ABSTRACT
The allergenic and toxicological acceptances of the bio-elicited peanut sprout powder (BPSP) have not been assessed. BPSP was generated from peanut kernels germinated at 26-28 °C for 72 h (designated as 72 h-NGS). The 72 h-NGS were subsequently sliced, incubated, dried, defatted and pulverized to generate bio-elicited peanut sprout powder (BPSP). Protein solubility of BPSP increased 2.6-fold compared to 72 h-NGS. SDS-PAGE analysis revealed BPSP production triggered extensive degradation of the high-molecular weight peanut allergic proteins, mainly Ara h 1 and Ara h 3. Western blotting detected with peanut allergic patients' IgE indicated decreased in vitro reactivity. Food safety assessment of BPSP was performed with ICR mice fed with basal (control) and three doses of formulated BPSP-supplemented diets containing 0.11 g (normal), 2.5 g (high) and 25 g (super high) BPSP /kg BW. Animals appeared healthy with steady body weight gain in all groups during the entire 35-day dietary intervention. Hematological and serum biochemical analyses revealed no significant difference among groups. Histopathological examination on the tissue sections of primary organs further supported safety with no pathologies. The in vitro allergic reduction and toxicological safety in the BPSP-supplemented dietary intervention in the ICR mice study, support moving forward with BPSP-involved product development. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05537-7.
ABSTRACT
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, peanut flour is also the active ingredient in peanut oral immunotherapy trials. Enzymatic hydrolysis was evaluated as a processing strategy to generate hydrolysates from peanut flour with reduced allergenicity. METHODS: Soluble fractions of 10% (w/v) light roasted peanut flour dispersions were hydrolyzed with the following proteases: Alcalase (pH 8.0, 60°C), pepsin (pH 2.0, 37°C) or Flavourzyme (pH 7.0, 50°C) for 60 min. Western blotting, inhibition ELISA and basophil activation tests were used to examine IgE reactivity. RESULTS: Western blotting experiments revealed the hydrolysates retained IgE binding reactivity and these IgE-reactive peptides were primarily Ara h 2 fragments regardless of the protease tested. Inhibition ELISA assays demonstrated that each of the hydrolysates had decreased capacity to bind peanut-specific IgE compared with nonhydrolyzed controls. Basophil activation tests revealed that all hydrolysates were comparable (p > 0.05) to nonhydrolyzed controls in IgE cross-linking capacity. CONCLUSIONS: These results indicate that hydrolysis of peanut flour reduced IgE binding capacity; however, IgE cross-linking capacity during hydrolysis was retained, thus suggesting such hydrolysates are not hypoallergenic.
Subject(s)
2S Albumins, Plant/immunology , Antigens, Plant/immunology , Glycoproteins/immunology , Peanut Hypersensitivity/immunology , Plant Extracts/immunology , Arachis/immunology , Arachis/metabolism , Binding Sites, Antibody , Endopeptidases/metabolism , Humans , Immunoglobulin E/immunology , Pepsin A/metabolism , Peptide Fragments/immunology , Plant Proteins/immunology , Proteolysis , Subtilisins/metabolismABSTRACT
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.
Subject(s)
Antigens, Plant/chemistry , Antigens, Plant/immunology , Arachis/immunology , Pepsin A/chemistry , Plant Proteins/chemistry , Plant Proteins/immunology , Polyphenols/chemistry , Arachis/chemistry , Digestion , Polyphenols/immunologyABSTRACT
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 human blood and less mast cell degranulation when used to orally challenge peanut-allergic mice. Polyphenol fortification of peanut flour resulted in a hypoallergenic matrix with reduced IgE binding and degranulation capacity, likely due to changes in protein secondary structure or masking of epitopes, suggesting potential applications for oral immunotherapy.
Subject(s)
Arachis/immunology , Immunotherapy , Peanut Hypersensitivity/prevention & control , Plant Proteins/administration & dosage , Polyphenols/administration & dosage , Administration, Oral , Arachis/metabolism , Chromatography, High Pressure Liquid , Electrophoresis, Polyacrylamide Gel , Humans , Plant Proteins/immunology , Polyphenols/immunology , Spectroscopy, Fourier Transform InfraredABSTRACT
Peanut (Arachis hypogaea L.) is an important crop grown worldwide for food and edible oil. The surge of peanut allergy in the past 25 years has profoundly impacted both affected individuals and the peanut and related food industries. In response, several strategies to mitigate peanut allergy have emerged to reduce/eliminate the allergenicity of peanuts or to better treat peanut-allergic individuals. In this review, we give an overview of peanut allergy, with a focus on peanut proteins, including the impact of thermal processing on peanut protein structure and detection in food matrices. We discuss several strategies currently being investigated to mitigate peanut allergy, including genetic engineering, novel processing strategies, and immunotherapy in terms of mechanisms, recent research, and limitations. All strategies are discussed with considerations for both peanut-allergic individuals and the numerous industries/government agencies involved throughout peanut production and utilization.
Subject(s)
Food Handling/methods , Immunotherapy , Peanut Hypersensitivity/prevention & control , Peanut Hypersensitivity/therapy , Allergens/analysis , Allergens/immunology , Arachis/chemistry , Arachis/genetics , Food Analysis , Food Industry , Genetic Engineering , History, 19th Century , History, 20th Century , History, 21st Century , Humans , Immunoglobulin E/immunology , Peanut Hypersensitivity/history , Plant Proteins/analysis , Plant Proteins/chemistry , Plant Proteins/immunology , Seeds/chemistry , Seeds/genetics , Seeds/immunologyABSTRACT
To investigate the protein composition and potential allergenicity of peanut testae or skins, proteome analysis was conducted using nanoLC-MS/MS sequencing. Initial amino acid analysis suggested differences in protein compositions between the blanched seed (skins removed) and skin. Phenolic compounds hindered analysis of proteins in skins when the conventional extraction method was used; therefore, phenol extraction of proteins was necessary. A total of 123 proteins were identified in blanched seed and skins, and 83 of the proteins were common between the two structures. The skins contained all of the known peanut allergens in addition to 38 proteins not identified in the seed. Multiple defense proteins with antifungal activity were identified in the skins. Western blotting using sera from peanut-allergic patients revealed that proteins extracted from both the blanched seed and skin bound significant levels of IgE. However, when phenolic compounds were present in the skin protein extract, no IgE binding was observed. These findings indicate that peanut skins contain potentially allergenic proteins; however, the presence of phenolic compounds may attenuate this effect.
Subject(s)
Arachis/chemistry , Immunoglobulin E/metabolism , Plant Proteins/analysis , Plant Proteins/immunology , Proteomics , Seeds/chemistry , Allergens/immunology , Antigens, Plant/immunology , Arachis/immunology , Humans , Peanut Hypersensitivity/immunology , Plant Proteins/chemistry , Seeds/immunologyABSTRACT
Peanuts in North America and Europe are primarily consumed after dry roasting. Standard industry practice is to roast peanuts to a specific surface color (Hunter L-value) for a given application; however, equivalent surface colors can be attained using different roast temperature/time combinations, which could affect product quality. To investigate this potential, runner peanuts from a single lot were systematically roasted using 5 roast temperatures (147, 157, 167, 177, and 187 °C) and to Hunter L-values of 53 ± 1, 48.5 ± 1, and 43 ± 1, corresponding to light, medium, and dark roasts, respectively. Moisture contents (MC) ranged from 0.41% to 1.70% after roasting. At equivalent roast temperatures, MC decreased as peanuts became darker; however, for a given color, MC decreased with decreasing roast temperature due to longer roast times required for specified color formation. Initial total tocopherol contents of expressed oils ranged from 164 to 559 µg/g oil. Peanuts roasted at lower temperatures and darker colors had higher tocopherol contents. Glucose content was roast color and temperature dependent, while fructose was only temperature dependent. Soluble protein was lower at darker roast colors, and when averaged across temperatures, was highest when samples were roasted at 187 °C. Lysine content decreased with increasing roast color but was not dependent on temperature. MC strongly correlated with several components including tocopherols (R(2) = 0.67), soluble protein (R(2) = 0.80), and peak force upon compression (R(2) = 0.64). The variation in characteristics related to roast conditions is sufficient to suggest influences on final product shelf life and consumer acceptability.
Subject(s)
Arachis/chemistry , Food Handling/methods , Amino Acids/analysis , Amino Acids/metabolism , Antioxidants/analysis , Carbohydrates/analysis , Chromatography, High Pressure Liquid/methods , Color , Europe , Hot Temperature , Linear Models , North America , Proteins/analysis , Proteins/metabolism , Tocopherols/analysis , Tocopherols/chemistry , Water/analysisABSTRACT
To explore a potential use for peanut skins as a functional food ingredient, milled skins were extracted with 70% ethanol and filtered to remove insoluble material; the soluble extract was spray-dried with or without the addition of maltodextrin. Peanut skin extracts had high levels of procyanidin oligomers (DP2-DP4) but low levels of monomeric flavan-3-ols and polymers. The addition of maltodextrin during spray-drying resulted in the formation of unknown polymeric compounds. Spray-drying also increased the proportion of flavan-3-ols and DP2 procyanidins in the extracts while decreasing larger procyanidins. Spray-dried powders had higher antioxidant capacity and total phenolics and increased solubility compared to milled skins. These data suggest that spray-dried peanut skin extracts may be a good source of natural antioxidants. Additionally, the insoluble material produced during the process may have increased value for use in animal feed due to enrichment of protein and removal of phenolic compounds during extraction.
Subject(s)
Antioxidants/analysis , Arachis/chemistry , Biflavonoids/analysis , Catechin/analysis , Phenols/analysis , Plant Extracts/analysis , Proanthocyanidins/analysis , Desiccation , Food Handling , Hygroscopic Agents/chemistry , Polysaccharides/chemistry , Seeds/chemistryABSTRACT
Juice is the most common form in which cranberries are consumed; however there is limited information on the changes of polyphenolic content of the berries during juice processing. This study investigated the effects of three different pretreatments (grinding plus blanching; only grinding; only blanching) for cranberry juice processing on the concentrations of anthocyanins, flavonols, and procyanidins throughout processing. Flavonols and procyanidins were retained in the juice to a greater extent than anthocyanins, and pressing resulted in the most significant losses in polyphenolics due to removal of the seeds and skins. Flavonol aglycones were formed during processing as a result of heat treatment. Drying of cranberry pomace resulted in increased extraction of flavonols and procyanidin oligomers but lower extraction of polymeric procyanidins. The results indicate that cranberry polyphenolics are relatively stable during processing compared to other berries; however, more work is needed to determine their fate during storage of juices.
Subject(s)
Anthocyanins/analysis , Beverages/analysis , Biflavonoids/analysis , Catechin/analysis , Flavonols/analysis , Food Handling/methods , Plant Extracts/analysis , Proanthocyanidins/analysis , Vaccinium macrocarpon/chemistrySubject(s)
Midwifery , Publishing , Women's Health , Female , Humans , Journal Impact Factor , PregnancyABSTRACT
The proximate composition and identification and quantification of polyphenolic compounds in dried cranberry pomace were determined. Proximate analysis was conducted based on AOAC methods for moisture, protein, fat, dietary fiber, and ash. Other carbohydrates were determined by the difference method. Polyphenolic compounds were identified and quantified by HPLC-ESI-MS. The composition of dried cranberry pomace was 4.5% moisture, 2.2% protein, 12.0% fat, 65.5% insoluble fiber, 5.7% soluble fiber, 8.4% other carbohydrates, 1.1% ash, and 0.6% total polyphenolics. It contained six anthocyanins (111.5 mg/100 g of DW) including derivatives of cyanidin and peonidin. Thirteen flavonols were identified (358.4 mg/100 g of DW), and the aglycones myricetin (55.6 mg/100 g of DW) and quercetin (146.2 mg/100 g of DW) were the most prominent. Procyanidins with degrees of polymerization (DP) of 1-6 were identified (167.3 mg/100 g of DW), the most abundant being an A-type of DP2 (82.6 mg/100 g of DW).
Subject(s)
Flavonoids/analysis , Phenols/analysis , Plant Extracts/analysis , Vaccinium macrocarpon/chemistry , Carbohydrates/analysis , Chromatography, High Pressure Liquid , Fruit/chemistry , Plant Proteins/analysis , PolyphenolsABSTRACT
Cranberry pomace was mixed with corn starch in various ratios (30:70, 40:60, 50:50 pomace/corn starch DW) and extruded using a twin-screw extruder at three temperatures (150, 170, 190 degrees C) and two screw speeds (150, 200 rpm). Changes in the anthocyanin, flavonol, and procyanidin contents due to extrusion were determined by HPLC. Antioxidant capacity of the extrudates was determined using oxygen radical absorbance capacity (ORAC). Anthocyanin retention was dependent upon barrel temperature and percent pomace. The highest retention was observed at 150 degrees C and 30% pomace. Flavonols increased by 30-34% upon extrusion compared to an unextruded control. ORAC values increased upon extrusion at 170 and 190 degrees C. An increase in DP1 and DP2 procyanidins was also observed; however, a decrease was observed in DP4-DP9 oligomers. These data suggest that extrusion alters the polyphenolic distribution of cranberry pomace and has application in the nutraceutical industry as a means of improving the functionality of this coproduct.
Subject(s)
Antioxidants/analysis , Flavonoids/analysis , Phenols/analysis , Plant Extracts/analysis , Vaccinium macrocarpon/chemistry , Carbohydrates/analysis , Chromatography, High Pressure Liquid , Fruit/chemistry , PolyphenolsABSTRACT
Procyanidins in plant products are present as extractable or unextractable/bound forms. We optimized alkaline hydrolysis conditions to liberate procyanidins and depolymerize polymers from dried cranberry pomace. Alkaline extracts were neutralized (pH 6-7) and then procyanidins were extracted with ethyl acetate and analyzed by normal phase high performance liquid chromatography. Alkaline hydrolysis resulted in an increase in low molecular weight procyanidins, and the increase was greater at higher temperature, short time combinations. The most procyanidins (DP1-DP3) were extracted at 60 degrees C for 15 min with each concentration of NaOH. When compared to conventional extraction using homogenization with acetone/water/acetic acid (70:29.5:0.5 v/v/v), treatment with NaOH increased procyanidin oligomer extraction by 3.8-14.9-fold, with the greatest increase being DP1 (14.9x) and A-type DP2 (8.4x) procyanidins. Alkaline treatment of the residue remaining after conventional extraction resulted in further procyanidin extraction, indicating that procyanidins are not fully extracted by conventional extraction methods.