Hazelnut Extracts Research Articles

Upgrading hazelnut skins: Green extraction of polyphenols from lab to semi-industrial scale

Hazelnut skins (HS) are usually managed as waste; however, this by-product is a source of bioactive compounds, with potential applications in feed and food sectors. Phenolic compounds can be extracted using green protocols combining enabling technologies and green solvents. This work investigates subcritical water extraction (SWE) of bioactive compounds from HS. A laboratory-scale study was performed on four different batches, with significant batch-to-batch heterogeneity. The evaluation of polyphenolic profiles and antioxidant activities afforded promising results compared to the benchmark of reflux maceration. To evaluate process effectiveness, the extraction protocol was replicated on a semi-industrial plant that processed 8 kg of matrix. Downstream processes have been optimized for scale-up, demonstrating the effectiveness of SWE in retaining product concentration and bioactivity avoiding excipients in spray-drying phase. Hazelnut extracts exhibited antibacterial properties against animal- and food-borne pathogens, supporting their potential use as sustainable feed ingredients for improved hazelnut production and animal farming practices.

Inducing Effect of Corylus avellana on Cytotoxic Activity in Lung and Breast Cancer Cells via Apoptosis

Turkish hazelnut (Corylus avellana L. cv Tombul) is a widely used nut in the chocolate industry and is also rich in polyphenol content, which promises anticancer effects. The anti-cancer and apoptotic effects of hazelnut leaves extracts examined on lung and breast cancer cells. Sulforhodamine B (SRB) and Adenosine 5’- triphosphate (ATP) assays were carried out for cell viability measurement. The mode of cell death was shown morphologically by the double fluorescence staining. Apoptosis was determined by performing caspase-mediated cytokeratin 18 (M30 ELISA) and western blot analysis. PARP, caspase 3, caspase 8, DR4, and GAPHD (Glyceraldehyde-3-phosphate Dehydrogenase) protein bands were visualized as markers of apoptosis. A wound healing test was employed to measure cell migration. Methanol extract of hazelnut leaf exhibited inhibition of cell growth activities in a dose-dependent manner. IC50 values were determined as 32.17 µg/ml in MCF-7, 32.16 µg/ml in MDA-MB-231, 20.40 µg/ml in A549 and 12.04 µg/ml in H1299 cells for ethanol extract while it was determined as 21.08 µg/ml in MCF-7, 40.16 µg/ml in MDA-MB-231, 22.04 µg/ml in A549 and 5.91 µg/ml in H1299 cells in methanol extract. In comparison, methanol leaf extracts were more effective in H1299 cells (IC50 value was 5.91 µg/ml).In comparison, ethanol leaf extracts were more effective in H1299 cells (IC50 value was 9.722 µg/ml). Western blot analysis demonstrated that hazelnut leaf extract treatment of cancer cells led to cell death via apoptosis and inhibited cell migration in lung and breast cancer cell lines. The cytotoxic effects of hazelnut extract on breast and lung cancer cells might be valuable and promising in elucidating cell death mechanisms for the development of new methods in cancer treatment.

Identification of New Allergens in Macadamia Nut and Cross-Reactivity with Other Tree Nuts in a Spanish Cohort.

The consumption of macadamia nuts has increased due to their cardioprotective and antioxidant properties. However, this rise is consistent with an increase in the cases of macadamia nut allergy, leading to severe reactions. Although two Macadamia integrifolia allergens (Mac i 1 and Mac i 2) have been identified in Australian and Japanese patients, the allergenic sensitization patterns in Western European populations, particularly in Spain, remain unclear. For this purpose, seven patients with macadamia nut allergy were recruited in Spain. Macadamia nut protein extracts were prepared and, together with hazelnut and walnut extracts, were used in Western blot and inhibition assays. IgE-reactive proteins were identified using MALDI-TOF/TOF mass spectrometry (MS). Immunoblotting assays revealed various IgE-binding proteins in macadamia nut extracts. Mass spectrometry identified three new allergens: an oleosin, a pectin acetylesterase, and an aspartyl protease. Cross-reactivity studies showed that hazelnut extract but not walnut extract inhibited macadamia nut oleosin-specific IgE binding. This suggests that oleosin could be used as marker for macadamia-hazelnut cross-reactivity. The results show an allergenic profile in the Spanish cohort different from that previously detected in Australian and Japanese populations. The distinct sensitization profiles observed highlight the potential influence of dietary habits and environmental factors exposure on allergenicity.

The ethanolic extract of Corylus avellana L. drives a microRNA-based cytotoxic effect on HepG2 hepatocarcinoma cells

An ethanolic extract of Corylus avellana L. hazelnut was characterised by liquid chromatography coupled to high resolution mass spectrometry. We here evaluated the in vitro cytotoxic response to such extract in HepG2 cells and tried to depict the underlying mechanism(s) in terms of microRNA-34b/c involvement. Following long-term exposure (144h) of HepG2 cells with 0.04-0.4 mg/ml of hazelnut extract, we demonstrated that miR-34 precursor RNA and both mature miR-34b and miR-34c molecules underwent a significant stimulation (>2-fold change, p < 0.05) in cells treated with the highest concentration. The epigenetic modulation was accompanied by the inhibition of cell proliferation, the decrease of viability and activation of apoptosis at 144h of treatment with 0.4 mg/ml of hazelnut. These in vitro findings demonstrate the cytotoxic effect of the C. avellana extract in HepG2 cells and open the way to in vivo validation of possible application of hazelnut-based extracts, and/or its metabolites, as promising epigenetics drugs.

Evaluation of Antimicrobial Effects of Fresh and Dried Fruit in Turkish Tombul Hazelnut Variety

Objective: The aim of the study was to determine the antimicrobial properties of fresh and dried fruits of Turkish Tombul hazelnut (Corylus avellana L.) variety.&#x0D; Materials and Methods: The Turkish Tombul hazelnuts used in the experiment were obtained from Helvacı Village/ Düzköy /Trabzon. Fresh hazelnuts were harvested in 2023, while dried hazelnuts were collected in 2022. The dried hazelnuts were dried at 105°C until they attained a consistent weight. This section was not created for fresh hazelnuts. The treated micelle was extracted for 4 hours with 100 mL of Ethyl alcohol (EtOH) for every 10 g of both the fresh and dried hazelnut samples crushed. The micelle (hazelnut+oil+solvent mixture) was filtered through coarse filter paper to remove particles before being blown away with a Rotary evaporator (Heidolph, Germany). The resulting extracts were used for antimicrobial testing. Antimicrobial activity of the strains was evaluated against Pseudomonas aeruginosa ATCC 27853, Enterobacter cloaceae ATCC2468, Enterococcus feacalis ATCC51299, Escherichia coli ATCC2471, Klebsiella pneumoniae ATCC700603, Salmonella typhimurium ATCC13311, Serretia marcescens ATCC13880, Staphylococcus epidermis ATCC14990, Staphylococcus aureus ATCC25923, Bacillus subtilis ATCC 6633, Streptococcus faecalis ATCC 9790, Yersinia pestis ATCC 19428 and Candida albicans ATCC10351. One-way analysis of variance (ANOVA) was run to determine any significant differences in the study groups by Duncan multiple range test was performed through SPSS.&#x0D; Results: Dried hazelnut extract was effective in all of them, while fresh hazelnut extract was only effective on Candida albicans ATCC10351 and Klebsiella pneumoniae ATCC700603 (F (3, 8) = 65.45, p

Development and validation of sensitive and rapid immunoassays to detect minute amounts of hazelnut in processed food and working surfaces

Hazelnut (Corylus avellana L.) represents one of the most allergenic nuts and it can be found as a hidden allergen in processed food due to cross contamination. Therefore, sensitive and specific analytical techniques are in high demand to be used in allergen risk management plans at food industry. In this study, sandwich ELISA and Lateral Flow Immunoassay (LFIA) to detect hazelnut have been developed based on the determination of Cor a 9, one of the most abundant and allergenic proteins of hazelnut. Results showed that cross-reactivity was only found with walnut and Pecan nut, which was lower than 0.1%. When analyzing food spiked with a hazelnut extract or blended with hazelnut flour, ELISA and LFIA were able to detect 0.1 ppm and 0.5 ppm of hazelnut protein with a recovery from 82 to 110%. ELISA and LFIA could also detect 0.15 and 0.6 ppm of hazelnut protein in baked cookies incurred with ground hazelnut, respectively. Furthermore, LFIA could detect 1.25 μg of hazelnut protein in working surfaces of stainless steel and melamine. The sandwich ELISA was in-house validated, showing acceptable results of precision. Likewise, ELISA and LFIA showed to be robust tests. The combined use of both assays could improve the allergen risk management plans in food industry to monitor the presence of hazelnut traces in raw ingredients, processed food and working surfaces.

Giresun'da Yetiştirilen Fındık (Corylus avellana L.) Yapraklarında Toplam Antioksidan Aktivite, Fenolik Madde ve İndirgeyici Güç Miktarlarının Belirlenmesi

In the present study, total antioxidant activity (TAC), phenolic compound amounts (TPC) and reducing power (RP) of hazelnut leaves collected from Giresun were investigated. Antioxidant levels were determined in the water extracts of hazelnut leaves by using methods according to the appropriate literature. In the results obtained from water extracts at three different doses (1, 2.5 and 5 mg/kg), it was determined that the total antioxidant capacity was high depending on the dose and phenolic content. The high antioxidant capacity of hazelnuts produced in humid regions in our country also depends on the phenolic substance content it has.

A Natural Additive Alternative to the Cosmetics Industry: Hazelnut and Its Waste Products

Background: Today, individuals tend to use natural products instead of synthetic additives in many areas. The hazelnut tree produces many by-products and fruit. Nuts and their by-products are rich in bioactive compounds. Objectives: This study investigated the biological activities of water and ethanol extracts obtained from hazelnut and its waste products to determine their potential usage in the cosmetic industry. Methods: In this experimental study, disc diffusion test, minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), or minimum fungicidal concentration (MFC) were applied to evaluate the antimicrobial potential of the extracts. The sun protection factor (SPF) of the extracts and commercial cream + extract mixtures was determined in vitro. In addition, antimicrobial cream formulations containing hazelnut extracts and Limosilactobacillus fermentum MA-7 probiotic candidate lactic acid bacteria from human milk were developed for the pharmaceutical industry to prevent infections. The good diffusion test was applied against test microorganisms to evaluate antimicrobial activity. Results: The hazelnut husk methanol extract had the highest inhibition zone diameter (19.41 mm) against Yersinia ruckeri. The MIC, MBC, or MFC of the extracts ranged from 1.25 to &gt; 40 µg/µL. The SPF values of the extracts (range: 6.85-27.64) and commercial cream + extract (range: 11.92-26.28) mixtures were determined in vitro to obtain their potential use in sunscreens. The cream groups containing hazelnut extracts and probiotics showed a high antimicrobial effect on the tested microorganisms. The results of statistical analysis indicated that the cream + extract + probiotic pellet + probiotic supernatant group was statistically significant (P &lt; 0.05) compared to other test groups. Conclusions: The results showed that hazelnuts and their by-products have the potential to be used as a natural source of antimicrobials. Hazelnut and its by-products can be an alternative to synthetic antimicrobials and sunscreens in the cosmetic industry as a natural bioactive substance. In addition, it might contribute to the country’s economy by evaluating hazelnuts and their waste and by-products resulting from their processing in the cosmetic industry.

Hemp seed: An allergen source with potential cross-reactivity to hazelnut

The increasing exposure of the population to Cannabis sativa has revealed allergies to different parts of the plant, among which hemp seed. Nonetheless, the major hemp seed allergens remain to be identified. Several known families of allergens are present in hemp seed, including notably seed storage proteins. We therefore aimed to investigate the potential allergenicity of the hemp seed storage proteins and their potential cross-reactivity to different seeds and nuts. For this, we extracted hemp seed proteins sequentially using buffers with increasing levels of salinity (H2O, T2 and T3) to yield extracts differentially enriched in storage proteins. We used these extracts to perform immunoblots and ELISAs using sera of patients either sensitized to hemp seeds or sensitized/allergic to other seeds and nuts. Immunoblots and proteomics analyses identified vicilins and edestins as potential hemp seed allergens. Moreover, ELISA analyses revealed a correlation between sensitization to hazelnut and the hemp seed T3 extract (enriched in storage proteins). The possible cross-reactivity between hazelnut and hemp seed proteins was further strengthened by the results from inhibition ELISAs: the incubation of sera from hazelnut-sensitized individuals with increasing concentrations of the T3 extract inhibited serum IgE binding to the hazelnut extract by about 25–30%. Our study thus identifies vicilins and edestins as potential hemp seed allergens and highlights a possible cross-reactivity with hazelnut. The clinical relevance of this cross-reactivity between hemp seed and hazelnut needs to be further investigated in hazelnut-allergic individuals.

Epigenetic-based antioxidant effect of an ethanolic extract of Corylus avellana L. on THLE-2 human primary hepatocytes

The ethanolic extract of Corylus avellana L hazelnut, prepared in our laboratories, has been previously characterized by liquid chromatography coupled to high resolution mass spectrometry. We here aimed at testing the antioxidant effect of such extract in H2O2-challenged THLE-2 human primary hepatocytes and verified whether it might be based on microRNA-34b/c expression changes. We here demonstrate that miR-34b/miR-34c undergo significant stimulation (≥2-fold change, p < 0.05) in THLE-2 when treated for 72h with not-toxic hazelnut concentrations (0.04–0.4 mg/ml), when compared with 0.06% ethanol control. When administered with H2O2 (1000–2000 µM, 24h), THLE-2 are significantly protected from oxidative stress if pre-treated with hazelnut, the H2O2-driven cytotoxicity and reactive oxygen species generation being recovered by hazelnut extract, through miR-34b/c stimulation. Although preliminary, our findings pave the way for further preclinical studies aimed at validating the possible health-related application of hazelnut matrix, and/or its metabolites, as powerful epigenetic-based drugs, food supplements or nutraceuticals.

Hazelnut extract-loaded nanostructured lipid carriers and evaluation of their antioxidant properties

Reactive oxygen species (ROS) are a common hallmark of many degenerative diseases, developing in all those cases where a failure of physiological antioxidant mechanisms occurs (in particular, antioxidant enzymes and the glutathione system), or in case of exposure to an extremely high level of oxidants. In this regard, antioxidant natural extracts are promising compounds as preventive or therapeutic agents against ROS-dependent degenerations. In this study, a deep investigation of hazelnut (Corylus avellana) extract has been performed in terms of mass spectroscopy, evaluation of phenolic content, and antioxidant capacity. Then, nanostructured lipid carriers (NLCs) have been exploited for encapsulation of the hazelnut extracts in order to achieve prolonged bioactivity, increased stability, and targeting through a sustainable delivery approach. The hazelnut extract-loaded NLCs (NE_NLCs) have been deeply characterized for their stability, production yield, and encapsulation efficiency. Moreover, NE_NLCs showed optimal cytocompatibility on human dermal fibroblast (HDF) cells, as well as excellent antioxidant activity, upon pro-oxidant stimulus on HDF cells.

THE CONTENT OF PHENOLIC COMPOUNDS AND THE ANTIOXIDANT ACTIVITY OF SOME TYPES OF NUTS CONSUMED IN FOOD

Phenolic compounds, flavonoids, anti-radical activity, and restorative power are found in walnuts, pecans, almonds, hazelnuts, hazelnuts, cashews, macadamia, and peanuts. The highest content of phenolic substances in the studied nuts was found in walnuts (536.6 mg of gallic acid per 100 g of dry matter), pistachios (512.9 mg of gallic acid per 100 g of dry matter) and pecans (377.6 mg of gallic acid per 100 g of dry matter). Wild hazel contains 1.4 times more phenolic substances compared to hazelnuts and 4.2 times more flavonoids. In this work, a method was used to determine the concentration of the extract at which 50% of the free radical is bound by the 2,2’-diphenyl-1-picrylhydrazyl (DPPH) radical. The antioxidant activity was found only in the extract of pecans, pistachios, walnuts, and hazelnuts. No antiradical activity was detected in the remaining extracts. The restorative power of all the studied extracts is mainly, to a small extent. Of the studied extracts, peanut and pistachio extracts showed the greatest restoring power. Hazelnut and pecan extracts also exhibit greater restorative power than other extracts studied.

Determination of some phenolic substances in six different populations of turkish hazel (Corylus colurna L.) leaves and comparison of phenolic fluctuation with water deficiency

Turkish hazel (Corylus colurna L.) is one of the naturally grown hazelnut species in Turkey. It can be easily separated from other hazel species with its thick single stem and tall appearance. It can be used in afforestation and erosion control studies due to low demand for habitat and strong root system. It contains substances with high medicinal value in its fruits and leaves. Hazel leaves have strong antioxidant activity due to their high phenolic content. Objective of the study was primarily to determine the individual phenolic constituents of six different population of Turkish Hazelnut and then to evaluate the effect of water deficiency stress generated by irrigation regime on phenolic constituents and photosystem II activity on these genotypes. Grafted plants were produced by taking scions from six different populations of Turkish Hazelnut (O&amp;#287;uzlar, Erenler, Merkeşler, Seben, Güney Felakettin and Pelitcik). The study was started when the grafted seedlings were 7 years old in greenhouse. During the experiment (June and July), two different levels of irrigation were applied (W1: the soil was fully irrigated to reach field capacity in each irrigation; W2: 50% reduction of W1 irrigation water). After the application of two different irrigation regimes, leaves were collected for each month, dried, extracted with methanol and then quantitatively analyzed and compared for individual phenolic constituents (gallic acid monohydrate, caffeic acid, rutin hydrate, luteolin-7-O-&amp;#946;-D glucoside, kaempferol, rosmarinic acid, myricetin, quercetin, coumarin and apigenin) by using high performance liquid chromatography (HPLC) coupled with a diode array detector (DAD). Generally, rutin, kaempferol and luteolin were dominant individual phenols in methanol extracts of Turkish hazelnut leaves. Pelitcik population was noticeable source of rutin and kaempferol in June, and the halved irrigation regime significantly increased the levels of both phenols in July. Similarly, the highest total phenolic content was observed in the Pelitcik population in June and the halved irrigation regime significantly increased the total phenolic content in both months in this population. It was also determined to what extent water deficiency physiologically affects the quantum efficiency (Fv/Fm) of photosystem II activity through chlorophyll fluorescence technique in hazelnut leaves. Generally, Fv/Fm value decreased with water deficiency. This study showed that water deficiency stress generally caused an increase in phenolic constituents in Turkish Hazel leaves and they may be proper natural sources of phenolic constituents with abiotic stress applications in pharmaceutical and food industry.

Measurement of IgE to hazelnut allergen components cannot replace hazelnut challenge in Dutch adults.

BackgroundComponent‐resolved diagnostics (CRD) help predict hazelnut allergy (HA) in children, but are of unknown diagnostic value in adults. This study aimed to evaluate the diagnostic accuracy of IgE to hazelnut extract and components in adults.MethodsA Dutch population of consecutively presenting adults suspected of HA, who underwent a double‐blind placebo‐controlled food challenge, were included. Serum IgE to hazelnut extract and Cor a 1, 8, 9, and 14 was measured on ImmunoCAP. Diagnostic accuracy was assessed by area under the curve (AUC) analysis.ResultsOf 89 patients undergoing challenge, 46 had challenge‐confirmed HA: 17 based on objective and 29 based on subjective symptoms. At commonly applied cutoffs 0.1 and 0.35 kUA/L, high sensitivity was observed for IgE to hazelnut extract and Cor a 1 (range 85–91%), and high specificity for IgE to Cor a 8, 9 and 14 (range 77–95%). However, the AUCs for hazelnut extract and components were too low for accurate prediction of HA (range 0.50–0.56). Combining hazelnut extract and component IgE measurements did not significantly improve accuracy. Higher IgE levels to Cor a 9 and 14 were tentatively associated with HA with objective symptoms, but the corresponding AUCs still only reached 0.68 and 0.63, respectively.ConclusionsAlthough hazelnut allergic adults are generally sensitized to hazelnut extract and Cor a 1, and hazelnut tolerant adults are usually not sensitized to Cor a 8, 9, or 14, challenge testing is still needed to accurately discriminate between presence and absence of HA in adults from a birch‐endemic country.

Effect of Sample Preparation on the Detection and Quantification of Selected Nuts Allergenic Proteins by LC-MS/MS.

The detection and quantification of nut allergens remains a major challenge. The liquid chroma-tography tandem mass spectrometry (LC-MS/MS) is emerging as one of the most widely used methods, but sample preparation prior to the analysis is still a key issue. The objective of this work was to establish optimized protocols for extraction, tryptic digestion and LC-MS analysis of almond, cashew, hazelnut, peanut, pistachio and walnut samples. Ammonium bicar-bonate/urea extraction (Ambi/urea), SDS buffer extraction (SDS), polyvinylpolypyrroli-done (PVPP) extraction, trichloroacetic acid/acetone extraction (TCA/acetone) and chloro-form/methanol/sodium chloride precipitation (CM/NaCl) as well as the performances of con-ventional tryptic digestion and microwave-assisted breakdown were investigated. Overall, the protein extraction yields ranged from 14.9 ± 0.5 (almond extract from CM/NaCl) to 76.5 ± 1.3% (hazelnut extract from Ambi/urea). Electrophoretic profiling showed that the SDS extraction method clearly presented a high amount of extracted proteins in the range of 0–15 kDa, 15–35 kDa, 35–70 kDa and 70–250 kDa compared to the other methods. The linearity of the LC-MS methods in the range of 0 to 0.4 µg equivalent defatted nut flour was assessed and recovery of internal standards GWGG and DPLNV(d8)LKPR ranged from 80 to 120%. The identified bi-omarkers peptides were used to relatively quantifier selected allergenic protein form the inves-tigated nut samples. Considering the overall results, it can be concluded that SDS buffer allows a better protein extraction from almond, peanut and walnut samples while PVPP buffer is more appropriate for cashew, pistachio and hazelnut samples. It was also found that conventional overnight digestion is indicated for cashew, pistachio and hazelnut samples, while microwave assisted tryptic digestion is recommended for almond, hazelnut and peanut extracts.

ANTIOXIDANT CAPACITY AND FLAVOR PRESERVED HAZELNUT EXTRACT, MACERATION AND SC-CO2 EXTRACTION AND COMPARISON OF EXTRACTION METHODS

In this study, Tombul type hazelnuts (Corylus avellana L.) were extracted by supercritical carbondioxide (SC-CO2) extraction and maceration method. The extraction yielded in 8.5% by SC-CO2 extraction when 0.84% by maceration. Extracted hazelnuts were analyzed by Dynamic Headspace Analysis/Gas Chromatography-Mass Spectrometry and 24 volatile compounds were detected after SC-CO2 method while 41 compounds were detected after maceration. Flavour and antioxidant value preserved Hazelnut extract by SC-CO2 technique showed better radical scavenging ability in 2,2-Diphenyl-1-picrylhydrazyl (DPPH) than the one by maceration. Antioxidant activities of the extracts obtained by SC-CO2 (12.35±0.06 μg/mL) and by maceration (8.79±0.23 μg/mL) had a medium impact compared with the synthetic antioxidant standards (P&amp;lt; 0.05). No significant difference was observed between the total phenolic contents of the hazelnut extracts obtained by SC-CO2 method and by maceration (P &amp;lt; 0.05). As a result, SC-CO2 technique for extraction of Tombul type hazelnuts was concluded to be more beneficial and suitable compared to maceration technique.

IgE cross-reactivity measurement of cashew nut, hazelnut and peanut using a novel IMMULITE inhibition method

Background Tree nut-allergic individuals are often sensitised towards multiple nuts and seeds. The underlying cause behind a multi-sensitisation for cashew nut, hazelnut, peanut and birch pollen is not always clear. We investigated whether immunoglobulin E antibody (IgE) cross-reactivity between cashew nut, hazelnut and peanut proteins exists in children who are multi-allergic to these foods using a novel IMMULITE®-based inhibition methodology, and investigated which allergens might be responsible. In addition, we explored if an allergy to birch pollen might play a role in this co-sensitisation for cashew nut, hazelnut and peanut. Methods Serum of five children with a confirmed cashew nut allergy and suffering from allergic symptoms after eating peanut and hazelnut were subjected to inhibition immunoassays using the IMMULITE® 2000 XPi. Serum-specific IgE (sIgE) to seed storage allergens and pathogenesis-related protein 10 (PR10) allergens were determined and used for molecular multicomponent allergen correlation analyses with observed clinical symptoms and obtained inhibition data. Results IgE cross-reactivity was observed in all patients. Hazelnut extract was a strong inhibitor of cashew nut sIgE (46.8%), while cashew nut extract was less able to inhibit hazelnut extract (22.8%). Peanut extract showed the least inhibition potency. Moreover, there are strong indications that a birch pollen sensitisation to Bet v 1 might play a role in the observed symptoms provoked upon ingestion of cashew nut and hazelnut. Conclusions By applying an adjusted working protocol, the IMMULITE® technology can be used to perform inhibition assays to determine the risk of sIgE cross-reactivity between very different food components.

Allergen components in diagnosing childhood hazelnut allergy: Systematic literature review and meta-analysis.

Hazelnut-specific IgE antibodies (sIgEs) in serum support the diagnosis of hazelnut allergy, but extract-based tests have low diagnostic specificity, commonly leading to over-diagnosis. Measuring sensitization to individual allergen components may enhance the diagnosis of hazelnut allergy. We systematically examined data on diagnostic accuracy of sIgE to commercially available hazelnut components to compare their individual contributions in diagnosing hazelnut allergy. Seven databases were searched for diagnostic studies on patients suspected of having hazelnut allergy. Studies employing component-specific IgE testing on patients whose final diagnosis was determined by oral food challenges were included in the meta-analysis. Study quality was assessed as recommended by Cochrane. Seven cross-sectional studies and one case-control study were identified, seven presenting data on children (N=635), and one on a mixed age population. Overall, the diagnostic accuracies of sIgE to both Cor a 9 and Cor a 14 were significantly higher than for Cor a 1-sIgE (P<.05). In children, the specificity of Cor a 14-sIgE at 0.35kUA /L cutoff was 81.7% (95% CI 77.1, 85.6), and 67.3% (60.3, 73.6) for Cor a 9-sIgE. The specificities for Cor a 1-sIgE and hazelnut-sIgE were 22.5% (7.4, 51.2) and 10.8% (3.4, 29.8), respectively. The sensitivity of Cor a 1-sIgE (60.2% [46.9, 72.2]) was lower than for hazelnut extract-sIgE (95.7% [88.7, 98.5]), while their specificities did not differ significantly. sIgE to Cor a 14 and Cor a 9 hazelnut storage proteins increases diagnostic specificity in assessing hazelnut allergy in children. The combined use of hazelnut extract and hazelnut storage proteins may improve diagnostic value.

Aflatoxin-specific monoclonal antibody selection for immunoaffinity column development.

Antibodies are the basic components of immunoanalytical systems used for detection of a wide range of analytes. Although there are some ground rules for antibody selection, analyte- and assay-specific criteria are the ones that determine the ultimate success of the immunoassays. In this study, we introduced an effective antibody selection procedure for the development of immunoaffinity columns for aflatoxins. The designed scheme puts emphasis on solvent- and matrix-related characterization steps and was used to comparatively evaluate eight monoclonal antibodies. The selected antibody was tolerant to 40% methanol, 20% acetonitrile, 30% acetone and 40% ethanol and did not interact with corn, red pepper or hazelnut extracts. Immunoaffinity columns developed with the selected antibody were validated by 15 independent aflatoxinanalysis laboratories.

Determination of microbiological contamination, antibacterial and antioxidant activities of natural plant hazelnut (Corylus avellana L.) pollen

The aim of our study is to determine microbial contamination, antibacterial and antioxidant activities of 14 pollen samples of Corylus avellana collected from different locations in Slovakia. Microbiological analysis was carried out in two steps: microbiological assays and studies of antibacterial activity of pollen extracts. The antimicrobial properties of pollen extracts were carried out with the disc-diffusion method. Methanol (70%), ethanol (70%) and distilled water were used for pollen extracts. Five strains of bacteria such as gram-negative (Salmonella enterica subsp. enterica CCM 3807, Escherichia coli CCM 2024, and Yersinia enterocolitica CCM 5671) and gram-positive (Staphylococcus aureus CCM 2461 and Bacillus thuringiensis CCM 19T) were tested. Antioxidant activity of pollen extracts was determined by the DPPH method. Bacterial analysis includes the determination of the total bacterial count ranged from 4.08 to 4.61 log CFU g−1, mesophilic aerobic bacteria ranged from 3.40 to 4.89 log CFU g−1, mesophilic anaerobic bacteria ranged from 3.20 to 4.52 log CFU g−1, coliform bacteria ranged from 3.30 to 4.55 log CFU g−1, yeasts and filamentous fungi ranged from 3.00 to 3.56 log CFU g−1. Microscopic filamentous fungi Aspergillus spp., Alternaria spp., Penicillium spp., Cladosporium spp., Rhizopus spp., and Paecylomyces spp. were isolated from hazelnut pollen. Yersinia enterocolitica was the most sensitive strain among ethanolic and methanolic pollen hazelnut extracts. Staphylococcus aureus was the most sensitive strain against aqueous hazelnut pollen extracts. We determined the following sensitivity against ethanol pollen extracts respectively: Yersinia enterocolitica > Salmonella enterica > Staphylococcus aureus > Bacillus thuringiensis > Escherichia coli. Methanol pollen extracts had shown following sensitivity: Yersinia enterocolitica > Salmonella enterica > Escherichia coli > Staphylococcus aureus > Bacillus thuringiensis. Aqueous extracts had shown the following sensitivity: Staphylococcus aureus > Salmonella enterica > Escherichia coli > Bacillus thuringiensis > Yersinia enterocolitica. Hazelnut pollen extracts have over 82% antioxidant capacity in samples from non-urban zones. An elevated level of antioxidant potential in the pollen is determined by its biological properties conditioned by biologically active substances. DPPH method allowed characterizing pollen as a source of antioxidants.