Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “peanut”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources
PubMed2000

[Risk of serious acute asthma due to lupine flour associated with peanut allergy].

UNLABELLED: Lupine flour (lupinus albus), recently authorized in France in human food, cross-reacts with peanuts. We report a case of acute asthma in a patient with allergy to peanuts. EXEGESIS: This patient has a severe allergy to peanuts, presenting as acute asthma. Skin prick-tests to raw and cooked lupine flour were positive. The level of specific-IgE (Allerbio, France) to lupine flour were high. Oral challenge test induced acute asthma at a dose of 965 mg of lupine flour. This quantity may be included in 100 g of bread. CONCLUSION: This case report points out the fact that lupine flour is a high-risk allergen in patients presenting allergy to peanuts. It is necessary to evaluate the allergenic risk of new foods before their introduction into human daily food intake and to establish a network of allergy vigilance.

Adolescent↗
PubMed1999

Phylogeny and diversity of Bradyrhizobium strains isolated from the root nodules of peanut (Arachis hypogaea) in Sichuan, China.

Twenty-two rhizobial strains isolated from the root nodules of two Chinese peanut cultivars (Arachis hypogaea L. Tianfu no. 3 and a local cultivar) growing at four different sites in the Sichuan province, Southwest China, were characterized by growth rate, rep-PCR, PCR-RFLP of 16S rDNA, partial sequencing of ribosomal genes, and fatty acid-methyl ester analysis (FAME), and compared with strains representing Bradyrhizobium japanicum, B. elkanii and other unclassified Bradyrhizobium sp. All peanut isolates from Sichuan were bradyrhizobia. Dendrograms constructed using the rep-PCR fingerprints grouped the strains mainly according to their geographic and cultivar origin. Based on PCR-RFLP and partial sequence analysis of 16S rDNA it appears that peanut bradyrhizobial strains from Sichuan are similar to peanut strains from Africa and Israel, and closely related to B. japonicum. In contrast, analysis of FAME data using two-dimensional principal component analysis indicated that Bradyrhizobium sp. (Arachis) were similar to, but slightly different from other bradyrhizobia. The presence and level of fatty acid 16:1 w5c was the distinguishing feature. The results of PCR-RFLP of the 16S rRNA gene, the partial sequence analysis of 16S rDNA, and FAME were in good agreement.

Arachis↗
PubMed2003

High-yield expression in Escherichia coli, purification, and characterization of properly folded major peanut allergen Ara h 2.

Allergic reactions to peanuts are a serious health problem because of their high prevalence, associated with potential severity, and chronicity. One of the three major allergens in peanut, Ara h 2, is a member of the conglutin family of seed storage proteins. Ara h 2 shows high sequence homology to proteins of the 2S albumin family. Presently, only very few structural data from allergenic proteins of this family exist. For a detailed understanding of the molecular mechanisms of food-induced allergies and for the development of therapeutic strategies knowledge of the high-resolution three-dimensional structure of allergenic proteins is essential. We report a method for the efficient large-scale preparation of properly folded Ara h 2 for structural studies and report CD-spectroscopic data. In contrast to other allergenic 2S albumins, Ara h 2 exists as a single continuous polypeptide chain in peanut seeds, and thus heterologous expression in Escherichia coli was possible. Ara h 2 was expressed as Trx-His-tag fusion protein in E. coli Origami (DE3), a modified E. coli strain with oxidizing cytoplasm which allows the formation of disulfide bridges. It could be shown that recombinant Ara h 2, thus overexpressed and purified, and the allergen isolated from peanuts are identical as judged from immunoblotting, analytical HPLC, and circular dichroism spectra.

2S Albumins, Plant↗
PubMed2006

Consumption and portion sizes of tree nuts, peanuts and seeds in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts from 10 European countries.

Tree nuts, peanuts and seeds are nutrient dense foods whose intake has been shown to be associated with reduced risk of some chronic diseases. They are regularly consumed in European diets either as whole, in spreads or from hidden sources (e.g. commercial products). However, little is known about their intake profiles or differences in consumption between European countries or geographic regions. The objective of this study was to analyse the population mean intake and average portion sizes in subjects reporting intake of nuts and seeds consumed as whole, derived from hidden sources or from spreads. Data was obtained from standardised 24-hour dietary recalls collected from 36 994 subjects in 10 different countries that are part of the European Prospective Investigation into Cancer and Nutrition (EPIC). Overall, for nuts and seeds consumed as whole, the percentage of subjects reporting intake on the day of the recall was: tree nuts = 4. 4%, peanuts = 2.3 % and seeds = 1.3 %. The data show a clear northern (Sweden: mean intake = 0.15 g/d, average portion size = 15.1 g/d) to southern (Spain: mean intake = 2.99 g/d, average portion size = 34.7 g/d) European gradient of whole tree nut intake. The three most popular tree nuts were walnuts, almonds and hazelnuts, respectively. In general, tree nuts were more widely consumed than peanuts or seeds. In subjects reporting intake, men consumed a significantly higher average portion size of tree nuts (28.5 v. 23.1 g/d, P<0.01) and peanuts (46.1 v. 35.1 g/d, P<0.01) per day than women. These data may be useful in devising research initiatives and health policy strategies based on the intake of this food group.

Arachis↗
PubMed2001

Non-detectable levels of trans-fatty acids in peanut butter.

The fatty acid composition of 11 brands of peanut butter and paste freshly prepared from roasted peanuts was analyzed with emphasis on isomeric trans-fatty acids. No trans-fatty acids were detected in any of the samples in an analytical system with a detection threshold of 0.01% of the sample weight. Hydrogenated vegetable oils are added to peanut butters at levels of 1--2% to prevent oil separation. Some hydrogenated vegetable oils are known to be sources of trans-fatty acids in the human diet. The addition of these products was not found to result in measurable amounts of trans-fatty acids in the peanut butters analyzed.

Arachis↗
PubMed2006

Confirmation of peanut protein using peptide markers in dark chocolate using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Detection of peptides from the peanut allergen Ara h 1 by liquid chromatography-mass spectrometry (LC-MS) was used to identify and estimate total peanut protein levels in dark chocolate. A comparison of enzymatic digestion subsequent to and following extraction of Ara h 1 from the food matrix revealed better limits of detection (LOD) for the pre-extraction digestion (20 ppm) than for the postextraction digestion (50 ppm). Evaluation of LC-MS instruments and scan modes showed the LOD could be further reduced to 10 ppm via a triple-quadrupole and multiple-reaction monitoring. Improvements in extraction techniques combined with an increase in the amount of chocolate extracted (1 g) improved the LOD to 2 ppm of peanut protein. This method provides an unambiguous means of confirming the presence of the peanut protein in foods using peptide markers from a major allergen, Ara h 1, and can easily be modified to detect other food allergens.

Allergens↗
PubMed2006

Biosynthesis enhancement and antioxidant and anti-inflammatory activities of peanut (Arachis hypogaea L.) arachidin-1, arachidin-3, and isopentadienylresveratrol.

UNLABELLED: Peanut is a potent plant to be induced to synthesize bioactive stilbenoids. Bioactivities of those stilbenoids except resveratrol have been meagerly investigated. When peanut kernels (Tainan 14, a Spanish cultivar) were imbibed, incubated 3 days for germination, sliced, incubated with artificial aeration, periodically sampled, lyophilized, extracted with methanol, and subjected to reverse-phase HPLC analysis, four major fractionations were detected and identified as trans-resveratrol (Res), trans-arachidin-1 (Ara-1), trans-arachidin-3 (Ara-3), and trans-isopentadienylresveratrol (IPD). During incubation of the peanut slices, contents of Res, Ara-1, and Ara-3 increased tremendously from initially trace or not detectable amounts up to 147.3, 495.7, and 2414.8 microg/g, corresponding to 20, 16, and 24 h of incubation, while IPD contents continued to increase up to 28 h (4474.4 microg/g). When the four stilbenoids and butylated hydroxytoluene (BHT) were subjected to antioxidant characterization by various measures, all have exhibited varied potencies of antioxidant activity. In particular, retardation of absorbance increase at 234 nm as formation of the conjugated diene hydroperoxides in a real pork oil system stored at 60 degrees C, supplement of Ara-1 at 100 microM has shown equivalent or even greater activity than did BHT. When the media were supplemented with Res, Ara-1, Ara-3, and IPD at 15 microM for cultivation of mouse macrophage RAW 264.7 cells activated by lipopolysaccharide (LPS), the LPS-induced extracellular production of prostaglandin E2 (PGE2) and nitric oxide (NO) was significantly inhibited by Ara-1 (p < 0.001), Res (p < 0.001), Ara-3 (p < 0.01), and IPD (p < 0.01). It is noteworthy and of merit that all test stilbenoids have exhibited potent antioxidant and anti-inflammatory activities and varied as affected by number of hydroxyl groups and isopentenyl or isopentadienyl moiety. KEYWORDS: Arachis hypogaea L.; peanut; groundnut; resveratrol; stilbenoids; arachidin; antioxidant; anti-inflammation.

Animals↗
PubMed1999

Signaling by glutamate dehydrogenase in response to pesticide treatment and nitrogen fertilization of peanut (Arachis hypogaea L.).

The responses of glutamate dehydrogenase (GDH) to NH(4)(+) and herbicides offer a new approach for probing the effects of NH(4)(+)-pesticide interactions at the whole-plant level. Although pesticides and fertilizers have greatly enhanced food production, their combined biochemical effects are not known in detail. Peanut plants were treated with different rates of Basagran (3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide), Bravo 720 (tetrachloroiso-phthalonitrile), and Sevin XLR Plus (1-naphthyl N-methylcarbamate), with and without 25 mM NH(4)Cl fertilization. Isoelectric focusing, followed by native 7.5% polyacrylamide gel electrophoresis (PAGE) fractionated the peanut seed GDH fully to its isoenzyme population patterns. The pesticide treatments induced positive skewing of the GDH isoenzymes, but NH(4)Cl-pesticide cotreatments induced a negatively skewed distribution. Basagran, Sevin, and Bravo increased the amination activities of GDH from 30.0 +/- 2.8 units in the control assay to 479.0 +/- 20.7, 63.0 +/- 5.8, and 35.2 +/- 2.2 units, respectively, therefore indicating a direct GDH-pesticide interaction. Neither the NH(4)(+) nor the pesticides increased the peanut seed protein yields above the threshold of 3.8 +/- 0.7 g per pot. But in the GDH combination of the signals from a pesticide and NH(4)(+), at least 70% of the pesticide signal was overridden by NH(4)(+) with concomitant increases in peanut seed protein yields to 7.0 +/- 1.8 g per pot. Basagran, Sevin, and Bravo possess different pesticidal properties, but their effects on GDH activity were related in the decreasing order of their nucleophilicity, viz. Basagran > Sevin > Bravo.

Arachis↗
PubMed2001

Conidial movement of nontoxigenic Aspergillus flavus and A. parasiticus in peanut fields following application to soil.

The use of nontoxigenic strains of Aspergillus flavus and A. parasiticus in biological control effectively reduces aflatoxin in peanuts when conidium- producing inoculum is applied to the soil surface. In this study, the movement of conidia in soil was examined following natural rainfall and controlled precipitation from a sprinkler irrigation system. Conidia of nontoxigenic A. flavus and A. parasiticus remained near the soil surface despite repeated rainfall and varying amounts of applied water from irrigation. In addition, rainfall washed the conidia along the peanut furrows for up to 100 meters downstream from the experimental plot boundary. The dispersal gradient was otherwise very steep upstream along the furrows and in directions perpendicular to the peanut rows. The retention of biocontrol conidia in the upper soil layers is likely important in reducing aflatoxin contamination of peanuts and aerial crops such as corn and cottonseed.

Aflatoxins↗
PubMed2002

Production of butanol from starch-based waste packing peanuts and agricultural waste.

We examined the fermentation of starch-based packing peanuts and agricultural wastes as a source of fermentable carbohydrates using Clostridium beijerinckii BA101. Using semidefined P2 medium containing packing peanuts and agricultural wastes, instead of glucose as a carbohydrate source, we measured characteristics of the fermentation including solvent production, productivity, and yield. With starch as substrate (control), the culture produced 24.7 g l(-1) acetone-butanol-ethanol (ABE), while with packing peanuts it produced 21.7 g l(-1) total ABE with a productivity of 0.20 g l(-1) h(-1) and a solvent (ABE) yield of 0.37. Cell growth in starch, packing peanuts, and agricultural wastes medium was different, possibly due to the different nature of these substrates. Using model agricultural waste, 20.3g l(-1) ABE was produced; when using actual waste, 14.8 g l(-1) ABE was produced. The use of inexpensive substrates will increase the economic viability of the conversion of biomass to butanol, and can provide new markets for these waste streams.

Acetic Acid↗
PubMed2000

Specificity of allergen skin testing in predicting positive open food challenges to milk, egg and peanut in children.

BACKGROUND: The specificity of allergen skin prick testing to diagnose clinically relevant food allergy is controversial. OBJECTIVES: To determine the specificity of the allergen weal diameter to correctly identify children who react on formal open food challenges. METHODS: Over a 9-year period children referred to a tertiary allergy clinic for the evaluation of suspected food allergy were prospectively studied. Allergen skin prick testing to cow milk, egg white and peanut extracts (Dome-Hollister-Stier, Spokane, WA, USA) was undertaken using a lancet technique. All children underwent open food challenges to the relevant food(s) in a hospital clinic. Challenges were classified as positive, if objective signs were seen; negative, if the child could tolerate normal quantities of the food, daily, for one week; or inconclusive if none of the former criteria were met. RESULTS: Five hundred and fifty-five challenges were undertaken in 467 children: 339 challenges to cow milk, 121 to egg, and 95 to peanut. Fifty-five percentage of challenges were positive, 37% negative, and 8% inconclusive. For each food it was possible to identify a skin weal diameter at, and above, which negative reactions did not occur: cow milk, 8 mm; egg, 7 mm; peanut, 8 mm. In contrast, positive reactions could occur with a skin wheal diameter of 0 mm. CONCLUSIONS: In this high risk referral population it was possible to define skin weal diameters to egg, milk and peanut above which open oral food challenges were positive (100% specificity). By utilizing these measurements the need for formal food challenges can be reduced.

Animals↗
PubMed2001

The US Peanut and Tree Nut Allergy Registry: characteristics of reactions in schools and day care.

OBJECTIVE: Severe food-allergic reactions occur in schools, but the features have not been described. STUDY DESIGN: Participants in the US Peanut and Tree Nut Allergy Registry (PAR) who indicated that their child experienced an allergic reaction in school or day care were randomly selected for a telephone interview conducted with a structured questionnaire. RESULTS: Of 4586 participants in the PAR, 750 (16%) indicated a reaction in school or day care, and 100 subjects or parental surrogates described 124 reactions to peanut (115) or tree nuts (9); 64% of the reactions occurred in day care or preschool, and the remainder in elementary school or higher grades. Reactions were reported from ingestion (60%), skin contact/possible ingestion (24%), and inhalation/possible skin contact or ingestion (16%). In the majority of reactions caused by inhalation, concomitant ingestion/skin contact could not be ruled out. Various foods caused reactions by ingestion, but peanut butter craft projects were commonly responsible for the skin contact (44%) or inhalation (41%) reactions. For 90% of reactions, medications were given (86% antihistamines, 28% epinephrine). Epinephrine was given in school by teachers in 4 cases, nurses in 7, and parents or others in the remainder. Treatment delays were attributed to delayed recognition of reactions, calling parents, not following emergency plans, and an unsuccessful attempt to administer epinephrine. CONCLUSIONS: School personnel must be educated to recognize and treat food-allergic reactions. Awareness must be increased to avoid accidental exposures, including exposure from peanut butter craft projects.

Adolescent↗
PubMed1998

Biochemical and structural analysis of the IgE binding sites on ara h1, an abundant and highly allergenic peanut protein.

Allergy to peanut is a significant IgE-mediated health problem because of the high prevalence, potential severity, and chronicity of the reaction. Ara h1, an abundant peanut protein, is recognized by serum IgE from >90% of peanut-sensitive individuals. It has been shown to belong to the vicilin family of seed storage proteins and to contain 23 linear IgE binding epitopes. In this communication, we have determined the critical amino acids within each of the IgE binding epitopes of Ara h1 that are important for immunoglobulin binding. Surprisingly, substitution of a single amino acid within each of the epitopes led to loss of IgE binding. In addition, hydrophobic residues appeared to be most critical for IgE binding. The position of each of the IgE binding epitopes on a homology-based molecular model of Ara h1 showed that they were clustered into two main regions, despite their more even distribution in the primary sequence. Finally, we have shown that Ara h1 forms a stable trimer by the use of a reproducible fluorescence assay. This information will be important in studies designed to reduce the risk of peanut-induced anaphylaxis by lowering the IgE binding capacity of the allergen.

Adult↗
PubMed1999

Heat-induced conformational changes of Ara h 1, a major peanut allergen, do not affect its allergenic properties.

Ara h 1, a major peanut allergen was isolated, and its structure on secondary, tertiary, and quaternary level at ambient temperature was investigated using spectroscopic and biochemical techniques. Ara h 1 appeared to be a highly structured protein on a secondary level, possesses a clear tertiary fold, and is present as a trimeric complex. Heat treatment of purified Ara h 1 results in an endothermic, irreversible transition between 80 and 90 degreesC, leading to an increase in beta-structures and a concomitant aggregation of the protein. Ara h 1 from peanuts that were heat-treated prior to the purification procedure exhibited a similar denatured state with an increased secondary folding and a decreased solubility. The effect of heat treatment on the in vitro allergenic properties of Ara h 1 was investigated by means of a fluid-phase IgE binding assay using serum from patients with a clinically proven peanut allergy. Ara h 1 purified from peanuts heated at different temperatures exhibited IgE binding properties similar to those found for native Ara h 1, indicating that the allergenicity of Ara h 1 is heat-stable. We conclude that the allergenicity of Ara h 1 is unaffected by heating, although native Ara h 1 undergoes a significant heat-induced denaturation on a molecular level, indicating that the recognition of conformational epitopes of Ara h 1 by IgE either is not a dominant mechanism or is restricted to parts of the protein that are not sensitive to heat denaturation.

Adult↗
PubMed2003

In-house direct cELISA for determining aflatoxin B1 in Thai corn and peanuts.

To overcome the problem of aflatoxins (AF) in Thai foods, a sensitive in-house direct cELISA using monoclonal antibody (mAb) was established and compared with a commercial ELISA kit and thin-layer chromatography for the determination of AFB(1) levels in corn and peanuts. Among eight in-house mAbs (AF1-8), AF5 was used in the direct cELISA owing to its excellent specificity and sensitivity with the detection limit of 4 microg kg(-1). The recovery of AFB(1) spiked at 5, 10, 20, 40 and 80 microg kg(-1) ranged from 88.1 to 99.5%. Correlation coefficients of the ELISA with the commercial ELISA kit and thin-layer chromatography were 0.912 and 0.802 for corn, and 0.941 and 0.832 for peanuts, respectively (p<0.05). The cost per sample was estimated to be about 16 times lower than the commercial ELISA kit. Subsequently, the in-house direct cELISA was successfully applied to screen the contamination of AFB(1) in Thai corn and peanuts. Mean levels of AFB(1) (per cent positive) were 73 microg kg(-1) (85.7%) in corn and 102 microg kg(-1) (67.9%) in peanuts, for which 46.4% of both foods were above the Thailand regulation limit (20 microg kg(-1)).

Aflatoxin B1↗
PubMedDate not supplied

The preparation, validation and certification of the aflatoxin content of two peanut butter reference materials.

The preparation of two peanut butter reference materials and the certification of their aflatoxins B1, B2, G1, G2 and total aflatoxin contents is described. The materials were prepared and certified within the BCR Programme of the Commission of the European Community as part of a broad activity to improve accuracy and agreement of measurements of importance in food and agriculture (Wagstaffe and Belliardo 1990). Reference material RM 385 was prepared from naturally contaminated peanuts, roasted and ground into a paste and then blended with uncontaminated peanut butter to achieve the desired aflatoxin concentrations. Details are given of the blending and canning procedure, and the checks to ensure homogeneity and stability of the material. Reference material RM 401 was similarly prepared but from an uncontaminated peanut butter. The certification exercise was carried out by nine laboratories using a variety of extraction and clean-up procedures, but all using high performance liquid chromatography (HPLC) as the determinative stage although operating under a variety of chromatographic conditions. RM 385 was certified as containing aflatoxins B1, B2, G1 and G2 at levels of 7.0 +/- 0.8 micrograms/kg, 1.1 +/- 0.2 micrograms/kg, 1.7 +/- 0.3 micrograms/kg and 0.3 +/- 0.2 micrograms/kg respectively (total aflatoxin content of 10.1 +/- 1.5 micrograms/kg) and RM 401 as containing aflatoxin B1, B2 and G2 at less than 0.2 micrograms/kg and aflatoxin G1 at less than 0.3 micrograms/kg (total aflatoxin content less than 0.9 micrograms/kg). The materials are intended for the verification of methods used to determine aflatoxins in nuts and nut products.

Aflatoxin B1↗
PubMedDate not supplied

Aspergillus flavus-induced chitosanase in germinating corn and peanut seeds: A. flavus mechanism for growth dominance over associated fungi and concomitant aflatoxin production.

Chitosanase, a new class of enzymes with antifungal properties was induced by toxigenic Aspergillus flavus in both germinating corn and peanut seeds. The enzyme was partially purified and fractioned by SDS-Polyacrylamide Gel Electrophoresis activity and copolymerized with chitosan or glycolchitosan as substrate, then quantified by scanning densitometry and a 2-dimensional analysis software program. Chitosanase enzyme was markedly induced by toxigenic A. flavus growing in germinating corn and peanut seeds, as compared to control (water) which showed the lowest activity (almost nil in corn). However, chitosanase induction was higher in seeds treated with chitosan from crustacea. Overall, enzyme activity was higher in peanut than in corn seeds. However, electrophoresed gels from peanut treated with A. flavus or water showed more polypeptides (three and one, respectively) than gels from corn seeds, which only showed one polypeptide for both A. flavus and water treatment. The enzyme molecular weight was estimated to be between 36,000 and 45,000.

Aflatoxins↗
PubMed1998

Cadmium levels in peanut products.

Samples of peanut products such as peanut butter, raw, roasted and crushed peanuts from various commercial producers and obtained from local markets in Brisbane contained generally low levels of cadmium with mean values ranging from 0.013 to 0.031 mg/kg. These values were lower than the maximum permitted concentration for cadmium in peanuts in Australia, which is currently set at 0.05 mg/kg. Pre-digestion of samples using a microwave digestion system was found to be very effective in reducing digestion time prior to dry ashing for the analysis of cadmium.

Arachis↗