Advances in ultra-high performance liquid chromatography coupled to tandem mass spectrometry for sensitive detection of several food allergens in complex and processed foodstuffs.
Sensitive detection of food allergens is affected by food processing and foodstuff complexity. It is therefore a challenge to detect cross-contamination in food production that could endanger an allergic customer's life. Here we used ultra-high performance liquid chromatography coupled to tandem mass spectrometry for simultaneous detection of traces of milk (casein, whey protein), egg (yolk, white), soybean, and peanut allergens in different complex and/or heat-processed foodstuffs. The method is based on a single protocol (extraction, trypsin digestion, and purification) applicable to the different tested foodstuffs: chocolate, ice cream, tomato sauce, and processed cookies. The determined limits of quantitation, expressed in total milk, egg, peanut, or soy proteins (and not soluble proteins) per kilogram of food, are: 0.5mg/kg for milk (detection of caseins), 5mg/kg for milk (detection of whey), 2.5mg/kg for peanut, 5mg/kg for soy, 3.4mg/kg for egg (detection of egg white), and 30.8mg/kg for egg (detection of egg yolk). The main advantage is the ability of the method to detect four major food allergens simultaneously in processed and complex matrices with very high sensitivity and specificity.
Experimental food allergy to peanut enhances the immune response to house dust mite in the airways of mice.
BACKGROUND: Food allergy has been associated with an increased risk for the development of allergic asthma. Asthma is a risk factor for the development of an anaphylactic response to food allergens. An immunological interplay between sensitization to different allergens in different compartments of the body might be involved. OBJECTIVE: To evaluate the immunological interplay between intragastrical peanut (PE) sensitization and respiratory sensitization to house dust mite (HDM) allergens. METHODS: BALB/c mice were intra-gastrically sensitized to peanut or sham-sensitized and challenged systemically to PE. Between sensitization and challenge, mice were intranasally exposed to HDM extract or PBS, as a control. The response to HDM (eosinophil recruitment, cytokine response, HDM specific immunoglobulins, and airway hyperreactivity) and to PE (cytokine response, mast cells in gut, mMCP-1 in serum, body temperature) was assessed. RESULTS: A preceding PE sensitization increased HDM induced production of IL-4, IL-5, IL-13 and IFNγ in lung draining lymph nodes and total IgE levels in HDM sensitized mice. However, recruitment of inflammatory cells to the airways or airway hyperreactivity was not aggravated in PE/HDM double-sensitized mice. Alternatively, HDM induced airway inflammation did not significantly affect the immune response or the anaphylactic response to a systemic challenge with peanut. CONCLUSION AND CLINICAL RELEVANCE: Our data show that a preceding peanut sensitization boosted IgE and HDM-specific Th2 response in the airways in mice. It contributes to the understanding of the underlying immunological mechanism of polysensitization which often occurs in allergic individuals over time.
Three peanut allergic/sensitized phenotypes with gender difference.
BACKGROUND: Peanut allergic reactions are heterogeneous ranging from mild symptoms to anaphylaxis. OBJECTIVE: Identify peanut allergic/sensitized phenotypes to personalize patient management. METHODS: A combined factor and cluster analysis was used to study the phenotypes of 696 patients diagnosed with peanut sensitization and enrolled in the MIRABEL survey. The method was first applied to the 247 patients with an Oral Food Challenge (OFC). It was then applied to the 449 patients without OFC to confirm the findings in an independent population. RESULTS: Three independent clusters emerged from the OFC subgroup. Cluster 1, "Severe peanut allergy with little allergic multimorbidity" (123 subjects), had the highest proportion of patients with positive OFC (92%), a medium level of peanut protein inducing a positive OFC (235 mg), lower percentage of allergic multimorbidity (2% asthma plus atopic dermatitis (A+AD), no cases of A+AD + multiple food allergies (MFA)). Cluster 2, "Severe peanut allergy with frequent allergic multimorbidity" (62 subjects), had a high proportion of patients with positive OFC (85%) with the lowest level of peanut protein inducing a positive OFC (112mg), 89% allergic subjects, 100% with allergic multimorbidity (A+AD) and 84% with A+AD+MFA. Cluster 3, "Mild peanut allergic/sensitized phenotype" (62 subjects), had the lowest mean age, the lowest proportion of patients with positive OFC (53%) with a high level of peanut protein inducing a positive OFC (770 mg), a low percentage of allergic multimorbidity (48% A+AD+MFA). The two severe peanut allergy phenotypes were more frequent in girls. The same clusters were found in the subgroup of patients without OFC. CONCLUSION & CLINICAL RELEVANCE: Besides the classic markers associated with lower threshold doses of OFC (such as SPT and rAra h2), allergic multimorbidity and female gender should also be taken into account to better adapt the progressive dosage of provocation tests.
Development of walnut dehulling machine and assessment of its performance using Ethephon and Tween-80 as pre-treatments for hull loosening.
A power- driven walnut dehulling machine was developed and tested. The machine was evaluated for dehulling after applying Ethephon and Tween-80 to green walnuts by dip and spray methods. The results showed that with the increase in dipping time and post dipping/spraying time, the effective throughput capacity, dehulling efficiency and fully dehulled walnut percentage increased, whereas partially dehulled walnut percentage and labour requirement decreased in both manual and mechanical dehulling. Maximum effective throughput capacity, dehulling efficiency and fully dehulled walnut percentage were observed, when green walnuts were subjected to dehulling after 4 days of Ethephon spray treatment (0.3 %). The effective throughput capacity, dehulling efficiency and fully dehulled walnut percentage were found significantly higher in mechanical dehulling than in manual dehulling.
Simultaneous determination of six mycotoxins in peanut by High-performance Liquid Chromatography with Fluorescence detector.
BACKGROUND: Mycotoxins, which may contaminate peanut and peanut products, are responsible for many diseases to human beings. AflatoxinB1(AFB1), aflatoxinG1(AFG1), aflatoxinB2(AFB2), aflatoxinG2(AFG2), ochratoxin A(OTA) and zearalenone(ZEN) are considered the most relevant groups of mycotoxins found in food. This work aimed to develop a high-performance liquid chromatography with fluorescence detector(HPLC-FLD) combined with dispersive liquid-liquid microextraction(DLLME) method for the simultaneous determination of the six mycotoxins in peanuts. The six mycotoxins were simultaneously determined under their best wavelength by means of changing wavelength. RESULTS: Under the optimum conditions, the linear ranges were 1 ~ 100 ng mL^-1 for AFB1, AFG1 and OTA, 0.3 ~ 30 ng mL^-1 for AFB2 and AFG2, 5 ~ 1000 ng mL^-1 for ZEN, with the correlation coefficient(R2) of 0.9969 ~ 0.9997. Limits of detection(LODs) were 0.10, 0.10, 0.30, 0.03, 0.03 and 1.0 µg kg^-1, respectively, and the mean recoveries were in the range of 83.1% to 99.3% with RSD<10%(n=6, independent analysis).Thirteen(46%) of these tested samples were contaminated with at least one mycotoxin. CONCLUSION: The proposed method was demonstrated to be simple, highly selective, accurate, reliable, and was successfully applied to simultaneously analyze of the six mycotoxins in real peanut samples from China.
Effects of different drying treatments on fungal population and ochratoxin A occurrence in sultana type grapes.
This study aimed to determine the changes in mould and ochratoxin A (OTA) occurrence in sultanas under three different conventional drying conditions. Five different vineyards were chosen, and the three different treatments were applied to these grapes while drying. At the end of the drying process, total mould and black aspergilli (BA) populations in the samples varied from 2.45 to 5.61 log colony-forming units (CFU) g-1 and from 0 to 4.92 log CFU g-1, respectively. Significant increases (p<0.05) occurred in mould loads depending on the extending drying period. However, independent of vineyard location, all of the samples treated with cold dipping solution showed the lowest fungal loads. These results indicate that dipping solution treatment was the most effective drying method to minimize fungal infection of grapes. The expected results could not be achieved by drying grapes artificially contaminated with ochratoxigenic Aspergillus carbonarius spores. Seventy-one of 96 isolates (73.95%) obtained during drying were Aspergillus spp., and the remaining (n=25, 26.05%) belonged to other genera, such as Penicillium, Trichoderma and Cladosporium. Grape juice-based agar medium was used to determine the realistic OTA production capacities of the isolated mould strains. The highest OTA production capacities were 809.70±9.19, 87.58±16.89 and 45.44±18.78 ng/g in 50% grape juice agar (GJ50), all 5 of which were from A. niger isolates. OTA was not present in any sample during the drying period; however, OTA was detected in two samples at 0.32±0.15 and 0.52±0.36 µg kg-1 after the end of the drying process. The Limit of Detection (LOD) and Limit of Quantitation (LOQ) of the method used for detecting OTA in samples were 0.1 and 0.3 µg kg-1, respectively.
Nuts and their co-products: The impact of processing (roasting) on phenolics, bioavailability, and health benefits - A comprehensive review.
Nuts serve as important healthful snacks worldwide. They are highly desirable due to the presence of numerous essential macro- and micronutrients and health-promoting phenolic compounds (polyphenols). Nuts are usually consumed either as raw (natural) or as roasted. In addition, nuts and their co-products have been demonstrated to be rich sources of phenolic compounds that possess various health-beneficial properties. Therefore, inclusion of these phenolic compounds from nut co-products into the human diet is highly recommended as these may provide inexpensive sources of natural antioxidants for use as functional food ingredients and nutraceuticals. Hence, the phenolic compositions and antioxidant activities of nuts (natural and roasted) and their co-products (such as skin, hard shell, hull, and pellet) are discussed in detail. The impact of processing (roasting) on nut phenolics and antioxidant activities are highlighted. The bioavailability and health benefits of the phenolic compounds from nuts, especially their co-products are also discussed. Research findings from the existing literature published within the last 10 years have been compiled and summarised.
Influence of a Mediterranean Dietary Pattern on Body Fat Distribution: Results of the PREDIMED-Canarias Intervention Randomized Trial.
OBJECTIVE: To assess the influence of a Mediterranean dietary pattern (MeDiet) on anthropometric and body composition parameters in one of the centers of the PREDIMED randomized dietary trial. SUBJECTS/SETTINGS: 351 Canarian free-living subjects aged 55 to 80 years, with type 2 diabetes or ≥3 cardiovascular risk factors. INTERVENTION: Participants were randomly assigned to one of 3 different dietary interventions: MeDiet + extra-virgin olive oil (EVOO), MeDiet + nuts (walnuts, almonds, and hazelnuts), or a control low-fat diet. Total energy intake was ad libitum. OUTCOME MEASURES: Measures included changes in anthropometric measures (weight, body mass index [BMI] and waist circumference [WC]), body fat distribution, energy, and nutrient intake after 1 year. Body composition (percentage of total body fat [%TBF], total fat mass [TFM], free fat mass [FFM], percentage of truncal fat [%TrF], truncal fat mass [TrFM]) and total body water (TBW) were estimated by octapolar electrical impedance analysis. STATISTICAL ANALYSES: Paired t tests were conducted to assess within-group changes. Analyses of variance (ANOVAs) were used to assess the effect of the dietary intervention on the percentage change in anthropometric variables, body composition, and dietary intake profile. All pairwise comparisons that were statistically significant in ANOVA were subsequently adjusted using the Benjamini-Hochberg test, which penalizes for multiple comparisons. RESULTS: After 1 year of intervention, significant within-group reductions in all anthropometric variables were observed for the MeDiet + EVOO and the control group. The MeDiet + nuts group exhibited a significant reduction in WC and TBW. The control group showed a significant increase in %TBF and a reduction in TBW. The control group showed a significant increase in the percentage of total body fat and a reduction in TBW. However, we did not find any between-group significant difference in anthropometric or body composition changes. CONCLUSIONS: Mediterranean diets enriched with EVOO or specific mixed nuts (walnuts, almonds, hazelnuts) that contain approximately 40% total fat can be alternative options to low-fat diets for weight maintenance regimes in older overweight or obese adults.
Cerebrovascular and cognitive benefits of high-oleic peanut consumption in healthy overweight middle-aged adults.
OBJECTIVE: Peanuts contain bioactive nutrients beneficial for vascular function. This study investigated whether consumption of unsalted peanuts (with skins) would enhance cerebrovascular perfusion and cognitive performance. METHOD: In a randomized crossover trial, 61 volunteers (29 males/32 females, 65 ± 7 years, BMI 31 ± 4 kg/m2) consumed their habitual diet ± high-oleic peanuts (56-84 g/day), each for 12 weeks. Nutrient intakes, vascular and cognitive function were assessed at baseline and at the end of each 12-week phase. Differences between the ends of each phase were compared by general linear repeated measures ANOVA controlling for baseline. Pearson's correlation analyses determined relationships between differences in cerebrovascular reactivity (CVR) and cognitive function. RESULTS: Intakes of bioactive nutrients increased during the peanut phase. CVR was 5% greater in the left middle cerebral artery (MCA) and 7% greater in the right MCA. Small artery elasticity was 10% greater after peanut consumption; large artery elasticity and blood pressure did not differ between phases. Measures of short-term memory, verbal fluency, and processing speed were also higher following the peanut phase; other cognitive measures did not change. Differences in CVR in the left MCA correlated with differences in delayed memory and recognition. DISCUSSION: Regular peanut consumption improved cerebrovascular and cognitive function; increased intakes of bioactive nutrients may have mediated these improvements. This clinical trial was registered with the Australian Clinical Trials Registry (ACTRN 12612000192886).
Non-polyphenolic compounds of a specific kind of dried grape (Maviz) inhibit memory impairments induced by beta-amyloid peptide.
OBJECTIVES: Although grape has been recently the topic of many investigations, Maviz (a kind of dried one) has remained neglected. The aim of this study was to assess anti-Alzheimer activity of Maviz. METHODS: To reach this goal, total phenolic content (TPC) of ethanolic (Eth) and aqueous (Aq) extracts were determined and radical scavenging activity was assayed by 2,2-diphenyl-1-picrylhydrazyl. Chemical compositions of each extract were also determined via GC-Mass. Behavioral changes were studied via passive avoidance and Morris water maze in Aβ-induced model of Alzheimer's disease. Catalase (CAT) and superoxide dismutase (SOD) determination were also done on rats' hippocampus. RESULTS: The results showed that seed Eth extract has a high level of TPC and radical scavenging activity. However, this extract had surprisingly no effect on memory and CAT and SOD activities. In contrast, fruit Aq and Eth extracts (containing furfurals as major compounds) inhibited memory impairment (P < 0.001) and elevated brain levels of CAT and SOD(P < 0.05). CONCLUSION: It seems that Maviz non-phenolic compounds-most probably 5-hydroxymethylfurfural and other similar derivatives-are responsible for these actions.