Peanut Protein Concentrate Research Articles

Angiotensin-Converting Enzyme and Renin-Inhibitory Activities of Protein Hydrolysates Produced by Alcalase Hydrolysis of Peanut Protein.

Hypertension is a major controllable risk factor associated with cardiovascular disease (CVD) and overall mortality worldwide. Most people with hypertension must take medications that are effective in blood pressure management but cause many side effects. Thus, it is important to explore safer antihypertensive alternatives to regulate blood pressure. In this study, peanut protein concentrate (PPC) was hydrolyzed with 3-5% Alcalase for 3-10 h. The in vitro angiotensin-converting enzyme (ACE) and renin-inhibitory activities of the resulting peanut protein hydrolysate (PPH) samples and their fractions of different molecular weight ranges were determined as two measures of their antihypertensive potentials. The results show that the crude PPH produced at 4% Alcalase for 6 h of hydrolysis had the highest ACE-inhibitory activity with IC50 being 5.45 mg/mL. The PPH samples produced with 3-5% Alcalase hydrolysis for 6-8 h also displayed substantial renin-inhibitory activities, which is a great advantage over the animal protein-derived bioactive peptides or hydrolysate. Remarkably higher ACE- and renin-inhibitory activities were observed in fractions smaller than 5 kDa with IC50 being 0.85 and 1.78 mg/mL. Hence, the PPH and its small molecular fraction produced under proper Alcalase hydrolysis conditions have great potential to serve as a cost-effective anti-hypertensive ingredient for blood pressure management.

Comparative Evaluation of the Antioxidant Properties of Whole Peanut Flour, Defatted Peanut Protein Meal, and Peanut Protein Concentrate

Defatted peanut meal is a low value agro-industrial residue from peanut oil production with potential use as a value addition food ingredient. In this study, peanuts were roasted at 100°C for 5 min, de-skinned and milled into whole peanut flour (WPF) from which the defatted meal (DPM) was prepared by acetone extraction and the peanut protein concentrate (PPC) obtained from the DPM using isoelectric pH precipitation. The protein content, amino acid profile, total phenolic content (TPC), total flavonoid content (TFC) and in vitro antioxidant properties of the peanut samples were then determined. Results showed that DPM had a TPC of 0.12 ± 0.02 mg gallic acid equivalent (GAE)/g, which was significantly (p < 0.05) higher than and twice the levels in WPF and PPC (0.06 ± 0.03 mg GAE/g). However, WPF had TFC of 0.21 ± 0.01 μg quercetin equivalent (QE)/g, which was significantly (p < 0.05) higher than DPM (0.16 ± 0.03 μg QE/g) and PPC (0.11 ± 0.05 μg QE/g). However, PPC had superior amino acid profile in addition to stronger radical scavenging and metal chelation activities than WPF and DPM. The results suggest that PPC is a protein rich product that could be utilized as an ingredient in food product fortification to enhance nutritional quality and in the formulation of functional foods with antioxidant benefits.

Peanuts in the Air - Clinical and Experimental Studies

To assess the prevalence of immunoglobulin E–mediated peanut allergy to airborne peanut protein and quantify the peanut protein present in the surrounding air.A total of 84 peanut-allergic children referred to an airborne peanut challenge at Sachs’ Children and Youths Hospital were included. The majority (74%) had a history of an allergic reaction to peanut; 26% had positive test results, with no reaction history.This was a retrospective case series. Children underwent an airborne challenge to either roasted peanuts or dry roasted peanuts 50 cm in distance away, with 30 minutes exposure time, followed by 1 hour observation postexposure. Patients were examined at baseline and every 10 minutes during the challenge. Electrostatic filter devices were used to collect aerosolized peanut protein and protein was detected by using the enzyme-linked immunosorbent assay. Measured amounts in air samples were used with confirmed peanut-allergic patients’ serum for basophil activation tests to assess in vitro if such miniscule amounts could trigger activation of basophils.No child in the study experienced anaphylaxis to airborne peanut allergens, and 98% revealed no signs or symptoms of peanut exposure; 2% of patients experienced mild symptoms, consistent with oral itch and rhino conjunctivitis. Peanut protein was detected in a low amount (comparable to the amount that can trigger a reaction in the 5% most sensitive patients) at 0 m distance from the bowl of peanuts. Detectable peanut protein was dramatically reduced when moving short distances (0.5 m) from the box of peanuts. Prolonging the exposure time of the filter did increase the peanut protein concentration that was detected.Severe reactions to airborne peanut protein were not observed in this study, and the majority of patients were asymptomatic. Peanut protein was confirmed in surrounding air and was also shown to be able to activate basophils in vitro at comparable concentrations. However, on the basis of the clinical data, these concentrations of proteins are not expected to lead to significant clinical reaction.Allergic reaction to airborne peanut protein is often a fear and source of anxiety for peanut-allergic patients and their parents. This study is reassuring that airborne exposure to peanut protein is low risk for occurrence of a severe reaction. These findings could be helpful when counseling patients about risks while trying to minimize unnecessary anxiety or activity restrictions.

Peanut Protein: Rich Source As Vegan Protein

Peanut is an important oilseed and defatted peanut flour is a byproduct of peanut oil milling industry with a rich source of protein. This protein can be concentrated as Peanut Protein Concentrate (PPC) and Peanut Protein Isolate (PPI) with around 80-85% and more than 90% protein, respectively.

The quest for ingested peanut protein in human serum

There is mounting evidence that systemic uptake of food allergens is key to triggering anaphylaxis. However, direct proof for this theory is still lacking. The purpose of this study was to quantify the absorption and to determine the absorption kinetics of immunoreactive peanut protein in relation to the allergic response in human. Quantitative protein assays including mass spectrometry, dot blots and Western blotting were developed to determine the level of Ara h 2 absorption in human serum. The double monoclonal sandwich ELISA was applied to quantify absorbed Ara h 2 and 6, and the basophil histamine release assay and the human passive cutaneous anaphylaxis test were utilized to study the absorption kinetics of immunologically intact peanut proteins. The protein assays worked but were not sensitive enough to trace the minute amounts of absorbed Ara h 2 in human serum. The level of Ara h 6 in serum was found to be up to 0.2ng/mL, but Ara h 2 could not be detected with the ELISA. Both the in vivo and the in vitro methods were successful in demonstrating that: immunoreactive peanut protein was absorbed shortly after ingestion (≤5minutes); the peanut protein concentration peaks between 1 and 4hours; and peanut proteins can circulate for at least 48hours in the bloodstream. Ingested peanut protein is absorbed systemically and retains its immunoreactive capacity in human serum. However, the precise quantities and the implication for the elicitation of anaphylaxis remains to be elucidated.

Substitution of peanut protein for soy protein as a non-meat binder in emulsion-type sausage production

In this study, peanut protein concentrate (PPC) was substituted for soy protein concentrate (SPC) in Vietnam emulsion-type sausage manufacture. Peanut protein concentrates yielded from the conventional and the combined ultrasonic and enzymatic extraction were used in the preparation of sausage samples PPC1 and PPC2, respectively. Soy protein concentrate was used in the sausage sample SPC as a control. Ten sausage samples including PPC1, PPC2, SPC and seven commercial samples in which soy protein (SP) was used were tested in three experiments. Instrumental Texture Profile Analysis (TPA), Flash Profile, and 9- point hedonic scale were conducted to observe sample differences. The instrumental TPA results indicated that PPC1 and PPC2 were insignificantly different from the control and one of the SP-added samples for hardness, springiness, and adhesiveness; but significantly for cohesiveness. In the first two sensory dimensions, assessors discriminated samples into three distinct directions in which PPC1 and PPC2 were positioned closely to SPC and two commercial SP-added sausages. Preference map further showed the same percentage of satisfied consumers - clustered with partial least square (PLS) regression - toward PPC1, PPC2, SPC, and the two commercial SP-added sausages. In general, the results proposed the potential use of PPC as a substitute for SP in Vietnam emulsion-type sausage production.

Quantitative risk reduction through peanut immunotherapy: Safety benefits of an increased threshold in Europe.

The clinical relevance of increasing an allergic individual's peanut sensitivity threshold by immunotherapy, that is, eliciting dose (ED) to 300 or 1000mg peanut protein, has not been previously characterized in a European population. In this study, we quantify the clinical benefits of an increased threshold of reaction following immunotherapy for the peanut-allergic individual. Quantitative risk assessments incorporated numerous inputs to predict the risk of an allergic reaction after exposure to residual peanut protein in packaged foods. The three primary inputs for the risk assessment were the peanut-allergic individual's clinical threshold value, the amount of food consumed per eating occasion of selected packaged foods, and the concentration of peanut protein in the consumed product. Individual risk reductions were calculated for both children and adolescents-adults. Using available consumption and packaged food contamination data, children reaching an ED of 300mg (if initial ED≤100mg) or 1000mg (if initial ED 300mg) achieved >99.99% risk reduction. Adolescents-adults also achieved >99.99% risk reduction in all cases but one. Adolescents-adults who reached an ED of 300mg (if initial ED≤100mg) achieved 99.3%-99.9% risk reduction when consuming ice cream. It is concluded that an increase in threshold following immunotherapy which achieves an eliciting dose of 300 or 1000mg peanut protein is clinically relevant for the European peanut-allergic population. Benefits of an increased threshold include a significant reduction in risk due to traces of peanut protein.

P333 Quantitative risk reduction through peanut immunotherapy: safety benefits of an increased threshold in Europe

Background: The clinical relevance of increasing an allergic individual's peanut sensitivity threshold by immunotherapy, that is, eliciting dose (ED) to 300 or 1000 mg peanut protein, has not been previously characterized in a European population. In this study, we quantify the clinical benefits of an increased threshold of reaction following immunothera\JVPfor the peanut-allergic individual. Methods: Quantitative risk assessments incorporated numerous inputs to predict the risk of an allergic reaction after exposure to residual peanut protein in packaged foods. The three primary inputs for the risk assessment were the peanut-allergic individual's clinical threshold value, the amount of food consumed per eating occasion of selected packaged foods, and the concentration of peanut protein in the consumed product. Individual risk reductions were calculated for both children and adolescents-adults. Results: Using available consumption and packaged food contamination data, children reaching an ED of 300 mg (if initial ED ≤ 100 mg) or 1000 mg (if initial ED 300 mg) achieved >99.99% risk reduction. Adolescents-adults also achieved >99.99% risk reduction in all cases but one. Adolescents-adults who reached an ED of 300 mg (if initial ED ≤ 100 mg) achieved 99.3%-99.9% risk reduction when consuming ice cream. Conclusions: It is concluded that an increase in threshold following immunothera\JVPwhich achieves an eliciting dose of 300 or 1000 mg peanut protein is clinically relevant for the European peanut-allergic population. Benefits of an increased threshold include a significant reduction in risk due to traces of peanut protein. © 2018 The Authors. Pediatric Allergy and Immunology Published by John Wiley & Sons Ltd

Assessing food allergy risks from residual peanut protein in highly refined vegetable oil

Refined vegetable oils including refined peanut oil are widely used in foods. Due to shared production processes, refined non-peanut vegetable oils can contain residual peanut proteins. We estimated the predicted number of allergic reactions to residual peanut proteins using probabilistic risk assessment applied to several scenarios involving food products made with vegetable oils. Variables considered were: a) the estimated production scale of refined peanut oil, b) estimated cross-contact between refined vegetable oils during production, c) the proportion of fat in representative food products and d) the peanut protein concentration in refined peanut oil.For all products examined the predicted risk of objective allergic reactions in peanut-allergic users of the food products was extremely low. The number of predicted reactions ranged depending on the model from a high of 3 per 1000 eating occasions (Weibull) to no reactions (LogNormal). Significantly, all reactions were predicted for allergen intakes well below the amounts reported for the most sensitive individual described in the clinical literature.We conclude that the health risk from cross-contact between vegetable oils and refined peanut oil is negligible. None of the food products would warrant precautionary labelling for peanut according to the VITAL® programme of the Allergen Bureau.

Risk assessment of peanut protein traces found in refined peanut oil

Highly refined peanut oil is considered to pose a risk to people with peanut allergy.[1] Although that risk has not been characterised, but controlled clinical challenges suggest it is negligible. A consequence is that the risk from cross contact between other refined vegetable oils and refined peanut oil during production must be assessed in order to assure consumer safety. Use of these refined vegetable oils in consumer food products potentially leads to very small amounts of peanut proteins in the final product. However, it is not clear yet if these amounts could reach levels that are relevant for public health. Allergen risk assessment using probabilistic techniques enables quantitative estimation of the risk after the consumption of a product that unintendedly contains an allergen. Several scenarios were defined for the unintended allergen levels in food products based on the estimated production scale of refined peanut oil in the UK, estimated figures for cross-contact and the peanut protein concentration in refined peanut oil. The consumption of 12 food products, selected for their high contribution to fat consumption including biscuits, margarine, ice cream and fried food, was combined with the peanut dose distribution. Food consumption data were derived from the National Diet and Nutrition Survey in the UK, and the Dutch National Food Consumption Survey. Peanut dosedistribution data were the same as used for the scientific review of VITAL® (Voluntary Incidental Trace Allergen Labelling).[2] We estimated that the amounts and distributions of peanut proteins posed a risk of objective allergic reactions in 0.03 to 0.6% of the peanut-allergic consumer population. The concentrations of peanut protein in selected food products would be below the limit of detection of current analytical methods and in all the scenarios examined, which included worst-case, the amounts consumed were below the VITAL reference dose for peanut. On that basis, the health risk is very small and none of those products would warrant precautionary labelling.

Thermal and Rheological Behavior of Peanut Protein Concentrate and Starch Composites

AbstractVegetable derivatives like peanut protein concentrates constitute an alternative for incorporation in starch‐based systems. In order to assess the capacity of peanut protein concentrate (PPC) to be incorporated in starch systems, the thermo‐mechanical behavior of pastes made with starches from different botanical sources (between 4.6 and 6 % w/w of corn, cassava and wheat starch), PPC (5.2–12.1 % w/w, which contributed between ~3 and ~6 % of final protein content), and sucrose (12.4–15 % w/w) was analyzed. Peanut proteins modified thermal behavior of starches as measured by the differential scanning calorimetry (DSC) technique. PPC increased the concentration of starch in the continuous phase and, consequently, the overall viscosity of the system during pasting. In addition, PPC increased the consistency of starch gels, although weaker structures were obtained. The syneresis of starch gels was reduced by PPC, which is advantageous for its incorporation in starch‐based systems.

Optimization of the protein concentration process from residual peanut oil-cake

The objective of this study was to find the best process conditions for preparing protein concentrate from residual peanut oil-cake (POC). The study was carried out on POC from industrial peanut oil extraction. Different protein extraction and precipitation conditions were used: water/ flour ratio (10:1, 20:1 and 30:1), pH (8, 9 and 10), NaCl concentration (0 and 0.5 M), extraction time (30, 60 and 120 min), temperature (25, 40 and 60 °C), extraction stages (1, 2 and 3), and precipitation pH (4, 4.5 and 5). The extraction and precipitation conditions which showed the highest protein yield were 10:1 water/flour ratio, extraction at pH 9, no NaCl, 2 extraction stages of 30 min at 40 °C and precipitation at pH 4.5. Under these conditions, the peanut protein concentrate (PC) contained 86.22% protein, while the initial POC had 38.04% . POC is an alternative source of protein that can be used for human consumption or animal nutrition. Therefore, it adds value to an industry residue.

False Positive Detection of Peanut Residue in Liquid Caramel Coloring Using Commercial ELISA Kits

Initial food industry testing in our laboratory using enzyme-linked immunosorbent assay (ELISA) methods indicated that the darkest caramel color (class IV) unexpectedly contained traces of peanut protein, a potential undeclared allergen issue. Caramel production centers on the heating of sugars, often glucose, under controlled heat and chemical processing conditions with other ingredients including ammonia, sulfite, and/or alkali salts. These ingredients should not contain any traces of peanut residue. We sought to determine the reliability of commercially available peanut allergen ELISA methods for detection of apparent peanut residue in caramel coloring. Caramel color samples of classes I, II, III, and IV were obtained from 2 commercial suppliers and tested using 6 commercially available quantitative and qualitative peanut ELISA kits. Five lots of class IV caramel color were spiked with a known concentration of peanut protein from light roasted peanut flour to assess recovery of peanut residue using a spike and recovery protocol with either 15 ppm or 100 ppm peanut protein on a kit-specific basis. A false positive detection of peanut protein was found in class IV caramel colors with a range of 1.2 to 17.6 parts per million recovered in both spiked and unspiked liquid caramel color samples. ELISA kit spike/recovery results indicate that false negative results might also be obtained if peanut contamination were ever to actually exist in class IV caramel color. Manufacturers of peanut-free products often test all ingredients for peanut allergen residues using commercial ELISA kits. ELISA methods are not reliable for the detection of peanut in class IV caramel ingredients and their use is not recommended with this matrix.

Airborne concentrations of peanut protein

Food allergy to peanut is a significant health problem, and there are reported allergic reactions to peanuts despite not eating or having physical contact with peanuts. It is presumed that an allergic reaction may have occurred from inhalation of airborne peanut allergens. The purpose of this study was to detect the possible concentrations of airborne peanut proteins for various preparations and during specific activities. Separate Ara h 1 and Ara h 2 monoclonal enzyme-linked immunosorbent assays and a polyclonal sandwich enzyme immunoassay for peanuts were used to detect the amount of airborne peanut protein collected using a Spincon Omni 3000 air collector (Sceptor Industries, Inc., Kansas City, MO) under different peanut preparation methods and situations. Air samples were measured for multiple peanut preparations and scenarios. Detectable amounts of airborne peanut protein were measured using a whole peanut immunoassay when removing the shells of roasted peanut. No airborne peanut allergen (Ara h 1 or Ara h 2) or whole peanut protein above the LLD was measured in any of the other peanut preparation collections. Ara h 1, Ara h 2, and polyclonal peanut proteins were detected from water used to boil peanuts. Small amounts of airborne peanut protein were detected in the scenario of removing shells from roasted peanuts; however, Ara h 1 and Ara h 2 proteins were unable to be consistently detected. Although airborne peanut proteins were detected, the concentration of airborne peanut protein that is necessary to elicit a clinical allergic reaction is unknown.

Optimization of extraction conditions for improving solubility of peanut protein concentrates by response surface methodology

By ethanol precipitation and physical separation procedures, the peanut protein concentrate (PPC) was isolated from defatted peanut flour (DPF) and the extraction times were determined as twice. The effects of liquid-to-solid ratio, ethanol concentration and reaction temperature on the solubility of PPC were studied for the primary extraction and the later two factors were studied for the second extraction by response surface methodology (RSM). The results showed that for both of the second-order models, the coefficient determination ( R 2) was good and a liquid-to-solid ratio of 11.79: 1 (v/w), an ethanol concentration of 85 mL/100 mL, an extract temperature of 36.35 °C for the primary extraction and a corresponding list of variables of 8:1 (v/w), 97.50 mL/100 mL and 38.40 °C for the secondary extraction were found to be optimal for the protein extraction from defatted peanut flour. By means of additional experiments, the adequacy of the model was confirmed.

Nanopore immunosensor for peanut protein Ara h1

A nanopore immunosensor is demonstrated for peanut protein Ara h1, a common food allergen. This biosensor is constructed by immobilizing the antibody to peanut protein Ara h1 within Au-coated pores of commercial nanoporous polycarbonate membranes. Peanut protein Ara h1 is detected as the change in the pore conductivity as the pores are partially obscured by antigen binding. Control experiments with the antibody to cockroach protein Bla g1 demonstrate that the observed effects do not arise from non-specific adsorption. Binding of peanut protein is studied as a function of the pore diameter (15, 30 and 50 nm), and as a function of the concentration of peanut protein. The results show the greatest sensitivity for membranes with the smallest pore diameter, and exhibit mass transfer effects for membranes with larger pore diameters. Approximate calculations of diffusion times for transport of peanut protein Ara h1 through these nanoporous membranes suggest that mass transport effects should not be observed. This discrepancy between experimental observations of mass transfer effects and model predictions suggest that diffusion of peanut protein Ara h1 is anomalously slow in this system.

Peanut Allergen Exposure Through Saliva: Assessment and Interventions to Reduce Exposure

Maloney JM, Chapman MD, Sicherer SH. J Allergy Clin Immunol. 2006;118:719–724 PURPOSE OF THE STUDY. To determine the time course of major peanut allergen (Arah1) persistence in saliva after ingestion of peanut butter and to evaluate mouth-cleansing interventions to reduce salivary peanut allergen. STUDY POPULATION. A convenient sample of adults without peanut allergy. METHODS. Thirty-eight individuals ingested 2 tablespoons of peanut butter, and saliva was collected at various time points. At another time, samples were collected after 5 interventions (brushing teeth, brushing and rinsing, rinsing, waiting then brushing, waiting then chewing gum). Detection of Arah1 was performed by a monoclonal-based enzyme-linked immunosorbent assay (detection limit: 15–20 ng/mL). RESULTS. Salivary peanut allergen Arah1 varied considerably immediately after ingestion but included levels expected to invoke reactions (as much as 40 μg/mL). Most (87%) subjects with detectable peanut after a meal had undetectable levels by 1 hour with no interventions. None had detectable levels several hours later after a peanut-free lunch. This result indicates (with 95% confidence) that 90% would have undetectable Arah1 in saliva under these circumstances. All of the immediate interventions reduced salivary Arah1, in some cases by >95%, but Arah1 remained detectable in ∼40% of the samples (although typically below thresholds reported to induce reactions). CONCLUSIONS. Patients with peanut allergy require counseling regarding the risks of kissing or sharing utensils, even if their partners have brushed their teeth or chewed gum. Advice to reduce risks, although not as ideal as total avoidance, includes waiting a few hours plus eating a peanut-free meal. REVIEWER COMMENTS. Passionate kissing was reported to cause allergic reactions to foods, including anaphylaxis. Waiting several hours and ingesting a peanut-free meal were more effective at reducing salivary peanut protein concentration than simple, immediate interventions. Teenagers with peanut and other food allergies need to be reminded that to stay safe, restraint and patience are necessary even in the most intimate situations.

Peanut protein concentrate: Production and functional properties as affected by processing

Peanut protein concentrate (PPC) was isolated from fermented and unfermented defatted peanut flour by isoelectric precipitation and physical separation procedures. PPC was dried by spray or vacuum drying. PPC powders from each drying technique were evaluated for proximate composition and functional properties (protein solubility, water/oil binding capacity, emulsifying capacity, foaming capacity and viscosity) along with defatted peanut flour and soy protein isolate as references. PPC contained over 85% protein versus 50% protein in the defatted peanut flour used as raw material for PPC production. PPC had a solubility profile similar to that of peanut flour, with minimum solubility observed at pH 3.5–4.5 and maximum solubility at pH 10 and higher. Roasting of peanut reduced all functional properties of defatted peanut flour while fermentation had the reverse effect. The type of drying significantly affected the functional properties of PPC. Spray dried PPCs exhibited better functional properties, particularly emulsifying capacity and foaming capacity, than vacuum oven dried PPC. Spray dried PPCs also showed comparable oil binding and foaming capacity to commercially available soy protein isolate (SPC). At equivalent concentrations and room temperature, PPC suspension exhibited lower viscosity than soy protein isolate (SPI) suspensions. However, upon heating to 90 °C for 30 min, the viscosity of PPC suspension increased sharply. Results obtained from this study suggest that the PPC could be used in food formulations requiring high emulsifying capacity, but would not be suitable for applications requiring high water retention and foaming capacity. PPC could be a good source of protein fortification for a variety of food products for protein deficient consumers in developing countries as well as a functional ingredient for the peanut industry. The production of PPC could also add value to defatted peanut flour, a low value by-product of peanut oil production.

Peanut allergen exposure through saliva: Assessment and interventions to reduce exposure

Exposure to food allergens through saliva (kissing, utensils) can cause local and systemic allergic reactions. To determine the time course of peanut allergen (Ara h 1) persistence in saliva after ingestion of peanut butter and to evaluate mouth cleansing interventions to reduce salivary peanut allergen. Thirty-eight individuals ingested 2 tablespoons of peanut butter, and saliva was collected at various time points. At another time, samples were collected after 5 interventions (brushing teeth, brushing and rinsing, rinsing, waiting then brushing, waiting then chewing gum). Detection of Ara h 1 was performed by a monoclonal-based ELISA (detection limit, 15-20 ng/mL). Salivary Ara h 1 varied considerably immediately after ingestion, but included levels expected to invoke reactions (as much as 40 microg/mL). Most (87%) subjects with detectable peanut after a meal had undetectable levels by 1 hour with no interventions. None had detectable levels several hours later after a peanut-free lunch. This result indicates (95% confidence) that 90% would have undetectable Ara h 1 in saliva under these circumstances. All of the interventions reduced salivary Ara h 1, in some cases by >95%, but Ara h 1 remained detectable in approximately 40% of samples (though typically below thresholds reported to induce reactions). Patients with peanut allergy require counseling regarding risks of kissing or sharing utensils, even if partners have brushed teeth or chewed gum. Advice to reduce risks, though not as ideal as total avoidance, includes waiting a few hours plus eating a peanut-free meal. Waiting several hours and ingesting a peanut-free meal were more effective at reducing salivary peanut protein concentration than simple, immediate interventions.

Detection of peanut allergens in breast milk of lactating women.

Most individuals who react to peanuts do so on their first known exposure. A potential but unproven route of occult exposure resulting in sensitization to peanut is via breast milk during lactation. To investigate the ability of maternal dietary peanut protein to pass into breast milk during lactation. Clinical investigation conducted at 2 North American hospitals from March 1999 to October 2000. Twenty-three healthy, lactating women aged 21 to 35 years. Each woman consumed 50 g of dry roasted peanuts, after which breast milk samples were collected at hourly intervals. Presence in breast milk of total peanut protein, analyzed by a sandwich enzyme-linked immunosorbent assay, and 2 major peanut allergens, Ara h 1 and Ara h 2, detected by immunoblot analysis. Peanut protein was detected in 11 of 23 subjects. It was detected in 10 subjects within 2 hours of ingestion and in 1 subject within 6 hours. The median peak peanut protein concentration in breast milk was 200 ng/mL (mean, 222 ng/mL; range, 120-430 ng/mL). Both major peanut allergens Ara h 1 and Ara h 2 were detected. Peanut protein is secreted into breast milk of lactating women following maternal dietary ingestion. Exposure to peanut protein during breastfeeding is a route of occult exposure that may result in sensitization of at-risk infants.