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Sivarooban T, Hettiarachchy NS, Johnson MG. Transmission electron microscopy study of Listeria monocytogenes treated with nisin in combination with either grape seed or green tea extract. J Food Prot 2008; 71:2105-9. [PMID: 18939761 DOI: 10.4315/0362-028x-71.10.2105] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The objective of this study was to use transmission electron microscopy to investigate the morphological changes that occurred in Listeria monocytogenes cells treated with grape seed extract (GSE), green tea extract (GTE), nisin, and combinations of nisin with either GSE or GTE. The test solutions were prepared with (i) 1% GSE, 1% GTE, 6,400 IU of nisin, and the combination of these dilutions with nisin or with (ii) the pure major phenolic constituents of GSE (0.02% epicatechin plus 0.02% catechin) or GTE (0.02% epicatechin plus 0.02% caffeic acid) and their combinations with 6,400 IU of nisin in tryptic soy broth with 0.6% yeast extract (TSBYE). Test solutions were inoculated with L. monocytogenes at approximately 10(6) CFU/ml and incubated for 3 or 24 h at 37 degrees C. After 3 h of incubation, cells were harvested and evaluated under a transmission electron microscope (JEOL-100 CX) operating at 80 kV (50,000X). Microscopic examination revealed an altered cell membrane and condensed cytoplasm when L. monocytogenes cells were exposed to a combination of nisin with either GSE or GTE or to pure compounds of the major phenolic constituents in combination. After 24 h of incubation at 37 degrees C, the combinations of nisin with GSE and nisin with GTE reduced the L. monocytogenes population to undetectable levels and 3.7 log CFU/ml, respectively. These observations indicate that the combination of nisin with either GSE or GTE had a synergistic effect, and the combinations of nisin with the major phenolic constituents were most likely associated with the L. monocytogenes cell damage during inactivation in TSBYE at 37 degrees C.
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Affiliation(s)
- T Sivarooban
- Department of Food Science, University of Arkansas, 2650 North Young Avenue, Fayetteville, Arkansas 72704, USA
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Affiliation(s)
- Ilankovan Paraman
- Department of Food Science, University of Arkansas, 2650 N. Young Avenue, Fayetteville, AR 72704
| | - N. S. Hettiarachchy
- Department of Food Science, University of Arkansas, 2650 N. Young Avenue, Fayetteville, AR 72704
- Corresponding author. Phone: 479-575-4779. Fax: 479-575-6936. E-mail address:
| | - Christian Schaefer
- DSM Nutritional Products, Dept. NRD/CF-Nutrition Research & Development and Center Formulation, PO Box 3255, 4002 Basel, Switzerland
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Paraman I, Hettiarachchy NS, Schaefer C. Glycosylation and Deamidation of Rice Endosperm Protein for Improved Solubility and Emulsifying Properties. Cereal Chem 2007. [DOI: 10.1094/cchem-84-6-0593] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Ilankovan Paraman
- Department of Food Science, University of Arkansas, 2650 N. Young Avenue, Fayetteville, AR 72704
| | - N. S. Hettiarachchy
- Department of Food Science, University of Arkansas, 2650 N. Young Avenue, Fayetteville, AR 72704
- Corresponding author. Phone: 479-575-4779. Fax: 479-575-6936. E-mail address:
| | - Christian Schaefer
- DSM Nutritional Products Ltd., Dept. NRD/CF-Nutrition Research & Development/Center Formulation, PO Box 3255, 4002 Basel, Switzerland
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Onofre FO, Hettiarachchy NS. Extraction, Quantification, and Characterization of Phenolics Extracted with the Aid of Sonication from Rice Bran. Cereal Chem 2007. [DOI: 10.1094/cchem-84-4-0337] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- F. O. Onofre
- Department of Food Science, University of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704
| | - N. S. Hettiarachchy
- Department of Food Science, University of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704
- Corresponding author. Phone: +1.479.575.4779. Fax: +1.479.575.6936. E-mail:
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Paraman I, Hettiarachchy NS, Schaefer C, Beck MI. Hydrophobicity, Solubility, and Emulsifying Properties of Enzyme-Modified Rice Endosperm Protein. Cereal Chem 2007. [DOI: 10.1094/cchem-84-4-0343] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | - N. S. Hettiarachchy
- Dept. Food Science, University of Arkansas, Fayetteville, AR 72704
- Corresponding author. Phone: 479-575-4779. Fax: 479-575-6936. E-mail address:
| | - Christian Schaefer
- DSM Nutritional Products Ltd, Dept. NRD/CF–Nutrition Research and Development/Center Formulation, P. O. Box 3255, 4002 Basel, Switzerland
| | - Markus I. Beck
- DSM Nutritional Products Ltd, Dept. NRD/CF–Nutrition Research and Development/Center Formulation, P. O. Box 3255, 4002 Basel, Switzerland
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Sivarooban T, Hettiarachchy NS, Johnson MG. Inhibition of Listeria monocytogenes using nisin with grape seed extract on turkey frankfurters stored at 4 and 10 degrees C. J Food Prot 2007; 70:1017-20. [PMID: 17477277 DOI: 10.4315/0362-028x-70.4.1017] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Recontamination of cooked ready-to-eat (RTE) chicken and beef products with Listeria monocytogenes has been a major safety concern. Natural antimicrobials in combinations can be an alternative approach for controlling L. monocytogenes. Therefore, the objectives of this study were to evaluate the inhibitory activities against L. monocytogenes of nisin (6,400 IU/ ml), grape seed extract (GSE; 1%), and the combination of nisin and GSE both in tryptic soy broth with 0.6% yeast extract (TSBYE) and on the surface of full-fat turkey frankfurters. TSBYE was incubated at 37 degrees C for 72 h and turkey frankfurters at 4 or 10'C for 28 days. Inocula were 6.7 or 5 log CFU per ml or g for TSBYE or frankfurters, respectively. After 72 h in TSBYE, nisin alone did not show any inhibitory activity against L. monocytogenes. The combination of nisin and GSE gave the greatest inhibitory activity in both TSBYE and on turkey frankfurters with reductions of L. monocytogenes populations to undetectable levels after 15 h and 21 days, respectively. This combination of two natural antimicrobials has the potential to control the growth and recontamination of L. monocytogenes on RTE meat products.
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Affiliation(s)
- T Sivarooban
- Department of Food Science, University of Arkansas, 2650 North Young Avenue, Fayetteville, Arkansas 72704, USA
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Paraman I, Hettiarachchy NS, Schaefer C, Beck MI. Physicochemical Properties of Rice Endosperm Proteins Extracted by Chemical and Enzymatic Methods. Cereal Chem 2006. [DOI: 10.1094/cc-83-0663] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Ilankovan Paraman
- Dept. Food Science, University of Arkansas, 2650 N. Young Avenue, Fayetteville, AR 72704
| | - N. S. Hettiarachchy
- Dept. Food Science, University of Arkansas, 2650 N. Young Avenue, Fayetteville, AR 72704
- Corresponding author. Phone: 479-575-4779. Fax: 479-575-6936. E-mail:
| | - Christian Schaefer
- DSM Nutritional Products Ltd, Dept. NRD/CF-Nutrition Research and Development/Center Formulation, PO Box 3255, 4002 Basel, Switzerland
| | - Markus I. Beck
- DSM Nutritional Products Ltd, Dept. NRD/CF-Nutrition Research and Development/Center Formulation, PO Box 3255, 4002 Basel, Switzerland
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Rababah T, Hettiarachchy NS, Horax R, Cho MJ, Davis B, Dickson J. Thiobarbituric Acid Reactive Substances and Volatile Compounds in Chicken Breast Meat Infused with Plant Extracts and Subjected to Electron Beam Irradiation. Poult Sci 2006; 85:1107-13. [PMID: 16776483 DOI: 10.1093/ps/85.6.1107] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The effect of irradiation on thiobarbituric acid reactive substances (TBARS) and volatile compounds in raw and cooked nonirradiated and irradiated chicken breast meat infused with green tea and grape seed extracts was investigated. Chicken breast meat was vacuum infused with green tea extract (3,000 ppm), grape seed extract (3,000 ppm), or their combination (at a total of 6,000 ppm), irradiated with an electron beam, and stored at 5 degrees C for 12 d. The targeted irradiation dosage was 3.0 kGy and the average absorbed dosage was 3.12 kGy. Values of TBARS and volatile compound contents of raw and cooked chicken meat were determined during the 12-d storage period. Thiobarbituric acid reactive substances values ranged from 15.5 to 71.4 mg of malondialdehyde/kg for nonirradiated raw chicken and 17.3 to 80.1 mg of malondialdehyde/kg for irradiated raw chicken. Values for cooked chicken ranged from 31.4 to 386.2 and 38.4 to 504.1 mg of malondialdehyde/kg for nonirradiated and irradiated chicken, respectively. Irradiation increased TBARS and hexanal values of controls and meat infused with plant extracts. Hexanal had the highest intensity of volatiles followed by pentanal and other volatiles. Cooking the samples significantly (P < 0.05) increased the amounts of TBARS and volatiles. Addition of plant extracts decreased the amount of TBARS as well as hexanal and pentanal values. Although irradiation increases lipid oxidation, infusion of chicken meat with plant extracts could reduce lipid oxidation caused by irradiation.
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Affiliation(s)
- T Rababah
- Department of Nutrition and Food Technology, Jordan University of Science and Technology, Irbid
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Cai R, Hettiarachchy NS, Jalaluddin M. High-performance liquid chromatography determination of phenolic constituents in 17 varieties of cowpeas. J Agric Food Chem 2003; 51:1623-7. [PMID: 12617595 DOI: 10.1021/jf020867b] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Seventeen varieties of cowpeas grown in Arkansas were analyzed for their phenolic constituents using high-performance liquid chromatography (HPLC). Protocatechuic acid was identified as the major phenolic acid present in esterified forms. The amount of protocatechuic acid increased from trace-3.6 to 9.3-92.7 mg/100 g of flour in the 17 varieties of cowpeas after hydrolysis. Six other phenolic acids, including, p-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, 2,4-dimethoxybenzoic acid, and cinnamic acid, were also identified. These phenolic acids were evenly distributed mainly in free acid forms at <7 mg/100 g of flour. Total phenolic contents determined using Folin-Ciocalteu's reagent were largely different among the 17 varieties, ranging from 34.6 to 376.6 mg/100 g of flour. A comparison of the HPLC chromatograms of the 17 cowpea phenolics before and after alkali hydrolysis indicated the conversion of a pattern with evenly distributed peaks to one with a single major peak for protocatechuic acid, suggesting that the chromatograms before hydrolysis better represent the identities of the cowpea varieties.
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Affiliation(s)
- R Cai
- Department of Food Science, University of Arkansas, Fayetteville 72704, USA
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Xie L, Hettiarachchy NS, Cai R, Tsuruhami K, Koikeda S. Conversion of Isoflavone Glycosides to Aglycones in SoyLife and Soymeal Using β-glycosidase. J Food Sci 2003. [DOI: 10.1111/j.1365-2621.2003.tb05689.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Park SK, Rhee CO, Bae DH, Hettiarachchy NS. Mechanical properties and water-vapor permeability of soy-protein films affected by calcium salts and glucono-delta-lactone. J Agric Food Chem 2001; 49:2308-2312. [PMID: 11368594 DOI: 10.1021/jf0007479] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Edible films were prepared from solutions of soy protein with calcium salts and glucono-delta-lactone (GDL). Calcium salts cross-linking interactions with soy-protein isolate (SPI) could result in the formation of films with rigid three-dimensional structure. GDL contributed to the formation of a homogeneous film structure due to increased protein--solvent attraction. Tensile strength (TS) of calcium sulfate treated SPI film (8.6 MPa) was higher than the TS of calcium chloride treated SPI films (6.4 MPa) and the control SPI film (5.5 MPa). Puncture strength (PS) of calcium sulfate treated SPI film (9.8 MPa) was higher than the PS of calcium chloride treated SPI films (8.5 MPa) and the control SPI film (5.9 MPa). SPI film formulated with GDL had larger elongation at break (39.4%) than that of SPI control film (18.2%). Calcium salts and GDL-treated SPI films had lower water-vapor permeability than the SPI control film.
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Affiliation(s)
- S K Park
- Departmen of Materials Science and Engineering, Kwangju Institute of Science and Technology, Korea
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Park SK, Hettiarachchy NS, Were L. Degradation behavior of soy protein-wheat gluten films in simulated soil conditions. J Agric Food Chem 2000; 48:3027-31. [PMID: 10898660 DOI: 10.1021/jf0000272] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Films containing soy protein and wheat gluten were exposed to simulated farmland soil mix over a period of 30 days and monitored for degradation. The simulated farmland soil mix (topsoil/sand/Sunshine compost/vermiculite, 59:6:25:10, wt %) was mixed and stored at ambient humidity (48-55%) and temperature (20-24 degrees C); the soil mix was constantly maintained at 15% moisture by weight. Research focused on evaluating the effectiveness of gluten and cysteine additions on biodegradable behavior in the simulated farmland soil conditions. The four types of films, soy protein (S:G 1:0); soy protein with cysteine addition (S:G 1:0 + CYS); soy protein-wheat gluten (S:G 4:1); and soy protein-wheat gluten with cysteine addition (S:G 4:1 + CYS), were prepared at pH 7. 0 for degradation studies. Soy protein-gluten film rapidly degraded with 50% weight loss in about 10 days and with up to 95% weight loss in 30 days. Tensile strength and elongation of all soy protein-gluten films significantly decreased in 3 days. However, cysteine addition delayed the degradation rate of soy protein-gluten films. Soy protein-wheat gluten film disintegrated after 20 days in the simulated farmland soil environment. These results suggest that wheat gluten and cysteine addition to soy protein-based films could delay degradation rates due to their high disulfide contents.
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Affiliation(s)
- S K Park
- Department of Food Science, University of Arkansas, Fayetteville, Arkansas 72704, USA.
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Affiliation(s)
- Sang K. Park
- ; Department of Food Science; University of Arkansas; 272 Young Ave. 72704 Fayetteville AR
| | - N. S. Hettiarachchy
- ; Department of Food Science; University of Arkansas; 272 Young Ave. 72704 Fayetteville AR
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Wang M, Hettiarachchy NS, Qi M, Burks W, Siebenmorgen T. Preparation and functional properties of rice bran protein isolate. J Agric Food Chem 1999; 47:411-416. [PMID: 10563909 DOI: 10.1021/jf9806964] [Citation(s) in RCA: 207] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Rice bran protein isolate (RBPI) containing approximately 92.0% protein was prepared from unstabilized and defatted rice bran using phytase and xylanase. The yield of RBPI increased from 34% to 74.6% through the use of the enzymatic treatment. Nitrogen solubilities of RBPI were 53, 8, 62, 78, 82, and 80% at pHs 2.0, 4.0, 6.0, 8.0, 10.0, and 12.0, respectively. Differential scanning calorimetry showed that RBPI had denaturation temperature of 83.4 degrees C with low endotherm (0.96 J/g of protein). RBPI had similar foaming properties in comparison to egg white. But emulsifying properties of RBPI were significantly lower than those of bovine serum albumin. The result of amino acid analysis showed that RBPI had a similar profile of essential amino acid requirements for 2-5-year-old children in comparison to that of casein and soy protein isolate.
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Affiliation(s)
- M Wang
- Department of Food Science, University of Arkansas, Fayetteville, 72703, USA
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Affiliation(s)
| | - U. Kalapathy
- Department of Food Science, University of Arkansas, Fayetteville, AR 72704
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Wu W, Hettiarachchy NS. Foaming and emulsifying properties of soy protein isolate and hydrolysates in skin and hair care products. J SURFACTANTS DETERG 1998. [DOI: 10.1007/s11743-998-0026-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kalapathy U, Hettiarachchy NS, Myers D, Rhee KC. Alkali-modified soy proteins: Effect of salts and disulfide bond cleavage on adhesion and viscosity. J AM OIL CHEM SOC 1996. [DOI: 10.1007/bf02523417] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- U. Kalapathy
- ; Department of Food Science; University of Arkansas; 272 Young Ave. Fayetteville AR 72704
| | - N. S. Hettiarachchy
- ; Department of Food Science; University of Arkansas; 272 Young Ave. Fayetteville AR 72704
| | - D. Myers
- ; Center for Crops Utilization Research; Iowa State University of Science and Technology; Ames Iowa 50011
| | - K. C. Rhee
- ; Food Protein Research and Development Center; Texas A&M University; College Station Texas 77843
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Hettiarachchy NS, Sri Kantha SS, Corea SM. The effect of oral contraceptive therapy and of pregnancy on serum folate levels of rural Sri Lankan women. Br J Nutr 1983; 50:495-501. [PMID: 6639914 DOI: 10.1079/bjn19830120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Serum folate level, packed cell volume and haemoglobin concentration of apparently healthy rural Sri Lankan women, between 20 and 45 years and earning up to Rs. 500 (Sri Lankan Rs. 35 congruent to 1 pound Sterling) per month, were estimated during pregnancy and when on oral contraceptive (OC) treatment with Ovulen 50 (ethinyl oestradiol 0.05 mg, ethinodiol diacetate 1 mg). Ovulen 50 administration led to a fall in serum folate levels which occurred very rapidly during the first 6 months and more slowly thereafter, stabilizing at 2.2 ng/ml in women of very low economic status and at 2.9 ng/ml in the more privileged. There was a steady fall in serum folate concentrations during pregnancy, the levels at the end of pregnancy being higher than those in women under OC treatment for 9 months. The need for folate supplementation during OC treatment is stressed.
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Abstract
DNA was prepared from isolated mitochondria of Acanthamoeba castellanii and was shown to behave as a single component in density gradients, on ;melting' and on renaturation. From measurements of renaturation kinetics, sedimentation coefficient and electron micrographs the genome size of the mitochondrial DNA was calculated to be about 3.4x10(7) daltons. A small proportion of the preparations could be isolated as relaxed circular molecules of mean contour length 16.2mum.
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