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Concept: Peanuts


Background In a randomized trial, the early introduction of peanuts in infants at high risk for allergy was shown to prevent peanut allergy. In this follow-up study, we investigated whether the rate of peanut allergy remained low after 12 months of peanut avoidance among participants who had consumed peanuts during the primary trial (peanut-consumption group), as compared with those who had avoided peanuts (peanut-avoidance group). Methods At the end of the primary trial, we instructed all the participants to avoid peanuts for 12 months. The primary outcome was the percentage of participants with peanut allergy at the end of the 12-month period, when the participants were 72 months of age. Results We enrolled 556 of 628 eligible participants (88.5%) from the primary trial; 550 participants (98.9%) had complete primary-outcome data. The rate of adherence to avoidance in the follow-up study was high (90.4% in the peanut-avoidance group and 69.3% in the peanut-consumption group). Peanut allergy at 72 months was significantly more prevalent among participants in the peanut-avoidance group than among those in the peanut-consumption group (18.6% [52 of 280 participants] vs. 4.8% [13 of 270], P<0.001). Three new cases of allergy developed in each group, but after 12 months of avoidance there was no significant increase in the prevalence of allergy among participants in the consumption group (3.6% [10 of 274 participants] at 60 months and 4.8% [13 of 270] at 72 months, P=0.25). Fewer participants in the peanut-consumption group than in the peanut-avoidance group had high levels of Ara h2 (a component of peanut protein)-specific IgE and peanut-specific IgE; in addition, participants in the peanut-consumption group continued to have a higher level of peanut-specific IgG4 and a higher peanut-specific IgG4:IgE ratio. Conclusions Among children at high risk for allergy in whom peanuts had been introduced in the first year of life and continued until 5 years of age, a 12-month period of peanut avoidance was not associated with an increase in the prevalence of peanut allergy. Longer-term effects are not known. (Funded by the National Institute of Allergy and Infectious Diseases and others; LEAP-On number, NCT01366846 .).

Concepts: Immune system, Epidemiology, Disease, Infectious disease, Hypersensitivity, Allergy, Peanut, Peanuts


Small studies suggest peanut oral immunotherapy (OIT) might be effective in the treatment of peanut allergy. We aimed to establish the efficacy of OIT for the desensitisation of children with allergy to peanuts.

Concepts: Clinical trial, Randomized controlled trial, Effectiveness, Efficacy, Peanut, Peanuts


BACKGROUND: A diagnosis of peanut allergy has a major impact on an individual’s quality of life. Exposure to even small amounts of peanut can trigger serious reactions. Common cleaning agents can easily remove peanut allergen from surfaces such as table tops. Parents of children with peanut allergy frequently ask if peanut allergen can persist on surfaces if they have not been cleaned.Objectives: The purpose of this study was to determine the persistence of peanut allergen on a typical table surface over time. METHODS: 5 mL of peanut butter was evenly smeared on a 12 inch by 12 inch (30.5 by 30.5 cm) square on a nonporous (laminated plastic) table surface. Five squares were prepared in the same manner. The table was kept in a regular hospital office at room temperature and ambient lighting. No cleaning occurred for 110 days. Samples were taken at regular intervals from different areas each time. A monoclonal-based ELISA for arachis hypogaea allergen 1 (Ara h 1), range of detection 1.95-2000 ng/mL, was used to assess peanut allergen on the table surface. RESULTS: At baseline, there was no detectable Ara h 1 allergen. Immediately post application and for 110 days of collecting, detectable Ara h 1 was found each time a sample was taken. There was no obvious allergen degradation over time. Active cleaning of the contaminated surface with a commercial cleaning wipe resulted in no detectable Ara h 1 allergen. CONCLUSIONS: Peanut allergen is very robust. Detectable Ara h 1 was present on the table surface for 110 days. Active cleaning of peanut contaminated surfaces easily removed peanut residue and allergen. Regular cleaning of surfaces before and after eating should be reinforced as a safety measure for all individuals with peanut allergy.

Concepts: Allergy, Fabaceae, Food allergy, Allergology, Peanut, Arachis, Peanut butter, Peanuts


This study was conducted to determine the release dynamics of a microencapsulated mixture of fipronil and chlorpyrifos in peanut fields and its efficacy against white grubs. The results indicated that microencapsulation significantly stabilized this mixture against degradation in the environment so that a single dose of this microencapsulated formulation applied through seed treatment effectively controlled white grubs throughout the entire growing season. During the experimental course, the concentration of chlorpyrifos in the soil with the microencapsulated formulation was 13.6±9.9 (n = 6) times that of the conventional formulation, and the concentration of fipronil was at least 2.2 times that of the conventional formulation in the soil and peanut roots. However, the residue risks of chlorpyrifos and fipronil in the kernels were different. At harvest, there was a low risk that the residual chlorpyrifos in the kernels exceeded the MRLs (maximum residue limit). In contrast, the amount of residual fipronil in some kernel samples reached the statutory MRL set by the European Union, which suggested that a higher application rate or the repeated application of the microencapsulated fipronil formulation would not be acceptable.

Concepts: European Union, Fabaceae, Fruit, Seed, Peanut, Arachis, Linux kernel, Peanuts


We previously estimated that the annual rate of accidental exposure to peanut in 1411 children with peanut allergy, followed for 2227 patient-years, was 11.9% (95% CI, 10.6, 13.5). This cohort has increased to 1941 children, contributing 4589 patient-years, and we determined the annual incidence of accidental exposure, described the severity, management, location, and identified associated factors.

Concepts: Epidemiology, Allergy, Food allergy, Allergology, Peanut, Peanuts


Due to recent large outbreaks, peanuts have been considered a product of potential risk for Salmonella. Usually, peanut products show a low water activity (aw) and high fat content, which contribute to increasing the thermal resistance and survival of Salmonella. This study evaluated the long-term kinetics of Salmonella survival on different peanut products under storage at 28°C for 420 days. Samples of raw in-shell peanuts (aw = 0.29), roasted peanuts (aw = 0.39), unblanched peanut kernel (aw = 0.54), peanut brittle (aw = 0.30), paçoca (aw = 0.40) and pé-de-moça (aw = 0.68) were inoculated with Salmonella Typhimurium ATCC 14028 at two inoculum levels (3 and 6 log cfu/ g). The Salmonella behavior was influenced (p<0.05) by aw, lipid, carbohydrate and protein content. In most cases for both inoculum levels, the greatest reductions were seen after the first two weeks of storage, followed by a slower decline phase. The lowest reductions were verified in paçoca and roasted peanuts, with counts of 1.01 and 0.87 log cfu/ g at low inoculum level and 2.53 and 3.82 log cfu/ g at high inoculum level at the end of the storage time. The highest loss of viability was observed in pé-de-moça, with absence of Salmonella in 10-g after 180 days at low inoculum level. The Weibull model provided a suitable fit to the data (R2≥0.81), with δ value ranging from 0.06 to 49.75 days. Therefore, the results demonstrated that Salmonella survives longer in peanut products, beyond the shelf life (>420 days), especially in products with aw around 0.40.

Concepts: Salmonella enterica, Peanut, Peanuts, Confectionery


The prevalence of peanut allergy in younger siblings of children with peanut allergy has been reported between 7 to 8.5%, but the anaphylactic risk at time of introduction is currently unknown, which limits our ability to best counsel parents on this issue.

Concepts: Risk, Utility, Allergology, Peanut, Peanuts


Peanut (Arachis hypogaea L.) is an important crop grown worldwide for food and edible oil. The surge of peanut allergy in the past 25 years has profoundly impacted both affected individuals and the peanut and related food industries. In response, several strategies to mitigate peanut allergy have emerged to reduce/eliminate the allergenicity of peanuts or to better treat peanutallergic individuals. In this review, we give an overview of peanut allergy, with a focus on peanut proteins, including the impact of thermal processing on peanut protein structure and detection in food matrices. We discuss several strategies currently being investigated to mitigate peanut allergy, including genetic engineering, novel processing strategies, and immunotherapy in terms of mechanisms, recent research, and limitations. All strategies are discussed with considerations for both peanut-allergic individuals and the numerous industries/government agencies involved throughout peanut production and utilization. Expected final online publication date for the Annual Review of Food Science and Technology Volume 5 is February 28, 2014. Please see for revised estimates.

Concepts: Protein, Protein structure, Nutrition, Allergy, Food, Peanut, Arachis, Peanuts


Oral immunotherapy (OIT) using roasted peanut flour can effectively desensitize peanut-allergic children [1] but is considered not to be ready for clinical practice [2] due to high rates (≥45%) of adverse events (AEs) [3] [4]. This necessitates medically supervised up-dosing in hospital and limits the number of patients that can be treated. In 2001 Beyer et. al proposed that the prevalence of peanut allergy in China was lower than that of the Western world because peanuts consumed in China were boiled, not roasted [5]. They demonstrated that boiling peanuts for 20 minutes reduced IgE binding in vitro when compared to roasted peanut. We have subsequently shown that extended boiling progressively reduced peanut IgE binding to 12.5% at 2 hours and to 5.3% at 12 hours compared to raw peanut while still retaining T cell reactivity [6]. Further, Inhibition ELISAs demonstrated that boiled peanuts have restricted ability (2-h ~70%, 12-h ~50%) to block the binding of patient IgE to raw peanut [6] suggesting boiled peanuts possess an incomplete repertoire of epitopes. This indicates that boiled peanuts alone are unlikely to expose a patient to the full spectrum of peanut epitopes and will therefore require a roasted peanut phase following the initial boiled peanut therapy. We hypothesize that AEs can be reduced by commencing OIT with hypoallergenic boiled peanut. Here we describe a pilot study that aims to characterize the incidence of AEs and successful desensitization in mild/moderate peanut allergic children using hypoallergenic 2-hour boiled peanut prior to roasted peanut OIT. Due to the home-based up-dosing procedure, a cautious approach was adopted which excluded severely allergic children. This article is protected by copyright. All rights reserved.

Concepts: Immune system, Immunoglobulin E, Allergy, Allergology, Peanut, Copyright, Peanuts, Boiled peanuts


Among the many roles played by Small and Medium Enterprises (SMEs) in the food industry is the production of heritage foods such as peanut sauce. Regretfully, the safety of peanut sauce is not always assured as the processing line is not controlled. Peanut sauce is usually made of peanuts and chilli, and these commodities are normally contaminated with Aspergillus spp. and aflatoxins (AFs). Hence, the objective of this study was to evaluate the practices related to reduction of AF hazard and the effect of interventions in peanut sauce processing. Peanut samples were collected from each step of peanut sauce processing from a small peanut sauce company according to four designs (1, 2, 3, and 4). The designs were (1) control (2) oil-less frying of chilli powder (3) addition of retort processing (4) combination of oil-less frying of chilli powder and retort processing. Oil-less frying of chilli powder (design 2) reduced total AFs by 33-41%, retort processing (design 3) reduced total AFs by 49%, while combination of these two thermal processing (design 4) significantly reduced total AFs by 57%. The present work demonstrated that design 4 yielded the highest reduction of total AFs and is therefore recommended to be employed by SME companies.

Concepts: Redox, Food, Aspergillus flavus, Aflatoxin, Design, Aspergillus, Peanut, Peanuts