The Experts below are selected from a list of 1419 Experts worldwide ranked by ideXlab platform
Larry R Beuchat - One of the best experts on this subject based on the ideXlab platform.
-
modelling the effects of Peanut Flour feed moisture content and extrusion temperature on physical properties of an extruded snack product
International Journal of Food Science and Technology, 2007Co-Authors: Witoon Prinyawiwatkul, Larry R Beuchat, Dixon R Phillips, Anna V. A. ResurreccionAbstract:Summary A mixture experimental design was used to evaluate the combined effects of non-fermented (PDPF) and fermented (F-PDPF) Peanut Flours, added feed moisture content, and extrusion temperature on physical properties of extruded cornstarch-Peanut Flour-based snacks. Moisture content, expansion ratio, bulk density, modified Kramer compression-shear force and colour of extrudates were significantly affected by the amount of PDPF and F-PDPF in the formulation. Oil absorption by extrudates was only influenced by the type of Peanut Flour. Within the range of (per 1-kg batch) 0.30–0.34 g g−1 added water, 0.16–0.20 g g−1 PDPF and/or F-PDPF, and extrusion temperatures of 125 to 150°C, extrudates with a wide range of functional characteristics can be produced.
-
modelling the effect of Peanut and cowpea Flour supplementation on quality of chinese type noodles
International Journal of Food Science and Technology, 2007Co-Authors: Penkwan Chompreeda, Anna V. A. Resurreccion, Y C Hung, Larry R BeuchatAbstract:Summary Chinese-type noodles were prepared from wheat Flour fortified with 7–21% defatted Peanut and 4–12% cowpea Flours. A full factorial 4X4 design was used. Fifteen supplemented Chinese-type noodle formulae and a control sample were analysed for protein content and physical and sensory qualities. The protein content of noodles was increased as the level of Peanut/cowpea Flours increased. Colour and cutting force of supplemented noodles were affected negatively by cowpea and Peanut Flours, respectively. Sensory scores for firmness and yellowness of supplemented Chinese-type noodles were decreased as the level of Peanut/cowpea Flours increased. Computer-generated response surface and contour plot interpretations revealed that up to 15% Peanut Flour and 8% cowpea Flour supplementation will produce acceptable supplemented Chinese noodles with high protein content (21%).
-
characteristics of acid hydrolysate from defatted Peanut Flour
Journal of Food Science, 1995Co-Authors: Rudeepan Waltanapat, Tommy Nakayama, Larry R BeuchatAbstract:We hypothesized that aflatoxin-contaminated defatted Peanut Flour could be acid hydrolyzed to produce an aflatoxin-free seasoning sauce. Physical and chemical properties and amino acid composition of the Flour hydrolyzed at 120°C for 4 hr with 5N HCI and destruction of aflatoxin B 1 during hydrolysis were investigated. The pH (5.72), specific gravity (1.20), total solids (402 mg mL -1 ), and reducing sugar (2.9 mg mL -1 ) and total nitrogen (17.5 mg mL -1 ) contents of the Peanut hydrolysate were similar to those of commercial soy sauces or seasoning sauces made by chemical processes. Glutamic acid, aspartic acid, arginine and glycine were the major amino acids in the hydrolysate and should contribute substantially to enhancing flavor. Aflatoxin B 1 was totally destroyed during acid hydrolysis at 100 or 120°C.
-
physical properties of cowpea paste and akara as affected by supplementation with Peanut Flour
Journal of Agricultural and Food Chemistry, 1994Co-Authors: Witoon Prinyawiwatkul, K H Mcwatters, Larry R Beuchat, Dixon R PhillipsAbstract:Changes in the physical properties of cowpea paste and akara as influenced by the addition of partially defatted nonfermented (PDPF) and fermented (FPDPF) Peanut Flour were investigated. PDPF and FPDPF decreased the water absorption capacity of cowpea meal and increased the specific gravity and lowered the volume of whipped pastes. The apparent viscosity of pastes was influenced by increasing levels of Peanut Flour, increasing with PDPF and decreasing with FPDPF. The external color L * and b * values of akara containing only cowpea meal were higher than those of akara containing Peanut Flour. Akara containing PDPF (50%) and FPDPF (12.5 and 25.0%) required more force and energy to shear-compress than unsupplemented akara. Increased protein and decreased oil content were observed in akara containing Peanut Flour
-
kinetics of acid hydrolysis of defatted Peanut Flour
Journal of Food Science, 1994Co-Authors: Rudeepan Waltanapat, Larry R Beuchat, Tommy Nakayama, Dixon R PhillipsAbstract:The kinetics of hydrolysis of defatted Peanut Flour as affected by treatment at 100, 110 and 120°C in 3N and 5N HCl were determined. Rates of hydrolysis of protein and destruction of reducing sugars were rapid at 120°C and in 5N HCl. About 90% of total amino acids were released after 4 hr. The overall rate of reaction followed second-order kinetics as monitored by the generation of free amino acids over time. This relationship was reliable for all acid and temperature treatment conditions when the extent of hydrolysis was less than 80%. The rate of hydrolysis of Peanut protein was about 2.2 times faster for every 10°C increase. Hydrolysis in 3N HCl was about 2.3 times faster than in 3N HCl at the same temperature. The activation energy was =24 kcal mol−1. The rate of liberation of individual amino acids with respect to temperature and HCl concentration, however, varied.
Michael D. Kulis - One of the best experts on this subject based on the ideXlab platform.
-
Specific allergen profiles of Peanut foods and diagnostic or therapeutic allergenic products
The Journal of Allergy and Clinical Immunology, 2017Co-Authors: Stephanie Filep, Denise Block, Bryan R.e. Smith, Eva M. King, Scott P. Commins, Michael D. Kulis, Brian P. Vickery, Martin D. ChapmanAbstract:Background Generic immunoassays for Peanut cannot discriminate between allergen levels in Peanut-derived food products or therapeutics. Clinical trials of oral immunotherapy (OIT) are strengthened by using standardized Peanut preparations with defined doses of major allergens. Objective This article describes measurement of Ara h 1, Ara h 2, and Ara h 6 in Peanut foods and in Peanut Flour extracts used for allergy diagnosis and OIT. Methods Monoclonal antibody–based enzyme immunoassays for Ara h 1, Ara h 2, and Ara h 6 were used to compare allergen levels in Peanut (n = 16) and tree nut (n = 16) butter, Peanut Flour (n = 11), oils (n = 8), extracts used for diagnosis and OIT (n = 5), and the National Institute for Standards and Technology Peanut Butter Standard Reference Material 2387. Results Roasted Peanut butters contained 991 to 21,406 μg/g Ara h 1 and exceeded Ara h 2 and Ara h 6 levels by 2- to 4-fold. Similarly, National Institute for Standards and Technology Peanut Butter Standard Reference Material 2387 contained 11,275 μg/g Ara h 1, 2,522 μg/g Ara h 2, and 2,036 μg/g Ara h 6. In contrast, Peanut Flours contained 787 to 14,631 μg/g Ara h 2 and exceeded Ara h 1 levels by 2- to 20-fold. Flour extracts used for OIT contained 394 to 505 μg/mL Ara h 1, 1,187 to 5,270 μg/mL Ara h 2, and 1,104 to 8,092 μg/mL Ara h 6. In most cases specific Peanut allergens were not detected in tree nut butters or Peanut oils. Conclusions The results show marked differences in specific Peanut allergen profiles in Peanut butter and Flour and Peanut preparations for clinical use. Roasting can increase Ara h 1 levels in Peanut butter. Variability in allergen levels could affect the outcome of clinical trials of Peanut OIT, especially with respect to Ara h 1. Specific allergen measurements will improve standardization and provide accurate dosing of Peanut preparations that are being used for OIT.
-
Preparation and Analysis of Peanut Flour Used in Oral Immunotherapy Clinical Trials
The journal of allergy and clinical immunology. In practice, 2017Co-Authors: Jelena P. Berglund, A. Wesley Burks, Nicole Szczepanski, Anusha Penumarti, Ayeshia Beavers, Janelle Kesselring, Kelly Orgel, Bruce K. Burnett, Michael D. KulisAbstract:Background Oral immunotherapy (OIT) is an investigational therapeutic approach for the treatment of food allergies. Characterization of the drug product used in oral immunotherapy trials for Peanut allergy has not been reported. Objective To quantify relative amounts of the major Peanut allergens and microbial load present in Peanut Flour used in OIT trials and assess whether these parameters change over a 12-month period. We also anticipate that this report will serve as a guide for investigators seeking to conduct OIT trials under Food and Drug Administration–approved Investigational New Drug applications. Methods Densitometric scanning of Ara h 1 and Ara h 2 resolved on SDS-PAGE gels was used to assess allergen content in Peanut Flour extracts. Microbial testing was conducted on Peanut Flour under US Pharmacopeia guidelines for the presence of Escherichia coli , salmonella, yeast, mold, and total aerobic bacteria. In addition, aflatoxin was quantified in Peanut Flour. Reported results were obtained from 4 unique lots of Peanut Flour. Results Relative amounts of the major Peanut allergens were similar between different lots of Peanut Flour and remained stable over a 12-month period. E coli and salmonella were absent from all lots of Flour. Yeast, mold, total aerobic bacteria, and aflatoxin were within established US Pharmacopeia guidelines on all lots tested and remained within the criteria over a 12-month period. Conclusions Peanut Flour used as a drug product contains the major Peanut allergens and has low levels of potentially harmful microbes. Both these parameters remain stable over a 12-month period.
-
allergenic properties of enzymatically hydrolyzed Peanut Flour extracts
International Archives of Allergy and Immunology, 2013Co-Authors: Xiaolei Shi, Brittany L White, Jack P Davis, Rishu Guo, Wesley A Burks, Adrienne Yancey, Timothy H Sanders, Michael D. KulisAbstract:Background: Peanut Flour is a high-protein, low-oil, powdered material prepared from roasted Peanut seed. In addition to being a well-established food ingredient,
R D Phillips - One of the best experts on this subject based on the ideXlab platform.
-
purification activity and sequence of angiotensin i converting enzyme inhibitory peptide from alcalase hydrolysate of Peanut Flour
Journal of Agricultural and Food Chemistry, 2009Co-Authors: Cuie Guang, R D PhillipsAbstract:Peanut hydrolysate obtained after 6 h of digestion by Alcalase was used to isolate angiotensin I converting enzyme (ACE) inhibitory peptides. After centrifugation and ultrafiltration through a 0.2 microm nylon filter, the hydrolysate was filtered through the polyethersulfone membrane with a molecular weight cutoff (MWCO) of 10 kDa. The resulting permeate was then separated by primary reverse-phase high performance liquid chromatography (RP-HPLC). Eluate was divided into six major fractions according to eluation time. The fraction with eluting time 50-60 min showed the most potent ACE inhibition and was subjected to further purification by the secondary RP-HPLC. Four peaks were found to have strong ACE inhibitory activities, and their IC(50) values were determined. Peptide mass for the most potent peak was obtained by matrix-assisted laser desorption and ionization (MALDI), and sequence was determined by MALDI tandem TOF-TOF (time-of-flight) mass spectrometer (MS/MS) to be Lys-Ala-Phe-Arg.
-
Consumer-based optimization of a third-generation product made from Peanut and rice Flour
Journal of Food Science, 2007Co-Authors: I. D. Choi, R D Phillips, Anna V. A. ResurreccionAbstract:Indirectly puffed snacks were produced by an extrusion process with partially defatted (12% fat) Peanut Flour (30%, 40%, 50%) at different levels of screw speed (200, 300, 400 rpm) and feed rate (4, 5, 6 kg/h). Extrudates were dried to obtain half-products (11% to 12% MC) followed by puffing with deep-fat frying. The puffed snack prototypes were subjected to consumer acceptance test. Consumers rated higher than 6.0 (= like slightly) for all products produced within the experimental factor ranges on the attributes of crispness and texture, whereas consumer scores for appearance, color, flavor, and overall liking were lower than 6.0 for the product containing 50% Peanut Flour regardless of screw speed and feed rate. The product extruded with 50% Peanut Flour at screw speed of 400 rpm and feed rate of 6 kg/h received the lowest score of 5.5 on overall liking in a 9-point hedonic score. Predicted regression models indicated that feed rate had the largest effect on consumer attributes followed by Peanut Flour and screw speed. From the superimposed contour plot of individual contour plot of consumer attributes, the optimum region was identified as the area beginning at the 42.0% to 43.0% Peanut Flour and 4.0 kg/h feed rates, rising to a maximum at 45% Peanut Flour and 4.6 kg/h feed rates and decreasing to the 33.0% to 34.0% Peanut Flour and 6.0 kg/h feed rates. Verification confirmed the ability of predictive regression models to identify Peanut-based snacks, which would be scored higher than 6.0 by consumer evaluation.
-
effects of twin screw extrusion of Peanut Flour on in vitro digestion of potentially allergenic Peanut proteins
Journal of Food Protection, 2005Co-Authors: L Chen, R D PhillipsAbstract:Partially defatted Peanut Flour was processed in a twin-screw extruder. Resulting extrudates were dried, ground, and incubated with simulated gastric fluid for various time periods. Soluble protein content of the resulting digesta was measured after 10% trichloroacetic acid treatment to evaluate the digestibility. In vitro digestion using pepsin increased the solubility of Peanut protein in 10% trichloroacetic acid solution from 2 to 6% to 65 to 75%. Four strong IgE-binding subunits (65, 22, 17, and 14 kDa) were found with immunoblotting in Peanut proteins extracted from unextruded Peanut Flour; no IgE-binding bands were observed in extrudates. The 65-kDa (putative Ara h 1) subunit was insolubilized during extrusion, and its IgE-binding property was susceptible to in vitro digestion. Following extrusion cooking, no IgE-binding bands were detected by immunoblotting, including the strongly IgE-binding 14-kDa fraction, a strong IgE-binding band from native Peanut protein that is stable in pepsin. The 22- and 17-kDa (putative Ara h 2) subunits retained a small amount of IgE-binding potential and became susceptible to pepsin hydrolysis after extrusion.
-
cellular structure of Peanut based extruded snack products using scanning electron microscopy
Journal of Texture Studies, 2004Co-Authors: I. D. Choi, R D Phillips, H S JeongAbstract:A mixture of partially defatted Peanut Flour (12% fat) and rice Flour was extruded to produce indirectly, puffed extrudates using a corotating twin-screw extruder. Extrudates were dried to obtain half-products of 11-12% moisture content, and the half-products were expanded by deep-fat frying. The effects of three levels of Peanut Flour (30, 40, and 50%), screw speed (200, 300, and 400 rpm) and feed rate (4, 5, and 6 kg/h) were studied by characterizing the cellular structure of expanded snack products using Scanning Electron Microscopy (SEM). Average cell size (mm 2 ) and the number of cells per unit area (cm 2 ) were determined from the interior cross-section area of snack products. Those parameters were influenced mainly by the level of Peanut Flour followed by screw speed and feed rate. Increasing Peanut Flour from 40 to 50% produced less puffed final products resulting in small cell size compared to snacks of 30 - 40% Peanut Flour. The maximum cell size was produced in the snack products extruded with Peanut Flour of 30 - 40% at screw speed of 250 - 330 rpm and feed rate of 4.7 - 5.7 kg/h. While the number of cells was relatively similar regardless of screw speed and feed rate, increasing Peanut Flour increased the number of cells. The cell walls became thicker with increasing feed rate.
-
physical properties of directly expanded extrudates formulated from partially defatted Peanut Flour and different types of starch
Food Research International, 1997Co-Authors: K Suknark, R D Phillips, Manjeet S ChinnanAbstract:Abstract Blends of tapioca, corn, Cereal Crisp® or Crisp Film® starch and partially defatted (10% fat) Peanut Flour (PDPF) with starch-to-PDPF at different ratios were extruded at 18, 20, and 22% moisture content [wet basis (wb)]to form directly puffed products. The extrudates were analyzed for their physical and chemical properties. The optimum conditions were determined using response surface methodology (RSM). The conditions which provided high expansion, low bulk density, and low shear strength of tapioca, corn, and Cereal Crisp® starch were 20–30% PDPF at 18–19% moisture content, 5–30% PDPF at 18–19% moisture content, and 10–35% PDPF at 18–22% moisture content, respectively. Crisp Film® combined with ≥30% PDPF did not expand except at 30% PDPF and 20% moisture content. Regardless of PDPF content, as amylose content of starch increased, the expansion ratio increased.
Mary Ann Lila - One of the best experts on this subject based on the ideXlab platform.
-
Peanut protein polyphenol aggregate complexation suppresses allergic sensitization to Peanut by reducing Peanut specific ige in c3h hej mice
Food Chemistry, 2019Co-Authors: Rishipal R Bansode, Mary Ann Lila, Nathalie J Plundrich, Priscilla Randolph, Leonard L WilliamsAbstract:Peanut allergy is usually lifelong and accidental exposure impose formidable risk. The aim of this study was to assess the capacity of Peanut proteins complexed to polyphenol extracts to reduce allergic response in C3H/HeJ mice. Mice were sensitized to Peanut Flour followed by exposure to amino acid diets fortified with Peanut protein-polyphenol aggregates of either with low (15%; w/w) or high (40%; w/w) complexation ratios of blueberry (BB-Low and BB-High) and cranberry (CB-Low and CB-High) extracts. Treatment groups on diets with high complexation ratios of blueberry and cranberry aggregates showed significant reduction in Peanut specific plasma Immunoglobulin E (IgE). Western blot analysis of spleen lysates showed CD63 protein expression was reduced in a dose-dependent manner in blueberry and cranberry complexed Peanut protein supplemented diet groups. Our results demonstrate for the first time that complexation of polyphenols to Peanut Flour can potentially lower plasma IgE of Peanut-sensitized C3H/HeJ mice.
-
novel value added uses for sweet potato juice and Flour in polyphenol and protein enriched functional food ingredients
Food Science and Nutrition, 2015Co-Authors: Mary H Grace, Ilya Raskin, An N Truong, Vanden Truong, Mary Ann LilaAbstract:Blackcurrant, blueberry, and muscadine grape juices were efficiently sorbed, concentrated, and stabilized into dry granular ingredient matrices which combined anti-inflammatory and antioxidant fruit polyphenols with sweet potato functional constituents (carotenoids, vitamins, polyphenols, fibers). Total phenolics were highest in blackcurrant-orange sweet potato ingredient matrices (34.03 mg/g), and lowest in muscadine grape-yellow sweet potato matrices (10.56 mg/g). Similarly, anthocyanins were most concentrated in blackcurrant-fortified orange and yellow sweet potato matrices (5.40 and 6.54 mg/g, respectively). Alternatively, other protein-rich edible matrices (defatted soy Flour, light roasted Peanut Flour, and rice protein concentrate) efficiently captured polyphenols (6.09–9.46 mg/g) and anthocyanins (0.77–1.27 mg/g) from purple-fleshed sweet potato juice, with comparable efficiency. Antioxidant activity correlated well with total phenolic content. All formulated ingredient matrices stabilized and preserved polyphenols for up to 24 weeks, even when stored at 37°C. Complexation with juice-derived polyphenols did not significantly alter protein or carbohydrate profiles of the matrices. Sensory evaluation of the ingredient matrices suggested potential uses for a wide range of functional food products.
-
stability and immunogenicity of hypoallergenic Peanut protein polyphenol complexes during in vitro pepsin digestion
Food & Function, 2015Co-Authors: Nathalie J Plundrich, Brittany L White, Lisa L Dean, Jack P Davis, Allen E Foegeding, Mary Ann LilaAbstract:Allergenic Peanut proteins are relatively resistant to digestion, and if digested, metabolized peptides tend to remain large and immunoreactive, triggering allergic reactions in sensitive individuals. In this study, the stability of hypoallergenic Peanut protein–polyphenol complexes was evaluated during simulated in vitro gastric digestion. When digested with pepsin, the basic subunit of the Peanut allergen Ara h 3 was more rapidly hydrolyzed in Peanut protein–cranberry or green tea polyphenol complexes compared to uncomplexed Peanut Flour. Ara h 2 was also hydrolyzed more quickly in the Peanut protein–cranberry polyphenol complex than in uncomplexed Peanut Flour. Peptides from Peanut protein–cranberry polyphenol complexes and Peanut protein–green tea polyphenol complexes were substantially less immunoreactive (based on their capacity to bind to Peanut-specific IgE from patient plasma) compared to peptides from uncomplexed Peanut Flour. These results suggest that Peanut protein–polyphenol complexes may be less immunoreactive passing through the digestive tract in vivo, contributing to their attenuated allergenicity.
-
novel strategy to create hypoallergenic Peanut protein polyphenol edible matrices for oral immunotherapy
Journal of Agricultural and Food Chemistry, 2014Co-Authors: Nathalie J Plundrich, Mary H Grace, Brittany L White, Jack P Davis, M Kulis, Rishu Guo, Wesley A Burks, Mary Ann LilaAbstract:Peanut allergy is an IgE-mediated hypersensitivity. Upon Peanut consumption by an allergic individual, epitopes on Peanut proteins bind and cross-link Peanut-specific IgE on mast cell and basophil surfaces triggering the cells to release inflammatory mediators responsible for allergic reactions. Polyphenolic phytochemicals have high affinity to bind proteins and form soluble and insoluble complexes with unique functionality. This study investigated the allergenicity of polyphenol-fortified Peanut matrices prepared by complexing various polyphenol-rich plant juices and extracts with Peanut Flour. Polyphenol-fortified Peanut matrices reduced IgE binding to one or more Peanut allergens (Ara h 1, Ara h 2, Ara h 3, and Ara h 6). Attenuated total reflectance−Fourier transform infrared spectroscopy (ATR-FTIR) suggested changes in secondary protein structure. Peanut protein–cranberry polyphenol fortified matrices triggered significantly less basophil degranulation than unmodified Flour in an ex vivo assay using h...
-
stable binding of alternative protein enriched food matrices with concentrated cranberry bioflavonoids for functional food applications
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Mary H Grace, Ivette Guzman, Diana E Roopchand, Kristin Moskal, Diana M Cheng, Natasha Pogrebnyak, Ilya Raskin, Amy B Howell, Mary Ann LilaAbstract:Defatted soy Flour (DSF), soy protein isolate (SPI), hemp protein isolate (HPI), medium-roast Peanut Flour (MPF), and pea protein isolate (PPI) stably bind and concentrate cranberry (CB) polyphenols, creating protein/polyphenol-enriched matrices. Proanthocyanidins (PAC) in the enriched matrices ranged from 20.75 mg/g (CB-HPI) to 10.68 mg/g (CB-SPI). Anthocyanins (ANC) ranged from 3.19 mg/g (CB-DSF) to 1.68 mg/g (CB-SPI), whereas total phenolics (TP) ranged from 37.61 mg/g (CB-HPI) to 21.29 mg/g (CB-SPI). LC-MS indicated that the enriched matrices contained all identifiable ANC, PAC, and flavonols present in CB juice. Complexation with SPI stabilized and preserved the integrity of the CB polyphenolic components for at least 15 weeks at 37 °C. PAC isolated from enriched matrices demonstrated comparable antiadhesion bioactivity to PAC isolated directly from CB juice (MIC 0.4–0.16 mg/mL), indicating their potential utility for maintenance of urinary tract health. Approximately 1.0 g of polyphenol-enriched mat...
Steve L Taylor - One of the best experts on this subject based on the ideXlab platform.
-
comparison of recovery and immunochemical detection of Peanut proteins from differentially roasted Peanut Flour using elisa
Food Chemistry, 2019Co-Authors: Shyamali Jayasena, Steve L Taylor, Stef J Koppelman, Balunkeswar Nayak, Joseph L. BaumertAbstract:The effect of heat on extractability and immunoreactivity of proteins from roasted Peanut Flours and whole Peanuts was evaluated using two general protein assays and six commercial Peanut ELISA kits, respectively. The highest amount of protein was recovered from roasted Peanuts with all ELISAs, while recovery showed a decrease with increasing levels of roasting of the Peanut Flours. Only the Morinaga kit showed sufficient sensitivity to detect Peanut at low concentrations of the dark roast Peanut Flours. Both the protein and immunoassays indicated a decrease in protein solubility with roasting. The underestimation by immunoassays is a combination of decreased solubility and heat induced changes in the proteins that are being targeted by the ELISA antibodies. These findings suggest that most commercial ELISA kits may not reliably quantify Peanut present in dark roast Peanut Flours at ≤25 ppm.
-
Release of Major Peanut Allergens from Their Matrix under Various pH and Simulated Saliva Conditions-Ara h2 and Ara h6 Are Readily Bio-Accessible
Nutrients, 2018Co-Authors: Stef J Koppelman, Steve L Taylor, Govardus A.h. De Jong, Mieke Smits, Monic M. M. Tomassen, Joseph L. Baumert, Renger F. Witkamp, Robert Jan Veldman, Raymond Pieters, Harry J. WichersAbstract:The oral mucosa is the first immune tissue that encounters allergens upon ingestion of food. We hypothesized that the bio-accessibility of allergens at this stage may be a key determinant for sensitization. Light roasted Peanut Flour was suspended at various pH in buffers mimicking saliva. Protein concentrations and allergens profiles were determined in the supernatants. Peanut protein solubility was poor in the pH range between 3 and 6, while at a low pH (1.5) and at moderately high pHs (>8), it increased. In the pH range of saliva, between 6.5 and 8.5, the allergens Ara h2 and Ara h6 were readily released, whereas Ara h1 and Ara h3 were poorly released. Increasing the pH from 6.5 to 8.5 slightly increased the release of Ara h1 and Ara h3, but the recovery remained low (approximately 20%) compared to that of Ara h2 and Ara h6 (approximately 100% and 65%, respectively). This remarkable difference in the extraction kinetics suggests that Ara h2 and Ara h6 are the first allergens an individual is exposed to upon ingestion of Peanut-containing food. We conclude that the Peanut allergens Ara h2 and Ara h6 are quickly bio-accessible in the mouth, potentially explaining their extraordinary allergenicity.
-
an evaluation of the sensitivity of subjects with Peanut allergy to very low doses of Peanut protein a randomized double blind placebo controlled food challenge study
The Journal of Allergy and Clinical Immunology, 1997Co-Authors: Jonathan Ob Hourihane, Sally Kilburn, Julie A Nordlee, Susan L Hefle, Steve L Taylor, J O WarnerAbstract:Abstract Background: The minimum dose of food protein to which subjects with food allergy have reacted in double-blind, placebo-controlled food challenges is between 50 and 100 mg. However, subjects with Peanut allergy often report severe reactions after minimal contact with Peanuts, even through intact skin. Objective: We sought to determine whether adults previously proven by challenge to be allergic to Peanut react to very low doses of Peanut protein. Methods: We used a randomized, double-blind, placebo-controlled food challenge of 14 subjects allergic to Peanuts with doses of Peanut ranging from 10 μg to 50 mg, administered in the form of a commercially available Peanut Flour. Results: One subject had a systemic reaction to 5 mg of Peanut protein, and two subjects had mild objective reactions to 2 mg and 50 mg of Peanut protein, respectively. Five subjects had mild subjective reactions (1 to 5 mg and 4 to 50 mg). All subjects with convincing objective reactions had short-lived subjective reactions to preceding doses, as low as 100 μg in two cases. Five subjects did not react to any dose up to 50 mg. Conclusion: Even in a group of well-characterized, highly sensitive subjects with Peanut allergy, the threshold dose of Peanut protein varies. As little as 100 μg of Peanut protein provokes symptoms in some subjects with Peanut allergy. (J Allergy Clin Immunol 1997;100:596-600.)