Effect of pretreatments on mycotoxin profiles and levels in dried figs.
The aim of this explorative study was to investigate how effective drying preservation methods are in reducing mycotoxin content in figs. Dried autochthonous varieties of white and dark figs (Petrovača Bijela and Šaraguja, respectively) were analysed for mycotoxins using an LC-MS/MS "dilute and shoot" method capable of determining 295 fungal and bacterial secondary metabolites. Before drying in a cabinet dryer the figs were preserved with 0.5 % citric acid solution or 0.5 % ascorbic acid solution or 0.3 % L-cysteine solution or 0.2 % chestnut extract solution or 0.15 % Echinacea extract solution by immersion. We found nine metabolites: aflatoxin B1 (AFB1), ochratoxin A, ochratoxin alpha, kojic acid, emodin, altenuene, alternariol methyl ether, brevianamide F, and tryptophol. The most efficient preserver was L-cysteine (15 % reduction), while ascorbic acid favoured mycotoxin production (158 % increase). However, all pretreatment solutions reduced AFB1, which is a major fig contaminant.
Structural characterisation of polysaccharides from roasted hazelnut skins.
Two polysaccharide fractions sequentially extracted with water 1W and alkali 1A, were isolated from the hazelnut skins. The monosaccharide composition together with the FTIR and NMR analyses, indicated that both fractions are formed from a mixture of polysaccharides. The fraction 1W consists of methyl-esterified pectic polysaccharide with rhamnogalacturonan I blocks, branching with arabinose side chains, and with 1,5-, 1,3,5-arabinan and galactan polysaccharides. The fraction 1A is a mixture of deesterified rhamnogalacturonan I and 1,5-, 1,3,5-arabinan and 4-O-Me-glucuronoxylan polysaccharides. The presence of unsaturated galacturonic acid and the heterogeneity of the molecular weights, which Mw ranged between 3.6 and 39 kg mol-1, indicated the pectin degradation during roasting.
Fungi Associated with and Influence of Moisture on Development of Kernel Mold of Hazelnut.
Kernel mold on hazelnuts is defined by the United States Department of Agriculture, U.S.A., as any visible fungal growth either on the outside or inside of the kernel. Only one yeast and one filamentous fungus have been associated with kernel mold of hazelnut in Oregon. In this report, fungi were isolated from kernels with mold and identified using morphological and molecular characters. Penicillium spp. were isolated most often from kernels with mold, but species of Aspergillus and Cladosporium and Diaporthe rudis were also frequently isolated. Additional fungi from three other genera were also isolated. All of the same fungi were also isolated from symptomless kernels. Eremothecium coryli or Ramularia sp. previously associated with kernel defects in Oregon were not found associated with symptoms of kernel mold. Incidence of mold was the highest when nuts were incubated in moist chambers on wet, nonautoclaved orchard soil and was significantly higher than kernel mold found in nuts incubated on either air-dried soil or wet, autoclaved soil. Preventing hazelnuts from coming in contact with wet soil in the field using elevated wire screens resulted in significantly less mold development in two out of three years evaluated. Nuts on screens had a greater chance to dry out between rainstorms as measured by significantly lower nut moisture levels at harvest.
Ozone-based treatments for inactivation of Salmonella enterica in tree nuts: Inoculation protocol and surrogate suitability considerations.
The feasibility of using gaseous ozone, alone or in combination with other treatments, to decontaminate in-shell almonds and pistachios, prepared under different pathogen-inoculation conditions, was explored. Nuts were inoculated with either Salmonella enterica serovar Enteritidis or a potential Salmonella surrogate, Enterococcus faecium OSY 31284. The effect of inoculation method (with or without vacuum application), and of drying inoculated nuts (up to three days) on treatment efficacy was investigated. Inoculated nuts were subjected to gaseous ozone alone (almonds, pistachios) or ozone in combination with heating in brine solution (pistachios). Ozone treatment included application of vacuum (10 in Hg), followed by vessel pressurization to 12.5 psig with ozone‑oxygen mixture (160 g ozone/m3 gas mixture) and holding for 30 min. Heating was conducted in a brine solution (5% NaCl) at 70 °C, for 10 min. Ozone-based treatments were significantly more effective (P < 0.05) on almonds than pistachios, with maximum S. Enteritidis reduction of 2.9 vs. 0.8 log CFU/g, regardless of inoculation method or the drying time. Treatment of inoculated pistachios with heated brine and gaseous ozone reduced S. Enteritidis population by 5.0 to 7.0 log CFU/g and was not significantly more effective than treatment with heated brine alone (reduction of 4.8 to 7.1 log CFU/g). Application of vacuum during inoculation increased bacterial population on nut kernels by approximately 1.2 log CFU/g, but the increase in inoculum population had no effect on inactivation of either species of inoculated bacteria. Decontamination treatments were less effective against both bacteria by up to 2 log CFU/g when drying time of inoculated nuts increased. E. faecium was significantly more resistant to heat and ozone treatment (P < 0.05) than was S. Enteritidis on pistachios, but not on almonds. Results of this study show that laboratory methodology affects observed treatment effectiveness. Considering its high resistance to the heat-ozone combination, E. faecium may not be a suitable surrogate for S. Enteritidis during processing of pistachios by this treatment. Efficacy of ozone gas to decontaminate S. Enteritidis-inoculated nuts depends heavily on the type of nut. Although reductions of S. Enteritidis populations on in-shell pistachios are low, treatment of in-shell almonds resulted in greater reductions, indicating the promise of this technology to enhance the safety of specific nut products.
Efficacy and safety of oral immunotherapy for peanut allergy: a pilot study in Singaporean children.
BACKGROUND: Peanut allergy is an increasing problem in Singapore and strict avoidance is difficult as peanut is ubiquitous in Asian cuisine. OBJECTIVE: We aimed to assess the efficacy and safety of peanut oral immunotherapy (OIT) in children with obvious peanut allergy in Singapore. METHODS: This was an open-label study of peanut OIT in children living in Singapore, with 2 weekly dose escalation until final maintenance dose of 3,000 mg of peanut protein and a maintenance phase of 12 months. An oral food challenge was performed at 6 months to assess for desensitisation and at 4 weeks after discontinuation of OIT having completed 12 months of maintenance therapy to assess for possible sustained unresponsiveness. The adverse events were monitored using the symptom diaries. RESULTS: Nine subjects were started on OIT, with 7 managing to complete maintenance phase of therapy. Of these 7, all were able to tolerate at least 3,000 mg of peanut protein by 6 months of maintenance therapy, showing that the OIT was effective. Of these 7, 3 patients complied with the 4-week abstinence period after completion of OIT before another peanut challenge; 2 of the 3 subjects showed a significant decrease from the initial ability to tolerate 3,000 mg of peanut protein. Side effects were mainly gastrointestinal in nature and were more common during the updosing phase than the maintenance phase. No episodes of anaphylaxis were observed in this study. CONCLUSION: Peanut OIT seemed to be effective and safe in our cohort of Singaporean children.
The importance of early peanut ingestion in the prevention of peanut allergy.
Peanut allergy appears to have increased in prevalence, is often severe and is typically life-long. Therefore, reducing its incidence through a primary prevention strategy is a priority. Guidelines on peanut introduction have evolved with time and given evidence of peanut allergy risk reduction with early infant ingestion exposure, the current US advice promotes early introduction for infants, particularly targeting those at highest risk. Areas covered: This article describes the evolution of peanut introduction guidelines in infants in the US, as shaped by key research over the last 20-30 years and culminates in the landmark LEAP study. It also compares and contrasts current iterations of peanutintroduction guidelines in infants globally. Finally, the early successes and barriers of implementation of early peanut introduction guidelines are discussed. We included literature from original articles, reviews, and consensus guidelines found in database searches through December 2018. Expert commentary: LEAP guideline implementation has proven to be successful, in the study setting, in decreasing the incidence of peanut allergy. However, its implementation in the community has been met with obstacles including low awareness among stakeholders, and access to testing when needed.
Effect of Epicutaneous Immunotherapy vs Placebo on Reaction to Peanut Protein Ingestion Among Children With Peanut Allergy: The PEPITES Randomized Clinical Trial.
IMPORTANCE: There are currently no approved treatments for peanut allergy. OBJECTIVE: To assess the efficacy and adverse events of epicutaneous immunotherapy with a peanut patch among peanut-allergic children. DESIGN, SETTING, AND PARTICIPANTS: Phase 3, randomized, double-blind, placebo-controlled trial conducted at 31 sites in 5 countries between January 8, 2016, and August 18, 2017. Participants included peanut-allergic children (aged 4-11 years [n = 356] without a history of a severe anaphylactic reaction) developing objective symptoms during a double-blind, placebo-controlled food challenge at an eliciting dose of 300 mg or less of peanut protein. INTERVENTIONS: Daily treatment with peanut patch containing either 250 μg of peanut protein (n = 238) or placebo (n = 118) for 12 months. MAIN OUTCOMES AND MEASURES: The primary outcome was the percentage difference in responders between the peanut patch and placebo patch based on eliciting dose (highest dose at which objective signs/symptoms of an immediate hypersensitivity reaction developed) determined by food challenges at baseline and month 12. Participants with baseline eliciting dose of 10 mg or less were responders if the posttreatment eliciting dose was 300 mg or more; participants with baseline eliciting dose greater than 10 to 300 mg were responders if the posttreatment eliciting dose was 1000 mg or more. A threshold of 15% or more on the lower bound of a 95% CI around responder rate difference was prespecified to determine a positive trial result. Adverse event evaluation included collection of treatment-emergent adverse events (TEAEs). RESULTS: Among 356 participants randomized (median age, 7 years; 61.2% male), 89.9% completed the trial; the mean treatment adherence was 98.5%. The responder rate was 35.3% with peanut-patch treatment vs 13.6% with placebo (difference, 21.7% [95% CI, 12.4%-29.8%; P < .001]). The prespecified lower bound of the CI threshold was not met. TEAEs, primarily patch application site reactions, occurred in 95.4% and 89% of active and placebo groups, respectively. The all-causes rate of discontinuation was 10.5% in the peanut-patch group vs 9.3% in the placebo group. CONCLUSIONS AND RELEVANCE: Among peanut-allergic children aged 4 to 11 years, the percentage difference in responders at 12 months with the 250-μg peanut-patch therapy vs placebo was 21.7% and was statistically significant, but did not meet the prespecified lower bound of the confidence interval criterion for a positive trial result. The clinical relevance of not meeting this lower bound of the confidence interval with respect to the treatment of peanut-allergic children with epicutaneous immunotherapy remains to be determined.
Mouse strain differences in response to oral immunotherapy for peanut allergy.
BACKGROUND: Promising therapies for food allergy are emerging, mostly based on animal experimentation. However, different mouse strains are used, which may make it hard to compare experiments. The current study investigated whether the immunological differences between C3H/HeOuJ (C3H) and BALB/c mice lead to differences in efficacy of peanut-specific immunotherapy. METHODS: After sensitization using peanut extract (PE), C3H and BALB/c mice received oral immunotherapy (OIT) by intragastric dosing for three weeks. Hereafter, mice were exposed to PE via the intradermal, intragastric and intraperitoneal route, to determine allergic outcomes. Furthermore, PE-specific antibody and cytokine production were determined and the number of various immune cells at different time points during the study were measured. RESULTS: OIT protected C3H mice against anaphylaxis, whereas no anaphylaxis was seen in BALB/c mice. In contrast, OIT induced an increase in MMCP-1 levels in BALB/c mice but not in C3H mice. No effect of OIT on the acute allergic skin response was observed in either strain. Specific antibody responses showed similar patterns in both strains for IgA and IgG1. IgE levels were a tenfold higher in BALB/c mice and after the intragastric challenge (day 70) OIT-treated BALB/c mice showed induced IgE levels. Moreover, in C3H mice IgG2a levels were higher and increased in response to OIT and challenges. After the final challenge, but not at other timepoints MLN-derived lymphocytes from OIT-treated BALB/c mice produced less IL-13 and IL-5 compared to control-treated mice, whereas no differences were seen in case of C3H mice. CONCLUSIONS: Taken together, these results show that the C3H strain is more suitable to study clinical outcomes of OIT, whereas the BALB/c strain is more optimal to study T cell responses.
A critical review of the specifications and performance of antibody and DNA-based methods for detection and quantification of allergens in foods.
Despite the availability of a large number of antibody and DNA based methods for detection and quantification of allergens in food there remain significant difficulties in selecting the optimum technique to employ. Published methods from research groups mostly contain sufficient detail concerning target antigen, calibration procedures and method performance to allow replication by others. However, routine allergen testing by the food industry relies upon commercialised test kits and frequently the suppliers provide disappointingly little specification detail on the grounds that this is proprietary information. In this review we have made a critical assessment of the published literature describing the performance of both commercial and non-commercial test kits for food allergens over the period 2008-2018. Mass spectrometric methods, which have the potential to become reference methods for allergens, are not covered in this review. Available information on the specifications of commercial ELISA and LFD test kits are tabulated for milk, egg and peanut allergens, where possible linking to publications concerning collaborative studies and proficiency testing. For a number of commercial PCR test kits, specifications provided by manufacturers for detection of a small selection of allergen are tabulated. In conclusion we support the views of others of the critical need for allergen reference materials as the way forward to improve the comparability of different testing strategies in foods.
Age at introduction to complementary solid food and food allergy and sensitization: a systematic review and meta‐analysis.
BACKGROUND AND OBJECTIVE: An infant's age at introduction of complementary solids may contribute to food allergy. We aimed to synthesize the literature on the association between age at introduction of complementary solids, excluding milk products, and food allergy and sensitization. DESIGN: We searched the electronic databases PubMed and EMBASE (January 1946-February 2017) using solid food, allergy and sensitization terms. METHODS: Two authors selected papers according to inclusion criteria, identifying 16 cohort studies, 1 case-control study and 8 randomized controlled trials (RCTs). Pooled effects across studies were estimated using random-effects meta-analysis. RESULTS: Cohort studies - Introducing complementary solids at age ≥4 months versus <4 months was not associated with food allergy (OR 1.22; 95%CI, 0.76-1.96) but was associated with food sensitization (OR 1.93; 95%CI 1.57-2.38). First exposure from age 4-6 months versus <4 months was not associated with food allergy (OR 1.01; 95%CI, 0.64-1.60) but was associated with food sensitization (OR 2.46; 95%CI 1.55-3.86). RCTs - Egg exposure from age 4 months was associated with reduced egg allergy (OR 0.63, 95%CI, 0.44-0.90) and sensitization (OR 0.76, 95%CI, 0.51-0.95). Peanut exposure from age 4 months compared to delayed exposure was associated with reduced peanut allergy (OR 0.28, 95%CI 0.14-0.57). CONCLUSIONS: We found no evidence from observational studies that introducing solids before 4 months protected against food allergy, but there was evidence for protection against food sensitization. From RCTs, introducing egg from 4-6 months and peanut from 4-11 months, reduced the risk of egg allergy, peanut allergy and egg sensitization.