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Summary: The native, perennial shrub American hazelnut (Corylus americana) is cultivated in the Midwestern United States for its significant ecological benefits, as well as its high‐value nut crop. Implementation of modern breeding methods and quantitative genetic analyses of C. americana requires high‐quality reference genomes, a resource that is currently lacking. We therefore developed the first chromosome‐scale assemblies for this species using the accessions 'Rush' and 'Winkler'. Genomes were assembled using HiFi PacBio reads and Arima Hi‐C data, and Oxford Nanopore reads and a high‐density genetic map were used to perform error correction. N50 scores are 31.9 Mb and 35.3 Mb, with 90.2% and 97.1% of the total genome assembled into the 11 pseudomolecules, for 'Rush' and 'Winkler', respectively. Gene prediction was performed using custom RNAseq libraries and protein homology data. 'Rush' has a BUSCO score of 99.0 for its assembly and 99.0 for its annotation, while 'Winkler' had corresponding scores of 96.9 and 96.5, indicating high‐quality assemblies. These two independent assemblies enable unbiased assessment of structural variation within C. americana, as well as patterns of syntenic relationships across the Corylus genus. Furthermore, we identified high‐density SNP marker sets from genotyping‐by‐sequencing data using 1343 C. americana, C. avellana and C. americana × C. avellana hybrids, in order to assess population structure in natural and breeding populations. Finally, the transcriptomes of these assemblies, as well as several other recently published Corylus genomes, were utilized to perform phylogenetic analysis of sporophytic self‐incompatibility (SSI) in hazelnut, providing evidence of unique molecular pathways governing self‐incompatibility in Corylus. [ABSTRACT FROM AUTHOR]

Background: Hazelnut is one of the most consumed nuts in the world. Appropriate drying methods should be chosen to prevent microbiological and oil oxidation, which will affect the quality of hazelnuts after harvest. Results: Total phenolic and flavonoid contents of fresh and dried hazelnuts were detected between 40.83 (fresh (control)) and 82.98 mg GAE/100 g (conventional oven) to 105.95 (control) and 234.05 mg/100 g (conventional oven), respectively. Also, antioxidant activities of fresh and dried hazelnuts changed between 4.08 mmol/kg (control) and 7.46 mmol/kg (conventional oven). Gallic acid, 3,4‐dihydroxybenzoic acid, catechin, caffeic acid, syringic acid and rutin were the abundant phenolic compounds of fresh and dried hazelnuts. Catechin amounts of hazelnut samples varied between 12.53 (control) and 37.78 mg/100 g (conventional oven). Also, while oleic acid amounts of hazelnut oils are determined between 73.21 (microwave) and 73.80% (air), linolenic acid amount of the ash of fresh and dried hazelnuts were identified between 17.57 (control) and 18.33% (conventional oven). P, K, Ca, Mg, S were the key macroelements of fresh and dried hazelnuts, while Fe, Cu and Zn are determined as the abundant microelements of hazelnuts. Results showed charges depending on drying types compared to the control. Conclusion: As a result, the differences in the nutritional properties and phytochemicals of hazelnuts were revealed during the drying of hazelnuts with different drying types, which is important due to their nutritional and physiological importance. Drying types and times were effective on the elemental contents of hazelnuts. Generally, considering the oil content, bioactive properties, phenolic components and fatty acids of hazelnut, it is thought that the conventional oven drying system can be chosen because it can achieve better results for consumers. [ABSTRACT FROM AUTHOR]

The results of the measurements of IgE to hazelnut extract, Cor a 9, 14, 11 and 16 (sum of the N- and C-terminal parts), are shown in Figure 2A. IgE levels of 0.10 kU SB A sb /L or greater to the four hazelnut components were found in 98%, 69%, 65% and 80% of the samples, respectively, with observations distributed across and even beyond the measuring range of the assay. A new vicilin-like allergen in hazelnut giving rise to a spectrum of IgE-binding low-molecular-weight N-terminal fragments Keywords: allergen; allergy; hazelnut; IgE; vicilin EN allergen allergy hazelnut IgE vicilin 1208 1212 5 10/13/22 20221001 NES 221001 Key Messages A new vicilin-like allergen in hazelnut, Cor a 16, is reported A spectrum of IgE-binding vicilin N peptides in hazelnut originates mainly from Cor a 16 Cor a 16 appears as a major allergen in hazelnut-sensitized children Hazelnut is a frequent trigger of food allergic reactions with symptoms ranging from local and mild in individuals with a pollen-related food allergy to severe and even life-threatening among those with a primary food allergy. On the other hand, a database search revealed similarity to segments in the N-terminal region of vicilin-like sequences from macadamia and pecan, suggesting that additional vicilin-related peptides may be present in the IgE-reactive LMW fraction from hazelnut. [Extracted from the article]

During the last decade, the European hazelnut (Corylus avellana) has been threatened by several bacterial and fungal infections. In particular, at least four different Pseudomonas species have developed the capability to converge into the same host. However, one of these species, Pseudomonas avellanae, may infect other hosts as well. Here, we newly provide the complete genome sequence of two Pseudomonas avellanae strains obtained by a combination of long Oxford Nanopore Technologies reads (ONT) and short Illumina reads. These have been included in a comparative analysis with all the genomes of Pseudomonas strains known to infect Corylus avellana available on the NCBI database, and the genomes of Pseudomonas avellanae strains infecting other host plants, like Prunus, Actinidia and from the river epilithon. The Pseudomonas strains clustered according to their taxonomy, host and geographic origins. The identification of specific traits related to each population cluster could give us insights regarding the host–pathogen interaction and the host range specificity. Indeed, the Pseudomonas avellanae strains infecting hazelnut have a peculiar set of three type III secretion effectors, while the Pseudomonas avellanae infecting Prunus and Actinidia are carrying the genomic WHOP island, necessary for woody‐host infection. The syringae cluster, instead, contains more phytotoxins, the ice nucleation cluster, but less effectors. Thus, here, we confirmed that the convergence into the same host was possible due to different unrelated mechanisms of infection. [ABSTRACT FROM AUTHOR]

Hazelnut kernels inoculated using both techniques showed the same severe necrosis and rotting seven to ten days after inoculation, whereas the controls remained non-symptomatic (Fig. Keywords: Hazelnut; Kernel rot; Italy EN Hazelnut Kernel rot Italy 1 3 3 05/30/23 20230401 NES 230401 Hazelnut ( I Corylus avellana i ) is one of the most cultivated nut crops worldwide, with Turkey (665,000 tonnes) and Italy (140,560 tonnes) representing the leading countries in global production (Król & Gantner, [2]). [Extracted from the article]

Background: The species Xanthomonas arboricola comprises up to nine pathovars, two of which affect nut crops: pv. juglandis, the causal agent of walnut bacterial blight, brown apical necrosis, and the vertical oozing canker of Persian (English) walnut; and pv. corylina, the causal agent of the bacterial blight of hazelnut. Both pathovars share a complex population structure, represented by different clusters and several clades. Here we describe our current understanding of symptomatology, population dynamics, epidemiology, and disease control. Taxonomic status: Bacteria; Phylum Proteobacteria; Class Gammaproteobacteria; Order Lysobacterales (earlier synonym of Xanthomonadales); Family Lysobacteraceae (earlier synonym of Xanthomonadaceae); Genus Xanthomonas; Species X. arboricola; Pathovars: pv. juglandis and pv. corylina. Host range and symptoms: The host range of each pathovar is not limited to a single species, but each infects mainly one plant species: Juglans regia (X. arboricola pv. juglandis) and Corylus avellana (X. arboricola. pv. corylina). Walnut bacterial blight is characterized by lesions on leaves and fruits, and cankers on twigs, branches, and trunks; brown apical necrosis symptoms consist of apical necrosis originating at the stigmatic end of the fruit. A peculiar symptom, the vertical oozing canker developing along the trunk, is elicited by a particular genetic lineage of the bacterium. Symptoms of hazelnut bacterial blight are visible on leaves and fruits as necrotic lesions, and on woody parts as cankers. A remarkable difference is that affected walnuts drop abundantly, whereas hazelnuts with symptoms do not. Distribution: Bacterial blight of walnut has a worldwide distribution, wherever Persian (English) walnut is cultivated; the bacterial blight of hazelnut has a more limited distribution, although disease outbreaks are currently more frequently reported. X. arboricola pv. juglandis is regulated almost nowhere, whereas X. arboricola pv. corylina is regulated in most European and Mediterranean Plant Protection Organization (EPPO) countries. Epidemiology and control: For both pathogens infected nursery material is the main pathway for their introduction and spread into newly cultivated areas; additionally, infected nursery material is the source of primary inoculum. X. arboricola pv. juglandis is also disseminated through pollen. Disease control is achieved through the phytosanitary certification of nursery material (hazelnut), although approved certification schemes are not currently available. Once the disease is present in walnut/hazelnut groves, copper compounds are widely used, mostly in association with dithiocarbamates; where allowed, antibiotics (preferably kasugamycin) are sprayed. The emergence of strains highly resistant to copper currently represents the major threat for effective management of the bacterial blight of walnut. Useful websites: https://gd.eppo.int/taxon/XANTJU, https://gd.eppo.int/taxon/XANTCY, https://www.euroxanth.eu, http://www.xanthomonas.org [ABSTRACT FROM AUTHOR]

Caleosins are involved in several cellular and biological processes that are closely associated with the synthesis, degradation and stability of oil bodies (OB).Because of the importance and the multiple roles of these OB‐associated proteins, in silico identification of sequences corresponding to putative caleosins in the hazelnut genome has been performed, and the association with seed OB was verified using a proteomic approach.Five full‐length sequences (CavCLO‐H1, CavCLO‐H2, CavCLO‐H3, CavCLO‐L1, CavCLO‐L2), belonging to the two groups of caleosins (H and L), have been identified in the hazelnut genome. The number of identified caleosins is in agreement with that previously observed in other plant species, confirming that caleosins comprise small gene families in plants.A proteomic approach allowed us to verify only the presence of CavCLO‐H1 in hazelnut OB, suggesting that several members inside this family could have different roles during plant growth and development. In silico analysis also suggests that CavCLO‐H1 may act as a peroxygenase. [ABSTRACT FROM AUTHOR]

Background: 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. Methods: 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. Results: 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 0.35 kUA/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. Conclusion: 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. [ABSTRACT FROM AUTHOR]

The article discusses a 2021 report on the powdery mildew infection of Corylus avellana in Spain caused by Erysiphe corylacearum. It states that infected hazelnut plants had the symptoms or roundish spots of white mycelium on the adaxial side of the leaves, with fruit also being affected and damaged. Also noted is the first occurrence of E. corylacearum causing powdery mildew on hazelnut in Spain in the report.

Summary: This study investigated the effects of high‐pressure processing (HPP) and thermal processing (TP) on the overall quality attributes of hazelnut milk. HPP achieved the same microbial safety as TP, and the pH, °Brix and sugar contents were maintained at the levels of fresh hazelnut milk. Although HPP caused colour changes, the ∆E was smaller than that of the TP sample. Increasing pressure significantly decreased the immunoreactivity of the hazelnut milk by 70%, while simultaneously reducing the levels of essential and non‐essential amino acids and chemical score (CS) and the essential amino acid index (EAAI) values. However, neither HPP nor TP significantly affected the fatty acid composition of hazelnut milk. HPP retained higher total phenolic and flavonoid levels of the hazelnut milk, with a better antioxidant capacity than TP samples. Thus, the HPP maintained microbial safety during cold storage, and physicochemical properties of the treated hazelnut milk were not significantly different from those of the fresh hazelnut milk. [ABSTRACT FROM AUTHOR]

In this study, the effect of different sonication times (10, 20, and 30 min) on oil yields, extracted by using soxhlet together with preultrasonic treatment, and fatty acid composition of seed/kernels were investigated. The sonication of samples for 30 min caused the highest increase in oil yield of hazelnut (from 62.38 to 63.60%) and black cumin (from 27.90 to 31.80%) ( p < .05). The appropriate sonication time for oil yield of peanut was 10 min, with the range of 51.50%. After sonication process, the dominant fatty acid contents of all samples showed a change and the major decrease in oleic acid amount of hazelnut (from 75.20 to 74.27%) and peanut oils (from 57.10 to 56.69%) and linoleic acid content of black cumin (from 58.38 to 57.50%) were determined when samples sonicated for 30 min ( p < .05). Sonication process caused a decreasing in black cumin oil, and the reduction increased with sonication time. Practical applications Ultrasound-assisted extraction method can be used as an alternative extraction method for conventional extraction. Ultrasonic-assisted extraction has some advantages as being efficiency, speed and using low temperatures, which prevents thermal damage. The ultrasound process enables to greater influence of solvent into the sample matrix and increases mass transfer. Thereby, the higher extract yield, almost 23%, provided with ultrasonic-assisted extraction in comparison to soxhlet extraction. [ABSTRACT FROM AUTHOR]

Vegetable 'milk' obtained by aqueous extraction of oil bodies from maize germ, hazelnut, or sesame seed, followed by concentration of the extracts by ultrafiltration were subjected to thermal treatment to ensure their microbial quality and safety. Thermal treatment did not induce any important variations on the volatile profile of the hazelnut and sesame seed 'milk' products, while the aroma character of maize germ 'milk' was appreciably affected. The physical stability of both the maize germ and hazelnut 'milk' was not adversely influenced by the thermal treatment as they exhibited satisfactory stability against droplet aggregation/coalescence during storage. On the contrary, the heated sesame seed 'milk' was destabilized through the development of droplet aggregates. Studies on the oxidative stability of the 'milk' products revealed a positive effect of heating while no losses in different classes of endogenous bioactive constituents (tocopherols and lignans) were observed. The potential industrial applications are discussed. Practical applications: The consumption of food products with enhanced health benefits such as vegetable 'milk' is gaining ground due to the change of the dietary habits of the consumers towards non-dairy products. The stability of 'milk' products based on concentrated (i.e., by ultrafiltration) aqueous oil body extracts of maize germ, hazelnut, and sesame seed has never been examined before. The investigation of the impact of thermal treatment on the microbiological, physical, and oxidative stability of such product is of scientific interest as well as of practical application since it reflects the quality assurance and the higher economic sustainability of such products in the market. The hazelnut and maize germ 'milks' are promising novel products while sesame seed 'milk' can be used as raw material for other applications. [ABSTRACT FROM AUTHOR]

Peanut nut and tree nut allergy are characterised by IgE mediated reactions to nut proteins. Nut allergy is a global disease. Limited epidemiological data suggest varying prevalence in different geographical areas. Primary nut allergy affects over 2% of children and 0.5% of adults in the UK. Infants with severe eczema and/or egg allergy have a higher risk of peanut allergy. Primary nut allergy presents most commonly in the first five years of life, often after the first known ingestion with typical rapid onset IgE-mediated symptoms. The clinical diagnosis of primary nut allergy can be made by the combination of a typical clinical presentation and evidence of nut specifc IgE shown by a positive skin prick test (SPT) or specific IgE (sIgE) test. Pollen food syndrome is a distinct disorder, usually mild, with oral/pharyngeal symptoms, in the context of hay fever or pollen sensitisation, which can be triggered by nuts. It can usually be distinguish clinically from primary nut allergy. The magnitude of a SPT or sIgE relates to the probability of clinical allergy, but does not relate to clinical severity. SPT of ≥ 8 mm or sIgE ≥ 15 KU/L to peanut is highly predictive of clinical allergy. Cut off values are not available for tree nuts. Test results must be interpreted in the context of the clinical history. Diagnostic food challenges are usually not necessary but may be used to confirm or refute a conflicting history and test result. As nut allergy is likely to be a long-lived disease, nut avoidance advice is the cornerstone of management. Patients should be provided with a comprehensive management plan including avoidance advice, patient specific emergency medication and an emergency treatment plan and training in administration of emergency medication. Regular re-training is required. [ABSTRACT FROM AUTHOR]

Background: Sensitization to hazelnut (HN) is frequent and requires clarification to determine whether this sensitization is clinically relevant. The aim of this study was to investigate basophil activation profiles in HN-sensitized and allergic subjects. Methods: Basophil activation was determined by flow cytometric analyses of CD63 and CD203c expression using several HN allergen concentrations. Depending on their clinical reaction pattern, an oral allergy symptom group (OAS, n = 20), a systemic reaction group (n = 12) and a sensitized group without clinical symptoms (n = 20) were identified. Additionally, 10 non-allergic and non-sensitized individuals served as controls. Results: CD63 and CD203c expression differed between allergic (OAS and systemic group) and sensitized subjects. The HN concentration required to activate 30% of CD203c+ basophils [effective concentration (EC)30] was significantly higher in sensitized versus the allergic group (p = 0.0089). This was more pronounced when the basophil allergen threshold sensitivity (CD-sens) was calculated (CD63: p = 0.018; CD203c: p = 0.009). Conclusion: Our data indicate that the basophil activation test may provide information to better distinguish between sensitized and allergic subjects if several allergen concentrations are considered. CD203c expression displayed a better discrimination compared to CD63; therefore, its diagnostic value might be superior compared with CD63. [ABSTRACT FROM AUTHOR]

Background: Sensitization to hazelnut (HN) is frequent and requires clarification to determine whether this sensitization is clinically relevant. The aim of this study was to investigate basophil activation profiles in HN‐sensitized and allergic subjects. Methods: Basophil activation was determined by flow cytometric analyses of CD63 and CD203c expression using several HN allergen concentrations. Depending on their clinical reaction pattern, an oral allergy symptom group (OAS, n = 20), a systemic reaction group (n = 12) and a sensitized group without clinical symptoms (n = 20) were identified. Additionally, 10 non‐allergic and non‐sensitized individuals served as controls. Results: CD63 and CD203c expression differed between allergic (OAS and systemic group) and sensitized subjects. The HN concentration required to activate 30% of CD203c+ basophils [effective concentration (EC)30] was significantly higher in sensitized versus the allergic group (p = 0.0089). This was more pronounced when the basophil allergen threshold sensitivity (CD‐sens) was calculated (CD63: p = 0.018; CD203c: p = 0.009). Conclusion: Our data indicate that the basophil activation test may provide information to better distinguish between sensitized and allergic subjects if several allergen concentrations are considered. CD203c expression displayed a better discrimination compared to CD63; therefore, its diagnostic value might be superior compared with CD63. [ABSTRACT FROM AUTHOR]

Background: Sensitization to hazelnut allergens vary depending on the geographic origin and age of the patients. The objective of this study was to further investigate the allergenic activity of hazelnut allergens using sera from patients recruited in various European regions and presenting different sensitization patterns to hazelnut proteins. Methods: Natural Cor a 11 and Cor a 9 were purified from hazelnut whereas Cor a 1 and Cor a 8 were produced as recombinant proteins (rCor a 1.04 and rCor a 8). Sera from hazelnut allergic patients were collected in France (n = 5), Switzerland (n = 2), Greece (n = 11) and Spain (n = 3), within the Europrevall project. Total and allergen-specific IgE were quantified by enzyme allergosorbent test and IgE immunoblot were performed using pooled sera from birch-pollen endemic region or from Greece. Histamine Release (HR) assays were performed with stripped basophils passively sensitized with individual sera and challenged by a hazelnut extract or the different hazelnut allergens. Results: As previously described, hazelnut allergic patients from Mediterranean countries are mainly sensitized to the nsLTP Cor a 8 whereas patients from France and Switzerland are sensitized to pollen-related allergens. Interestingly, an intermediate profile was evidenced in patients from Madrid. Hazelnut 7S globulin (Cor a 11) and 11S globulin (Cor a 9) were found to be minor allergens, recognized only by patients from Mediterranean countries. The biologic activity of the 4 tested allergens, analysed by HR assay, further confirmed the sensitization patterns, but also demonstrated the very high elicitation potency of Cor a 8. Conclusions: This work, extending previously published researches, represents a step towards the better understanding of the complexity of hazelnut allergy and provides new data on the biological activity of hazelnut allergens and extracts. [ABSTRACT FROM AUTHOR]

The oil yields of hazelnut kernels collected from Germany (Münster) and Turkey range from 8.1 to 64.1%. The main fatty acids in hazelnut kernel oils are oleic (76.3-82.6%), linoleic (6.5-14.0%), and palmitic (5.7-6.5%). The hazelnut kernel oils contained an appreciable amount of α-tocopherol (19.9-63.9 mg/100 g), with a mean value of 40.02 mg/kg, and γ-tocopherol (1.3-15.5 mg/100 g), with a mean value of 4.84. α-Tocopherol was the predominant tocopherol in all hazelnut kernels. The major sterols were β-sitosterol, ranging from 78.13 to 82.56 mg/kg; campesterol, ranging from 4.79 to 7.42 mg/kg; and δ5-avanasterol, ranging from 1.26 to 5.24 mg/kg. The highest minerals were K and P followed by Ca, Mg, Na, and Zn. P contents of all samples were established between 2029.90 and 4376.66 ppm. The results may also be useful for the evaluation of nutritional information. As a result, the present study showed that the kernels of hazelnut are a potential source of valuable oil which might be used for food and non-food applications. In addition, hazelnut kernel oil has a high nutritive value and can be recommended for processing of healthy food products. [ABSTRACT FROM AUTHOR]

Allergy to hazelnut (Corylus avellana) can be severe and occur at young age. Atopic dermatitis (AD) can involve sensitization to various foods. The objective is to investigate the pattern of hazelnut sensitization in infants with AD. Sera of 34 infants all under 1 year of age and suffering from AD were selected according to prior specific IgE results. Twenty-nine infants were sensitized to traditional food allergens, five were not. From the 29 infants with a sensitization to at least one food allergen, 20 demonstrated IgE reactivity to hazelnut. All sera were analyzed with the allergen microarray immunoassay (ImmunoCAP ISAC). Twelve (60%) of the children with IgE reactivity to hazelnut demonstrated sensitization to Cor a 9, the 11S leguminlike seed-storage protein from hazelnut. In these infants, no sensitization to Cor a 1, the homologue of the major birch pollen allergen Bet v 1 (Betula verrucosa), or the lipid transfer protein (Cor a 8) from hazelnut was demonstrable. Half of the children sensitized to Cor a 9 demonstrated IgE reactivity to its homologue in peanut (Arachis hypogaea; Ara h 3) from which five were also sensitized to Gly m 6 from soy (Glycine max). None of the infants with AD without IgE reactivity to hazelnut demonstrated sensitization to Cor a 1, 8, or 9. In conclusion, young infants with atopic dermatitis sensitized to hazelnut can already display IgE reactivity to Cor a 9, a potentially dangerous hazelnut component. The mechanism(s) of this early sensitization and its clinical significance remain elusive. [ABSTRACT FROM AUTHOR]

Background: Symptoms of hazelnut allergy seem related to geographic and possibly age variations in allergen recognition. Objective: To investigate sensitization profiles of hazelnut allergy in different age groups in a birch-endemic region using component resolved diagnosis (CRD) by microarray. Methods: Sixty-five patients with hazelnut allergy, 27 healthy control individuals tolerant to hazelnut, and 34 birch pollen allergic but hazelnut tolerant individuals were included. All blood samples were analyzed using ISAC microarray. Results: Twenty-nine patients with hazelnut allergy suffered from a systemic reaction (17 preschool children with a median age of 2 years, six school children, and six adults), whereas 36 patients reported an oral allergy syndrome (OAS; three preschool and nine school children and 24 adults). In the hazelnut allergic preschool children with systemic reactions, 65% were sensitized to Cor a 9, 12% to Cor a 8, 18% to Cor a 1.04, 6% to Cor a 1.0101, and 29% to Bet v 1. Of the school-aged systemic reactors, 50% were sensitized to Cor a 9, 17% to Cor a 8, 50% to Cor a 1.04 and Cor a 1.0101, and 67% to Bet v 1. In adults with hazelnut allergy, 3.3% were sensitized to Cor a 9, 6.7% to Cor a 8, 90% to Cor a 1.04 and Bet v 1, and 87% to Cor a 1.0101. In regard to systemic reactors in this group, 17% were sensitized to Cor a 9, 33% to Cor a 8 and Cor a 1.0101, and 50% to Cor a 1.04 and Bet v 1. In the patients with OAS, irrespective the age group, all were sensitized to Bet v 1 and over 97% to Cor a 1.04 and Cor a 1.0101. No sensitization to Cor a 9 or Cor a 8 was found in patients with only an OAS. Of the patients with birch pollen allergy, tolerant to hazelnut, none were sensitized to Cor a 9 or Cor a 8, 56% to Cor a 1.0101, 82% to Cor a 1.04, and 92% to Bet v 1. In healthy controls, no sensitization to components of hazelnut, hazel pollen or birch pollen was demonstrable. Conclusion: Hazelnut allergy in a birch-endemic region exhibits age-related sensitization profiles with distinct clinical outcomes that can be identified using CRD. The majority of hazelnut allergic preschool and school children in a birch-endemic region show systemic reactions on consumption of processed hazelnut, mostly being sensitized to the hazelnut legumin-like allergen Cor a 9 but unrelated to birch pollen allergy. In contrast, adults generally suffer from an OAS apparently as a result of cross-reactivity between Cor a 1.04 from hazelnut and Bet v 1 from birch pollen. [ABSTRACT FROM AUTHOR]

With 6 figures and 6 tables European hazelnut ( Corylus avellana L.) is an important crop in Turkey, Georgia and Azerbaijan, where cultivars were selected from the native vegetation. Accessions from Turkey have been assigned to the Black Sea group, and cultivars from Georgia and Azerbaijan have a similar phenotype. Genetic diversity was investigated in 88 accessions from these three countries and compared with cultivars from Spain and Italy using 12 microsatellite loci. A high level of genetic diversity ( He = 0.71, Ho = 0.70) was observed in the Black Sea accessions. Six Turkish accessions in the US hazelnut collections were found to be synonyms of cultivars in the Turkish collection in Giresun. An unweighted pair-group method using arithmetic average dendrogram and principal component analysis of 109 unique accessions showed a tendency to form subgroups by country of origin, and high diversity within each subgroup. A moderate shift in allelic frequencies ( FST = 0.114–0.131) was seen between accessions from the Black Sea and the Spanish-Italian accessions. Simple sequence repeat analysis identified the putative parents of two Turkish cultivars. [ABSTRACT FROM AUTHOR]

Background IgE antibodies specific for the major birch-pollen allergen, Bet v 1, cross-react with homologous allergens in particular foods, e.g. apples, carrots and hazelnuts. In a high number of tree pollen-allergic individuals, this cross-reactivity causes clinical symptoms, commonly known as the ‘birch-fruit-syndrome’. Objective To characterize the T cell response to the Bet v 1-related major allergen in hazelnuts, Cor a 1.04, and its cellular cross-reactivity with Bet v 1 and the homologous hazel pollen allergen, Cor a 1. Methods Using recombinant Cor a 1.04, T cell lines (TCL) and T cell clones (TCC) were established from peripheral blood mononuclear cells of tree pollen-allergic patients with associated food allergy. T cell epitopes were determined using overlapping synthetic peptides in Cor a 1.04-reactive TCL and TCC. In parallel, reactivity to Bet v 1 and Cor a 1 was tested. Results In total, 20 distinct T cell epitopes on the hazelnut allergen were identified. Several Cor a 1.04-specific TCL and TCC reacted with pollen allergens albeit less pronounced than with the hazelnut allergen. Several Cor a 1.04-specific TCC did not react with pollen allergens. Interestingly, these clones were found to react with the Bet v 1-related major allergen in carrots, Dau c 1. The cellular cross-reactivity between both food allergens could be associated with the most frequently recognized T cell epitope of Cor a 1.04, Cor a 1.04142–153. Conclusions The major hazelnut allergen cross-reacts with the major allergens of birch and hazel pollen but apparently contains a relevant T cell epitope not shared with pollen allergens. Our finding may have important implications for the specific immunotherapy of tree pollen-allergic patients suffering from concomitant hazelnut allergy. [ABSTRACT FROM AUTHOR]

In a double-blind placebo-controlled food challenge (DBPCFC), it is necessary that recipes comprising the allergen cannot be distinguished from placebo. We investigated whether the method of paired comparisons, a sensory difference test, could be used to test the suitability of recipes for a DBPCFC. We used two recipes, each with three concentrations of peanut or hazelnut flour. The recipe for peanut consisted of mashed potatoes with 2.7, 8.9, or 26.8 mg of peanut flour, and the recipe for hazelnut of oatmeal porridge with 74, 247, or 742 mg of hazelnut flour. Corresponding amounts of protein in the provided 15 g portions of each recipe were 0.7, 2.3, and 6.8 mg for peanut, and 11.6, 39, and 117 mg for hazelnut, respectively. Recipes were offered together with a placebo, and evaluated on sensory features by 81 healthy volunteers. The sensory test was easy to perform. Volunteers were not able to detect peanut flour in mashed potatoes, but they recognized hazelnut flour in oatmeal porridge on visual features. Sensory testing by means of the method of paired comparisons is a useful method to evaluate masking of foods for DBPCFC. [ABSTRACT FROM AUTHOR]

Summary By use of the DneasyTM Plant Tissue kit (Qiagen Inc.) plant DNA could be extracted from chocolate and related matrices. The polymerase chain reaction (PCR) detection of mitochondrial plant DNA is directly correlated with the length of the amplified fragment indicating shearing of DNA during chocolate production. Hazelnut DNA could be specifically detected in chocolate matrices with primers derived from the intron between exon B and C of the mitochondrial gene nad 1. Specificity was confirmed towards individual chocolate ingredients and in 20 hazelnut negative chocolates. From taxonomically closely related plant species, only Carpinus turczaninovii , Ostrya carpinifolia and Corylus americana showed cross reaction, this was because of the identical sequence of the nad 1 fragment. Application of extra MgCl2 throughout the DNA extraction procedure and of a specially designed Mg2+ buffered PCR, increased the detection sensitivity of co-processed hazelnut in chocolate to 0.001% or 10 ppm. [ABSTRACT FROM AUTHOR]

Background: Allergy to hazelnuts is a common example of birch pollen related food allergy. Symptoms upon ingestion are often confined to the mouth and throat, but severe systemic reactions have been described in some patients. The aim of the study was to evaluate the reduction in allergenicity by roasting of the nuts. Methods: Double-blind, placebo-controlled food challenges (DBPCFC) with roasted hazelnuts (140°C, 40 min) were performed in 17 birch pollen allergic patients with DBPCFC-confirmed food allergy to raw hazelnuts. The effect of roasting was further evaluated by skin prick test (SPT), histamine release (HR), measurement of specific IgE, and IgE-inhibition experiments. Results: In 5/17 patients the DBPCFC with the roasted nuts were positive. The symptoms were generally mild and included OAS (oral allergy syndrome) in all patients. Roasting of the nuts significantly reduced the allergenic activity evaluated by SPT, HR, specific IgE, and IgE-inhibition. Immunoblotting experiments with recombinant hazelnut allergens showed sensitization against Cor a 1.04 in 16/17 patients and against Cor a 2 in 7/17 patients. None of the patients were sensitized to Cor a 8. Challenge-positive patients did not differ from the rest in IgE-binding pattern. Conclusions: All the applied methods indicated that roasting of hazelnuts reduces the allergenicity, but since 5/17 birch pollen allergic patients were DBPCFC-positive to the roasted nuts, ingestion of roasted hazelnuts or products containing roasted hazelnuts can not be considered safe for a number of hazelnut allergic consumers. For patients with a history of severe allergic symptoms upon ingestion of hazelnuts, thorough and conscientious food labelling of hazelnuts and hazelnut residues is essential. [ABSTRACT FROM AUTHOR]

Background: Several associations have been described between tree and plant pollens and certain foods. The objective of this study is to verify whether there is cross-reactivity between Platanus pollen and vegetable origin foods. Methods: We selected 56 patients allergic to vegetable foods and subjected them to cutaneous tests with aeroallergens and vegetable foods. A statistical analysis was performed to evaluate the association of Platanus pollen with foods and with other aeroallergens. Later, a specific IgE determination was performed as well as a RAST (radioallergosorbent) inhibition experiment, to verify the existence of cross-reactivity in vitro. Results: In the cutaneous tests we found a positive correlation between Platanus pollen and hazelnut, peanut, banana and celery. The results of the RAST inhibition experiment indicate an important cross-reactivity between the pollen of Platanus acerifolia and hazelnut and banana fruit, and an intermediate cross-reactivity with celery and peanut. Conclusion: We have described an association between the pollen of the Platanus tree and some vegetable foods such as hazelnut, banana, peanut and celery. This association could be explained by the in vitro IgE cross-reactivity detected. [ABSTRACT FROM AUTHOR]

Background: Patients with birch and grass allergy often suffer from oral allergy symptoms when ingesting cross-reacting fresh fruits and vegetables. However, fruit and vegetable allergen extracts are often readily degradable or contain clinically irrelevant cross-reacting epitopes, resulting in diagnostic discrepancies when fruit and vegetable allergic reactions are evaluated. The risk of using nonstandardized fresh food extracts for skin testing may also be of concern. The objective was to compare and evaluate the clinical utility of selected recombinant grass and birch cross-reacting food allergens with fresh and commercial melon, hazelnut, and apple extracts. Methods: Thirty-six grass- and or birch-allergic patients and 17 control subjects consented to participate in the study. All subjects were skin prick tested and had basophil histamine-release tests done with fresh fruits and various extracts of hazelnut, apple, and melon. The diagnosis of oral allergy syndrome was confirmed by oral challenges. In addition, histamine release to recombinant Bet v 1 and Bet v 2, and recombinant Phl p 1 and Phl p 2, Phl p 5 was performed. Results: The skin prick test with fresh hazelnut, apple, and melon showed sensitivities of 0.97, 0.92, and 0.89, respectively. The corresponding specificities were 0.78, 0.72, and 0.82, respectively. In contrast, the histamine-release test with hazelnut, apple, and melon gave sensitivities of 0.87, 0.71, and 1.00, respectively. The corresponding specificities were 0.65, 0.93, and 0.43. The skin prick test showed excellent negative predictive value (>90%). No added value of recombinant allergen testing was noted. Oral challenge did not result in severe systemic reactions, and no systemic reactions were observed with skin prick tests with fresh fruits. Conclusions: The skin prick test showed an almost optimal diagnostic value with a satisfactory sensitivity (>89%) and excellent negative predictive value with fresh fruits. When the skin prick test with fresh nut and apple cannot be performed, histamine release is a diagnostic alternative. Histamine release with melon showed lack of specificity. This was probably due to extensive IgE cross-reactivity with pollen, since these patients also responded to recombinant Phl p 1 and Bet v 1. Skin testing and challenges with fresh fruits were safe. [ABSTRACT FROM AUTHOR]

We have identified hrp genes, encoding harpin proteins, of two strains of Pseudomonas avellanae originating, from the Latium and Piedmont regions, respectively. These strains belong to two populations differing in phenotypic, molecular and pathogenic characteristics. For this purpose, hrpZ primers of Pseudomonas syringae pv. syringae strain 61 (hrpZPss) and hrpW primers of Pseudomonas syringae pv. tomato strain DC3000 (hrpWPst) were used for amplification, by polymerase chain reaction, of presumptive hrpZ and hrpW genes in P. avellanae strains. The hrpW primers were able to amplify, in both P. avellanae strains, a 1.2 kb fragment corresponding in size to the hrpW gene, whereas hrpZ primers did not give amplification products. To obtain information about this gene, a hrpZ fragment of about 500 nucleotides was amplified, using sequence-degenerate oligonucleotides. The nucleotide sequences of these amplified hrp genes of P. avellanae are reported and compared with the known sequences of these genes reported in the GenBank-EMBL Data Bank. [ABSTRACT FROM AUTHOR]

Background An association between sensitization to Compositae pollens and hyper sensitivity to hazelnut has been previously described. There is no previous in vitro study about crossreactivity between mugwort pollen and hazelnut. Objectives To study mugwort pollen and hazelnut allergens and to assess if there is IgE crossreactivity between mugwort pollen and hazelnut. Methods A serum pool formed by 28 individual sera with specific IgE to mugwort pollen and hazelnut was used to investigate IgE crossreactivity. RAST-inhibition, SDS-PAGE/IEF immunoblotting inhibition assays were performed by preincubation of the sera with mugwort pollen and hazelnut. Results RAST to hazelnut was inhibited up to 63% by mugwort pollen, but the mugwort pollen RAST was only inhibited up to 36% by hazelnut. In SDS-PAGE immunoblotting main allergens: 42 kDa, 17 kDa and <16 kDa (two bands). In the SDS-PAGE immunoblotting inhibition hazelnut partially inhibited all the mugwort pollen bands, except that with 19 kDa, whereas mugwort pollen produced a nearly total inhibition of all the hazelnut allergens. In isoelectrofocusing immunoblotting mugwort pollen had two groups of allergens: pI 7.5-8.5 and pI 3.5-5.2 and hazelnut one group of allergens: pI 5.2-5.8. In the isoelectrofocusing immunoblotting inhibition hazelnut produced a partial inhibition of all the bands of mugwort pollen and mugwort pollen partially inhibited all the allergenic bands of hazelnut. Conclusions The RAST and SDS-PAGE/IEF immunoblotting inhibition results provide evidence of IgE cross reactivity between mugwort pollen and hazelnut allergens. The inhibition of hazelnut by mugwort pollen is higher than the inhibition of mugwort pollen by hazelnut in both RAST inhibition and SDS-PAGE immunoblotting inhibition. These results suggest that mugwort pollen allergens would behave as primary immunogens in the association between sensitivity to mugwort pollen and hazelnut. [ABSTRACT FROM AUTHOR]

During formation of adventitious roots, the effects of 2-chlorethylphosphonic acid (CEPA), 1 -aminocyclopropane-1 -carboxylic acid (ACC) and aminoethoxyvinylgly- cine (AVG) added to a Cheng basal medium, supplemented with indole-3-butyric acid (IBA) and kinetin were determined on peroxidase (PO; EC 1.11.1.7) and polyphenol oxidase (PPO; EC 1.10.3.1) activities in cotyledon explants of hazelnut (Corylus avellana L. cv. Casina). CEPA stimulated PO and PPO activities while AVG inhibited. SDS-polyacrylamide gel electrophoresis of preparations from hazelnut cotyledons showed a correlation between proteins and rooting. Ethylene seems to modify total protein content and the activities of PO and PPO. As compared to the control extracts, AVG inhibited the anodic (53, 30.7 and 27 kDa) and cathodic (66.2 and 53.4 kDa) isoperoxidases and anodic (27.5 and 21 kDa) and cathodic (67.5 kDa) isopolyphenol oxidases, whereas CEPA promoted the anodic (30.7, 28.8 and 27 kDa) and cathodic (53.4 and 27.2 kDa) isozymes with PO activity. The increased PO activity during rooting in hazelnut cotyledons could enhance isozymes with lignin biosynthetic activity. [ABSTRACT FROM AUTHOR]

Ethylene may be one of the many factors that play a role in rooting. However, in some studies ethylene promoted rooting, while in others it was inhibitory or had no effect. Using cotyledons of hazelnut (Corylus avellana L. cv. Casina) observations were made of the effect of ethylene precursors on adventitious root formation. 1-methionine (Met) or 1-aminocyclopropane-1-carboxylic acid (ACC) added to a standard indole-3-butyric acid (IBA)-kinetin-containing medium did not enhance rooting, while 2-chloroethylphosphonic acid (CEPA) did. The ethylene inhibitor, aminoethoxyvinylglycine (AVG), inhibited root formation, but its effect was reversed by ACC when cotyledonary segments were transferred to rhizogenic medium plus ACC at day 10. Ethylene production by cotyledons cultured on rhizogenic medium or rhizogenic medium plus CEPA was high at the beginning of rooting. Thus, the wound-induced ethylene is a key stimulatory factor in the formation of root primordia. The data support the hypothesis that ethylene plays a positive role in root formation. [ABSTRACT FROM AUTHOR]

The article presents information on a survey that was undertaken to describe what characterizes in vitro the clinically relevant cross-reactivities in birch-pollen-sensitized patients and the severity of symptoms. The survey also probed whether there is a correlation between the magnitude of the IgE response to basic proteins, apple, hazelnut, celery and carrot and the clinical situation. Results of the survey revealed that Birch-pollen-allergic patients with symptoms after eating apple, hazelnut and carrot showed significantly higher IgE levels to the respective food items than asymptomatic patients. There were no significant differences in the IgE level between patients with localized or systemic symptoms.

This study aimed, first, to study the prevalence in The Netherlands of atopy caused by apple, peach, and hazelnut in patients with tree pollinosis, and, second, to compare three extraction procedures for skin prick testing with two different apple strains. Skin prick tests and RAST were performed on 79 consecutive patients with tree pollinosis, visiting the department of allergology during spring 1995. In skin prick tests, we used three different extracts (juice, freeze-dried extract, and low-temperature acetone powder extract) of two apple strains, Golden Delicious and Granny Smith. Case histories for apple, peach, and hazelnut were positive in 35 (44.3%). 23 (29%), and 35 (44.3%) patients, respectively. More than two-thirds of the patients had symptoms characteristic of oral allergy syndrome. Skin prick tests for apple, peach, and hazelnut were positive in 51 (64.6%), 61 (77.2%), and 71(89.9%) patients, respectively. Granny Smith showed more positive skin reactions and a better agreement with clinical history than Golden Delicious, and juice was superior to the two other extraction procedures for both apple strains. RAST for apple, peach, and hazelnut was positive in 53 (68.8%), 13 (16.9%), and 31 (40.3%) patients. respectively Concordance between skin prick test and case history was found in 77%, 52%, and 54%, for apple, peach, and hazelnut, respectively. We found a high percentage of concurrence of clinical allergy to birch pollen and apple, peach, and hazelnut, confirmed by both skin prick testing and RAST. Approximately half of these patients had symptoms (especially oral allergy syndrome) after eating these products. We also found an easy extraction procedure (juice extract) suitable for apple skin prick testing. superior even to freeze-dried extraction or the low-temperature acetone powder technique. [ABSTRACT FROM AUTHOR]

Hazelnut ( Corylus avellana L.) samples were collected from six different cultivars of trees grown in an experimental orchard at Lincoln University. Three U.S. commercial cultivars (Butler, Ennis, and Barcelona), two European commerical cultivars (Tonda di Giffoni and Campanica), and one New Zealand selection (Whiteheart) were evaluated. The total oil, stability to oxidation of the oil, and fatty acid, tocopherol, and sterol composition were determined on samples of freshly extracted hazelnut oil. The total oil content of the seeds ranged from 54.6 to 63.2% while the stability of the oil, as measured by the Rancimat test ranged from 15.6 to 25.3 h. The content of the monounsaturated oleic acid in the oils ranged from 73.8 to 80.1% of the total fatty acids, while the tocopherol content ranged from 225.8 to 552.0 mg/g freshly extracted oil. The major desmethylsterols were sitosterol, ranging from 1416 to 1693 µg/g, campesterol, ranging from 78 to 114 µg/g, and Δ5-avenasterol, ranging from 110 to 170 µg/g. The oil extracted from the cultivar Whiteheart was more stable (measured by Rancimat) than the oil from all other cultivars grown at the same location and under the same conditions. Whiteheart contained higher levels of total and γ-tocopherol when compared to the other cultivars. The higher levels of tocopherol in Whiteheart help to explain the greater stability of the oil during the oxidative stress test. These results suggest that nuts from the cultivar Whiteheart could be stored longer than the other nuts tested. [ABSTRACT FROM AUTHOR]

The article reports on the detection of powdery mildew disease symptoms on leaves of Corylus avellana (hazelnut) and C. colurna (Turkish hazelnut) in eastern and southern Austria. The disease was found to be Corylus spp. growing in mixed deciduous forests, hedges as well as city gardens and parks. It is noted that Erysiphe corylacearum has been a severe invasive alien pathogen, which causes significant yield losses in hazelnut orchards in Iran, Turkey and Georgia.

The article focuses on record of Erysiphe corylacearum on Corylus avellana in Switzerland and in central Europe. It mentions molecular phylogenetic analysis showed that the Swiss strains had identical ITS sequences to those of E. corylacearum from Azerbaijan, Georgia, Iran and Turkey. It also mentions pathogen differs from the native hazelnut powdery mildew Phyllactinia guttata, with which it sometimes co-occurs,by forming mycelia on the upper leaf surface and having smaller chasmothecia.

The article focuses on the importance of the study of the effects of food components on immunoreactivity in experimental animals. It has been indicated by the author that animal experiments have provided important information on the degree to which intestine immune responses depend on several factors of antigen administration. However, the author added that there are still no established animal models for predicting potentially allergenic protein components.

Pseudomonas avellanae is the main cause of hazelnut (Corylus avellana L.) decline, the so called ‘moria’, in central Italy where it has already killed more than 30 000 trees. Its current identification is very long requiring biochemical, physiological and nutritional tests as well as pathogenicity tests and takes not less than 6 months for its completion. In the present study the reliability of the repetitive polymerase chain reaction (rep-PCR) technique for a rapid and accurate identification of such a pathogen was compared with the traditional identification method. In order to assess the variability of the pathogen, REP, BOX and ERIC primer sets were used in preliminary work to generate genomic fingerprints of 60 P. avellanae reference strains previously isolated from different areas of hazelnut cultivation. ERIC primers yielded the most discriminative clustering of strains that were grouped according to their geographic origin. Sixty field isolates collected from hazelnut orchards of central Italy, planted with different cultivars, during the years 1996–98 were submitted to either the traditional identification methods or to rep-PCR by using ERIC primers. The latter technique accurately identified all the isolates that were also identified by the traditional methods. Whole-cell protein analysis by means of sodium dodecyl sulphate-polyacrylamide gel electrophoresis confirmed this achievement. Rep-PCR can be successfully adopted for the rapid and accurate identification of P. avellanae in central Italy and it constitutes a very useful tool for the sanitation of the area. [ABSTRACT FROM AUTHOR]