Almond Skin Research Articles

Recycling of Almond By-Products for Intestinal Inflammation: Improvement of Physical-Chemical, Technological and Biological Characteristics of a Dried Almond Skins Extract.

Background: Almond skins are rich in bioactive compounds that undergo oxidation/degradation phenomena and are poorly soluble in water, reducing in vivo absorption and bioavailability, factors that influence the pharmacological activity of an active product. We developed a dried acetonic almond skins extract/cyclodextrin complex to improve extract solubility, dissolution rate and biological activity. Methods: A lyophilized acetonic almond skin extract was produced. To optimize complex formulation, phase solubility studies and complex characterization (absorption studies, differential scanning calorimetry (DSC), morphology, solubility studies) were performed. To evaluate a possible use in healthy products, tumor necrosis factor-α levels and reactive oxygen species release, as well as cicloxygenase-2 and inducible nitric oxide synthase expression in intestinal epithelial cells, were also evaluated. Results: Phase solubility studies showed a Bs-type profile. A 1:1 dried acetonic almond skins extract/cyclodextrin ratio was able to improve extract water solubility and dissolution rate (100% in 45 min). The UV-Vis spectra of complex revealed a hypsochromic and hyperchromic effect, probably due to a partial inclusion of extract in cyclodextrin cavity through weak bonds, confirmed by DSC and morphology studies. The technological improvement in the extract characteristics also led to better biological activity. In fact, the complex effectively reduces tumor necrosis factor-α levels with respect to the pure extract and significantly inhibits the reactive oxygen species release, even if only at the lower concentration of 5 μg/mL. Conclusion: The complex was able to overcome solubility problems and could be used in inflammatory disease.

How does water stress affect the low molecular weight phenolics of hydroSOStainable almonds?

Water scarcity is a threat for food production because, water, is more and more limited and force farmers to use new deficit irrigation (DI) strategies without affecting fruit yield and quality. No information exists on almond polyphenols and proanthocyanidins (PAs) produced under DI. The present work studied the effect of 2 regulated DI (RDI) and one sustained (SDI) on the low molecular weight phenolics together with the antioxidant activity (AA) in almonds. Fifteen phenolic compounds were identified (13 flavonoids and 2 non-flavonoids) and 10 PAs. Kaempferol-3-O-galactoside was the predominant compound in almond skin and whole kernel but it was not found in deskinned kernels. The use of moderate RDI significantly increased the total phenolic content in skin (∼9.8%), PAs, and the AA. Consequently, after one season the application of DI positively affected the almond cv. Vairo phenols, however, several seasons must be evaluated in order to corroborate the present results.

Metabolite profiling and antioxidant activity of the polar fraction of Italian almonds (Toritto and Avola): Analysis of seeds, skins, and blanching water

The health benefits of almonds along with their ability to prevent atheroschlerosis as well as cardiovascular and diabetes risks are well known. Previous works were focused mainly on the lipid fraction, thus a lack of information about the polar constituents still persists. In order to provide deeper insight into the chemical composition of almond, the polar fraction of Italian almond cultivars (Toritto and Avola) was investigated. The MeOH extract of the Toritto cultivar was submitted to LC-ESI-(HR)MS/MS experiments, highlighting the occurrence of several compounds, mainly cyanogenic glycosides, glycosylated flavonoids, proanthocyanidins, and a diterpene glycoside. EtOH and EtOH:H2O solution were also employed for extractions, resulting selective for flavonoids and proanthocyanidins, while cyanogenic glycosides were mainly detected in EtOH:H2O extract. Almonds were also blanched to afford skins and blanching water which were analyzed by LC-ESI-(HR)MS/MS experiments in order to establish the source of the identified compounds. Cyanogenic glycosides were detected in the peeled almonds, while flavonoids and proanthocyanidins were detected in almond skins and blanching water. The LC-ESI-(HR)MS/MS analyses of the almonds of the Avola cvs (Fascionello, Pizzuta and Romana) were compared with those of the Toritto cv., showing clear differences in their metabolome, probably due to the different growing conditions. Finally, total phenolic content and radical scavenging activity of the extracts and blanching waters were evaluated by Folin-Ciocalteu assay and by DPPH and ABTS+ assays, highlighting interesting antioxidant properties possessed by almond skins and blanching water, suggesting their potential employment in pharmaceutical, cosmetic and nutraceutical formulations.

Novel Antioxidant Packaging Films Based on Poly(ε-Caprolactone) and Almond Skin Extract: Development and Effect on the Oxidative Stability of Fried Almonds.

Antioxidant films based on poly(ε-caprolactone) (PCL) containing almond skin extract (ASE) were developed for food packaging applications. The effect of ASE incorporation on the morphological, structural, colour, mechanical, thermal, barrier and antioxidant properties of the prepared films were evaluated. The structural, tensile and thermal properties of the films were not altered due to ASE addition. Although no significant differences were observed for the oxygen permeability of samples, some increase in water absorption and water vapour permeability was observed for active films due to the hydrophilic character of ASE phenolic compounds, suggesting the suitability of this novel packaging for fatty foods conservation. ASE conferred antioxidant properties to PCL films as determined by the DPPH radical scavenging activity. The efficiency of the developed films was evaluated by the real packaging application of fried almonds at different ASE contents (0, 3, 6 wt.%) up to 56 days at 40 °C. The evolution of peroxide and p-anisidine values, hexanal content, fatty acid profile and characteristic spectroscopy bands showed that active films improved fried almonds stability. The results suggested the potential of PCL/ASE films as sustainable and antioxidant food packaging systems to offer protection against lipid oxidation in foods.

Almond Skin Extracts and Chlorogenic Acid Delay Chronological Aging and Enhanced Oxidative Stress Response in Yeast.

Almond (Prunus dulcis (Mill.) D.A.Webb) is one of the largest nut crops in the world. Recently, phenolic compounds, mostly stored in almond skin, have been associated with much of the health-promoting behavior associated with their intake. The almond skin enriched fraction obtained from cold-pressed oil residues of the endemic Moroccan Beldi ecotypes is particularly rich in chlorogenic acid. In this study, both almond skin extract (AE) and chlorogenic acid (CHL) supplements, similar to traditional positive control resveratrol, significantly increased the chronological life-span of yeast compared to the untreated group. Our results showed that AE and CHL significantly reduced the production of reactive oxygen and nitrogen species (ROS/RNS), most likely due to their ability to maintain mitochondrial function during aging, as indicated by the maintenance of normal mitochondrial membrane potential in treated groups. This may be associated with the observed activation of the anti-oxidative stress response in treated yeast, which results in activation at both gene expression and enzymatic activity levels for SOD2 and SIR2, the latter being an upstream inducer of SOD2 expression. Interestingly, the differential gene expression induction of mitochondrial SOD2 gene at the expense of the cytosolic SOD1 gene confirms the key role of mitochondrial function in this regulation. Furthermore, AE and CHL have contributed to the survival of yeast under UV-C-induced oxidative stress, by reducing the development of ROS/RNS, resulting in a significant reduction in cellular oxidative damage, as evidenced by decreased membrane lipid peroxidation, protein carbonyl content and 8-oxo-guanine formation in DNA. Together, these results demonstrate the interest of AE and CHL as new regulators in the chronological life-span and control of the oxidative stress response of yeast.

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).

A Quick, Green and Simple Ultrasound-Assisted Extraction for the Valorization of Antioxidant Phenolic Acids from Moroccan Almond Cold-Pressed Oil Residues

Almond (Prunus dulcis (Mill.) D.A. Webb) is one of the most important nut crops both in terms of area and production. Over the last few decades, an important part of the beneficial actions for health associated with their consumption was attributed to the phenolic compounds, mainly accumulated in almond skin. Interestingly, after cold-pressed oil extraction, most of these antioxidant phenolic compounds are retained in a skin-enriched by-product, a so-called almond cold-pressed oil residue. In Morocco, the fifth highest ranking producer in the world, this production generates an important part of this valuable byproduct. In the present study, using a multivariate Box–Behnken design, an ultrasound-assisted extraction method of phenolic compounds from Moroccan almond cold-pressed oil residue was developed and validated. Response surface methodology resulted in the optimal extraction conditions: the use of aqueous ethanol 53.0% (v/v) as a green solvent, applying an ultrasound frequency of 27.0 kHz for an extraction duration of 29.4 min. The present ultrasound-assisted extraction allowed substantial gains in terms of extraction efficiency compared to conventional heat reflux extraction. Applied to three different local Beldi genotypes growing at three different experimental sites, the optimal conditions for ultrasound-assisted extraction led to a total phenolic content of 13.86 mg/g dry weight. HPLC analysis revealed that the main phenolic compounds from this valuable byproduct were: chlorogenic acid followed by protocatechuic acid, p-hydroxybenzoic acid, and p-coumaric acid. The accumulation of these phenolic compounds appeared to be more dependent on the genetic background than on the environmental impact here represented by the three experimental culture sites. Both in vitro cell free and cellular antioxidant assays were performed, and revealed the great potential of these extracts. In particular, correlation analysis provided evidence of the prominent roles of chlorogenic acid, protocatechuic acid, and p-hydroxybenzoic acid. To summarize, the validated ultrasound-assisted extraction method presented here is a quick, green, simple and efficient for the possible valorization of antioxidant phenolic compounds from Moroccan almond cold-pressed oil residues, making it possible to generate extracts with attractive antioxidant activities for future nutraceutical and/or cosmetic applications.

Almond skin extract mediated optimally biosynthesized antibacterial silver nanoparticles enable selective and sensitive colorimetric detection of Fe+2 ions

The safety of drinking water is one of the most important public health issues as very high concentrations of metal like iron acts as a useful surrogate for other heavy metals. The present study demonstrates the use of almond skin extract (ASE) for simple and rapid synthesis of antibacterial silver nanoparticles (AgNPs) for the development of a highly selective and sensitive colorimetric method for the detection of Fe+2 in water samples. The optimization of various biogenic synthesis parameters showed ASE:AgNO3 ratio of 4:1,1 mM of AgNO3, pH 6 and incubation for 10 min at 70 °C were the optimum conditions. The test of antibacterial activity against widely used, representative Gram-negative and positive bacteria showed that AgNPs exhibit good activity against all five tested bacterial strains and comparatively were more effective against Gram-negative bacteria. Further, the test of AgNPs as a colorimetric probe for the detection of 20 different metal ions demonstrated that AgNPs were highly selective and sensitive towards the detection of Fe+2. The study of sensitivity of Fe+2 detection showed 245 ppm as the Limit of detection whereas, the intra-day recovery of Fe+2 in the range of 87.2–100.1 % with %RSD in the range of 4.2–6.5 % and inter-day recovery of Fe+2 in the range of 92.02–96.59 % with %RSD in the range of 2.9–3.8 % demonstrated the excellent precision and accuracy of the assay method. Thus, our AgNPs based selective and sensitive assay can be applied to the analysis of iron in drinking water samples.

Sustainable approach to almond skin mediated synthesis of tunable selenium microstructures for coating cotton fabric to impart specific antibacterial activity

Currently, the synthesis of nanostructured inorganic materials with tunable morphology is still a great challenge. In this study, almond skin extract was employed for the biogenic synthesis of selenium nanoparticles with tunable morphologies such as rods and brooms. The effects of various synthesis parameters on morphologies were investigated using UV–Visible spectroscopy and scanning electron microscopy (SEM) which indicated that selenium brooms (SeBrs) were best synthesized using almond skin extract and optimized conditions of SeO2, ascorbic acid, pH, incubation temperature and time. Based on these results, the mechanism of SeBrs synthesis is proposed as having involved four stages such as nucleation, self-assembly, Ostwald ripening, and decomposition. Further, the test of antibacterial activity together with minimum inhibitory concentrations and minimum bactericidal concentrations indicated the selective, specific and good activity against B. subtilis. In addition, in situ coating of SeBrs on cotton fabric and its investigation by SEM demonstrated successful coating. Evident from plate-based assay and study of growth kinetics, coated fabric exhibited excellent anti-B. subtilis activity which demonstrated that biogenic SeBrs can be employed to coat cotton fabrics that can be used in operation theatres to reduce the episodes of Bacillus related Bacteraemia.

On compressive and morphological features of 3D printed almond skin powder reinforced PLA matrix

This paper reports the compressive, morphological and surface hardness properties of almond skin powder reinforced polylactic acid (PLA) matrix based 3D printed functional prototypes prepared by fused filament fabrication (FFF) as biomedical scaffolds. In this study the 3D printed functional parts were subjected to compression, morphological and Shore D hardness investigations. The results of this study highlight that maximum compressive strength at peak (37.712 MPa), maximum compressive strength at break (33.93 MPa) and Young’s modulus (387.80 MPa) was observed in case of sample printed at infill density 100%, infill angle 90° and infill speed 70 mm s−1 (as per ASTM D695). The maximum modulus of toughness as 3.47 MPa was observed in the case of printed sample at infill density 60%, infill angle 60° and infill speed 70 mm s−1. The results are supported by optical photomicrographs and Shore D hardness. Finally mathematical equations were developed (as empirical model) to predict different mechanical properties (based upon historical data approach) supported by Taguchi analysis.

On effect of almond skin powder waste reinforcement in PA6: Rheological, thermal and wear properties

The use of almond skin powder (ASP) as reinforcement in different thermoplastics has been widely explored for improving mechanical properties. But hitherto little has been reported on ASP reinforcement in polyamide6 (PA6) for establishing rheological, thermal (heat capacity) and wear properties in 3D printing applications. This paper reports the effect of ASP reinforcement in PA6 on rheological, thermal and wear properties for possible 3D printing by using commercial fused deposition modelling (FDM). The results of study suggests that with increase in ASP reinforcement (0–7.5 wt% the melt flow index (MFI) increases from 17.27 g/10 min to 26.23 g/10 min but as ASP wt% increases to 10% in PA6, the reduction in MFI (19 g/10 min) was observed. As regards to thermal stability was concerned it has been ascertained that with increase of ASP reinforcement in PA6, the heat capacity significantly reduces (with addition of ASP in PA6 0–10 wt% from 43.75j/g to 22.16j/g) based upon differential scanning calorimeter (DSC) analysis. Further based upon pin on disk test (under dry sliding conditions) the significant decrease in wear rate was noticed (453–200 µm) with addition of ASP in PA6. The results are supported with optical photo-micrographic analysis (for surface properties).

On mechanical, thermal and morphological investigations of almond skin powder-reinforced polylactic acid feedstock filament

The almond skin powder is one of the biodegradable and biocompatible food wastes that can be used as reinforcement in polylactic acid (PLA) for preparation of biomedical scaffolds/implants (for high mechanical performance) by fused filament fabrication. The present study deals with the melt processing of almond skin powder as reinforcement from 0 wt% to 5 wt% in the PLA matrix by twin-screw extrusion process. The results of the study suggested that reinforcing the almond skin powder as 2.5 wt% in the PLA matrix mechanically strengthens the feedstock filaments but the increase in the proportion up to 5 wt% reduces the mechanical strength to a significant level. A similar trend has been observed in differential scanning calorimeter observations for thermal stability analysis. As regard to the rheological property is concerned, the melt flow index shows a significant reduction with reinforcement of almond skin powder in PLA. The results are also supported by photomicrographic analysis (for surface properties) and Taguchi-based optimization of twin-screw extrusion process parameters (for multifactor optimization).

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.

Polyphenols in Almond Skins after Blanching Modulate Plasma Biomarkers of Oxidative Stress in Healthy Humans.

Almond skins are a waste byproduct of blanched almond production. Polyphenols extracted from almond skins possess antioxidant activities in vitro and in vivo. Thus, we examined the pharmacokinetic profile of almond skin polyphenols (ASP) and their effect on measures of oxidative stress. In a randomized crossover trial, seven adults consumed two acute ASP doses (225 mg (low, L) or 450 mg (high, H) total phenols) in skim milk or milk alone. Plasma flavonoids, glutathione peroxidase (GPx), glutathione (GSH), oxidized GSH (GSSG), and resistance of low- density lipoprotein (LDL) to oxidation were measured over 10 h. The H dose increased catechin and naringenin in plasma, with maximum concentrations of 44.3 and 19.3 ng/mL, respectively. The GSH/GSSG ratio at 3 h after the H doses was 212% of the baseline value, as compared to 82% after milk (p = 0.003). Both ASP doses upregulated GPx activity by 26–35% from the baseline at 15, 30, 45, and 120 min after consumption. The in vitro addition of α-tocopherol extended the lag time of LDL oxidation at 3 h after L and H consumption by 144.7% and 165.2% of that at 0 h compared to no change after milk (p ≤ 0.05). In conclusion, ASP are bioavailable and modulate GSH status, GPx activity, and the resistance of LDL to oxidation.

Analysis of Oral Food Challenge Outcomes in IgE-Mediated Food Allergies to Almond in a Large Cohort

Although almond specific IgE-mediated food allergies have traditionally been equated with other tree nut allergies, outcomes of oral food challenges to almond and the utility of clinical testing to predict IgE-mediated almond hypersensitivity are not well known. To describe almond oral challenge outcomes and assess the predictive value of clinical testing. A total of 603 almond challenges performed for 590 patients, aged 1 to 66 years, were analyzed from Massachusetts General Hospital allergy practices. Reactions were graded using the Niggemann and Beyer allergic reaction grading system and the Sampson 2006 National Institute of Allergy and Infectious Diseases anaphylaxis definition. Almond challenges included 545 passes (92%), 15 (3%) indeterminates, and 30 (5%) failures, in contrast with 31% challenge failures for other foods. Most reactions were mild; 21 (4%) had grade 2/3 allergic symptoms, and 3 (0.5%) had anaphylaxis. Median almond specific IgE level was 0.89 kU/L (range, <0.35 to >100 kU/L), median skin prick test wheal diameter was 4.0 mm (range, 0-28 mm), and 475 subjects (81%) were sensitized to almond. Failure was associated with higher almond specific IgE level (P < .001), larger almond skin prick test wheal diameter (P= .001), higher peanut IgE level (P= .003), and a history of almond reaction (P < .029). Almond specific IgE level, almond skin prick test wheal diameter, and age at challenge combined demonstrated good predictive value for grade 2/3 allergic reactions by receiver-operating characteristic analysis (area under the curve, 0.83). The proportion of failed almond challenges (5%) was low in contrast with other allergens, suggesting that some almond challenges may be safely conducted with higher patient-to-staff ratios or potentially introduced at home. Although reactions are usually uncommon and mild, anaphylaxis is possible with high almond sensitization.

Irrigation deficit turns almond by-products into a valuable source of antimicrobial (poly)phenols

Almond (Prunus dulcis (Mill.) D. A. Webb) production keeps an increasing trend worldwide, leading to augment in generation of harmful by-products that should be valorized as a source of bioactive phytochemicals with application in the development of new added-value products. The assessment of almond hulls and skins on their (poly)phenolic composition was developed upon two seasons, under five irrigation regimes, regarding total phenolics, flavonoids, and ortho-diphenols, as well as individual phenolic compounds analyzed by High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD). As functional tests, extracts were assessed on their radical scavenging activity in vitro and reducing power, and screened on their antimicrobial activity against multidrug resistant bacterial pathogens. The phenolic profile and antioxidant activities were evaluated in blanching water as well. Naringenin-7-O-glucoside and isorhamnetin-3-O-rutinoside were the most abundant phenolics in almond hulls and skins. Influence of irrigation treatments and season on phenolic content differed among by-products; hulls being more influenced by irrigation and skins by the agro-climatic conditions. The synthesis of individual phenolics was more influenced by season than treatment. According to the chemical and biological correlations, the presence of (poly)phenols seems to be responsible for the antioxidant and antimicrobial properties revealed. The knowledge generated upon the present work contributes to understand the variability of almond by-products composition attributable to seasonal and irrigation conditions, and to envisage valorization alternatives for these under explored residues and blanching water.

Co-ingestion of whole almonds and almond oil with carbohydrate suppresses postprandial glycaemia in mice in an insulin-dependent and insulin-independent manner.

Co-ingestion of almonds with carbohydrate prevents excessive increase in plasma glucose level (PGL), but information about the functional fraction is limited. Identifying the functional fraction is necessary to use almonds more efficiently in terms of controlling postprandial glycaemia after a high-carbohydrate meal. In the present study, we evaluated the effects of almond skin, oil, water-soluble fraction and water-insoluble fraction on both postprandial glycaemia and insulinaemia. The effect of almond skin was tested by comparing the effect of whole almonds with the effect of skinless almonds. Male ICR mice were administered dextrin and 4g/kg body weight test samples. After the administration, 2-h postprandial changes in glycaemia and insulinaemia were measured. Oil was the only fraction being able to blunt postprandial glycaemia. Interestingly, when co-ingesting with dextrin, almond oil did not change the insulin level compared with the control but whole almonds or skinless almonds triggered a 4-fold increase in insulin level. The co-ingestion of whole almonds or skinless almonds similarly suppressed the PGL at 15 and 30min (P<0·05), which means almond skin has no effect on postprandial glycaemia. Neither soluble nor insoluble fractions lead to any significant changes in postprandial glycaemia and insulinaemia. In conclusion, oil is the main functional component accounting for the glycaemia-lowering effect without altering insulin level.

Almond by-products: Extraction and characterization of phenolic compounds and evaluation of their potential use in composite dough with wheat flour

Blanched skins and blanching water, by-products of almond processing, were evaluated as potential ingredients of bakery products. The research included three phases: i) optimization of skin drying; ii) optimization of quali-quantitative determination of phenolic compounds, by comparing three extracting protocols; iii) assessment of the impact of by-products on the rheology of composite doughs with wheat flour. The least time-consuming drying mode (at 60 °C for 30 min) retained better odor notes, higher content of phenolics (814 μg/g d.m. by HPLC, with the most effective extracting method) and greater antioxidant activity than sun-drying. Blanching water showed 917 μg/mL phenolics. Dried almond skins altered alveograph and farinograph indices of dough at doses higher than 30 and 50 g/kg, respectively, whereas blanching water did not cause significant changes. Therefore, almond skins could be used in products tolerating weak gluten network, such as cookies, whereas blanching water could be added to any bakery good.

Multiple Reaction Monitoring Profiling to Assess Compliance with an Almond Consumption Intervention

BackgroundAlmonds are extremely rich sources of lipids and flavonoids, and their consumption is associated with several health benefits. However, there are no analytical methods available to document compliance with prescribed or self-reported chronic almond consumption. ObjectiveThe aim was to use an analytical approach that identifies metabolic profiles associated with long-term almond consumption to ascertain compliance with prescribed consumption. MethodsA multiple reaction monitoring (MRM)–profiling strategy was designed to isolate metabolic changes in erythrocytes after 12 wk of almond consumption. MRM-profiling data acquisition and analysis involve performing separate discovery and screening steps to detect molecular features related to metabolic changes between experimental groups. Samples used for this research were erythrocytes recovered at baseline, after 12 wk of almond consumption (W12-almond group), and after 12 wk of a nut-free diet (W12-control group). For the MRM-profiling discovery step, representative samples (pools) of erythrocytes from individuals of all groups were interrogated by precursor ion and neutral loss scan experiments on the basis of previous knowledge of chemical functional groups present in the samples. The outputs of the discovery phase were methods used for the MRM-profiling screening phase to interrogate individual samples on the basis of fast-MRM measurements. In addition, we screened the literature for flavonoids identified in almond skins and included them for individual sample screening. ResultsOf the 254 m/z values monitored, 5 ratios and combinations of specific ions with receiver operating characteristic curve AUCs >0.89 provided a sensitivity of 74.2% and a specificity of 90% for blind samples presented in the model. Eight of the 31 participants (25.8%) in the W12-almond group and 3 of the 30 (10%) participants in the W12-control group were misclassified by all 5 ratios. Ratios and combinations of specific transitions were mainly related to membrane lipids. ConclusionThe misclassifications observed as a result of ratio performance evaluation may indicate noncompliance as supported by the dietary intake data. The parent trial was registered at www.clinicaltrials.gov as NCT02360787.

Almond Skin Extracts Abrogate HSV-1 Replication by Blocking Virus Binding to the Cell.

The aim of the present research was to determine the effect of almond skin extracts on herpes simplex virus 1 (HSV-1) replication. Drug-resistant strains of HSV frequently develop following therapeutic treatment. Therefore, the discovery of novel anti-HSV drugs deserves great effort. Here, we tested both natural (NS) and blanched (BS) polyphenols-rich almond skin extracts against HSV-1. HPLC analysis showed that the prevalent compounds in NS and BS extracts contributing to their antioxidant activity were quercetin, epicatechin and catechin. Results of cell viability indicated that NS and BS extracts were not toxic to cultured Vero cells. Furthermore, NS extracts were more potent inhibitors of HSV-1 than BS extracts, and this trend was in agreement with different concentrations of flavonoids. The plaque forming assay, Western blot and real-time PCR were used to demonstrate that NS extracts were able to block the production of infectious HSV-1 particles. In addition, the viral binding assay demonstrated that NS extracts inhibited HSV-1 adsorption to Vero cells. Our conclusion is that natural products from almond skin extracts are an extraordinary source of antiviral agents and provide a novel treatment against HSV-1 infections.