Recognition of nuts and seeds in children with/without food allergies and their mothers: A reflection of culinary culture

BACKGROUND

Nuts and seeds are among the leading causes of food allergy. Effective food allergy management hinges on the ability to identify and avoid relevant foods.

AIM

To evaluate the nut/seed recognition ability in both children and mothers.

METHODS

Primary caregivers (mothers) and their children (6-18 years old) with/without food allergies were shown photographs of nuts/seeds, and their products with visible/hidden allergens to assess their ability to recognize accurately.

RESULTS

A total of 196 children and 184 mothers participated. The median ages of the children and mothers were 7.6 (6.8-10) and 37.8 (33.1-41.5) years, respectively. Over 75% of the children/adolescents and over 90% of the mothers accurately identified the kernel forms of nuts/seeds, except pine nuts. Walnuts, hazelnuts, almonds, and cashews were the most accurately recognized kernel forms by both populations. Generally, the kernel forms were recognized 5-20% more accurately than their in-shell forms, followed by products with visible and hidden forms, respectively. Some Turkish culinary-specific products with visible/hidden allergens were recognized as frequently as the kernel/in-shell forms by both study groups. Although there was a similar recognition pattern between study groups and subgroups (nut/seed allergy, other food allergy, controls), higher rates of recognition were found in mothers than in their children and adolescents than in schoolchildren.

CONCLUSION

In Eastern Mediterranean region, nuts and sesame seeds are highly recognized by both mothers and their children. Accurate identification of these foods is likely a culinary feature, but not the result of increased awareness. More information is needed on whether this ability reduces the risk of exposure.

Feasibility and safety of introducing cashew nut spread in infant diets-A randomized trial

BACKGROUND

To reduce peanut allergy prevalence, infant feeding guidelines now recommend introducing peanuts in an age-appropriate form (such as peanut butter) as part of complementary feeding. However, due to a lack of randomized trial evidence, most infant feeding and food allergy prevention guidelines do not include tree nuts. The aims of this trial were to determine safety and feasibility of dosage consumption recommendations for infant cashew nut spread introduction.

METHODS

This is a parallel, three-arm (1:1:1 allocation), single-blinded (outcome assessors), randomized controlled trial. General population term infants were randomized at 6-8 months of age to either a one teaspoon (Intervention 1 n = 59) or increasing dosage regime of one teaspoon at 6-7 months, two teaspoons at 8-9 months, and three teaspoons from 10 months of age onwards (Intervention 2 n = 67) cashew nut spread, both three times per week, or no specific advice on cashew introduction (Control n = 70). At 1 year of age, food challenge proven IgE-mediated cashew nut allergy was assessed.

RESULTS

Compliance in Intervention 1 (92%) was higher than Intervention 2 (79%), p = .04. Only one infant had delayed (at 5 h) facial swelling and eczema flare to cashew introduction at 6.5 months, but no cashew allergy at 1 year. Only one infant (Control) had cashew allergy at 1 year, and this infant had not been introduced to cashew prior to 12 months of age.

CONCLUSION

Regular infant consumption of one teaspoon of cashew nut spread three times per week from 6 to 8 months of age was found to be feasible and safe.

Characteristics of tree nut, peanut, and seed consumption in the eastern Mediterranean region

BACKGROUND

Nuts and seeds are among the most common causes of food allergy (FA), and consumption differences across cultures and geographic regions are thought to account for the diversity of these allergies.

METHODS

Caregivers of infants (age 12-24 months) with or without FA were questioned in face-to-face interviews to identify the nut and seed consumption practices in the household, during pregnancy, breastfeeding, and early childhood.

RESULTS

Of the 171 infants (median age: 17.3 months) included in the study, 75 were healthy and 96 had FA. More than two-thirds of the infants in the whole group started to be fed with walnuts, sesame/tahini, hazelnuts, almonds, and sunflower seeds. The percentages of healthy infants who were not fed with tree nuts, seeds, and peanuts were 4%, 4%, and 49.3%, respectively, for the healthy infants, and 11.8%, 11.8%, and 67.8% for those with FA. In the FA group, sesame and peanut consumption was initiated at a younger age, and walnut, hazelnut, and almond consumption at an older age compared to the healthy infants (p < 0.05 for each). Walnuts and sesame/tahini were the most consumed nuts at home, and peanuts and pumpkin seeds were the least consumed. Mothers reported that they increased tree nut consumption during pregnancy due to their positive effect on health and sesame/tahini consumption during breastfeeding to increase breast milk, respectively.

CONCLUSION

The uniqueness of Turkish culinary culture is characterized by the frequent consumption of tree nuts and seeds, with further increases during pregnancy/lactation and early introduction to the diet of infants.

TreEAT trial: Protocol for a randomized controlled trial investigating the efficacy and safety of early introduction of tree nuts for the prevention of tree nut allergy in infants with peanut allergy

INTRODUCTION

Children with peanut allergy are at increased risk of developing tree nut allergies, which can be severe and for most lifelong. Introduction of peanut in the first year of life can reduce the risk of peanut allergy; however, prevention strategies for tree nut allergies have not been established. We aimed to test the efficacy and safety of a novel strategy, a supervised multi-nut oral food challenge (OFC) compared with standard care for tree nut allergy prevention in infants at high risk of developing tree nut allergy, TreEAT.

METHODS AND ANALYSIS

TreEAT is a 2-armed, open-label, randomized, controlled trial (RCT). Infants (n = 212) aged 4-11 months with peanut allergy will be randomized 1:1 at peanut allergy diagnosis to either a hospital-based multi-tree nut (almond, cashew, hazelnut, and walnut) OFC using multi-nut butter or standard care (home introduction of individual tree nuts). All infants will be assessed at age 18 months, with questionnaires and SPT to peanut and tree nuts. Peanut and tree nut OFCs will be performed as required to determine the allergy status for each nut. The primary outcome is tree nut allergy at age 18 months. Secondary outcomes include peanut allergy resolution, proportion, and severity of adverse events related to tree nut ingestion, number and frequency of tree nuts ingested, quality of life and parental anxiety, and allergy-related healthcare visits from randomization to 18 months of age. Analyses will be performed on an intention-to-treat basis.

ETHICS AND DISSEMINATION

TreEAT was approved by the Royal Children's Hospital Human Research Ethics Committee (#70489). Outcomes will be presented at scientific conferences and disseminated through publication.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov ID: NCT04801823.

Cross-Serological Reaction of Glandless Cottonseed Proteins to Peanut and Tree Nut Allergic IgE

Food allergy is a potentially life-threatening health concern caused by immunoglobulin E (IgE) antibodies that mistakenly recognize normally harmless food proteins as threats. Peanuts and tree nuts contain several seed storage proteins that commonly act as allergens. Glandless cottonseed, lacking the toxic compound gossypol, is a new food source. However, the seed storage proteins in cottonseed may act as allergens. To assess this risk, glandless cottonseed protein extracts were evaluated for IgE binding by peanut and tree nut allergic volunteers. ELISA demonstrated that 25% of 32 samples had significant binding to cottonseed extracts. Immunoblot analysis with pooled sera indicated that IgE recognized a pair of bands migrating at approximately 50 kDa. Excision of these bands and subsequent mass-spectrometric analysis demonstrated peptide matches to cotton C72 and GC72 vicilin and legumin A and B proteins. Further, in silico analysis indicated similarity of the cotton vicilin and legumin proteins to peanut vicilin (Ara h 1) and cashew nut legumin (Ana o 2) IgE-binding epitopes among others. The observations suggest both the cotton vicilin and legumin proteins were recognized by the nut allergic IgE, and they should be considered for future allergen risk assessments evaluating glandless cottonseed protein products.

Diversity and Pathogenicity of Botryosphaeriaceae Associated with Macadamia Branch Dieback in Australia

Botryosphaeria branch dieback is a serious disease of macadamia in Australia, but its etiology has not been clearly defined, which limits effective disease control. Therefore, this study examined whether the causal agents of branch dieback in commercial macadamia orchards in five agroecological regions in Australia are similar in prevalence and aggressiveness. The identity of the causal agents was determined using conventional culturing techniques and DNA sequencing that targets the internal transcribed spacer (ITS), translation elongation factor 1-alpha (tef1α), β-tubulin (tub2), and DNA-directed RNA polymerase II second largest subunit (rpb2) gene loci. The pathogenic variation of the isolates, relative to the source (region and host plant part), was examined using in vivo and in planta assays. Lasiodiplodia and Neofusicoccum were the dominant fungal genera obtained from surveys of 59 macadamia orchards across the agroecological regions. Phylogenetic analysis of 52 representative isolates identified four putative novel Lasiodiplodia clades, with three other Lasiodiplodia spp. (Lasiodiplodia iraniensis, L. pseudotheobromae, and L. theobromae) and three Neofusicoccum spp. (Neofusicoccum luteum, N. mangroviorum, and N. parvum) from macadamia. L. pseudotheobromae that constituted 40% of the isolates from symptomatic tissues was the most prevalent in all the regions. Both the in vivo and in planta pathogenicity assays revealed that all isolates of the Botryosphaeriaceae, except N. mangroviorum, were pathogenic to macadamia. L. theobromae, N. luteum, and L. iraniensis were the most aggressive species causing dieback symptoms in macadamia.

Angiopoietin-Like Protein Responses to Pecan-Enriched Diets Versus a Nut-Excluded Diet

Daily pecan consumption improves fasting and postprandial triglycerides, but its effect on angiopoietin-like proteins (ANGPTLs) is unknown. The objective of this study was to investigate the impact of daily pecan consumption for 8 weeks on fasting and postprandial ANGPTL3, -8, and -4. This was an 8-week, randomized, controlled trial with three treatments: two pecan groups and a nut-free control group (n = 16). The ADD group (n = 15) consumed pecans (68 g) as part of a free-living diet, and the SUB group (n = 16) substituted the pecans (68 g) for isocaloric foods from their habitual diet. Fifty-six participants were randomized but nine subjects did not begin or finish the 8-week intervention and/or testing visits. At pre- and post-intervention, a high saturated fat meal was consumed with 3.5 h postprandial blood draws to determine changes in ANGPTL3, -8, and -4. There was a significant suppression in postprandial ANGPTL3 from pre- to post-intervention within ADD and SUB (P = .004 and P = .002, respectively) but not control (ns). There were no other changes within or between groups for fasting and postprandial outcomes. Daily pecan consumption improved postprandial ANGPTL3, which may mediate improvements in lipid metabolism.

Consumer Hedonic Ratings and Associated Sensory Characteristics and Emotional Responses to Fourteen Pecan Varieties Grown in Texas

Pecan is one of the top five most widely consumed tree nuts, and pecan nut quality is a major factor for consideration in breeding better pecan cultivars for use by producers. However, the pecan industry faces a hurdle to evaluate its nutmeat taste, and there has so far been limited evaluation of consumer attitudes toward pecan nutmeat. This study aimed to investigate the consumer (n = 198) hedonic rating, diagnostic sensory attribute intensity, and emotional response for 14 pecan samples, consisting of native/seedling and improved varieties. The results showed all kernels received positive hedonic scores (>5, 9-point hedonic scale) for overall acceptance and the acceptability of size, interior color, typical-pecan flavor, and raw-nut flavor. The primary sensory attributes (intensities > 5.0, 0−10 line scale) were typical-pecan and raw-nut flavors, followed by buttery flavor, sweetness, and astringency. Kernel off-flavors were not perceived in general. For 20 emotion-associated terms, the intensity of the satiating effect was medium, while the energizing effect was lower. The major emotional responses were healthy, satisfied, and comfort, followed by calm, interested, premium, and relaxed. Kernel variety difference was significant (p ≤ 0.05) for all these measured variables. Consumer overall acceptance toward pecan kernels was driven by the acceptability of flavor and interior color, flavor intensities, no off-flavors, and positive emotional responses; kernel size was not an impactful factor. The six most preferred varieties were 86TX2-1.5, Pawnee, Barton, 1997-09-0012, 1991-01-0026, and Harris Super. This study is the first to use consumer input to assess nut quality and consumption preference and will be foundational to ongoing breeding programs to develop new pecan cultivars that will better meet consumer preferences and expectations, and therefore will be accepted by the processing industry and growers.

Quantitative In Silico Evaluation of Allergenic Proteins from Anacardium occidentale, Carya illinoinensis, Juglans regia and Pistacia vera and Their Epitopes as Precursors of Bioactive Peptides

The aim of the study presented here was to determine if there is a correlation between the presence of specific protein domains within tree nut allergens or tree nut allergen epitopes and the frequency of bioactive fragments and the predicted susceptibility to enzymatic digestion in allergenic proteins from tree nuts of cashew (Anacardium occidentale), pecan (Carya illinoinensis), English walnut (Juglans regia) and pistachio (Pistacia vera) plants. These bioactive peptides are distributed along the length of the protein and are not enriched in IgE epitope sequences. Classification of proteins as bioactive peptide precursors based on the presence of specific protein domains may be a promising approach. Proteins possessing a vicilin, N-terminal family domain, or napin domain contain a relatively low occurrence of bioactive fragments. In contrast, proteins possessing the cupin 1 domain without the vicilin N-terminal family domain contain a relatively high total frequency of bioactive fragments and predicted release of bioactive fragments by the joint action of pepsin, trypsin, and chymotrypsin. This approach could be utilized in food science to simplify the selection of protein domains enriched for bioactive peptides.

Tree Nut-Induced Anaphylaxis in Canadian Emergency Departments: Rate, Clinical Characteristics and Management

BACKGROUND

Data are sparce regarding tree nut-induced anaphylaxis (TNA).

OBJECTIVE

We aimed to characterize rate, clinical characteristics, and management of TNA in children (0-17 years old) across Canada, and assess factors associated with severe reactions and epinephrine use.

METHODS

Between April 2011 and May 2020, data were collected on children presenting to five emergency departments (EDs) in Canada. Multivariate logistic analysis was used to evaluate factors associated with severe reactions (stridor, cyanosis, circulatory collapse, or hypoxia) and epinephrine use.

RESULTS

Among 3096 cases of anaphylaxis, 540 (17%) were induced by tree nut. The median age was 5.2 years [Interquartile range (IQR): 2.5-9.5] and 65.4% were males. Among all reactions, 7.0% were severe. The major tree nuts accounting for anaphylaxis were cashew (32.8%), hazelnut (20.0%) and walnut (11.5%). Cashew-induced anaphylaxis was more common in British Columbia [14.0% difference (95% CI, 1.6%-27.6%)] versus Ontario and Quebec, whereas pistachio-induced anaphylaxis was more common in Ontario and Quebec [6.3% difference (95% CI, 0.5%-12.2%)]. Pre-hospital and ED intramuscular (IM) epinephrine administration was documented in only 35.2% and 52.4% of cases, respectively. Severe reactions were more likely among males [adjusted Odds Ratio (aOR) 1.05 (95% CI, 1.01-1.10)] older children [aOR 1.00 (95% CI, 1.00-1.01)], and in reactions triggered by macadamia [aOR 1.27 (95% CI, 1.03-1.57)].

CONCLUSION

Different TNA patterns in Canada may be due to differences in lifestyle (higher prevalence of Asian ethnicity in British Columbia versus Arabic ethnicity in Ontario and Quebec). IM epinephrine underutilization urges for EAI stocking in schools and restaurants, patient education, and consistent policies across Canada.

Organ-specific symptom patterns during oral food challenge in children with peanut and tree nut allergy

BACKGROUND

Peanut and tree nut allergies are common in childhood and often severe in nature. The clinical picture shows a wide variety of symptoms.

OBJECTIVE

To analyze the distribution of clinical symptoms and severity during oral food challenges (OFC) in children.

METHODS

Analysis of 1.013 prospectively recorded, positive OFCs with peanut (n = 607), hazelnut (n = 266), walnut (n = 97), and cashew (n = 43). Symptoms were categorized as immediate-type skin, gastrointestinal, upper and lower respiratory, cardiovascular symptoms, and eczema exacerbation. Symptom severity and treatment were recorded.

RESULTS

Skin symptoms presented in 78%, followed by gastrointestinal (47%), upper (42%), and lower respiratory symptoms (32%). Cardiovascular symptoms presented in 6%. In three-quarter of the reactions, more than one organ was involved. Importantly, severe reactions occurred at every dose level. Peanut- and cashew-allergic patients had a higher relative risk of gastrointestinal symptoms compared with hazelnut- and walnut-allergic patients. Patients without vomiting had a 1.7 times higher risk developing immediate-type skin and/or lower respiratory symptoms. Three-quarter of the patients ever had eczema but worsening presented in only 10.5% of the OFCs. In patients with multiple food allergies, organs involved, eliciting dose and severity differed between allergens.

CONCLUSION

Although comparisons between allergen groups with different clinical history, severity, comorbidities and laboratory data are difficult and might contain bias, our data confirm the high allergenic potential of peanut and tree nuts. The rare occurrence of eczema worsening emphasizes that avoidance diets of peanuts and tree nuts to cure eczema seem to be unnecessary and may hamper tolerance maintenance.

Using texture analyzer to characterize pecan and olive oil tactile properties, compare to viscometer analysis, and link to fatty acid profile and total polyphenols

This study aimed to characterize mechanical properties of five pecan oils and one olive oil using a texture analyzer compared to a rotational viscometer; results were linked to fatty acid profile and total polyphenol content. The seven texture parameters (firmness, consistency, cohesiveness, viscosity index, stickiness at 5 sec, stickiness at 30 sec, and delta stickiness) showed significant difference (p≤0.05) among the six oils. Overall, olive oil had higher texture analysis values and significantly higher rotational viscosity than pecan oils. Chemically, C18 fatty acids accounted for approximately 90% of the total fatty acids in the five pecan oils. Olive oil had a higher amount of long-chain, unsaturated fatty acids. Total polyphenols in pecan oils were 8-15 mg gallic acid equivalent (GAE)/100 g, while olive oil contained 27.2 mg GAE/100 g. Correlation analysis demonstrated a significant, positive relationship between "consistency" texture and rotational viscosity measurement. Mechanical properties (seven texture parameters and rotational viscosity) were partially correlated to fatty acid profile, though no universal pattern was identified. PRACTICAL APPLICATIONS: Pecan is among the most commonly consumed tree nuts worldwide, while pecan oil is part of the emerging healthy, edible oil niche market. Few studies have investigated pecan oil sensory quality and associated physicochemical compositions for aroma, taste, and texture and pecan oil textural parameters have not been characterized. This study characterized pecan oil with seven textural parameters correlated to rotational viscosity and chemical composition, providing a novel instrumental approach to characterize edible oil textural properties. This article is protected by copyright. All rights reserved.

Discovery of Single Nucleotide Polymorphisms for Resistance to Abnormal Vertical Growth in Macadamia

Abnormal vertical growth (AVG) syndrome is a serious threat to the Australian macadamia industry as it decreases the yield of nuts by as much as 70% per annum. A lack of information on the cause of AVG has hindered the development of an effective disease management strategy. Discovery of genetic markers associated with disease resistance can be used as tool for rapid selection of elite cultivars, hence helps in efficient disease management. Differences in field susceptibility of macadamia cultivars provide an opportunity for discovery of genetic markers that are associated with host resistance. REML mixed model analysis was performed to estimate the AVG rating of 51 cultivars from multiple origins using phenotypic data from 359 trees planted in four sites. Most of the Hawaiian cultivars were found as susceptible, while selections from the Australian macadamia industry breeding program were predominantly resistant. All the cultivars were genotyped for 13,221 DArTseq-based single nucleotide polymorphism (SNP) markers. A bulked sample analysis was performed using 20 genotypes each at the extremes of AVG phenotypic ratings. Ten SNP markers were predicted to be associated with AVG resistance and two arbitrarily selected SNP markers were validated using PCR and Sanger sequencing. Our findings suggest that AVG resistance in the commercial cultivars may be derived from the genomic introgression of Macadamia tetraphylla through interspecific hybridization. The results may support marker-assisted selection for macadamia germplasm with AVG resistance.

Nut Allergy: Clinical and Allergological Features in Italian Children

Background: Nut allergies are an increasingly frequent health issue in the pediatric population. Tree nuts (TN) and peanuts are the second cause of food anaphylaxis in Italy. Unfortunately, knowledge of the clinical characteristics of a TN allergy in Italian children is limited. Our study aimed to identify the clinical and allergological characteristics of Italian children with a nut allergy (TN and peanut). Methods: A retrospective observational analysis was performed on the clinical charts of children with a history of nut reaction referred to the allergy unit of the hospital from 2015 to 2019. The studied population was represented by children with a confirmed nut allergy based on positive prick by prick and/or serum-specific IgE to nut plus a positive nut oral food challenge. Demographic, clinical, and allergological features were studied and compared among different nuts. Results: In total, 318 clinical charts were reviewed. Nut allergy was confirmed in 113 patients. Most patients (85/113, 75%) had a familial history of allergy and/or a concomitant allergic disorder (77/113, 68%). Hazelnut and walnut were the more common culprit nuts observed in allergic children. Anaphylaxis was the first clinical manifestation of nut allergy in a high percentage of children (54/113, 48%). The mean age of the first nut reaction was statistically higher with pine nuts. Over 75% of children reported a single nut reaction. During the OFCs, the signs and symptoms involved mainly the gastrointestinal system (82/113, 73%) and resolved spontaneously in most cases. Severe reactions were not frequent (22/113, 19%). Conclusion: To our knowledge, this is the first Italian study that provided a comprehensive characterization of children with a nut allergy. These results are important for clinicians treating children with a nut allergy.

Novel Botrytis and Cladosporium Species Associated with Flower Diseases of Macadamia in Australia

Macadamia (Macadamia integrifolia) is endemic to eastern Australia and produces an edible nut that is widely cultivated in commercial orchards globally. A survey of fungi associated with the grey and green mold symptoms of macadamia flowers found mostly species of Botrytis (Sclerotiniaceae, Leotiomycetes) and Cladosporium (Cladosporiaceae, Dothideomycetes). These isolates included B. cinerea, C. cladosporioides, and unidentified isolates. Amongst the unidentified isolates, one novel species of Botrytis and three novel species of Cladosporium were delimited and characterized by molecular phylogenetic analyses. The new species are Botrytis macadamiae, Cladosporium devikae, C. macadamiae, and C. proteacearum.

From Allergen Molecules to Molecular Immunotherapy of Nut Allergy: A Hard Nut to Crack

Peanuts and tree nuts are two of the most common elicitors of immunoglobulin E (IgE)-mediated food allergy. Nut allergy is frequently associated with systemic reactions and can lead to potentially life-threatening respiratory and circulatory symptoms. Furthermore, nut allergy usually persists throughout life. Whether sensitized patients exhibit severe and life-threatening reactions (e.g., anaphylaxis), mild and/or local reactions (e.g., pollen-food allergy syndrome) or no relevant symptoms depends much on IgE recognition of digestion-resistant class I food allergens, IgE cross-reactivity of class II food allergens with respiratory allergens and clinically not relevant plant-derived carbohydrate epitopes, respectively. Accordingly, molecular allergy diagnosis based on the measurement of allergen-specific IgE levels to allergen molecules provides important information in addition to provocation testing in the diagnosis of food allergy. Molecular allergy diagnosis helps identifying the genuinely sensitizing nuts, it determines IgE sensitization to class I and II food allergen molecules and hence provides a basis for personalized forms of treatment such as precise prescription of diet and allergen-specific immunotherapy (AIT). Currently available forms of nut-specific AIT are based only on allergen extracts, have been mainly developed for peanut but not for other nuts and, unlike AIT for respiratory allergies which utilize often subcutaneous administration, are given preferentially by the oral route. Here we review prevalence of allergy to peanut and tree nuts in different populations of the world, summarize knowledge regarding the involved nut allergen molecules and current AIT approaches for nut allergy. We argue that nut-specific AIT may benefit from molecular subcutaneous AIT (SCIT) approaches but identify also possible hurdles for such an approach and explain why molecular SCIT may be a hard nut to crack.

Neopestalotiopsis Species Associated with Flower Diseases of Macadamia integrifolia in Australia

Macadamia (Macadamia integrifolia) is native to eastern Australia and produces an edible nut that is extensively cultivated in commercial orchards in several countries. Little is known about the diversity of fungi associated with diseases of macadamia inflorescences. A survey of fungi associated with the dry flower disease of macadamia detected several isolates of Neopestalotiopsis (Pestalotiopsidaceae, Sordariomycetes). Five new species of Neopestalotiopsis were identified based on molecular phylogenetic analyses of concatenated gene sequences of the internal transcribed spacer (ITS), β-tubulin (TUB), and the translation elongation factor 1-alpha (TEF1α). The new species are named Neopestalotiopsis drenthii, N. maddoxii, N. olumideae, N. vheenae, and N. zakeelii, and are described by molecular, morphological, and cultural characteristics. The ecology of the isolates and their pathogenic, saprophytic, or commensal ability were not determined.

Influence of climatic factors on dry flower, grey and green mould diseases of macadamia flowers in Australia

AIMS

Flower blights (grey mould, green mould and dry flower) are important diseases of macadamia. Lack of information on pathogen biology and disease epidemiology in macadamia has hampered control options. Effects of climatic variables including temperature, relative humidity (RH) and vapour pressure deficit (VPD) on the abundance, germination and growth of conidia of four fungal pathogens that cause various flower blights in macadamia were studied.

METHODS AND RESULTS

Mycelial growth, sporulation, conidial germination and germ tube growth for five isolates each of Botrytis cinerea, Cladosporium cladosporioides, Pestalotiopsis macadamiae and Neopestalotiopsis macadamiae, at eight temperatures, seven RH and the corresponding VPD regimes were determined in vitro. The optimal climatic range of each of the four pathogens was validated during macadamia flowering periods in the 2019 and 2020 seasons by conidia detected and quantified using quantitative PCR. Several growth models were fitted to the data with high significance; predicted optima from these models ranged from 0.9 to 1.1 kPa VPD for P. macadamiae and N. macadamiae and <0.6 kPa VPD for B. cinerea and C. cladosporioides.

CONCLUSIONS

This study showed that VPD, as a determinant of the fecundity and growth of the four fungal pathogens, was predictive of flower blight incidence in macadamia. The importance of temperature, RH and, thus, VPD for defining the conditions for infection and flower blight epidemics was established.

SIGNIFICANCE AND IMPACT OF THE STUDY

This information provides a firm basis for the development of prediction tools for flower blights in macadamia.

Total Nut, Tree Nut, and Peanut Consumption and Metabolic Status in Southern Italian Adults

Background: Nut consumption has been associated with cardio-metabolic health benefits. However, studies conducted in the Southern Italian population, where adherence to the Mediterranean diet has been reported being relatively high, are rather scarce. The aim of this study was to test the association between consumption of total and specific types of nuts and metabolic status among adults living in Sicily, Southern Italy. Methods: Demographic and dietary characteristics of 2044 adults living in Southern Italy were analyzed. Multivariate logistic regression analyses were performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of the association between nut consumption and metabolic status adjusting for potential confounding factors. Results: The energy-adjusted model revealed that higher nut intake was inversely associated with occurrence of hypertension, type-2 diabetes, and dyslipidemia. However, the association did not remain significant for the latter after adjusting for the main background characteristics, while an inverse association was stably confirmed for hypertension (OR = 0.61, 95% CI: 0.46–0.80 and OR = 0.44, 95% CI: 0.26–0.74, respectively) even after adjusting for adherence to the Mediterranean diet. Among individual nut types, most of the associations were null except for higher almond intake, which was inversely associated with occurrence of hypertension (OR = 0.70, 95% CI: 0.49–0.99). Conclusions: Higher nut consumption is associated with overall better metabolic status in individuals living in the Mediterranean area.

Predictive factors of allergy to pistachio in children allergic to cashew nut

BACKGROUND

Cashew nut (CN) allergy prevalence has increased over the last few years. In children allergic to CN, complete avoidance of pistachio is usually recommended, but recent study showed that only one third of children allergic to CN were also allergic to pistachio. The aim of our study was to identify predictive factors of allergy to pistachio in children allergic to CN.

METHODS

All children who had a positive oral food challenge (OFC) to CN between November 2013 and October 2017 in the Paediatric Allergy Department of the University Hospital of Nancy were included. Logistic regression models were used to predict the probability of allergy to pistachio.

RESULTS

Among the 147 children included, tolerance or allergy to pistachio was known for 51. Out of these, 40 were allergic to pistachio (78.4%). Children allergic to pistachio had a larger weal size of skin prick test to CN (P = .01) and pistachio (P = .0007) and a lower reaction dose to CN (P < .0001). In multivariate analysis, only the reaction dose to CN was significantly associated with allergy to pistachio. Children with a low reaction dose to CN were significantly more at risk to have an allergy to pistachio (P = .01).

CONCLUSION

A low reaction dose to CN seems to be a predictive factor of allergy to pistachio in children allergic to CN. In order to limit unnecessary food eviction, a pistachio OFC should be performed in children having high reaction dose whatever the importance of the skin or the specific IgE sensitization to pistachio.

Spatiotemporal Spread of Abnormal Vertical Growth of Macadamia in Australia Informs Epidemiology

Australian macadamia production is threatened by a disorder known as abnormal vertical growth (AVG), for which the etiology is unknown. AVG is characterized by vigorous upright growth and reduced lateral branching, flowering, and nut set that results in over 70% yield loss annually. Six commercial macadamia orchards were surveyed in 2012 and again in 2018 to examine spatiotemporal dynamics of the epidemic. Data were subjected to point-pattern and geostatistical analyses. AVG incidence in all orchards showed a better fit to the beta-binomial distribution than the binomial distribution. AVG incidence in the different orchards varied between 5 and 47% in 2012, and 13 and 55% in 2018 and the rate of spread was slow, averaging at about 2% increase in disease incidence per annum. Spatial patterns of AVG were highly aggregated on both survey years and spread was mainly between neighboring trees in a row or trees that were opposite to each other in different rows. Semivariograms showed large range values (approximately 15 to 120), indicating aggregation of AVG-affected trees beyond quadrat levels. Furthermore, clusters of disease were mainly at the edge of the orchard on the first survey date and the disease progressed toward the center of the orchard over time. It is concluded that AVG is caused by an infectious agent, and based on patterns of spread, we hypothesize that spread is facilitated by root grafting or root-to-root contact. Furthermore, a vascular-limited pathogen could be involved that modulates plant hormone production.

Efficacy of Sulfuryl Fluoride Against Fourth-Instar Pecan Weevil (Coleoptera: Curculionidae) in Pecans for Quarantine Security

The efficacy of sulfuryl fluoride was evaluated for control of fourth-instar pecan weevil, Curculio caryae (Horn), at 25°C for a 24-h exposure. Larvae, collected as they naturally emerged from pecans, were used to artificially infest pecan nuts. Infested nuts were fumigated with six concentration by time (CT) treatment dosages of sulfuryl fluoride (0-750 g-h/m3) within air-tight, glass containers. The sulfuryl fluoride concentration in each fumigation container was analyzed 30 min after sulfuryl fluoride introduction and just prior to termination of the experiment. Mean sulfuryl fluoride CT dosages were calculated from sulfuryl fluoride measurements and were used for probit analysis. The lethal accumulated dosage (LAD99) of sulfuryl fluoride for pecan weevil was 1052.0 g-h/m3 with a 95% C.I. of 683.21-2,573.0 g-h/m3. For the confirmatory trial, we used two sulfuryl fluoride CT dosage treatments, 1,100 and 1,300 g-h/m3, and a nonfumigated control. All larvae were dead in both fumigation treatments by 14-d postfumigation. Due to higher mortality in the nonfumigated control in the confirmatory trial compared to that of the dose-response trial, 1300 g-h/m3 was selected as the sulfuryl fluoride CT dosage for a proposed quarantine treatment schedule. Fumigating pecans with sulfuryl fluoride can control larval pecan weevil infestations in commercially traded nuts and maintain compliance with quarantine regulations both within and outside the United States.

Application of real-time PCR for tree nut allergen detection in processed foods

Currently, food allergies are an important health concern worldwide. The presence of undeclared allergenic ingredients or the presence of traces of allergens due to accidental contamination during food processing poses a great health risk to sensitized individuals. Therefore, reliable analytical methods are required to detect and identify allergenic ingredients in food products. Real-time PCR allowed a specific and accurate amplification of allergen sequences. Some processing methods could induce the fragmentation and/or degradation of genomic DNA and some studies have been performed to analyze the effect of processing on the detection of different targets, as thermal treatment, with and without applying pressure. In this review, we give an updated overview of the applications of real-time PCR for the detection of allergens of tree nut in processed food products. The different variables that contribute to the performance of PCR methodology for allergen detection are also review and discussed.

BSACI guideline for the diagnosis and management of peanut and tree nut allergy

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.

A Pecan-Rich Diet Improves Cardiometabolic Risk Factors in Overweight and Obese Adults: A Randomized Controlled Trial

Evidence from observational and intervention studies has shown a high intake of tree nuts is associated with a reduced risk of cardiovascular disease (CVD), mortality from type 2 diabetes (T2DM), and all-cause mortality. However, there is limited data regarding their effects on indicators of cardiometabolic risk other than hypercholesterolemia, and little is known about the demonstrable health benefits of pecans (Carya illinoensis (Wangenh.) K.Koch). We conducted a randomized, controlled feeding trial to compare the effects of a pecan-rich diet with an isocaloric control diet similar in total fat and fiber content, but absent nuts, on biomarkers related to CVD and T2DM risk in healthy middle-aged and older adults who are overweight or obese with central adiposity. After 4 weeks on a pecan-rich diet, changes in serum insulin, insulin resistance (HOMA-IR) and beta cell function (HOMA-β) were significantly greater than after the control diet (p < 0.05). Pecan consumption also lowered the risk of cardiometabolic disease as indicated by a composite score reflecting changes in clinically relevant markers. Thus, compared to the control diet, the pecan intervention had a concurrent and clinically significant effect on several relevant markers of cardiometabolic risk.

Combination Phenyl Propionate/Pheromone Traps for Monitoring Navel Orangeworm (Lepidoptera: Pyralidae) in Almonds in the Vicinity of Mating Disruption

Aerosol mating disruption is used for management of navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), in an increasing portion of California almonds and pistachios. This formulation suppresses pheromone monitoring traps far beyond the treatment block, potentially complicating monitoring and management of this key pest. Phenyl propionate is an attractant used to capture adults in the presence of mating disruption, completely suppressing pheromone traps, and lures combining phenyl propionate with a pheromone lure (PPO-combo lure) synergize trap capture in the presence of mating disruption. In this study, laboratory and field trials of different phenyl propionate dispensers indicate a useful life of six weeks. Controlled experiments found similar numbers of adults captured in phenyl propionate and PPO-combo lures in the presence of varying levels of mating disruption intensity. A subsequent trial compared monitoring of field plots at various distances from fields under commercial mating disruption for much of the growing season with pheromone and PPO-combo lures. Although there was some evidence of partial suppression of capture in PPO-combo traps closer to mating disruption compared with lures farther away, there was no failure of detection as occurred with pheromone lures. The ratio of adults in pheromone and PPO-combo traps varied with proximity from treated fields. These results indicate that, in addition to monitoring in mating disruption plots, phenyl propionate lures can be useful for insuring against failure of detection of navel orangeworm pressure in areas where mating disruption is widely used.

Impact of different types of tree nut, peanut, and soy nut consumption on serum C-reactive protein (CRP): A systematic review and meta-analysis of randomized controlled clinical trials

BACKGROUND

The effects of different types of tree nut, peanut, and soy nut consumption on serum C - reactive protein (CRP) are not well established. we aimed to undertake a systematic review and meta-analysis of prospective studies to determine the effect of nut consumption (tree nuts, peanuts, and soy nuts) on serum CRP.

METHOD

PubMed-Medline, Web of Science, Cochrane Database, and Google Scholar databases were searched (up until April 20 2016) to identify prospective studies evaluating the impact of tree nut, peanut, and soy nut consumption on serum CRP. Random effects models meta-analysis was used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. Heterogeneity was quantitatively assessed using the I index. Systematic review registration: CRD42016038044.

RESULTS

From a total of 844 entries identified via searches, 20 studies were included in the final selection. The meta-analysis indicated a nonsignificant increase in serum CRP concentrations following nut consumption (weighted mean difference [WMD] 0.17 mg/L, (95% CI -0.67 to 0.33, I 52.1%). The WMDs for IL6 was -0.06(ng/dL), (95% CI -0.69 to 0.56, I 9.6%), -0.71(mg/dL), (95% CI -1.11 to -0.30, I 6.3%), for leptin, and -0.60(mg/dL), (95% CI -1.88 to 0.68, I 5.6%) for adiponectin, and -0.18(mg/dL), (95% CI -1.24 to 0.88, I 9.3%) for IL10 and -0.37 (pg/mL), (95% CI -0.90 to 0.16, I 7.9%) for TNF-α. These findings were robust in sensitivity analyses.

CONCLUSIONS

This meta-analysis suggests that nut consumption significantly decrease leptin while have no significant effect on CRP, IL6, adiponectin, IL10, and TNF-α.

Managing nut-induced anaphylaxis: challenges and solutions

The prevalence of peanut and tree nut allergy in the USA has increased, especially in the pediatric population. Nut allergy remains the leading cause of fatal anaphylactic reactions. Management of anaphylaxis includes not only treatment of symptoms during a reaction, but strict dietary avoidance and education on potential situations, which may place the patient at high risk for accidental exposure. Cross-reactivity between various nuts along with various cross-contamination sources should be discussed with all nut-allergic individuals. Exciting research continues to emerge on other potential treatments for patients allergic to nuts, including allergen immunotherapy. Results of such interventions have been encouraging, though further studies are needed regarding safety and long-term outcomes before these can be applied to clinical practice.

Impact of Trap Design and Density on Effectiveness of a Commercial Pheromone Lure for Monitoring Navel Orangeworm (Lepidoptera: Pyralidae)

The navel orangeworm is an important pest of almonds, pistachios, and walnuts. A commercial pheromone lure for this pest became publicly available in 2013. We compared effectiveness of this synthetic lure (NOW Biolure) between common commercial trap designs, and with unmated females in wing traps. Orange wing traps and delta traps captured similar numbers of males when each was baited with females, although there was a significantly greater density of captured males on the smaller glue area of the delta traps. In contrast, lure-baited wing traps captured about half the males captured in female-baited wing traps in single-night tests. In these single-night tests, wing traps baited with NOW Biolure captured significantly more males than delta traps baited with NOW Biolure, and bucket traps and delta traps baited with NOW Biolure captured similar numbers of males. When the sampling interval was extended to a week, the performance of lure-baited and female-baited wing traps was more similar. Delta and bucket traps baited with NOW Biolure generally performed more poorly than wing traps baited with NOW Biolure in these weekly monitoring tests. However, the bucket traps occasionally outperformed the other trap types during periods of peak abundance. Navel orangeworm traps at a density of one per 4 ha detected differences in abundance between adjacent walnut varieties, whereas such differences were not detected with one trap per 20 ha. The implications of these findings for monitoring for navel orangeworm in these different host crops are discussed.

Characterization of low molecular weight allergens from English walnut (Juglans regia)

Although English walnut is a commonly allergenic tree nut, walnut allergens have been poorly characterized to date. The objective of this work was to characterize the natural, low molecular weight (LMW) allergens from walnut. A protocol was developed to purify LMW allergens (specifically 2S albumins) from English walnuts. In addition to 2S albumins, a series of peptides from the N-terminal region of the 7S seed storage globulin proprotein were also identified and characterized. These peptides comprised a four-cysteine motif (C-X-X-X-C-X10-12-C-X-X-X-C) repeated throughout the 7S N-terminal region. Upon IgE immunoblotting, 3/11 and 5/11 sera from walnut-allergic subjects showed IgE reactivity to the 7S N-terminal fragments and 2S albumin, respectively. The mature 7S protein and the newly described 7S N-terminal peptides represent two distinct types of allergens. Because the proteolytic processing of 7S globulins has not been elucidated in many edible plant species, similar protein fragments may be present in other nuts and seeds.

Characterizing the relationship between sesame, coconut, and nut allergy in children

Sesame and coconut are emerging food allergens in the United States. We sought to examine whether children allergic to peanuts and tree nuts are at increased risk of having an allergy to sesame or coconut. We performed a retrospective chart review of children who underwent skin prick testing (SPT) to sesame and coconut and identified 191 children who underwent SPT to sesame and 40 to coconut. Sensitization to sesame was more likely in children with positive SPT to peanuts (odds ratio [OR] = 6.7, 95% confidence interval [CI] [2.7-16.8], p < 0.001) and tree nuts (OR = 10.5, 95% CI [4.0-27.7], p < 0.001). Children with histories of both peanut and tree nut reaction were more likely to have a history of sesame reaction (OR = 10.2, 95% CI [2.7-38.7], p < 0.001). Children with sensitization or allergy to peanuts or tree nuts were not more likely to be sensitized or allergic to coconut. In conclusion, children with peanut or tree nut sensitization were more likely to be sensitized to sesame but not coconut. Children with clinical histories of both peanut and tree nut allergy were more likely to be allergic to sesame.

Timing of Fungicide Applications for Control of Husk Spot Caused by Pseudocercospora macadamiae in Macadamia

Pseudocercospora macadamiae is an important pathogen of macadamia in Australia, causing a disease known as husk spot. Growers strive to control the disease with a number of carbendazim and copper treatments. The aim of this study was to consider the macadamia fruit developmental stage at which fungicide application is most effective against husk spot, and whether application of copper-only applications at full-size fruit developmental stage toward the end of the season contributed to effective disease control. Fungicides were applied to macadamia trees at four developmental stages in three orchards in two subsequent production seasons. The effects of the treatments on disease incidence and severity were quantified using area under disease progress curve (AUDPC) and logistic regression models. Although disease incidence varied between cultivars, incidence and severity on cv. A16 showed consistent differences between the treatments. Most significant reduction in husk spot incidence occurred when spraying commenced at match-head sized-fruit developmental stage. All treatments significantly reduced husk spot incidence and severity compared with the untreated controls, and a significant positive linear relationship (R² = 73%) between AUDPC and severity showed that timing of the first fungicide application is important for effective disease control. Application of fungicide at full-size fruit stage reduced disease incidence but had no impact on premature fruit drop.