Isolation,cloning, and characterization of the 2S albumin: A new allergen from hazelnut

Scope: 2S albumins are the major allergens involved in severe food allergy to nuts, seeds, and legumes. We aimed to isolate, clone, and express 2S albumin from hazelnut and determine its allergenicity. Methods: 2S albumin from hazelnut extract was purified using size exclusion chromatography and RP‐HPLC. After N‐terminal sequencing, degenerated and poly‐d(T) primers were used to clone the 2S albumin sequence from hazelnut cDNA. After expression in Escherichia coli and affinity purification, IgE reactivity was evaluated by Immunoblot/ImmunoCAP (inhibition) analyses using sera of nut‐allergic patients. Results: N‐terminal sequencing of a ～10 kDa peak from size exclusion chromatography/RP‐HPLC gave two sequences highly homologous to pecan 2S albumin, an 11 amino acid (aa) N‐terminal and a 10aa internal peptide. The obtained clone (441 bp) encoded a 147aa hazelnut 2S albumin consisting of a putative signal peptide (22 aa), a linker peptide (20 aa), and the mature protein sequence (105 aa). The latter was successfully expressed in E. coli. Both recombinant and natural 2S albumin demonstrated similar IgE reactivity in Immunoblot/ImmunoCAP (inhibition) analyses. Conclusion: We confirmed the postulated role of hazelnut 2S albumin as an allergen. The availability of recombinant molecules will allow establishing the importance of hazelnut 2S albumin for hazelnut allergy.     

芝麻过敏原分子特征与检测方法研究进展

食物过敏已成为全世界范围存在的公共健康问题,芝麻是一种常见的食物过敏原,对芝麻过敏原的研究日渐深入。目前,芝麻中已确定的过敏原蛋白有7 种（Ses i 1～Ses i 7）。本文综述了近几年来各国对芝麻过敏原的管理规定、芝麻过敏原蛋白的结构特征、加工过程对其结构及致敏性影响、检测方法等方面的研究进展,以期为采用不同工艺、方法消除或降低芝麻过敏原的致敏性提供理论参考,也为过敏原标签标识的实施提供理论依据。最后,本文总结了芝麻过敏原的研究现状并对未来研究趋势进行了展望。     

Optimization of extraction of phenolic content from hazelnut shell using response surface methodology

Response surface methodology was applied to predict the optimum conditions for extraction of phenolic compounds in hazelnut shell. The phenolic content in the shell extract was determined spectrophotometrically according to the Folin‐Ciocalteu method and expressed as gallic acid equivalent (mg GAE g^?1). Two central composite designs were used to investigate the effects of two independent variables, namely solvent composition (%) and extraction time (min), on phenolic extraction. In a first series of repeated batch extractions, the solvent consisted of different methanol percentages in distilled water at pH 4, while in a second series methanol was substituted by ethanol. The highest phenolic content (6.67 mg GAE g^?1 of shell) was predicted at the extraction conditions of 55.7% ethanol and 108.7 min. These best conditions, obtained and applied to 13 different cultivars, showed values varying from 9.18 mg GAE g^?1 of shell for Barcelona to 3.00 mg GAE g^?1 of shell for Tonda di Giffoni. Copyright © 2007 Society of Chemical Industry     

免疫学技术在食品过敏原检测中的应用

食品过敏原可引起机体产生过敏反应,严重危害人类健康及生命安全。目前食品包装上过敏原信息标注规 范尚不完善,因此食品过敏原检测技术对于预防含有过敏原食品进入流通领域,减少过敏事件发生至关重要。本文 综述了免疫学检测技术在食品过敏原检测中应用,并展望了其未来的发展趋势。     

芥末等8种食物过敏原的多重PCR检测技术

依据芥末Sin a I基因、羽扇豆核糖体内转录间隔区(ITS)基因、胡桃Jug r 2基因、榛果Oleosin基因、芹菜Mtd基因、杏仁Pru du 1基因、燕麦Avenin基因和芝麻2S albumin mRNA基因设计的特异性引物序列,在普通PCR方法的基础上,通过2组4重PCR扩增,建立了同时检测芹菜、杏仁、燕麦、芝麻、芥末、羽扇豆、胡桃和榛果等8种食物过敏原的方法。该方法特异性强,灵敏性高,可应用于食品中多种食物过敏原的快速检测和监控。     

Advances in cultivar choice,hazelnut orchard management,and nut storage to enhance product quality and safety: an overview

European hazelnut (Corylus avellana L.) is a major species of interest for nutritional use within the Betulaceae family and its nuts are widely used throughout the world in the chocolate, confectionery, and bakery industries. Recently its cultivation has been expanded in traditional producer countries and established in new places in the southern hemisphere, including Chile, South Africa, and Australia. Introducing hazelnut in new environments could reduce its productivity, lead the trees to experience eco‐physiological disorders, and expose the crop to high pressure from common and new pests and diseases. Thus, new approaches in cultivar choice guidance, in the sustainable orchard management and even in nut storage and kernel quality evaluation are urgently required to improve the hazelnut production and processing chain. The main objective of this study was to systematize the published information regarding recent findings about the cultural operations that directly influence nut and kernel quality, support varietal choice for new plantations, and list the recent advances in nut storage and in quality and safety evaluation. © 2020 Society of Chemical Industry     

New Trends in Food Allergens Detection: Toward Biosensing Strategies

Food allergens are a real threat to sensitized individuals. Although food labeling is crucial to provide information to consumers with food allergies, accidental exposure to allergenic proteins may result from undeclared allergenic substances by means of food adulteration, fraud or uncontrolled cross-contamination. Allergens detection in foodstuffs can be a very hard task, due to their presence usually in trace amounts, together with the natural interference of the matrix. Methods for allergens analysis can be mainly divided in two large groups: the immunological assays and the DNA-based ones. Mass spectrometry has also been used as a confirmatory tool. Recently, biosensors appeared as innovative, sensitive, selective, environmentally friendly, cheaper and fast techniques (especially when automated and/or miniaturized), able to effectively replace the classical methodologies. In this review, we present the advances in the field of food allergens detection toward the biosensing strategies and discuss the challenges and future perspectives of this technology.     

Mechanical behaviour of hazelnuts used for table consumption under compression loading

Nuts of four hazelnut varieties and five new selections used for table consumption were compressed at the moisture content of 6% wet basis to measure shell resistance to breakage. Rupture force, rupture energy and nut specific deformation were measured under three compression loading positions. Physical parameters of nuts were also evaluated to relate them to the data obtained by compression test measurements. Rupture force and nut specific deformation are the most discriminant parameters that can be used to describe the behaviour under compression, while rupture energy values show fewer differences among the considered varieties. The values of force required to break nut shell ranged from 322.2 to 769.3 N. The lowest values of force were generally obtained along the y‐axis, the transverse axis containing the major dimension at right angles to the longitudinal axis. Nut specific deformation ranged from 3.35 to 11.76%. Correlations between physical and texture parameters showed that values of force, energy and deformation were dependent on different parameters that varied in the three considered axis. The most used varieties, Ennis and Barcelona, showed high mean values of force rupture to break shell and low deformability, while Tonda Giffoni and Tonda Bianca were easy to break. Among the new selections, L35 and B6, with mean values of force rupture less than 428 N and values of nut specific deformation higher than 8%, were suitable for table consumption. Copyright © 2006 Society of Chemical Industry     

Characterisation of selected hazelnut cultivars: phenology, growing and yielding capacity, market quality and nutraceutical value

BACKGROUND: Sixteen hazelnut cultivars growing in the continental climate of Slovenia were analysed over 15 years for their phenology, growth habit, yield potential, susceptibility to hazelnut weevil and the pomological traits and phenolic content of their nuts in order to obtain a complex value of these cultivars for growers, the confectionary industry and consumers. RESULTS: Blooming occurred over an interval of 10–23 days for female (pistillate) flowers and 11–22 days for male (staminate) flowers. Nocchione, Romai, Pauetet, ID and Daria were the most productive cultivars, with a nine‐year cumulative yield ranging from 31.8 to 44.7 kg per plant. Pauetet, F. Coutard, Nocchione and Segorbe were less susceptible to unfavourable weather conditions during blooming and fertilisation, in terms of maintaining acceptable yields with limited blank production. Under integrated pest management, less than 2% of the nuts of Romai, Daria, TGDL and Nocchione were affected by hazelnut weevil, compared with an average of 5.5% for the other cultivars. Daria, Pauetet and T. Giffoni performed best with regard to kernel percentage and blanching ratio. The results suggest that raw kernels are a good source of the natural antioxidants gallic acid and epicatechin. CONCLUSION: The results of this study provide direction when choosing hazelnut cultivars for planting, consuming or processing. They can be applied not only in Slovenia and nearby countries but also in other parts of central and northern European countries with similar climates and growing conditions. Copyright © 2011 Society of Chemical Industry     

Nut and kernel traits and chemical composition of hazelnut (Corylus avellana L.) cultivars

BACKGROUND: Nut and kernel traits and chemical composition of 24 Italian and foreign hazelnut cultivars were analysed in 2002–2004 in order to study the effect of genotype and environment on nut quality. Nuts were sampled in a germplasm collection in the Italian province of Viterbo. RESULTS: Quantitative and qualitative determinations of sugars, organic acids and lipids revealed good nutritional and health potential of the nuts, with several differences among cultivars and years. The total contents of oil and sugars ranged from 563.69 to 656.36 g kg^?1 dry weight (DW) and from 39.80 to 59.51 g kg^?1 DW respectively. Fatty acid profile and sugar and total phenolic contents varied with the year. Significantly higher palmitic acid concentration (6.18%) was found in the hot summer year 2003; lower saturated fatty acid concentration (8.20%) and higher unsaturated/saturated acid ratio (11.27) were observed in the coolest year (2004). These differences among years were highlighted by discriminant analysis. CONCLUSION: The information relating to secondary components such as sugars, organic acids and phenolics was useful for discriminating among cultivars and years. Owing to the effect of these compounds on sensory attributes perceived by consumers, their concentration and the varietal differences can be considered primary determinants of nut quality and should be valued when planning the cultivar choice for new plantations. Copyright © 2008 Society of Chemical Industry     

Isolation and characterization of natural Ara h 6: evidence for a further peanut allergen with putative clinical relevance based on resistance to pepsin digestion and heat

Peanut allergy is a significant health problem because of its prevalence and the potential severity of the allergic reaction. The characterization of peanut allergens is crucial to the understanding of the mechanism of peanut allergy. Recently, we described cloning of the peanut allergen Ara h 6. The aim of this study was isolation and further characterization of nAra h 6. We purified nAra h 6 from crude peanut extract using gel filtration and anion exchange chromatography. The preparation was further characterized by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) with subsequent immunoblotting. Stability of nAra h 6 was studied by an in vitro digestibility assay as well as by resistance against thermal processing. Sequencing of nAra h 6 identified the N-terminal amino acid sequence as MRRERGRQGDSSS. Further results clearly demonstrated stability of nAra h 6 against pepsin digestion and heating. Immunoglobulin G (IgE) binding analysis and its biological activity shown by RBL 25/30-test of natural Ara h 6 supported the importance of this peanut allergen. Investigation of nAra h 6 revealed evidence for a further peanut allergen with putative clinical relevance based on resistance to pepsin digestion and heat.     

Advances on the molecular characterization,clinical relevance,and detection methods of Gadiform parvalbumin allergens

Gadiform order includes several fish families, from which Gadidae and Merlucciidae are part of, comprising the most commercially important and highly appreciated fish species, such as cod, pollock, haddock, and hake. Parvalbumins, classified as calcium-binding proteins, are considered the main components involved in the majority of fish allergies. Nine and thirteen parvalbumins were identified in different fish species from Gadidae and Merlucciidae families, respectively. This review intends to describe their molecular characterization and the clinical relevance, as well as the prevalence of fish allergy. In addition, the main protein- and DNA-based methods to detect fish allergens are fully reviewed owing to their importance in the safeguard of sensitized/allergic individuals.     

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.     

Campylobacter jejuni: A Review of its Characteristics,Pathogenicity, Ecology,Distribution, Subspecies Characterization and Molecular Methods of Detection

Campylobacter jejuni is considered to be the leading cause of enteric illness in the United States and other industrialized nations, causing mild to severe symptoms including serious infections of the extremities and permanent neurological symptoms. The organism is a cytochrome oxidase positive, microaerophilic, curved Gram-negative rod exhibiting corkscrew motility and is carried in the intestine of many wild and domestic animals, particularly avian species including poultry, where the intestine is colonized resulting in healthy animals as carriers. Wildlife have long been considered an infectious reservoir for campylobacters because of their close association with and contamination of surface waters. This review deals with the areas of: phenotypic characteristics of C. jejuni and related human pathogenic species of Campylobacter, their ecological distribution, virulence factors, isolation of C. jejuni from foods, serotyping of Campylobacter isolates, bacteriophage typing, molecular methods of detecting and typing campylobacters, the viable but nonculturable state of campylobacters, the coccoid form of C. jejuni and immunomagnetic capture of C. jejuni.     

Campylobacter jejuni: A Review of its Characteristics, Pathogenicity, Ecology, Distribution, Subspecies Characterization and Molecular Methods of Detection

Campylobacter jejuni is considered to be the leading cause of enteric illness in the United States and other industrialized nations, causing mild to severe symptoms including serious infections of the extremities and permanent neurological symptoms. The organism is a cytochrome oxidase positive, microaerophilic, curved Gram-negative rod exhibiting corkscrew motility and is carried in the intestine of many wild and domestic animals, particularly avian species including poultry, where the intestine is colonized resulting in healthy animals as carriers. Wildlife have long been considered an infectious reservoir for campylobacters because of their close association with and contamination of surface waters. This review deals with the areas of: phenotypic characteristics of C. jejuni and related human pathogenic species of Campylobacter, their ecological distribution, virulence factors, isolation of C. jejuni from foods, serotyping of Campylobacter isolates, bacteriophage typing, molecular methods of detecting and typing campylobacters, the viable but nonculturable state of campylobacters, the coccoid form of C. jejuni and immunomagnetic capture of C. jejuni.     

A Comprehensive Review on Kiwifruit Allergy: Pathogenesis,Diagnosis, Management,and Potential Modification of Allergens Through Processing

Kiwifruit is rich in bioactive components including dietary fibers, carbohydrates, natural sugars, vitamins, minerals, omega‐3 fatty acids, and antioxidants. These components are beneficial to boost the human immune system and prevent cancer and heart diseases. However, kiwifruit is emerging as one of the most common elicitors of food allergies worldwide. Kiwifruit allergy results from an abnormal immune response to kiwifruit proteins and occur after consuming this fruit. Symptoms range from the oral allergy syndrome (OAS) to the life‐threatening anaphylaxis. Thirteen different allergens have been identified in green kiwifruit and, among these allergens, Act d 1, Act d 2, Act d 8, Act d 11, and Act d 12 are defined as the “major allergens.” Act d 1 and Act d 2 are ripening‐related allergens and are found in abundance in fully ripe kiwifruit. Structures of several kiwifruit allergens may be altered under high temperatures or strong acidic conditions. This review discusses the pathogenesis, clinical features, and diagnosis of kiwifruit allergy and evaluates food processing methods including thermal, ultrasound, and chemical processing which may be used to reduce the allergenicity of kiwifruit. Management and medical treatments for kiwifruit allergy are also summarized.     

Characterization of several hazelnut (Corylus avellana L.) cultivars based in chemical, fatty acid and sterol composition

Nineteen cultivars of hazelnuts (Corylus avellana L.) collected during the 2001 crop, from Vila Real, Portugal, were analysed for chemical composition, including moisture, total oil content, crude protein, ash, carbohydrates and nutritional value. Fat was the predominant component, ranging from 59.3 to 69.0%. Total oil was extracted and analysed for fatty acid and sterol compositions and oxidative stability. Fatty acid and sterol compositions were determined by Gas–Liquid Chromatography coupled to a Flame Ionisation Detector (GLC/FID). Monounsaturated fatty acids, particularly oleic acid, were predominant (78.7–84.6%). Total phytosterol content ranged from 133.8 to 263.0 mg/100 g of oil. Among the nine sterols identified and quantified, β-sitosterol was the major one with a mean percentage of 83.6%, while Δ⁵-avenasterol and campesterol were the second and the third components of the group with mean values of 6.1 and 5.8%, respectively. Since hazelnut oil can be used in olive oil adulteration, the values obtained were compared with published mean values of olive oils from different geographical origins.     

Vibrio parahaemolyticus,a Notably Lethal Human Pathogen Derived From Seafood: A Review of its Pathogenicity,Characteristics, Subspecies Characterization,and Molecular Methods of Detection

Vibrio parahaemolyticus is a gram-negative enteropathogenic marine Vibrio that is capable of causing mild gastroenteritis to severe debilitating dysentery. Infections of the G.I. tract are usually due to consumption of raw shellfish. In addition, extraintestinal infections have been reported to be due to the organism such as eye and ear infections, and wound infections of the extremities. Virulence has been found to be associated with two principle genes that code for (1) a thermally stable direct acting hemolysin (tdh) and (2) a thermally stable direct acting–related hemolysin (trh) that is thermally lable. Virulent strains are usually characterized as Kanagawa Phenomenon (KP) positive which refers to β-hemolysis on a special blood agar known as Wagatsuma blood agar. Epidemiological studies have indicated that specific clones of certain serotypes, notably 03:K6 having enhanced virulence have become endemically established in certain global locals.     

Vibrio parahaemolyticus, a Notably Lethal Human Pathogen Derived From Seafood: A Review of its Pathogenicity, Characteristics, Subspecies Characterization, and Molecular Methods of Detection

Vibrio parahaemolyticus is a gram-negative enteropathogenic marine Vibrio that is capable of causing mild gastroenteritis to severe debilitating dysentery. Infections of the G.I. tract are usually due to consumption of raw shellfish. In addition, extraintestinal infections have been reported to be due to the organism such as eye and ear infections, and wound infections of the extremities. Virulence has been found to be associated with two principle genes that code for (1) a thermally stable direct acting hemolysin (tdh) and (2) a thermally stable direct acting-related hemolysin (trh) that is thermally lable. Virulent strains are usually characterized as Kanagawa Phenomenon (KP) positive which refers to β-hemolysis on a special blood agar known as Wagatsuma blood agar. Epidemiological studies have indicated that specific clones of certain serotypes, notably 03:K6 having enhanced virulence have become endemically established in certain global locals.