Toward new benchmark adsorbents: preparation and characterization of activated carbon from argan nut shell for bisphenol A removal

The use of argan nut shell as a precursor for producing activated carbon was investigated in this work. Two activated carbons AC-HP and AC-Na were prepared from argan nut shell by chemical activation method using phosphoric acid (H₃PO₄) and sodium hydroxide (NaOH), respectively. Textural, morphological, and surface chemistry characteristics were studied by nitrogen physisorption, TGA, SEM, TXRF, FTIR, XRD, and by determining the pH_PZC of the AC-HP. The adsorption experiments revealed that AC-HP was more efficient in adsorption of BPA due to high specific surface area (1372 m²/g) compared to AC-Na (798 m²/g). The obtained adsorption data of BPA on AC-HP correlated well with the pseudo-second-order model and the Langmuir isotherm (Qmax = 1250 mg/g at 293 K). The thermodynamic parameters (ΔG° < 0, ΔH° < 0, and ΔS° < 0) indicate that adsorption of BPA on AC-HP was spontaneous and exothermic in nature. The regeneration of AC-HP showed excellent results after 5 cycles (95-93%). This work does not only provide a potential way to use argan nut shell but also represents a sustainable approach to synthesize AC-HP, which might be an ideal material for various applications (energy storage, catalysis, and environmental remediation).

Natural variation of selenium in Brazil nuts and soils from the Amazon region

Brazil nut tree (Bertholletia excelsa) is native of the Amazon rainforest. Brazil nuts are consumed worldwide and are known as the richest food source of selenium (Se). Yet, the reasoning for such Se contents is not well stablished. We evaluated the variation in Se concentration of Brazil nuts from Brazilian Amazon basin, as well as soil properties, including total Se concentration, of the soils sampled directly underneath the trees crown, aiming to investigate which soil properties influence Se accumulation in the nuts. The median Se concentration in Brazil nuts varied from 2.07 mg kg^-1 (in Mato Grosso state) to 68.15 mg kg^-1 (in Amazonas state). Therefore, depending on its origin, a single Brazil nut could provide from 11% (in the Mato Grosso state) up to 288% (in the Amazonas state) of the daily Se requirement for an adult man (70 μg). The total Se concentration in the soil also varied considerably, ranging from <65.76 to 625.91 μg kg^-1, with highest Se concentrations being observed in soil samples from the state of Amazonas. Se accumulation in Brazil nuts generally increased in soils with higher total Se content, but decreased under acidic conditions in the soil. This indicates that, besides total soil Se concentration, soil acidity plays a major role in Se uptake by Brazil nut trees, possibly due to the importance of this soil property to Se retention in the soil.

Three new areca alkaloids from the nuts of Areca catechu

Three new areca alkaloids arecatemines A-C (1-3), together with five known ones (4-8), were isolated from the nuts of Areca catechu. The structures of new compounds including absolute configurations were elucidated using comprehensive spectroscopic and electronic circular dichroism (ECD). The known compounds were identified by comparing with data in the literature.

Phenol metabolism and preservation of fresh in-hull walnut stored in modified atmosphere packaging

BACKGROUND

The effects of modified atmosphere packaging (MAP) on phenol metabolism and preservation of fresh in-hull walnuts have been investigated. Fruit was packaged under MAP1 (film thickness, 30 μm), MAP2 (45 μm) and MAP3 (50 μm) and stored at -0.5 to 1.0 °C for up to 60 days.

RESULTS

Firmness, soluble solid concentration, total phenols, total flavonoids and total antioxidant activity of the green hull were maintained at higher levels under the MAP conditions, whereas decay incidence was lower compared to the control during storage. Green hull of fruit under MAP conditions contained lower polyphenol oxidase activity than the control and the peroxidase activity was at a similar level to the control after 18 days. Phenylalanine ammonialyase activity was enhanced by MAP conditions, with two peaks on days 18 and 36. Until day 60, the peroxide value and acid value of kernel oils under MAP conditions were lower than that of the control.

CONCLUSION

The MAP3 treatment was most effective for maintaining kernel quality. The protective role of MAP conditions on phenolic contents in green hull may contribute to the mitigation of decay and the maintenance of kernel quality. © 2017 Society of Chemical Industry.

Arecoline N-Oxide Upregulates Caspase-8 Expression in Oral Hyperplastic Lesions of Mice

Areca nut is strongly associated with oral squamous cell carcinoma (OSCC) occurrence. Arecoline N-oxide (ANO), a metabolite of the areca alkaloid arecoline, exhibits an oral fibrotic effect in NOD/SCID mice. Caspase-8, a cysteine protease encoded by the CASP8 gene, is a central mediator in the extrinsic apoptotic pathway via death receptors. Deregulation of caspase-8 in OSCC has been reported. This study investigates the regulation of caspase-8 in ANO-induced oral squamous epithelial hyperplasia that represents the initial highly proliferative stage of oral carcinogenesis. CASP8 somatic mutations were identified from whole-exome sequencing of OSCC samples. Immunohistochemical staining showed upregulation of caspase-8 in ANO-induced hyperplasia of both NOD-SCID and C57BL/6 mice. Levels of expression of CASP8, APAF-1, BAX, and BAD increased in ANO-treated DOK cells. Co-localization of increased caspase-8 and PCNA levels was detected in ANO-induced hyperplastic lesions, whereas no co-localization among γ-H2A.X, caspase-3, and upregulated caspase-8 was observed. The findings indicate that upregulation of caspase-8 is involved in cell proliferation rather than apoptosis during the initial stage of ANO-mediated oral tumorigenesis.

Characterization and Identification of Cryptic Biopeptides in Carya illinoinensis (Wangenh K. Koch) Storage Proteins

The objective of this research was to identify and characterize the encoded peptides present in nut storage proteins of Carya illinoinensis. It was found, through in silico prediction, proteomic analysis, and MS spectrometry, that bioactive peptides were mainly found in albumin and glutelin fractions. Glutelin was the major fraction with ~53% of the nut storage proteins containing at least 21 peptides with different putative biological activities, including antihypertensives, antioxidants, immunomodulators, protease inhibitors, and inhibitors of cell cycle progression in cancer cells. Data showed that using 50 μg/mL tryptic digests of enriched peptides obtained from nut glutelins is able to induce up to 19% of apoptosis in both HeLa and CasKi cervical cancer cells. To our knowledge, this is the first report that shows the potential value of the nut-encoded peptides to be considered as adjuvants in cancer therapies.

Microwave-Assisted Extraction of Cannabinoids in Hemp Nut Using Response Surface Methodology: Optimization and Comparative Study

Hemp nut is commonly incorporated into several food preparations; however, most countries set regulations for hemp products according to their cannabinoid content. In this study, we have developed an efficient microwave-assisted extraction (MAE) method for cannabinoids (i.e., Δ9-tetrahydrocannabinol, cannabidiol, and cannabinol) in hemp nut. Optimization of the MAE procedure was conducted through single factor experiments and response surface methodology (RSM). A comparative study was also conducted to determine the differences in the extraction yields and morphology of hemp nut between MAE and reference extraction methods, namely heat reflux extraction (HRE), Soxhlet extraction (SE), supercritical fluid extraction (SFE), and ultrasound-assisted extraction (UAE). Among the independent variables in RSM, the temperature was the most significant parameter. The optimal conditions of MAE were as follows: extraction solvent of methanol, microwave power of 375 W, temperature of 109 °C, and extraction time of 30 min. Compared with reference extraction methods, MAE achieved the highest extraction yields of total cannabinoids in hemp nut (6.09 μg/g for MAE; 4.15 μg/g for HRE; 5.81 μg/g for SE; 3.61 μg/g for SFE; 3.73 μg/g for UAE) with the least solvent consumption and shortest time. Morphological observations showed that substantial cell rupturing occurred in the microstructure of hemp nut after MAE, indicating enhanced dissolution of the target compounds during the extraction process. The MAE method is thus a rapid, economic, and environmentally friendly extraction method that is both effective and practical for industrial applications.

Fruit position within the canopy affects kernel lipid composition of hazelnuts

BACKGROUND

The aim of this research was to study the variability in kernel composition within the canopy of hazelnut trees.

RESULTS

Kernel fresh and dry weight increased linearly with fruit height above the ground. Fat content decreased, while protein and ash content increased, from the bottom to the top layers of the canopy. The level of unsaturation of fatty acids decreased from the bottom to the top of the canopy. Thus, the kernels located in the bottom layers of the canopy appear to be more interesting from a nutritional point of view, but their lipids may be more exposed to oxidation. The content of different phytosterols increased progressively from bottom to top canopy layers.

CONCLUSION

Most of these effects correlated with the pattern in light distribution inside the canopy. The results of this study indicate that fruit position within the canopy is an important factor in determining hazelnut kernel growth and composition. © 2017 Society of Chemical Industry.

Optimization of process condition for the preparation of amine-impregnated activated carbon developed for CO2 capture and applied to methylene blue adsorption by response surface methodology

The present research describes the optimal adsorption condition for methylene blue (MB). The adsorbent used here was monoethanol amine-impregnated activated carbon (MEA-AC) prepared from green coconut shell. Response surface methodology (RSM) is the multivariate statistical technique used for the optimization of the process variables. The central composite design is used to determine the effect of activation temperature, activation time and impregnation ratio on the MB removal. The percentage (%) MB adsorption by MEA-AC is evaluated as a response of the system. A quadratic model was developed for response. From the analysis of variance, the factor which was the most influential on the experimental design response has been identified. The optimum condition for the preparation of MEA-AC from green coconut shells is the temperature of activation 545.6°C, activation time of 41.64 min and impregnation ratio of 0.33 to achieve the maximum removal efficiency of 98.21%. At the same optimum parameter, the % MB removal from the textile-effluent industry was examined and found to be 96.44%.

Effect of Drying Moisture Exposed Almonds on the Development of the Quality Defect Concealed Damage

Concealed damage (CD), is a term used by the nut industry to describe a brown discoloration of kernel nutmeat that becomes visible after moderate heat treatments (e.g., roasting). CD can result in consumer rejection and product loss. Postharvest exposure of almonds to moisture (e.g., rain) is a key factor in the development of CD as it promotes hydrolysis of proteins, carbohydrates, and lipids. The effect of drying moisture-exposed almonds between 45 to 95 °C, prior to roasting was evaluated as a method for controlling CD in roasted almonds. Additionally, moisture-exposed almonds dried at 55 and 75 °C were stored under accelerated shelf life conditions (45 °C/80% RH) and evaluated for headspace volatiles. Results indicate that drying temperatures below 65 °C decreases brown discoloration of nutmeat up to 40% while drying temperatures above 75 °C produce significant increases in brown discoloration and volatiles related to lipid oxidation, and nonsignificant increases in Amadori compounds. Results also demonstrate that raw almonds exposed to moisture and dried at 55 °C prior to roasting, reduce the visual sign of CD and maintain headspace volatiles profiles similar to almonds without moisture damage during accelerated storage.

Pistachio nut allergy: An updated overview

Pistachio nut (Pistacia vera) is highly appreciated for its organoleptic characteristics and potential health benefits. However, this tree nut is also responsible for triggering moderate to severe IgE-mediated reactions in allergic individuals. Currently, pistachio nut allergy has gained some special attention, mainly due to its intrinsic relation with cashew nut allergy. Like for other nuts, the prevalence of pistachio nut allergy seems to be increasing at a global scale. Until now, there are five allergenic proteins officially listed for pistachio nut (Pis v 1, Pis v 2, Pis v 3, Pis v 4 and Pis v 5). Relevant data on their biochemical classification has become available, enabling establishing a correlation with the respective clinical symptoms. The establishment of an effective allergen risk assessment is a key issue for the food industry, policy makers and regulatory agencies. Thus, the availability of fast, specific and sensitive methods to detect trace amounts of allergens in processed foods is crucial. In the specific case of pistachio nut, there are some protein- and DNA-based methods for its detection/quantification in foods, which can aid to verify label information. Accordingly, all relevant research advances on this topic were summarised, updated and critically discussed in this review.

Prebiotic nut compounds and human microbiota

Nut consumption is clearly related to human health outcomes. Its beneficial effects have been mainly attributed to nut fatty acid profiles and content of vegetable protein, fiber, vitamins, minerals, phytosterols and phenolics. However, in this review we focus on the prebiotics properties in humans of the non-bioaccessible material of nuts (polymerized polyphenols and polysaccharides), which provides substrates for the human gut microbiota and on the formation of new bioactive metabolites and the absorption of that may partly explain the health benefits of nut consumption.

Effects of roasting on kernel peroxide value, free fatty acid, fatty acid composition and crude protein content

Roasting nuts may alter their chemical composition leading to changes in their health benefits. However, the presence of testa may alleviate the negative effects of thermal treatments. Hence, this study aimed to explore the effects of roasting on kernel chemical quality and colour development of Canarium indicum and examine to what extent testa would protect kernels against damage from roasting. Roasting decreased peroxide value but increased free fatty acid, probably due to increased cell destruction and lack of enzyme inactivation, respectively. Protein content of kernels significantly decreased after roasting compared to raw kernels. However, testa-on kernels contained significantly higher protein content compared to testa-off kernels. Whilst colour development and mottling were observed in temperatures beyond 120°C, roasting did not alter fatty acid compositions of kernels. The mild roasting and presence of testa in kernels can be used to enhance health benefits of kernels.

In vitro antioxidant and antibacterial activity of various extracts from exocarps and endocarps of walnut

Juglans regia seed has been used in traditional medicines as antimicrobial, antihelmintic and anti-diarrhoeal. In the present study, the antibacterial capabilities dichloromethane, ethyl acetate, methanol and aqueous extracts of endocarp and exocarp of walnut were determined against two Gram-positive bacteria and one Gram-negative bacteria. The antioxidant activity was screened by 2, 2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) assays. The highest antioxidant activity was observed for methanol extract of endocarp in both methods and it was stronger than positive control butylated hydroxy toluene (BHT). The total phenolic contents were ranging between 34.59 to 68.34mg GAE/g DW. The results revealed that all extracts had antibacterial activity against selected bacteria except aqueous extract. The methanol extract of endocarp presented the highest zone of inhibition against tested pathogens (9-21mm). From the results it is conclude that the methanol extract from endocarp of walnut could be used as a natural preservative ingredient in food and pharmaceutical industries.

Analysis of α-helix unfolding in the pine nut peptide Lys-Cys-His-Lys-Pro induced by pulsed electric field

BACKGROUND

A variety of analytical techniques were applied to explore the effects of pulsed electric field (PEF) on α-helix structural changes in the novel antioxidant peptide Lys-Cys-His-Lys-Pro (KCHKP, 611.76 Da).

RESULTS

The relative α-helix content of the KCHKP peptide was significantly altered from 100% to 89.91 ± 0.97% when the electric pulse frequency was 1800 Hz and the field intensity was 10 kV cm^-1 . Moreover, the 1,1-diphenyl-2-pycryl-hydrazyl (DPPH) and 2,2-azinobis diammonium salt (ABTS) radical-scavenging activities of PEF-treated KCHKP were increased from 56.31% ± 0.74% to 84.33% ± 1.23% and from 40.56% ± 0.78% to 51.33% ± 0.27%, respectively.

CONCLUSION

PEF treatment increased peptide linkage stretch vibration and altered hydrogen bonding of KCHKP. The stability of the α-helix structure was influenced by hydrogen bonds within the peptide linkage of KCHKP induced by PEF and was related to changes in antioxidant activity. © 2017 Society of Chemical Industry.

Evaluation of migration of heavy metals and performance of product during co-pyrolysis process of municipal sewage sludge and walnut shell

A feasible and efficient type of biological sludge-activated carbon (BSAC) was produced by co-pyrolysis of municipal sewage sludge (MSS) and walnut shell (4:1, w/w) at 500 °C. It was found that BSAC was typical mesoporous material with favorable pore structure and abundant surface functional groups, whose performance was improved compared with conventional sludge-activated carbon (CSAC), combined with walnut shell-activated carbon (WSAC). The migration and transformation behavior of heavy metals (Zn, Cu, Ni, Cd, and Cr) in raw material after co-pyrolysis process were investigated. The results indicated that co-pyrolysis could promote mobile fraction (acid soluble/exchangeable and reducible fractions) of heavy metals to stable fraction (oxidizable and residual fractions). The leaching concentrations Cu, Ni, Cd, Cr, and Zn were lower than restrictive standards in China, and the environmental risk assessment results showed that after co-pyrolysis, the risk levels of Cu, Ni, and Cd were decreased to low risk, especially Cr in product was confirmed to no risk.

Pesticide residues in nut-planted soils of China and their relationship between nut/soil

Twenty-nine pesticide residues in nut-planted soils from China were investigated. One organophosphate (chlorpyrifos) was detected in 5.3% soils, and the residue levels of 7.2 μg/kg to 77.2 μg/kg. The concentrations of six organochlorines (DDT, HCH, endosulfan, quintozene, aldrin and dieldrin) detected in 78.9% soils were 0.6 μg/kg to 90.1 μg/kg. The residue levels of six pyrethroids (bifenthrin, fenpropathrin, cyhalothrin, cypermethrin, fenvalerate and deltamethrin) detected in 65.8% soils were 1.5 μg/kg to 884.3 μg/kg. Triadimefon and buprofezin were found in 71.1% and 52.6% samples, respectively, with the corresponding concentrations of 9.8 μg/kg to 193.7 μg/kg and 87.9 μg/kg to 807.4 μg/kg. The multiple residues were found in 76.3% soils. A significant correlation between pesticide residues in nuts and soils was observed, with the correlation coefficient (r) 0.83 (P < 0.001). In addition, the bioconcentration factor (BCF) values for the explanation of pesticides from soils into nuts were ranged from 0.8 to 16.5. The results showed that some pesticides could accumulate in nut by the uptake effect from soil.

Separation of Ellagitannin-Rich Phenolics from U.S. Pecans and Chinese Hickory Nuts Using Fused-Core HPLC Columns and Their Characterization

U.S. pecans and Chinese hickory nuts possess a wide array of phenolic constituents with potential health benefits including phenolic acids and proanthocyanidins. Only limited information is available, however, on their compositions. The present study optimized the separation performance and characterized the low-molecular-weight phenolic fractions of these nuts with C18 and pentafluorophenyl (PFP) fused-core LC columns by employing a kinetic approach. Although both types of reversed-phase columns demonstrated similar performance in general, the PFP column furnished greater plate numbers and superior peak shapes for the low-molecular-weight fractions as well as overall separations of ellagic acid derivatives. The high-molecular-weight fraction of pecans, analyzed by a 3-μm HILIC column, possessed more proanthocyanidins than the Chinese hickory nuts with dimers and trimers (31.4 and 18.34 mg/g crude extract, respectively) being present at the greatest levels. Chinese hickory nuts had lower proanthocyanidin content but possessed tetramers and pentamers at 4.46 and 4.01 mg/g crude extract, respectively.

Metabolic and Blood Pressure Effects of Walnut Supplementation in a Mouse Model of the Metabolic Syndrome

There is extensive evidence that walnut consumption is protective against cardiovascular disease and diabetes in the healthy population, but the beneficial effects of walnut consumption in individuals with the metabolic syndrome (MetS) remain uncertain. We compared a range of cardio-metabolic traits and related tissue gene expression associated with 21 weeks of dietary walnut supplementation in a mouse model of MetS (MetS-Tg) and wild-type (WT) mice (n = 10 per genotype per diet, equal males and females). Compared to standard diet, walnuts did not significantly alter food consumption or body weight trajectory of either MetS-Tg or WT mice. In MetS-Tg mice, walnuts were associated with reductions in oral glucose area under the curve (gAUC, standard diet 1455 ± 54, walnut 1146 ± 91, p = 0.006) and mean arterial blood pressure (MAP, standard diet 100.6 ± 1.9, walnut 73.2 ± 1.8 mmHg, p < 0.001), with neutral effects on gAUC and MAP in WT mice. However, in MetS-Tg mice, walnuts were also associated with trends for higher plasma cholesterol (standard diet 4.73 ± 0.18, walnut 7.03 ± 1.99 mmol/L, p = 0.140) and triglyceride levels (standard diet 2.4 ± 0.5, walnut 5.4 ± 1.6 mmol/L, p = 0.061), despite lowering cholesterol and having no effect on triglycerides in WT mice. Moreover, in both MetS-Tg and WT mice, walnuts were associated with significantly increased liver expression of genes associated with metabolism (Fabp1, Insr), cell stress (Atf6, Ddit3, Eif2ak3), fibrosis (Hgf, Sp1, Timp1) and inflammation (Tnf, Ptpn22, Pparg). In conclusion, dietary walnuts were associated with modest favourable effects in WT mice, but a combination of beneficial and adverse effects in MetS-Tg mice, and up-regulation of hepatic pro-fibrotic and pro-inflammatory genes in both mouse strains.

Impact of pecan nut shell aqueous extract on the oxidative properties of margarines during storage

BACKGROUND

The oxidative properties of margarines supplemented with pecan nut shell extract, rosemary extract and butylated hydroxytoluene (BHT) were investigated.

RESULTS

The extracts of pecan nut shell and rosemary showed a high content of total phenolics and condensed tannins (93 and 102.9 mg GAE g^-1 and 46 and 38.9 mg CE g^-1 respectively) as well as a high antioxidant activity (1257 and 2306 µmol TEAC g^-1 and 293 and 856 mg TEAC g^-1 by ABTS and DPPH methods respectively). Gallic acid, chlorogenic acid, p-hydroxybenzoic acid, epicatechin and epicatechin gallate were identified in the pecan nut shell extract. Peroxide and p-anisidine values of 3.75-4.43 meq kg^-1 and 1.22-2.73 respectively, Totox values of 9.88-10.8 and specific extinction values of 4.38-4.59 and 0.92-0.94 at 232 and 268 nm respectively were observed after 8 months of storage in the studied samples.

CONCLUSION

Margarines supplemented with pecan nut shell extract, rosemary extract or BHT during prolonged storage were found to be of equal quality within the degree of confidence limits. The extract of pecan nut shell may be considered as a natural product replacement for the synthetic antioxidant BHT. © 2016 Society of Chemical Industry.

Protective Effect of Juglans regia L. Walnut Extract Against Oxidative DNA Damage

Walnuts (Juglans regia L.) are relevant components of the Mediterranean diet providing important macronutrients, micronutrients and other bioactive constituents including unsaturated fatty acids, proteins, fiber, vitamins, minerals, phytosterols and polyphenols. Although the walnut beneficial effects in human health are widely recognized by a lot of epidemiologic studies very little is known regarding its effect on damaged DNA. The aim of the present study was to investigate the effect of Juglans regia L. ethanolic extract from kernel on the induction of DNA strand breaks by thiol/Fe³⁺/O₂ mixed function oxidase, tert-butyl hydroperoxide or UVC radiations in acellular and cellular models. Plasmid DNA cleavage and fast Halo assay were used to monitor oxidative damage to DNA. Both approaches showed protection of oxidatively injured DNA. These results agree with a lot of scientific proofs which recommend walnut as dietary adjunct in health promotion and prevention as well as in treatment of lifestyle-related oxidative diseases.

Chemical and Sensory Characterization of Oxidative Changes in Roasted Almonds Undergoing Accelerated Shelf Life

In almonds, there is no standard method for detecting oxidative changes and little data correlating consumer perception with chemical markers of rancidity. To address this, we measured peroxide values (PV), free fatty acid values (FFAs), conjugated dienes, tocopherols, headspace volatiles, and consumer hedonic response in light roasted (LR) and dark roasted (DR) almonds stored under conditions that promote rancidity development over 12 months. Results demonstrate that, although rancidity develops at different rates in LR and DR almonds, consumer liking was not significantly different between LR and DR almonds. Average hedonic ratings of almonds were found to fall below a designated acceptable score of 5 ("neither like nor dislike") by 6 months of storage. This did not correspond with recommended industry rejection standard of PV < 5 mequiv peroxide/kg oil and FFA < 1.5% oleic. FFAs remain well below <1.5% oleic during storage, indicating that FFAs are not a good marker of rancidity in roasted almonds stored in low humidity environments. Regression of consumer liking to concentration of rancidity indicators revealed that selected headspace volatiles, including heptanal, octanal, nonanal, 2-octenal, 2-heptanone, 2-pentylfuran, hexanal, and pentanal, had a better correlation with liking than did nonvolatile indicators.

Analysis of Alkaloids in Areca Nut-Containing Products by Liquid Chromatography-Tandem Mass Spectrometry

Chewing of areca nut in different forms such as betel quid or commercially produced pan masala and gutkha is common practice in the Indian subcontinent and many parts of Asia and is associated with a variety of negative health outcomes, particularly oral and esophageal cancers. Areca nut-specific alkaloids arecoline, arecaidine, guvacoline, and guvacine have been implicated in both the abuse liability and the carcinogenicity of the areca nut. Therefore, variations in the levels of areca alkaloids could potentially contribute to variations in addictive and carcinogenic potential across areca nut-containing products. Here, we developed an accurate and robust liquid chromatography-tandem mass-spectrometry (LC-MS/MS) method for simultaneous quantitation of all four areca alkaloids and applied this method to the analysis of a range of products obtained from India, China, and the United States. The results of the analyses revealed substantial variations in the levels of alkaloids across the tested products, with guvacine being the most abundant (1.39-8.16 mg/g), followed by arecoline (0.64-2.22 mg/g), arecaidine (0.14-1.70 mg/g), and guvacoline (0.17-0.99 mg/g). Substantial differences in the relative contribution of individual alkaloids to the total alkaloid content were also observed among the different products. Our results highlight the need for systematic surveillance of constituent levels in areca nut-containing products and a better understanding of the relationship between the chemical profile and the harmful potential of these products.

ASSESSMENT OF A STABLE COSMETIC PREPARATION BASED ON ENZYMATIC INTERESTERIFIED FAT, PROPOSED IN THE PREVENTION OF ATOPIC DERMATITIS

Atopic dermatitis is one of the most common skin disorders seen in infants, children and adults. Proper prevention might slow the atopic symptoms. The purpose of the work was a sensory analysis, an evaluation of moistening properties and stability of emulsions based on an enzymatic interesterified fat blend (mutton tallow and walnut oil) and homogenized at different revolutions and different contents of thickener. The emulsions were evaluated with respect to sensory and skin moisturizing properties by 78 respondents. Stability tests, particle size, distribution, dispersity index, morphology structure of the emulsions were determinated too. Taking into consideration all properties of the emulsions, emulsion IV (containing 0.9 g carboxymethyl cellulose and homogenized at 18000 rpm) and emulsion V (1.5 g of carboxymethyl cellulose and homogenized at 24000 rpm) were found to be of optimum composition. The emulsions exhibited good stability, were highly rated in sensory terms and displayed optimum moistening properties. It has been proven that model emulsions based on interesterified fats containing partial acylglicerols, with optimum carboxymethyl cellulose content and specific revolutions at the time of homogenization are an opportunity for developing preparations targeted at skins requiring special care (e.g., with atopic dermatitis or psoriasis). The work proved the use of enzymatic process to create the emulsifier, which represents the innovative contribution of this work. Also it showed an additional application of enzymatic interesterified fats which since has been used only in food industries.

Pinolenic Acid in Structured Triacylglycerols Exhibits Superior Intestinal Lymphatic Absorption As Compared to Pinolenic Acid in Natural Pine Nut Oil

The positional distribution pattern of fatty acids (FAs) in the triacylglycerols (TAGs) affects intestinal absorption of these FAs. The aim of this study was to compare lymphatic absorption of pinolenic acid (PLA) present in structured pinolenic TAG (SPT) where PLA was evenly distributed on the glycerol backbone, with absorption of pine nut oil (PNO) where PLA was predominantly positioned at the sn-3 position. SPT was prepared via the nonspecific lipase-catalyzed esterification of glycerol with free FA obtained from PNO. Lymphatic absorption of PLA from PNO and from SPT was compared in a rat model of lymphatic cannulation. Significantly (P < 0.05) greater amounts of PLA were detected in lymph collected for 8 h from an emulsion containing SPT (28.5 ± 0.7% dose) than from an emulsion containing PNO (26.2 ± 0.6% dose), thereby indicating that PLA present in SPT has a greater capacity for lymphatic absorption than PLA from PNO.

Dissolution and fractionation of nut shells in ionic liquids

The aim of this work was to study the dissolution of raw peanut and chestnut shells in ionic liquids. Dissolution of raw biomass up to 7wt% was achieved under optimized operatory conditions. Quantification of polysaccharides dissolved through quantitative ¹³Cq NMR revealed extractions of the cellulosic material to ionic liquids as high as 87%. Regeneration experiments using an antisolvent mixture allowed to recover the cellulosic material and the ionic liquid. The overall mass balance presented very low loss rates (<8%), recoveries of 75% and 95% of cellulosic material from peanut and chestnut shells, respectively, and the recovery of more than 95% of the ionic liquid in both cases. These results show the high potential of using nut shells and ionic liquids for biorefining purposes. Moreover, high recovery of ionic liquids favors the process from an economical point of view.

Static Hot Air and Infrared Rays Roasting are Efficient Methods for Aflatoxin Decontamination on Hazelnuts

Aflatoxins are a group of secondary metabolites produced by members of Aspergillus Section Flavi that are dangerous to humans and animals. Nuts can be potentially contaminated with aflatoxins, often over the legal threshold. Food processes, including roasting, may have different effects on mycotoxins, and high temperatures have proven to be very effective in the reduction of mycotoxins. In this work, two different roasting methods-traditional static hot air roasting and infra-red rays roasting-were applied and compared for the detoxification of hazelnuts from Italy and Turkey. At the temperature of 140 °C for 40 min of exposure, detoxification was effective for both roasting techniques. Residual aflatoxins after infra-red rays treatments were lower compared to static hot air roasting. On Italian hazelnuts, residual aflatoxins were lower than 5%, while for Turkish hazelnuts they were lower than 15% after 40 min of exposure to an infra-red rays roaster. After roasting, the perisperm was detached from the nuts and analyzed for aflatoxin contents. Residual aflatoxins in the perisperm ranged from 80% up to 100%. After roasting, the lipid profile and the nutritional quality of hazelnuts were not affected. Fatty acid methyl esters analyses showed a similar composition for Italian and Turkish hazelnuts.

Probabilistic uncertainty analysis based on Monte Carlo simulations of co-combustion of hazelnut hull and coal blends: Data-driven modeling and response surface optimization

The aim of present study is to investigate the thermogravimetric behaviour of the co-combustion of hazelnut hull (HH) and coal blends using three approaches: multi non-linear regression (MNLR) modeling based on Box-Behnken design (BBD) (1), optimization based on response surface methodology (RSM) (2), and probabilistic uncertainty analysis based on Monte Carlo simulation as a function of blend ratio, heating rate, and temperature (3). The response variable was predicted by the best-fit MNLR model with a predicted regression coefficient (R²_pred) of 99.5%. Blend ratio of 90/10 (HH to coal, %wt), temperature of 405°C, and heating rate of 44°Cmin^-1 were determined as RSM-optimized conditions with a mass loss of 87.4%. The validation experiments with three replications were performed for justifying the predicted-mass loss percentage and 87.5%±0.2 of mass loss were obtained under RSM-optimized conditions. The probabilistic uncertainty analysis were performed by using Monte Carlo simulations.

Identification and Characterization of Ana o 3 Modifications on Arginine-111 Residue in Heated Cashew Nuts

Raw and roasted cashew nut extracts were evaluated for protein modifications by mass spectrometry. Independent modifications on the Arg-111 residue of Ana o 3 were observed in roasted but not raw cashew nuts. The mass changes of 72.0064 or 53.9529 Da are consistent with the formation of carboxyethyl and hydroimidazolone modifications at the Arg-111 residue. These same modifications were observed in Ana o 3 purified from roasted but not raw cashew nuts, albeit at a relatively low occurrence. Circular dichroism indicated that Ana o 3 purified from raw and roasted cashew nuts had similar secondary structure, and dynamic light scattering analysis indicated there was no observable difference in particle size. The stability of Ana o 3 purified from raw and roasted cashew nuts to trypsin was similar in the absence of or following treatment with a reducing agent. Only minor differences in IgE binding to Ana o 3 were observed by ELISA among a cohort of cashew-allergic patient sera.

Preparation and characterization of baru (Dipteryx alata Vog) nut protein isolate and comparison of its physico-chemical properties with commercial animal and plant protein isolates

BACKGROUND

The Brazilian leguminous tree locally known in the Cerrado Biome as baru (Dipteryx alata Vog), provides a healthy edible oil source. The proteinaceous cake remaining after oil extraction could be transformed into new products to foodstuff development, such as protein concentrates and isolates, adding value to the production chain. In this study, it is described the preparation and characterization of baru nut protein isolate (BPI) from deffated baru flour, and measurements of its functional, nutritional, and thermal properties, in comparison to the more common vegetable (soybeans) and animal (casein and albumin) protein sources of the food industry.

RESULTS

BPI presented higher protein content than soybean, casein and albumin commercial protein isolates, despite losses of albumins and low molecular weight globulins during the isolation procedure. Thermodynamics studies suggested that BPI has a well-conserved protein arrangement and lower thermostability than the other protein sources. BPI showed high in vitro digestibility and suitable and desirable functional properties such as water and oil absorption capacity, emulsifying activity, and foam formation and stability at mild and neutral pH.

CONCLUSION

BPI could be used either as a substitute ingredient in oily food formulations or in the development of new products of its own. © 2016 Society of Chemical Industry.

Food Fingerprinting: Metabolomic Approaches for Geographical Origin Discrimination of Hazelnuts (Corylus avellana) by UPLC-QTOF-MS

Ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was used for geographical origin discrimination of hazelnuts (Corylus avellana L.). Four different LC-MS methods for polar and nonpolar metabolites were evaluated with regard to best discrimination abilities. The most suitable method was used for analysis of 196 authentic samples from harvest years 2014 and 2015 (Germany, France, Italy, Turkey, Georgia), selecting and identifying 20 key metabolites with significant differences in abundancy (5 phosphatidylcholines, 3 phosphatidylethanolamines, 4 diacylglycerols, 7 triacylglycerols, and γ-tocopherol). Classification models using soft independent modeling of class analogy (SIMCA), linear discriminant analysis based on principal component analysis (PCA-LDA), support vector machine classification (SVM), and a customized statistical model based on confidence intervals of selected metabolite levels were created, yielding 99.5% training accuracy at its best by combining SVM and SIMCA. Forty nonauthentic hazelnut samples were subsequently used to estimate as realistically as possible the prediction capacity of the models.

Corrosion inhibition property of polyester-groundnut shell biodegradable composite

The use of natural fibers as reinforcing materials in thermoplastics and thermoset matrix composites provide optimistic environmental profits with regard to ultimate disposability and better use of raw materials. The present work is focused on the corrosion inhibition property of a polymer matrix composite produced by the use of groundnut shell (GNS) waste. Polyester (PE) was synthesized by condensation polymerization of symmetrical 1,3,4-oxadiazole and pimelic acid using sodium lauryl sulfate as surfactant. The polyester-groundnut shell composite (PEGNS) was prepared by ultrasonication method. The synthesized polyester-groundnut shell composite was characterized by FT-IR, TGA and XRD analysis. The corrosion inhibitory effect of PEGNS on mild steel in 1M H₂SO₄ was investigated using gravimetric method, electrochemical impedance spectroscopy, potentiodynamic polarization, atomic absorption spectroscopy and scanning electron microscopy. The results showed that PEGNS inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration and decrease with increasing temperature. The composite inhibited the corrosion of mild steel through adsorption following the Langmuir adsorption isotherm. Changes in the impedance parameters R_t, C_dl, I_corr, E_corr, b_a and b_c suggested the adsorption of PEGNS onto the mild steel surface, leading to the formation of protective film.

Monitoring of aflatoxin G1, B1, G2, and B2 occurrence in some samples of walnut

This research was conducted to monitor the aflatoxigenic fungi and aflatoxin contamination of walnut in the Hamedan province. For this purpose, 40 samples were analyzed. Aspergillus, Alternaria, Rhizopus, Cladosporium, Fusarium, yeast, and some different bacteria were isolated from walnuts. Aspergillus is the most frequent genus. Aspergillus flavus was predominantly isolated. HPLC was used for evaluation of aflatoxin contamination of walnut samples. Aflatoxins G1 (AFG1), B1 (AFB1), G2 (AFG2), and B2 (AFB2) were produced by 20 isolates. AFG1 and AFB1 were being predominant at concentration ranges of 1.7-18.2 and 0-8.2 ngg^-1, respectively. Highest levels were found in one sample that was highly contaminated with Aspergillus flavus/Aspergillus parasiticus. Methyl beta cyclodextrin also was performed for detection of aflatoxigenic Aspergillus isolates. The results showed that only 31.6% (p < 0.05) of A. flavus and A. parasiticus isolates were able to produce aflatoxin. A significant difference was shown between shielded and unshielded walnut in aflatoxin contamination. The content of aflatoxin in most of the walnut samples did not reach to maximum tolerable limit for aflatoxin B1 in EU standard (p > 0.05). Thus, systematic and continues monitoring of walnuts is recommended.

Antioxidant and Anticancer Activities of Walnut (Juglans regia L.) Protein Hydrolysates Using Different Proteases

Walnut (Juglans regia L.) contains approximately 20-25 % protein with abundant essential amino acids. The enzymatic hydrolysate of Persian walnut (Chandler) seed proteins was prepared by incubation with three different proteases, including pancreatic chymotrypsin and trypsin, and a microbial enzyme proteinase K. The hydrolysates were found to possess excellent antioxidant capacities. The peptide fractions scavenged the 2, 2'-anizo-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radicals and inhibited the activity of reactive oxygen species. Walnut protein hydrolysates were also tested, for the first time, against the viability of human breast (MDA-MB231) and colon (HT-29) cancer cell lines. MTT, [3-(4, 5dimethylthiazolyl)-2,5-diphenyl-tetrazolium bromide], assay was used to assess in vitro cancer cell viability upon treatment with the peptide fractions. The peptide fractions showed cell growth inhibition of 63 ± 1.73 % for breast cancer and 51 ± 1.45 % for colon cancer cells. Thus, a direct correlation between antioxidant and anticancer activities of walnut peptide fractions exists and supports their potential therapeutic benefit.

Schistosomicidal Activity of Alkyl-phenols from the Cashew Anacardium occidentale against Schistosoma mansoni Adult Worms

Bioassay-guided study of the ethanol extract from the cashew Anacardium occidentale furnished cardol triene (1), cardol diene (2), anacardic acid triene (3), cardol monoene (4), anacardic acid diene (5), 2-methylcardol triene (6), and 2-methylcardol diene (7). 1D- and 2D-NMR experiments and HRMS analysis confirmed the structures of compounds 1-7. Compounds 2 and 7 were active against Schistosoma mansoni adult worms in vitro, with LC₅₀ values of 32.2 and 14.5 μM and selectivity indices of 6.1 and 21.2, respectively. Scanning electron microscopy of the tegument of male worms in the presence of compound 7 at 25 μM after 24 h of incubation showed severe damage as well as peeling and reduction in the number of spine tubercles. Transmission electron microscopy analyses revealed swollen mitochondrial membrane, vacuoles, and altered tegument in worms incubated with compound 2 (25 μM after 24 h). Worms incubated with compound 7 (25 μM after 24 h) had lysed interstitial tissue, degenerated mitochondria, and drastically altered tegument. Together, the results indicated that compound 7 presents promising in vitro schistosomicidal activity.

Effect of natural antioxidants in Spanish salchichón elaborated with encapsulated n-3 long chain fatty acids in konjac glucomannan matrix

The effect of natural antioxidants on physicochemical properties, lipid and protein oxidation, volatile compounds and free fatty acids (FFA) were determined in Spanish salchichón enriched with n-3 fatty acids encapsulated and stabilized in konjac matrix. Phenolic compounds of beer residue extract (BRE), chestnut leaves extract (CLE) and peanut skin extract (PSE) were also identified and quantified. Five batches of salchichón were prepared: control (CON, without antioxidants), butylated hydroxytoluene (BHT), BRE, CLE and PSE. The main phenolic compounds were catechin and benzoic acid for BRE, gallic acid and catechin for CLE and catechin and protocatechuic acid for PSE. Statistical analysis did not show significant differences on chemical composition among treatments. Reductions in luminosity (P<0.05) and pH (P<0.001) were observed with the CLE batch, whereas the other colour parameters were not affected by the addition of natural antioxidants. Finally, the inclusion of antioxidants (P<0.001) decreased the hexanal content, whereas the FFA content increased by the addition of natural extracts.

[Analysis on contamination of aflatoxins in food samples in Shaanxi Province from 2012-2015]

OBJECTIVE

To investigate the contamination of aflatoxins in food in Shaanxi Province, and provide the basic data of dietary intakes of aflatoxins for food safety assessment.

METHODS

In year 2012- 2015, 1007 food samples of eight kinds of food including grains, beans, vegetable oil, nuts and seeds, condiment, liquor, tea and infants' food were collected randomly from ten cities, and determined with UPLC.

RESULTS

1007 samples were detected aflatoxins and the total detection rate was 10. 7%. The detection range was 0. 070- 323 μg / kg, with the mean value of 2. 34 μg / kg. Among all food samples, only peanut products were more seriously polluted than other kinds of foods.

CONCLUSION

The overall level of aflatoxins contamination in market food is low, but peanut products might be the contaminated foods with aflatoxins in Shaanxi Province, and should be given more attention.

Pyrolysis polygeneration of pine nut shell: Quality of pyrolysis products and study on the preparation of activated carbon from biochar

A lab-scale pyrolysis reactor was utilized to investigate the effect of pyrolysis temperature (300-700°C) on the yield, quality, and energy distribution of products issued from the pyrolysis polygeneration of pine nut shells. Afterward, activated carbon was prepared from biochar using the steam activation method. Pyrolysis temperatures ranging from 500 to 600°C were found to be optimal in inducing products with improved properties, such as higher heating values of non-condensable gas, lower water content and elevated heating values of bio-oil, and substantial fixed carbon content and greater specific surface area of biochar. In addition, it was noticed that the activation conditions had a significant effect on the yield and adsorption performance of the activated carbon. As a result, activated carbon with elevated specific surface area reaching 1057.8m(2)/g was obtained at the optimal conditions of 850°C activation temperature, 80min activation time, and 1.5 steam/biochar ratio.

Effect of high pressure processing on dispersive and aggregative properties of almond milk

BACKGROUND

A study was conducted to investigate the impact of high pressure (450 and 600 MPa at 30 °C) and thermal (72, 85 and 99 °C at 0.1 MPa) treatments on dispersive and aggregative characteristics of almond milk. Experiments were conducted using a kinetic pressure testing unit and water bath. Particle size distribution, microstructure, UV absorption spectra, pH and color changes of processed and unprocessed samples were analyzed.

RESULTS

Raw almond milk represented the mono model particle size distribution with average particle diameters of 2 to 3 µm. Thermal or pressure treatment of almond milk shifted the particle size distribution towards right and increased particle size by five- to six-fold. Micrographs confirmed that both the treatments increased particle size due to aggregation of macromolecules. Pressure treatment produced relatively more and larger aggregates than those produced by heat treated samples. The apparent aggregation rate constant for 450 MPa and 600 MPa processed samples were k450MPa,30°C  = 0.0058 s(-1) and k600MPa,30°C  = 0.0095 s(-1) respectively.

CONCLUSIONS

This study showed that dispersive and aggregative properties of high pressure and heat-treated almond milk were different due to differences in protein denaturation, particles coagulation and aggregates morphological characteristics. Knowledge gained from the study will help food processors to formulate novel plant-based beverages treated with high pressure. © 2015 Society of Chemical Industry.

Effect of supplementing crop substrate with defatted pistachio meal on Agaricus bisporus and Pleurotus ostreatus production

BACKGROUND

This work assesses the agronomic performance of defatted pistachio meal, after oil extraction, as a nutritional substrate supplement when growing the mushroom species Agaricus bisporus (Lange) Imbach and Pleurotus ostreatus (Jacq.) P. Kumm. Materials were applied at different doses at spawning. Along with non-supplemented substrates, commercial nutritional supplements were used as controls. Proximate analysis of mushrooms is also considered.

RESULTS

For the cultivation of champignon, defatted pistachio meal has provided larger mushrooms (unitary weight and cap diameter) with firmer texture and greater content in dry weight and protein, without significant alterations in quantitative parameters. For Pleurotus ostreatus, the supplement led to significant yield increase, even providing up to 34.4% of increment compared to non-supplementation with meal, reaching a biological efficiency of 129.9 kg dt(-1) , when applied to the 15 g kg(-1) compost dose. Supplementation has also been conducted to increase dry weight, protein and fibre within carpophores and to decrease the energy value. Defatted pistachio meal has similar or better results compared to the commercial supplements used as reference.

CONCLUSIONS

Compost supplementation with defatted pistachio meal in A. bisporus concerns mainly the quantitative parameters (size, texture, dry weight and protein). Based on the results obtained, this technique has greater potential of development for P. ostreatus commercial crops, basically due to expected increases in production, with a direct impact on benefits and crop profitability. © 2015 Society of Chemical Industry.

Walnut Phenolic Extract and Its Bioactive Compounds Suppress Colon Cancer Cell Growth by Regulating Colon Cancer Stemness

Walnut has been known for its health benefits, including anti-cardiovascular disease and anti-oxidative properties. However, there is limited evidence elucidating its effects on cancer stem cells (CSCs) which represent a small subset of cancer cells that provide resistance against chemotherapy. This study aimed to evaluate the anti-CSCs potential of walnut phenolic extract (WPE) and its bioactive compounds, including (+)-catechin, chlorogenic acid, ellagic acid, and gallic acid. In the present study, CD133⁺CD44⁺ cells were isolated from HCT116 cells using fluorescence-activated cell sorting (FACS) and then treated with WPE. As a result, survival of the CD133⁺CD44⁺ HCT116 cells was inhibited and cell differentiation was induced by WPE. In addition, WPE down-regulated the CSC markers, CD133, CD44, DLK1, and Notch1, as well as the β-catenin/p-GSK3β signaling pathway. WPE suppressed the self-renewal capacity of CSCs. Furthermore, the WPE exhibited stronger anti-CSC effects than its individual bioactive compounds. Finally, the WPE inhibited specific CSC markers in primary colon cancer cells isolated from primary colon tumor. These results suggest that WPE can suppress colon cancer by regulating the characteristics of colon CSCs.

Comparative evaluation of cyanide removal by adsorption, biodegradation, and simultaneous adsorption and biodegradation (SAB) process using Bacillus cereus and almond shell

The present study aimed to investigate the removal efficiency of cyanide from contaminated water by adsorption, biodegradation and simultaneous adsorption and biodegradation (SAB) process individually in a batch reactor. Adsorption was achieved by using almond shell granules and biodegradation was conducted with suspended cultures of Bacillus cereus, whereas SAB process was carried out using Bacillus cereus and almond shell in a batch reactor. The effect of agitation time, pH, and initial cyanide concentration on the % removal of cyanide has been discussed. Under experimental conditions, optimum removal was obtained at pH 7 with agitation time of 48 hrs and temperature of 35 degrees C. Cyanide was utilized by bacteria as sole source of nitrogen for growth. The removal efficiencies of cyanide by adsorption, biodegradation, and SAB were found to be 91.38%, 95.87%, and 99.63%, respectively, at initial cyanide concentration of 100 mg l(-1). The removal efficiency of SAB was found to be better as compared to that of biodegradation and adsorption alone.

Developmental patterning and segregation of alkaloids in areca nut (seed of Areca catechu) revealed by magnetic resonance and mass spectrometry imaging

Areca nut (seed of Areca catechu) is consumed by people from different parts of Asia, including India. The four major alkaloids present in areca nut are arecoline, arecaidine, guvacoline and guvacine. Upon cutting, the nut reveals two kinds of regions; white and brown. In our present study, we have monitored the formation of these two regions within the nut during maturation, using the non-invasive techniques of magnetic resonance imaging (MRI) and volume localized magnetic resonance spectroscopy (MRS). Electrospray ionization mass spectrometry (ESI MS) and desorption electrospray ionization mass spectrometry (DESI MS) imaging have been used to study the associated change in the alkaloid contents of these two regions during the growth of the nut. Our study reveals that white and brown regions start forming within the nut when the liquid within starts solidifying. At the final stage of maturity, arecoline, arecaidine and guvacoline get segregated in the brown region whereas guvacine gets to the white region of the nut. The transport of molecules with maturity and corresponding pattern formation are expected to be associated with a multitude of physiochemical changes.

Molecular Characterization, Antioxidant and Protein Solubility-Related Properties of Polyphenolic Compounds from Walnut (Juglans regia)

Aqueous ethanol extraction of partially defatted walnut flours provides a simple and reliable method to obtain extracts with high content of polyphenolic compounds. These were characterized by means of HPLC-ESI-MS/MS analytical techniques and molecular parameters. Considering the whole set of polyphenolic compounds identified, a high average number of phenolic-OH groups was found. Although these represent potential hydrogen-atom transfer sites, which are associated with high free-radical scavenging capacity, results show that such a property could be strongly limited by the low lipophilicity of polyphenols affecting the accessibility of these molecules to lipid substrates. Variations in pH values were found to change the ionization behavior of phenolic compounds. These changes, however, had minor effects on walnut protein solubility-related properties. The results obtained in this study highlight the importance of molecular characterization of walnut phenolic compounds in order to assess better their bioactive properties.

Use of Cold Atmospheric Plasma to Detoxify Hazelnuts from Aflatoxins

Aflatoxins, produced by Aspergillus flavus and A. parasiticus, can contaminate different foodstuffs, such as nuts. Cold atmospheric pressure plasma has the potential to be used for mycotoxin detoxification. In this study, the operating parameters of cold atmospheric pressure plasma were optimized to reduce the presence of aflatoxins on dehulled hazelnuts. First, the effect of different gases was tested (N₂, 0.1% O₂ and 1% O₂, 21% O₂), then power (400, 700, 1000, 1150 W) and exposure time (1, 2, 4, and 12 min) were optimized. In preliminary tests on aflatoxin standard solutions, this method allowed to obtain a complete detoxification using a high power for a few minutes. On hazelnuts, in similar conditions (1000 W, 12 min), a reduction in the concentration of total aflatoxins and AFB₁ of over 70% was obtained. Aflatoxins B₁ and G₁ were more sensitive to plasma treatments compared to aflatoxins B₂ and G₂, respectively. Under plasma treatment, aflatoxin B₁ was more sensitive compared to aflatoxin G₁. At the highest power, and for the longest time, the maximum temperature increment was 28.9 °C. Cold atmospheric plasma has the potential to be a promising method for aflatoxin detoxification on food, because it is effective and it could help to maintain the organoleptic characteristics.

Adsorption of naphthalene from aqueous solution onto fatty acid modified walnut shells

The removal of polycyclic aromatic hydrocarbons (PAHs) from aqueous solution is challenging to environmental technologists. Agricultural waste is apparently the most attractive materials in removing PAHs because of its abundance, renewability, and economic advantage. The adsorption of PAHs (e.g., naphthalene) onto walnut shell (WNS) and its fatty acid (e.g., capric acid, lauric acid, palmitic acid, and oleic acid)-modified equivalent were investigated in this work to develop low-cost biosorbents for hydrophobic organic compounds. Compared with other modified sorbents, oleic acid graftted walnut shell (OWNS) showed the maximum partition coefficient (4330 ± 8.8 L kg(-1)) because of its lowest polarity and highest aromaticity. The adsorption capacity (7210 μg g(-1)) of OWNS at the temperature of 298 K was observed for an initial naphthalene concentration of 25 mg L(-1) with contact time of 40 h, sorbent dosage of 1 g L(-1), and in neutral condition. Furthermore, the regeneration capability of OWNS implied that it was a promising biosorbent for naphthalene removal.

Residue levels and risk assessment of pesticides in nuts of China

The pesticide residue levels of three nuts (chestnut, walnut, pinenut) collected from seven main producing areas of China were investigated. Twenty-nine pesticides, including organophosphates (OPs), organochlorines (OCs), pyrethroids (PYs) and two fungicides (triadimefon and buprofezin) were analyzed by gas chromatography (GC). Four OPs (acephate, dimethoate, chlorpyrifos and parathion-methyl) were found in 11.4% samples, with the concentrations of 19.0 µg kg(-1) to 74.0 µg kg(-1). Six OCs (DDT, HCH, endosulfan, quintozene, aldrin and dieldrin) were found in 18.2% samples, with the concentrations of 2.0 µg kg(-1) to 65.7 µg kg(-1). Among OCs, p,p-DDE and α-HCH were the dominant isomer for DDT and HCH. Five PYs (fenpropathrin, fenvalerate, cypermethrin, bifenthrin and cyhalothrin) were found in 15.9% samples, with the concentrations of 2.5 µg kg(-1) to 433.0 µg kg(-1). Fenpropathrin was the most frequently detected pesticide. In addition, triadimefon and buprofezin were detected only in two samples. For the tested nuts, 25.0% samples with multiple residues (containing more than two pesticides) were noted, even up to 9.1% samples with five pesticide residues. The residue of 15.9% samples was higher than the maximum residue limits (MRLs) of China. The short-term risks for the tested nuts were below 1.2%, and the highest long-term risk was 12.58%. The cumulative risk (cHI) for the tested pesticides were 8.43% (OPs), 0.42% (OCs), 12.82% (PYs) and 0.15% (fungicides), respectively. The total cHI was 21.82%. There was no significant health risk for consumers via nuts consumption.

Type I Diacylglycerol Acyltransferase (MtDGAT1) from Macadamia tetraphylla: Cloning, Characterization, and Impact of Its Heterologous Expression on Triacylglycerol Composition in Yeast

Acyltransferase enzymes have been reported as useful biotechnological tools in order to increase oil yield and modify fatty acid composition. Macadamia species are able to accumulate unusually high levels of palmitoleic acid that besides oleic acid amounts to over 80% of monounsaturated fatty acids in the seed oil. In this work, a gene encoding a type 1 acyl-CoA:diacylglycerol acyltransferase (DGAT1) was cloned from M. tetraphylla. DGAT activity of the protein encoded by MtDGAT1 was confirmed by heterologous expression in a yeast mutant. Fatty acid composition of triacylglycerols synthesized by MtDGAT1 was compared to that of DGAT1 enzymes from Arabidopsis and Echium, with the results suggesting a substrate preference for monounsaturated over polyunsaturated fatty acids. Characteristics of MtDGAT1 may contribute to biochemical mechanisms determining the particular fatty acid composition of Macadamia oil and also indicate the possibility of using this enzyme in biotechnological approaches where a reduction of polyunsaturated fatty acids in the oil is desired.

Development of an Enzyme-Linked Immunosorbent Assay Method Specific for the Detection of G-Group Aflatoxins

To detect and monitor G-group aflatoxins in agricultural products, we generated class-specific monoclonal antibodies that specifically recognized aflatoxins G₁ and G₂. Of the final three positive and stable hybridomas obtained, clone 2G6 produced a monoclonal antibody that had equal sensitivity to aflatoxins G₁ and G₂, and did not cross-react with aflatoxins B₁, B₂, or M₁. Its IC50 values for aflatoxins G₁ and G₂ were 17.18 ng·mL(-1) and 19.75 ng·mL(-1), respectively. Using this new monoclonal antibody, we developed a competitive indirect enzyme-linked immunosorbent assay (CI-ELISA); the method had a limit of detection of 0.06 ng·mL(-1). To validate this CI-ELISA, we spiked uncontaminated peanut samples with various amounts of aflatoxins G₁ and G₂ and compared recovery rates with those determined by a standard HPLC method. The recovery rates of the CI-ELISA ranging from 94% to 103% were comparable to those of the HPLC (92% to 102%). We also used both methods to determine the amounts of G-group aflatoxins in five peanut samples contaminated by aflatoxin B₁-positive, and their relative standard deviations ranged from 8.4% to 17.7% (under 20%), which demonstrates a good correlation between the two methods. We further used this CI-ELISA to assess the ability of 126 fungal strains isolated from peanuts or field soils to produce G-group aflatoxins. Among these, seven stains producing different amounts of G-group aflatoxins were identified. Our results showed that the monoclonal antibody 2 G6-based CI-ELISA was suitable for the detection of G-group aflatoxins present in peanuts and also those produced by fungi.

Thermogravimetric characterization and gasification of pecan nut shells

This study focuses on the evaluation of pecan nut shells as an alternative source of energy through pyrolysis and gasification. The physicochemical characteristics of the selected biomass that can influence the process efficiency, consumption rates, and the product yield, as well as create operational problems, were determined. In addition, the thermal decomposition kinetics necessary for prediction of consumption rates and yields were determined. Finally, the performance of a downdraft gasifier fed with pecan nut shells was analyzed in terms of process efficiency and exit gas characteristics. It was found that the pyrolytic decomposition of the nut shells can be modeled adequately using a single equation considering two independent parallel reactions. The performance of the gasification process can be influenced by the particle size and air flow rate, requiring a proper combination of these parameters for reliable operation and production of a valuable syngas.