmful effects of UV irradiation (UVR) on a bacterial model and hairless mice. The MELR components were separated and analyzed via HPLC-UV-ESI-MS. Antioxidant activity was evaluated by the ability of MERL to scavenge DPPH and ABTS free radicals and by its FRAP capacity. The toxicity of MELR was evaluated in keratinocyte cultures. The photoprotective capacity of MELR was assessed through challenge experiments using models with bacteria and hairless CD1 et/et mice; cytokines related to the damage caused by UVR were also measured. In the methanolic extract of L. racemosa, five metabolites were detected and identified: two isomers of quercetin 6-C glycoside, orientin, quercetin 3-(6″-acetylglycoside) and quercetin 3-(6″-galloylglycoside) 7-(2,3-dihydroxytetrahydro-2H-pyran-4-yl acetate). MELR exhibited DPPH and ABTS radical scavenging properties, in addition to Fe ion reducing activity. MELR showed a photoprotective effect against UVB radiation-induced death in Escherichia coli bacteria. At the histological level, topical treatment of CD-1 et/et mice with MERL reduced the damage caused by UVR. Quantification of interleukins in the blood of mice revealed that the expression of IL-12 was greater in the control group treated with ultraviolet radiation than in the group protected with MELR. The methanolic extract of L. racemosa has photochemoprotective properties.

Subcritical Water Extraction for Valorisation of Almond Skin from Almond Industrial Processing

Almond skin (AS) is an agro-industrial residue from almond processing that has a high potential for valorisation. In this study, subcritical water extraction (SWE) was applied at two temperatures (160 and 180 °C) to obtain phenolic-rich extracts (water-soluble fraction) and cellulose fibres (insoluble fraction) from AS. The extraction conditions affected the composition and properties of both valorised fractions. The dry extracts obtained at 180 °C were richer in phenolics (161 vs. 101 mg GAE. g-1 defatted almond skin (DAS)), with greater antioxidant potential (1.063 vs. 1.490 mg DAS.mg-1 DPPH) and showed greater antibacterial effect (lower MIC values) against L. innocua (34 vs. 90 mg·mL-1) and E. coli (48 vs. 90 mg·mL-1) than those obtained at 160 °C, despite the lower total solid yield (21 vs. 29%) obtained in the SWE process. The purification of cellulose from the SWE residues, using hydrogen peroxide (H2O2), revealed that AS is not a good source of cellulose material since the bleached fractions showed low yields (20-21%) and low cellulose purity (40-50%), even after four bleaching cycles (1 h) at pH 12 and 8% H2O2. Nevertheless, the application of a green, scalable, and toxic solvent-free SWE process was highly useful for obtaining AS bioactive extracts for different food, cosmetic, or pharmaceutical applications.

Antioxidant Activity of a Sicilian Almond Skin Extract Using In Vitro and In Vivo Models

Almond skins are known for their antioxidative and anti-inflammatory properties, which are mainly due to the presence of polyphenols. The aim of the present study was to evaluate the antioxidant and anti-inflammatory effects of almond skin extract (ASE) obtained from the Sicilian cultivar "Fascionello" and to evaluate the possible mechanisms of action using an in vitro model of human monocytic U937 cells as well as an in vivo model of carrageenan (CAR)-induced paw edema. The in vitro studies demonstrated that pretreatment with ASE inhibited the formation of ROS and apoptosis. The in vivo studies showed that ASE restored the CAR-induced tissue changes; restored the activity of endogenous antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione; and decreased neutrophil infiltration, lipid peroxidation, and the release of proinflammatory mediators. The anti-inflammatory and antioxidant effects of ASE could be associated with the inhibition of the pro-inflammatory nuclear NF-κB and the activation of the nuclear factor-erythroid 2-related factor 2 (Nrf2) antioxidant pathways. In conclusion, almond skin could reduce the levels of inflammation and oxidative stress and could be beneficial in the treatment of several disorders.

Chemical and Sensory Properties of Waffles Supplemented with Almond Skins

Almonds are one of the most produced nuts worldwide and numerous studies have shown that they have nutritional and medicinal characteristics, which gives them the possibility of being applied in various products. However, several by-products are generated during their production, which have characteristics of interest but remain underutilised, namely, the almond skins. This work aimed to study samples of waffles supplemented with almond skins. The waffles were evaluated for their total polyphenol content, antioxidant capacity, total flavonoids, ortho-diphenols, soluble sugars, starch, texture, and colour. They were also sensorially evaluated using a panel of tasters specialised in this type of evaluation and a quantitative descriptive analysis test (QDA) sensory test. The results showed that the waffles with the highest levels of phenolic compounds as well as the highest antioxidant activity (by the ABTS, DPPH, and FRAP methods) were the waffles supplemented with 10% almond skin. The total phenol contents obtained for the prepared extracts varied between 0.127 mg GAE/g and 0.415 mg GAE/g, the flavonoid contents ranged from 0.067 mg CAE/g to 0.339 mg CAE/g and the ortho-diphenol contents varied between 0.163 mg ACE /g and 0.303 mg ACE/g. Regarding the quantification of soluble sugars, the values were presented in percentage of fresh weight, and ranged from 30.148 to 38.054%; regarding the quantification of starch, the percentages varied from 14.488 to 21.982%. Sensorially, we verified that the samples were statistically different in terms of the descriptors "colour", "roasted aroma", and "dissolubility", with a higher score in these descriptors for the waffles with 10% of almond skin. This process of obtaining waffles, which can be industrialised, is interesting from both a nutritional point of view and for the possibility of creating new, differentiated, and innovative products.

A review on some properties of almond: ımpact of processing, fatty acids, polyphenols, nutrients, bioactive properties, and health aspects

This review was focused on the proximate compounds, nutritional values, total phenolic, flavonoid, antioxidant activity, fatty acid profile, polyphenols, health aspects and uses of almond kernel and oils. Almond contained about 24-73% crude oil, 50-84% oleic and 6-37% linoleic acids, 77-3908 mg/kg β-stosterol and 5-8 mg/100 g β-tocopherol. Almonds are a good source of mono- and unsaturated fatty acids, phytochemicals, bioactive components, minerals, vitamin E, polyphenols and phytosterols and at the same time almonds have healing effects. Since almond seeds or seed oils have versatile uses, they are consumed on their own or as part of a range of food products. Almonds are considered a healthy snack when consumed due to their potential cardioprotective effects. Since the composition of almonds and its effects on health will be effective both during cultivation and processing, studies should be carried out in a way that preserves the product quality.

Graphical abstract

In this study, the proximate compounds, harvest and irrigation effect, nutritional values (protein, amino acids, vitamins minerals), total phenol, flavonoid, antioxidant activity, fatty acid profile, polyphenols, and uses of almond kernel and oils were summarized.

Effect of Apple Polyphenols on the Antioxidant Activity and Structure of Three-Dimensional Printed Processed Cheese

Additives can influence the processability and quality of three-dimensional (3D)-printed foods. Herein, the effects of apple polyphenols on the antioxidant activity and structure of 3D-printed processed cheese were investigated. The antioxidant activities of processed cheese samples with different contents of apple polyphenols (0%, 0.4%, 0.8%, 1.2%, or 1.6%) were evaluated using 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) assays. In addition, the rheological properties and structural characteristics of the processed cheeses were investigated using rheometry, Fourier transform infrared spectroscopy, and fluorescence spectroscopy. Then, the final printed products were analyzed for comparative molding effects and dimensional characteristics. it was found that apple polyphenols can significantly improve the antioxidant activity of processed cheese. When the amount of apple polyphenols added was 0.8%, the 3D shaping effect was optimal with a porosity rate of 4.1%. Apple polyphenols can be used as a good antioxidant additive, and the moderate addition of apple polyphenols can effectively improve the antioxidant and structural stability of 3D-printed processed cheese.

Lipid Oxidation and Volatile Compounds of Almonds as Affected by Gaseous Chlorine Dioxide Treatment to Reduce Salmonella Populations

The effects of gaseous chlorine dioxide (ClO₂) treatment, applied to inactivate Salmonella, on lipid oxidation, volatile compounds, and chlorate levels of dehulled almonds were evaluated during a 3 month accelerated storage at 39 °C. At treatment levels that yielded a 2.91 log reduction of Salmonella, ClO₂ promoted lipid oxidation as indicated by increased peroxide values, total acid number, conjugated dienes, and thiobarbituric acid-reactive substances. Furthermore, several chlorine-containing volatile compounds including trichloromethane, 1-chloro-2-propanol, 1,1,1-trichloro-2-propanol, and 1,3-dichloro-2-propanol were identified in ClO₂-treated samples. However, all the volatile chlorine-containing compounds decreased during the 3 months of storage. Chlorate (26.4 ± 5.1 μg/g) was found on the ClO₂-treated samples. The amounts of non-ethanol alcohols, aldehydes, and carboxylic acids increased following ClO₂ treatments. Some volatiles such as 2,3-butanediol that were present in non-treated samples became non-detectable during post-ClO₂ treatment storage. Overall, our results demonstrated that gaseous ClO₂ treatment promoted lipid oxidation, generation of volatiles of lipid origin, and several chlorine-containing compounds.

Composition and Biological Properties of Blanched Skin and Blanch Water Belonging to Three Sicilian Almond Cultivars

The almond industry produces, by bleaching and stripping, two by-products: blanched skin (BS) and blanch water (BW). The aim of this study was to investigate the nutritional and polyphenolic profile, as well as the antioxidant, antimicrobial, antiviral, and potential prebiotic effects of BS and BW from three different Sicilian cultivars. The total phenols and flavonoids contents were ≥1.72 and ≥0.56 g gallic acid equivalents and ≥0.52 and ≥0.18 g rutin equivalents/100 g dry extract (DE) in BS and BW, respectively. The antioxidant activity, evaluated by 2,2-diphenyl-1-picrylhydrazyl scavenging ability, trolox equivalent antioxidant capacity, ferric-reducing antioxidant power, and oxygen radical absorbance capacity, was ≥3.07 and ≥0.83 g trolox equivalent/100 g DE in BS and BW, respectively. Isorhamnetin-3-O-glucoside was the most abundant flavonoid detected in both by-products. No antimicrobial effect was recorded, whereas BS samples exerted antiviral activity against herpes simplex virus 1 (EC₅₀ 160.96 μg/mL). BS also showed high fibre (≥52.67%) and protein (≥10.99) contents and low fat (≤15.35%) and sugars (≤5.55%), making it nutritionally interesting. The present study proved that the cultivar is not a discriminating factor in determining the chemical and biological properties of BS and BW.

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.

Particle Size Distribution and Predicted Lipid Bioaccessibility of Almonds and the Effect of Almond Processing: A Randomised Mastication Study in Healthy Adults

Almonds are rich in unsaturated lipids, which play a role in some of the reported benefits of almond consumption for human health. Almond lipids are poorly bioaccessible due to almonds' unique physicochemical properties that influence particle size distribution (PSD) following mastication, allowing much intracellular lipid to escape digestion in the upper gastrointestinal tract. To investigate the impact of commercial processing (grinding almonds into flour), on PSD and predicted lipid bioaccessibility following mastication, a randomised cross-over design mastication study was conducted in healthy adults. The PSDs of masticated whole and ground almonds was assessed using two laboratory methods (mechanical sieving and laser diffraction). PSD from mechanical sieving was used to calculate lipid bioaccessibility using a theoretical mathematical model. Thirty-one healthy adults (18-45 years) completed both mastication sessions. Following mastication, ground almonds had a PSD with significantly fewer larger particles and more smaller particles, compared with whole almonds. Predicted lipid bioaccessibility of masticated ground almonds (10.4%, SD 1.8) was marginally but significantly greater than the predicted lipid bioaccessibility of masticated whole almonds (9.3%, SD 2.0; p = 0.017). Commercial grinding of almonds significantly influences the PSD of almonds following mastication, which results in a modest but significant increase in predicted lipid bioaccessibility.

Almond [Prunus dulcis (Mill.) DA Webb] Processing Residual Hull as a New Source of Bioactive Compounds: Phytochemical Composition, Radical Scavenging and Antimicrobial Activities of Extracts from Italian Cultivars ('Tuono', 'Pizzuta', 'Romana')

In this study we developed a new extract, by the use of conventional solid-solvent extraction and a food-grade hydroalcoholic solvent, rich in phenolic and triterpenoid components from almon hull to be employed as functional ingredient in food, pharma and cosmetic sectors. Two autochthonous Sicilian cultivars ('Pizzuta' and 'Romana') and an Apulian modern cultivar ('Tuono') have been tested for the production of the extract. Results showed that the two Sicilian varieties, and in particular the 'Romana' one, present the best characteristics to obtain extracts rich in triterpenoids and hydroxycinnamic acids, useful for the production of nutraceutical supplements. About triterpenoids, the performance of the hydroalcoholic extraction process allowed to never go below 46% of recovery for 'Pizzuta' samples, with significantly higher percentages of recovery for 'Tuono' and 'Romana' extracts (62.61% and 73.13%, respectively) while hydroxycinnamic acids were recovered at higher recovery rate (84%, 89% and 88% for 'Pizzuta', 'Romana' and 'Tuono' extracts, respectively). Invitro antioxidant and antimicrobial activities exerted by the extracts showed promising results with P. aeruginosa being the most affected strain, inhibited up to the 1/8 dilution with 'Romana' extract. All the three tested extracts exerted an antimicrobial action up to 1/4 dilutions but 'Romana' and 'Pizzuta' extracts always showed the greatest efficacy.

Effect of Phenolic Compounds from Almond Skins Obtained by Water Extraction on Pork Patty Shelf Life

The extraction of phenols from almond skin using water has not been applied before. The purpose of this study was to obtain aqueous extracts from almond skin to be added to pork patties to prolong their shelf life. Four different varieties of almonds were studied and aqueous extracts were obtained. The antioxidant capacity and composition of phenol compounds of the extracts were determined. Results showed that the use of water produces extracts with phenol compounds and antioxidant capacity, with the Antoñeta variety presenting the best performance in terms of antioxidant behavior. The most abundant phenolic compounds identified were isorhamentin-3-O-rutinoside, catechin and protocatechuic acid, all of them had a hydrophilic character due to the -OH groups in their molecules. The effect of almond skin extracts (ALMOND) on the shelf life of pork patties was compared with the effects of a control without extract (CONTROL NEG) and a control with sodium ascorbate (CONTROL POS). Throughout storage, values of pH, weight loss, headspace composition, color, TBARs and psychrotrophic aerobic bacteria were studied. CONTROL POS samples showed the lowest lipid oxidation values in comparison to CONTROL NEG or ALMOND extract samples.

Adsorption of Polyphenols from Almond Blanching Water by Macroporous Resin

The almond processing industry generates large volumes of effluent after the blanching process. Blanching water is one of the main by-products with a potential source of polyphenols. However, before being used or discharged, this by-product requires pretreatment. This work was aimed at paving the way toward using adsorption on XAD-7 HP macroporous resin for wastewater treatment. This promising technique could be easily scaled up and integrated into existing production lines. Adsorption was carried out with a fixed bed in counterflow, while desorption was performed by acetone in downflow. With this approach, it was possible to concentrate up to five times the phenolic content of the initial blanching water. The resulting extract was analyzed by ultraperformance liquid chromatography-mass spectrometry (UPLC-MS), identifying more than 89% procyanidins, in addition to catechin, epicatechin, and isorhamnetin-3-O-rutinoside. Applications such as spray-drying and prilling techniques were suggested to improve the efficiency of polyphenols by preserving their stability, bioactivity, and bioavailability.

Rosaceae food allergy: a review

This review provides a global overview on Rosaceae allergy and details the particularities of each fruit allergy induced by ten Rosaceae species: almond/peach/cherry/apricot/plum (Amygdaleae), apple/pear (Maleae), and raspberry/blackberry/strawberry (Rosoideae). Data on clinical symptoms, prevalence, diagnosis, and immunotherapies for the treatment of Rosaceae allergy are herein stated. Allergen molecular characterization, cross-reactivity/co-sensitization phenomena, the impact of food processing and digestibility, and the methods currently available for the Rosaceae detection/quantification in foods are also described. Rosaceae allergy has a major impact in context to pollen-food allergy syndrome (PFAS) and lipid transfer protein (LTP) allergies, being greatly influenced by geography, environment, and presence of cofactors. Peach, apple, and almond allergies are probably the ones most affecting the quality of life of the allergic-patients, although allergies to other Rosaceae fruits cannot be overlooked. From patients' perspective, self-allergy management and an efficient avoidance of multiple fruits are often difficult to achieve, which might raise the risk for cross-reactivity and co-sensitization phenomena and increase the severity of the induced allergic responses with time. At this point, the absence of effective allergy diagnosis (lack of specific molecular markers) and studies advancing potential immunotherapies are some gaps that certainly will prompt the progress on novel strategies to manage Rosaceae food allergies.

The Almond (Prunus dulcis): Chemical Properties, Utilization, and Valorization of Coproducts

Almonds (Prunus dulcis) are one of the most consumed tree-nuts worldwide, with commercial production in arid environments such as California, Spain, and Australia. The high consumption of almonds is partly due to their versatile usage in products such as gluten-free flour and dairy alternatives as well as them being a source of protein in vegetarian diets. They contain high concentrations of health-promoting compounds such as Vitamin E and have demonstrated benefits for reducing the risk of cardiovascular disease and improving vascular health. In addition, almonds are the least allergenic tree nut and contain minute quantities of cyanogenic glycosides. Production has increased significantly in the past two decades with 3.12 billion pounds of kernel meat produced in California alone in 2020 (USDA 2021), leading to a new emphasis on the valorization of the coproducts (e.g., hulls, shells, skins, and blanch water). This article presents a review of the chemical composition of almond kernels (e.g., macro and micronutrients, phenolic compounds, cyanogenic glycosides, and allergens) and the current research exploring the valorization of almond coproducts. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Impact of Analog Rice Derived from Different Composite Flours from Tubers, Germinated Legumes, and Cereals on Improving Serum Markers in Alloxan-Induced Diabetic Rats

This study aimed to evaluate the consumption of four types of analog rice made from different composite flours in alloxan-induced diabetic rats. Forty-two male Wistar rats were divided into seven groups and fed different food for six weeks: normal standard food (NSF), diabetic standard food (DSF), diabetic commercial rice (DCR), and diabetic analog rice (DAR) I∼IV. Total phenolic, dietary fiber, and resistant starch contents were evaluated in every analog and commercial type of rice. The parameters studied were fasting blood glucose, homeostatic model assessment (HOMA) insulin resistance (IR), HOMA β, lipid profile, atherogenic indexes (AI), weight changes, serum insulin and antioxidant activities. Total phenol, dietary fiber, and resistant starch were higher for analog rice IV than the other three analog rice. In addition, analog rice IV had a greater ability to lower fasting blood glucose, total cholesterol, triglycerides, and low-density lipoprotein levels. High density lipoprotein levels increased in all groups fed analog rice, and all diabetic rats fed four types of analog rice had improved weight, antioxidant activity, serum insulin levels, HOMA IR, HOMA β, and AI. Commercial rice consumption did not improve glucose or lipids profiles, antioxidant activity, serum insulin level, HOMA IR, HOMA β, or AI in diabetic mice. These results show that the four types of analog rice significantly improved serum markers in diabetic rats.

A Rapid HPLC-UV Protocol Coupled to Chemometric Analysis for the Determination of the Major Phenolic Constituents and Tocopherol Content in Almonds and the Discrimination of the Geographical Origin

Reversed phase-high-pressure liquid chromatographic methodologies equipped with UV detector (RP-HPLC-UV) were developed for the determination of phenolic compounds and tocopherols in almonds. Nineteen samples of Texas almonds originating from USA and Greece were analyzed and 7 phenolic acids, 7 flavonoids, and tocopherols (−α, −β + γ) were determined. The analytical methodologies were validated and presented excellent linearity (r² > 0.99), high recoveries over the range between 83.1 (syringic acid) to 95.5% (ferulic acid) for within-day assay (n = 6), and between 90.2 (diosmin) to 103.4% (rosmarinic acid) for between-day assay (n = 3 × 3), for phenolic compounds, and between 95.1 and 100.4% for within-day assay (n = 6), and between 93.2–96.2% for between-day assay (n = 3 × 3) for tocopherols. The analytes were further quantified, and the results were analyzed by principal component analysis (PCA), and agglomerative hierarchical clustering (AHC) to investigate potential differences between the bioactive content of almonds and the geographical origin. A decision tree (DT) was developed for the prediction of the geographical origin of almonds proposing a characteristic marker with a concentration threshold, proving to be a promising and reliable tool for the guarantee of the authenticity of the almonds.

Almond (Prunus dulcis cv. Casteltermini) Skin Confectionery By-Products: New Opportunity for the Development of a Functional Blackberry (Rubus ulmifolius Schott) Jam

This work proposes for the first time a model for reusing almond (Prunus dulcis cv. Casteltermini from Sicily, Southern Italy) skin to formulate a new functional blackberry (Rubus ulmifolius Schott) jam. For this purpose, blackberries were analysed fresh and as jam, traditionally prepared with a minimum fruit amount of 80%. Different percentages of almond skin (20, 15, and 10% w/w) were added to jam. The phytochemical profile of enriched jam was investigated by LC-ESI/LTQOrbitrap/MS analyses. Anthocyanins, hydrolysable tannins, and triterpenoids were identified in a blackberry extract, while proanthocyanidins, flavonoids, and oxylipins were identified in an almond extract. The n-hexane extract of P. dulcis skin, investigated by GC-MS, evidenced linoleic, palmitic, and oleic acids as the main abundant compounds. Samples were investigated for their antioxidant activity using DPPH, ABTS, β-carotene, and FRAP tests. The hypoglycaemic and hypolipidemic effects were studied by α-amylase, α-glucosidase, and lipase inhibitory assays. In order to evaluate the effect of thermal process on enriched jam bioactivity, pasteurisation was applied. An increase in activities for all samples was observed, in particular for jam enriched with 20% w/w of almond skin. Based on obtained data, and supported by sensory analysis, we propose enriched jam as a promising source of compounds useful for preventing diseases associated with oxidative stress.

An Updated Overview of Almond Allergens

Tree nuts are considered an important food in healthy diets. However, for part of the world’s population, they are one of the most common sources of food allergens causing acute allergic reactions that can become life-threatening. They are part of the Big Eight food groups which are responsible for more than 90% of food allergy cases in the United States, and within this group, almond allergies are persistent and normally severe and life-threatening. Almond is generally consumed raw, toasted or as an integral part of other foods. Its dietary consumption is generally associated with a reduced risk of cardiovascular diseases. Several almond proteins have been recognized as allergens. Six of them, namely Pru du 3, Pru du 4, Pru du 5, Pru du 6, Pru du 8 and Pru du 10, have been included in the WHO-IUIS list of allergens. Nevertheless, further studies are needed in relation to the accurate characterization of the already known almond allergens or putative ones and in relation to the IgE-binding properties of these allergens to avoid misidentifications. In this context, this work aims to critically review the almond allergy problematic and, specifically, to perform an extensive overview regarding known and novel putative almond allergens.

Health Benefits Related to Tree Nut Consumption and Their Bioactive Compounds

Long-term studies with regular tree nut consumption have indicated positive outcomes for multiple health benefits. Here, we review the beneficial effects of tree nuts, highlighting the impact on glucose modulation, body weight management, cardiovascular risk, inflammation, oxidative stress, cognitive performance, and gut microbiota. Nuts are important sources of nutrients and phytochemicals, which, together with a healthy lipid profile, could help prevent certain chronic diseases, protect against oxidative stress and inflammation, and improve cognitive performance, thus reducing the impact of aging and neurodegeneration.

Correlation between water stress and phenolic compounds of hydroSOStainable almonds

BACKGROUND

Water scarcity is currently affecting many areas of the world, reaching worrying levels in drought areas such as southern Spain. To cope with this issue, researchers in the agricultural sector have implemented deficit irrigation strategies intended to reduce water consumption by increasing fruit quality. Almond is among the most popular tree nuts worldwide and also the most nut cultivated in Spain. Almond consumption, together with other nuts, has been widely associated with improvements in cardiovascular health, metabolic syndrome and diabetes owing to their bioactive compounds such as polyphenols. Water deficit strategies generate hydroSOStainable almonds, raised under water stress conditions, with high content of bioactive compounds. The aim of this work was to study the relationship between water stress, color and polyphenols in hydroSOStainable almonds. For this, instrumental color, total phenolic content and phenolic compounds were measured and correlated using Pearson's correlation.

RESULTS

The results showed a strong relationship between water stress, color and polyphenols of almonds, showing that increasing water stress in plants up to ~100 MPa × day values of stress integral increase the polyphenols in almonds, leading to a reddish color.

CONCLUSION

Finally, this research demonstrated that implementing water-saving strategies help to improve the phenolic content and color of hydroSOStainable almonds and also that isorhamnetin-3-O-rutinoside, isorhamnetin-3-O-glucoside and kaempferol-3-O-glucoside could be important markers of hydroSOStainable almonds (cv. Vairo). Besides, hydroSOStainable almonds could be an important source of phenols, providing 25% of the estimated total polyphenolic daily intake. © 2020 Society of Chemical Industry.

Plant Prebiotics and Their Role in the Amelioration of Diseases

Prebiotics are either natural or synthetic non-digestible (non-)carbohydrate substances that boost the proliferation of gut microbes. Undigested fructooligosaccharides in the large intestine are utilised by the beneficial microorganisms for the synthesis of short-chain fatty acids for their own growth. Although various food products are now recognized as having prebiotic properties, several others, such as almonds, artichoke, barley, chia seeds, chicory, dandelion greens, flaxseeds, garlic, and oats, are being explored and used as functional foods. Considering the benefits of these prebiotics in mineral absorption, metabolite production, gut microbiota modulation, and in various diseases such as diabetes, allergy, metabolic disorders, and necrotising enterocolitis, increasing attention has been focused on their applications in both food and pharmaceutical industries, although some of these food products are actually used as food supplements. This review aims to highlight the potential and need of these prebiotics in the diet and also discusses data related to the distinct types, sources, modes of action, and health benefits.

Tree Nuts and Peanuts as a Source of Natural Antioxidants in our Daily Diet

Tree nuts and peanuts are healthy foods with a proven track record of helping to reduce the incidence of chronic diseases, most notably cardiovascular disease. At the point of consumption, all nuts contain low moisture and ≥ 50% lipid contents, but this is where similarities end. The levels of key nutrients and bioactives including vitamin C, vitamin E, L-arginine, minerals (such as selenium and zinc), and phenolics can differ markedly. Distinctions in the types and quantities of phenolic constituents for tree nut species, as well as the impact of digestion, will affect the nuts' antioxidant potential in vivo. This work provides some insight into the different types of phenolics found in tree nuts and peanuts, the antioxidant potential of their phenolic extracts using in vitro chemical assays, the effect of thermal processing on the stability of the nuts' endogenous phenolics, and the impact on biomarkers of human health arising from randomized clinical trials. Key biomarkers include measures in the reduction of LDL oxidation as well as increases in the levels of vitamin E and selected phenolic compounds in blood plasma postprandially from those of baseline.

Use of Almond Skins to Improve Nutritional and Functional Properties of Biscuits: An Example of Upcycling

Upcycling food industry by-products has become a topic of interest within the framework of the circular economy, to minimize environmental impact and the waste of resources. This research aimed at verifying the effectiveness of using almond skins, a by-product of the confectionery industry, in the preparation of functional biscuits with improved nutritional properties. Almond skins were added at 10 g/100 g (AS10) and 20 g/100 g (AS20) to a wheat flour basis. The protein content was not influenced, whereas lipids and dietary fiber significantly increased (p < 0.05), the latter meeting the requirements for applying "source of fiber" and "high in fiber" claims to AS10 and AS20 biscuits, respectively. The addition of almond skins altered biscuit color, lowering L* and b* and increasing a*, but improved friability. The biscuits showed sensory differences in color, odor and textural descriptors. The total sum of single phenolic compounds, determined by HPLC, was higher (p < 0.05) in AS10 (97.84 µg/g) and AS20 (132.18 µg/g) than in control (73.97 µg/g). The antioxidant activity showed the same trend as the phenolic. The p-hydroxy benzoic and protocatechuic acids showed the largest increase. The suggested strategy is a practical example of upcycling when preparing a health-oriented food product.

Verbesina crocata: A pharmacognostic study for the treatment of wound healing

Ethnopharmacological relevance

Verbesina crocata (Cav.) Less. (Arnica or Capitaneja) is an endemic plant from Mexico restricted to the western part of the country. The aerial parts are used in traditional medicine for the treatment of wounds and burns. The objective of this investigation was to carry out a pharmacognostic study of V. crocata and establish markers that allow for the recognition of the characteristics of the plant and validate its traditional use. The study includes anatomical and chemical characteristics of the plant as well as evaluations of its antioxidant capacity and wound healing ability in a murine model.

Materials and methods

An anatomical study of V. crocata was performed on the middle part of the leaf and stem. A methanolic extract of this species (VcME) was obtained by methanolic maceration of the aerial parts. Subsequently, a partition of the VcME was made to obtain a hexanic fraction (VcH). The phytochemical preliminary screening and characterization by high-performance liquid chromatography/mass spectrometry (HPLC-ESI/MS) of the VcME and VcH were performed. The antioxidant activity and total phenolic content were quantified. The wound healing capacity of the methanolic extract was determined in CD-1 mice by the healing rate, the tensiometric method, and histological analysis.

Results

The anatomical study of V. crocata showed the presence of two types of secretory structures and their position on the leaves. In addition, the characteristics of the middle vein and trichomes are potentially useful for recognition of the species. Chemical compounds detected by HPLC-ESI/MS reveal the presence of sitosterol glycoside and catechin derivatives as principal constituents of V. crocata. The VcME showed low antioxidant capacity and total phenolic. V. crocata had a similar healing effect to Recoveron® in the tensiometric method, but the rate of healing was higher. According to the histological analysis, the treatment of V. crocata promoted the remodelling phase 15 days after the incisional wound.

Conclusion

This is the first pharmacognostic study of this species that covers the plant anatomy, chemical content and biological properties related to its traditional use. V. crocata favours wound healing according to physical and histological evaluations. In addition, the characteristics of the middle vein, trichomes and catechin glycosides are potentially useful for the recognition of this species.

Estrogen receptor modulation of some polyphenols extracted from Daucus carota as a probable mechanism for antifertility effect: An in silico study

The seeds of Daucus carota, traditionally used by women in many countries to prevent conception, were proved to have negative impact on reproductive hormone levels as well as on the estrous cycles in albino mice affecting the fertility status. This study is an attempt to investigate the possible role of polyphenols present in the seeds in hampering the reproductive processes. The Molecular Docking, Molecular Dynamics (MD) simulation and binding free energy calculation studies reveal that six polyphenols present in the seeds can bind with the active sites of human Estrogen Receptor (ER) and may interfere in the estrogen signaling in human. These polyphenols were found to bind to a conservative pocket of ER[Formula: see text], which is comprised of residues 343–388, 421–428 and 525–540. Docking studies indicated the presence of strong hydrogen bonding, pi–pi interactions and numerous hydrophobic interactions that stabilize the ER[Formula: see text]-polyphenol complexes.

The docked complexes were further subjected to MM/GBSA analysis to calculate binding free energies. Molecular dynamic simulation studies carried out for a period of 20[Formula: see text]ns revealed low RMS deviation values suggesting high accuracy of the docking poses and stability of the complexes. Out of the six polyphenols, catechin and epicatechin have shown highest binding affinity towards the ER[Formula: see text] receptor. These findings will help in identifying ER modulators of plant origin targeting ER alpha and predicting their effects on the reproductive hormone homeostasis. Moreover, this study may form preliminary basis for further identification of potential herbal antifertility agents.

Turrón Coproducts as Source of Bioactive Compounds: Assessment of Chemical, Physico-Chemical, Techno-Functional and Antioxidant Properties

The goals of this research were determined the proximate composition, physico-chemical, techno-functional properties, the polyphenolic profile, the organic acids and sugar content and the antioxidant capacities of flours obtained from almonds skins var. comuna (ASFC) and var. fritz (ASFF) coproducts produced in Turrón industry. The chemical composition and physico-chemical properties (pH, water activity and color) were determined. The water holding, oil holding and swelling capacities were also determined, as well as the polyphenolic profile. For the antioxidant capacity, four different assays were used namely: 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay (DPPH^•); Ferrous ions chelating activity (FIC); Ferric reducing antioxidant power (FRAP) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assay (ABTS^•+). The flours obtained from ASFC and ASFF had a high content of dietary fiber (70.50 and 69.83 g/100 g, respectively). The polyphenolic profile, determined by High Performance Liquid Chromatography, identified 21 and 19 polyphenolic compounds in both ASFC and ASFF, being epicatechin and catechin the most abundant compounds. In reference to the antioxidant capacity regards, with all methods assayed except FRAP, ASFC had higher antioxidant activity than ASFF. These coproducts show good technological and antioxidant properties, which makes them a good alternative for its use in the development of new foods.

A One-Pot Ultrasound-Assisted Almond Skin Separation/Polyphenols Extraction and its Effects on Structure, Polyphenols, Lipids, and Proteins Quality

Almond skin is an important by-product in the almond processing industry, rich in potentially health-promoting phenolic compounds. The objective of this present study is to separate the skin from the almond and extract its polyphenol contents using Ultrasound-Assisted Extraction (UAE) at room temperature. Optimization was performed according to a two-variable central composite design (CCD), and the optimum combination of ultrasonic intensity and extraction temperature was obtained through multi-response optimization: ultrasonic intensity (UI), 9.47 W.cm−2; and temperature, 20 °C for an extraction time of 20 min. Under the above-mentioned conditions, total phenolic content was 258% higher with UAE than silent experiment. Mathematic modelling and microscopic investigations were achieved to enable understanding physical and structural effects of ultrasound on almond skins and comprehension of the mechanism behind the enhancement of mass transfer phenomena. Scanning Electron Microscopy (SEM) showed different acoustic cavitation impacts including fragmentation, sonoporation, and erosion. Extracts were analyzed by ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS), identifying a combination of flavanols, flavanones and non-flavonoids. UAE shows no negative effect on almond proteins and lipids when compared to natural almonds (NS).

Almonds (Prunus Dulcis Mill. D. A. Webb): A Source of Nutrients and Health-Promoting Compounds

Almonds (Prunus dulcis Miller D. A. Webb (the almond or sweet almond)), from the Rosaceae family, have long been known as a source of essential nutrients; nowadays, they are in demand as a healthy food with increasing popularity for the general population and producers. Studies on the composition and characterization of almond macro- and micronutrients have shown that the nut has many nutritious ingredients such as fatty acids, lipids, amino acids, proteins, carbohydrates, vitamins and minerals, as well as secondary metabolites. However, several factors affect the nutritional quality of almonds, including genetic and environmental factors. Therefore, investigations evaluating the effects of different factors on the quality of almonds were also included. In epidemiological studies, the consumption of almonds has been associated with several therapeutically and protective health benefits. Clinical studies have verified the modulatory effects on serum glucose, lipid and uric acid levels, the regulatory role on body weight, and protective effects against diabetes, obesity, metabolic syndrome and cardiovascular diseases. Moreover, recent researchers have also confirmed the prebiotic potential of almonds. The present review was carried out to emphasize the importance of almonds as a healthy food and source of beneficial constituents for human health, and to assess the factors affecting the quality of the almond kernel. Electronic databases including PubMed, Scopus, Web of Science and SciFinder were used to investigate previously published articles on almonds in terms of components and bioactivity potentials with a particular focus on clinical trials.

The Antimicrobial and Antiviral Activity of Polyphenols from Almond (Prunus dulcis L.) Skin

Due to their antimicrobial and antiviral activity potential in vitro, polyphenols are gaining a lot of attention from the pharmaceutical and healthcare industries. A novel antiviral and antimicrobial approach could be based on the use of polyphenols obtained from natural sources. Here, we tested the antibacterial and antiviral effect of a mix of polyphenols present in natural almond skin (NS MIX). The antimicrobial potential was evaluated against the standard American Type Culture Collection (ATCC) and clinical strains of Staphylococcus aureus, including methicillin-resistant (MRSA) strains, by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Herpes simplex virus type I was used for the antiviral assessment of NS MIX by plaque assay. Furthermore, we evaluated the expression of viral cascade antigens. NS MIX exhibited antimicrobial (MIC values of 0.31–1.25 mg/ml) and antiviral activity (decrease in the viral titer ** p < 0.01, and viral DNA accumulation * p < 0.05) against Staphylococcus aureus and HSV-1, respectively. Amongst the isolated compounds, the aglycones epicatechin and catechin showed the greatest activity against S. aureus ATCC 6538P (MIC values of 0.078–0.15 and 0.15 mg/ml, respectively), but were not active against all the other strains. These results could be used to develop novel products for topical use.

Phenolic compositions and antioxidant properties of leaves of eight persimmon varieties harvested in different periods

The compositions and contents of antioxidant components and antioxidant attributes (scavenging DPPH radicals, TEAC, ferric reducing power and inhibiting Cu²⁺-induced human LDL oxidation) for the leaves of eight persimmon varieties harvested from Sep. to Nov. were determined. Harvest time and variety were important factors affecting the compositions and contents of phenolic compounds in persimmon leaves; moreover, phenolic contents (polyphenol, flavonoid, condensed tannin and phenolic acid) of the leaves were significantly correlated with their antioxidant activities. For each variety, the leaves harvested in months with higher temperature, solar radiation and sunshine duration had higher phenolic contents contributing to better antioxidant properties (ranking: Sep. > Oct. > Nov.). In addition, the compositions and contents of phenolic components and antioxidant capacities for the leaves from various persimmon varieties were also different. The leaves of persimmon varieties belonging to pollination constant and astringent (PCA) had higher phenolic contents and also presented better antioxidant effects.

The new paradigm for androgenetic alopecia and plant-based folk remedies: 5α-reductase inhibition, reversal of secondary microinflammation and improving insulin resistance

ETHNOPHARMACOLOGICAL RELEVANCE

Research in the past half a century has gradually sketched the biological mechanism leading to androgenetic alopecia (AGA). Until recently the aetiological paradigm has been too limited to enable intelligent commentary on the use of folk remedies to treat or reduce the expression of this condition. However, our understanding is now at a point where we can describe how some folk remedies work, predict how effective they will be or why they fail.

RESULTS

The new paradigm of AGA is that inheritance and androgens (dihydrotestosterone) are the primary contributors and a secondary pathology, microinflammation, reinforces the process at more advanced stages of follicular miniaturisation. The main protagonist to microinflammation is believed to be microbial or Demodex over-colonisation of the infundibulum of the pilosebaceous unit, which can be ameliorated by antimicrobial/acaricidal or anti-inflammatory therapies that are used as adjuvants to androgen dependent treatments (either synthetic or natural). Furthermore, studies reveal that suboptimal androgen metabolism occurs in both AGA and insulin resistance (low SHBG or high DHT), suggesting comorbidity. Both can be ameliorated by dietary phytochemicals, such as specific classes of phenols (isoflavones, phenolic methoxy abietanes, hydroxylated anthraquinones) or polycyclic triterpenes (sterols, lupanes), by dual inhibition of key enzymes in AGA (5α-reductase) and insulin resistance (ie., DPP-4 or PTP1B) or agonism of nuclear receptors (PPARγ). Evidence strongly indicates that some plant-based folk remedies can ameliorate both primary and secondary aetiological factors in AGA and improve insulin resistance, or act merely as successful adjuvants to mainstream androgen dependent therapies.

CONCLUSION

Thus, if AGA is viewed as an outcome of primary and secondary factors, then it is better that a 'multimodal' or 'umbrella' approach, to achieve cessation and/or reversal, is put into practice, using complementation of chemical species (isoflavones, anthraquinones, procyanidins, triterpenes, saponins and hydrogen sulphide prodrugs), thereby targeting multiple 'factors'.

Anti-aging potential of tree nuts with a focus on the phytochemical composition, molecular mechanisms and thermal stability of major bioactive compounds

Tree nuts, complete functional foods, contain macro- and micronutrients of high biological value.

Phytochemical Composition and Biological Activities of Dyssodia tagetiflora Lag

While plants of the genus Dyssodia are used by man to a certain extent, few phytochemical and pharmacological studies have been performed with species of this genus. D. tagetiflora is an endemic plant of Mexico and has been used as fodder. The aim of this research was to isolate and identify the main bioactive components and evaluate the insecticidal, antioxidant, genotoxic and cytoprotective activities of D. tagetiflora. The isolated substances included an essential oil composed of six monoterpenes, and extracts containing two flavonols, three flavonol-glycosides and four thiophenes. The compounds were characterized using spectroscopic and spectrometric methods, including GC/MS, MS and NMR. The essential oil showed insecticidal activity against Drosophila melanogaster larvae. The methanolic extract of D. tagetiflora (DTME) had strong antioxidant activity against DPPH and ABTS radicals; DTME showed no evidence of genotoxic or cytotoxic effects. In contrast, DTME showed a cytoprotective effect attenuating the formation of H₂ O₂ -induced micronuclei in Vicia faba roots. This report is the first to describe the phytochemical and biological activity of D. tagetiflora.

Valorization Challenges to Almond Residues: Phytochemical Composition and Functional Application

Almond is characterized by its high nutritional value; although information reported so far mainly concerns edible kernel. Even though the nutritional and commercial relevance of the almond is restricted to almond meat; to date; increasing attention has been paid to other parts of this fruit (skin; shell; and hull); considered by-products that are scarcely characterized and exploited regarding their properties as valuable sources of bioactive compounds (mainly represented by phenolic acids and flavonoids). This lack of proper valorization procedures entails the continuation of the application of traditional procedures to almond residues that nowadays are mainly addressed to livestock feed and energy production. In this sense; data available on the physicochemical and phytochemical composition of almond meat and its related residues suggest promising applications; and allow one to envisage new uses as functional ingredients towards value-added foods and feeds; as well as a source of bioactive phytochemicals to be included in cosmetic formulations. This objective has prompted investigators working in the field to evaluate their functional properties and biological activity. This approach has provided interesting information concerning the capacity of polyphenolic extracts of almond by-products to prevent degenerative diseases linked to oxidative stress and inflammation in human tissues and cells; in the frame of diverse pathophysiological situations. Hence; this review deals with gathering data available in the scientific literature on the phytochemical composition and bioactivity of almond by-products as well as on their bioactivity so as to promote their functional application.