Citrate-phosphate Buffer Research Articles

Application of pulsed light to patulin reduction in McIlvaine buffer and apple products

Numerous studies around the world have reported the occurrence of patulin in commercialized apple products. The persistence of this mycotoxin in apple products indicates that current methods used to reduce it during the manufacturing process are not entirely successful and reflects the need to evaluate new detoxification methods. The purpose of the present study was to investigate the effect of pulsed light (PL) dose on patulin degradation in McIlvaine buffer, apple juice and apple purée. The exposure of all samples to PL doses between 2.4 and 35.8 J/cm2 resulted in a significant decrease in patulin levels. Patulin reduction in McIlvaine buffer did not depend markedly on the initial concentration of the mycotoxin. At the maximum dose tested, the remaining average patulin level dissolved in McIlvaine buffer was approximately 5–15%, while in apple juice the values declined up to 22%. In apple purée naturally contaminated with 29 μg/kg of patulin, exposure to a PL dose of 12 J/cm2 provoked a 51% reduction in patulin concentration, while no residual contamination was detected for higher irradiation times.These results suggested that PL treatment would be a potential alternative method to reduce patulin contamination in apple products. However, further investigations need to be conducted to evaluate toxicological safety of patulin degradation product(s).

Formation and structure of the complexes of sub-elementary fibrils of bacterial cellulose with fluorescent brightener molecules

The formation and structure of the complexes of sub-elementary fibrils (SEFs) of bacterial cellulose with fluorescent brightener (FB) molecules have been investigated using WAXD, SEM, and computer calculations of WAXD profiles. It is confirmed for the first time that the SEF-FB complexes are formed in 10 min by washing the cultivation product, which is prepared by the culture of Acetobacter xylinum in the presence of FB, with the pH 7 citrate–phosphate buffer solution and their thin sheet-like structure is grown almost two-dimensionally in 24 h in the medium. The same SEF-FB complexes are also produced by washing the product with NaCl aqueous solutions having concentrations higher than 0.1 wt%, while the original SEF structure is unchanged at lower concentrations. This indicates that the concentration of salt ions in washing media is a main factor to dominate the formation of the SEF-FB complexes from the cultivation product. The calculations of WAXD profiles reveal that the chain-slid, parallel-set, and sheet-slid/contracted models well reproduce the WAXD profile observed for the SEF-FB complexes. In these models, the following modifications are conducted in the a,b-modified unit cell of cellulose Iβ; the slide of the center chain along the b″ axis, the rotation of each chain around its own molecular axis, and the slide and contraction of the individual sheets composed of the center or origin chains. A single FB molecule is successfully packed into an energetically-allowable space in between the (010) planes in the 2a″ × b″ × 4c″ cell for the chain-slid model or in between the corresponding planes for the parallel-set and sheet-slid/contracted models. However, the detailed structure of FB in the complex is not yet determined due to the low crystallinity of the complexes.

Electrode reactions of several dissolved hydroquinones on a polyaniline-modified electrode and what occurs in the polyaniline

A conductive polymer polyaniline (PANI) was easily prepared on the electrode surface as a stable film by the electropolymerization of aniline in an acidic solution. In McIlvaine's buffer solution whose pH exceeded 4, no redox current of the dissolved species was observed on the PANI-modified electrode because PANI acted as an electric insulator. Even in a less acidic solution, the redox current of the dissolved hydroquinone was evident. On the other hand, in the potential region greater than 0.7V vs. Ag/AgCl, PANI acted as an electric insulator. Even in the electroinactive potential region, the redox current of the dissolved p-dimethoxybenzene was evident. These two electrochemical responses of the PANI film-modified electrode are caused by processes in which hydroquinone and p-dimethoxybenzene selectively permeate through the PANI film to reach the electrode substrate. The analyses of the rotating disk electrode (RDE) voltammograms using a PANI-modified RDE and steady-state current-potential curves using a PANI pellet electrode revealed that hydroquinone and p-dimethoxybenzene were concentrated in the PANI during the electro-oxidation. Furthermore, the concentration of hydroquinone and p-dimethoxybenzene increased the electric conductivity of the PANI from 6.50×10−7 to 2.73×10−3S/cm for hydroquinone and from 0.64 to 1.92S/cm for p-dimethoxybenzene.

Antioxidant treatment with edaravone or taurine ameliorates diabetes-induced testicular dysfunction in the rat

Diabetes mellitus with the subsequent generation of reactive oxygen species represents a major risk factor for testicular dysfunction (TD). We investigate whether administration of antioxidants edaravone and taurine could prevent type 1 diabetes-induced TD in the rat. Six-week-old male Wistar rats were divided into four groups. Group A was treated with citrate-phosphate buffer plus normal saline, whereas in the other three groups, diabetes was induced by streptozotocin (50 mg/kg intraperitoneally). Subsequently, the diabetic rats were treated for 4 weeks either with normal saline (group B), edaravone (10 mg/Kg/day, intraperitoneally; group C), or taurine (500 mg/Kg/day, intraperitoneally; group D). Body, testicular, and epididymal weight, serum glucose, malondialdehyde levels, 8-Hydroxy-2'-deoxyguanosine(8-OH-dG) levels, testicular catalase activity, and serum testosterone levels were determined. Histological examination and the Johnsen score were used to observe and evaluate, respectively, the morphological changes in the testes. TUNEL assay was used to examine DNA fragmentation. Mating studies were performed in order to evaluate the fertility potential of male rats in each group. Edaravone or taurine treatment prevented significantly the decreased body, testicular, and epididymal weight induced by diabetes. Moreover, edaravone or taurine significantly decreased the diabetes-induced malondialdehyde levels, 8-OHdG levels, the morphological damage, and the number of apoptotic cells. Taurine, but not edaravone, increased significantly the testicular catalase activity. The antioxidant treatment had no effect on the fertility potential of the diabetic rats. The morphological damage, increased lipid peroxidation, and apoptosis in testicular tissue can be significantly relieved by edaravone or taurine treatment through suppressing the increased oxidative stress in the rat testis.

Characterization of the newly isolated Geobacillus sp. T1, the efficient cellulase-producer on untreated barley and wheat straws

A thermophile cellulase-producing bacterium was isolated and identified as closely related to Geobacillus subterraneus. The strain, named Geobacillus sp. T1, was able to grow and produce cellulase on cellobiose, microcrystalline cellulose, carboxymethylcellulose (CMC), barley straw, wheat straw and Whatman No. 1 filter paper. However, barley and wheat straws were significantly better substrates for cellulase production. When Geobacillus sp. T1 was cultivated in the presence of 0.5% barley straw, 0.1% Tween 80 and pH 6.5 at 50°C, the maximum level of free cellulase up to 143.50U/mL was produced after 24h. This cellulase (∼54kDa) was most active at pH 6.5 and 70°C. The enzyme in citrate phosphate buffer (10mM) was stable at 60°C for at least 1h. Geobacillus sp. T1 with efficient growth and cellulase production on straws seems a potential candidate for conversion of agricultural biomass to fuels.

OC-140 Hydroxychloroquine as a treatment for crohn's disease: enhancing antibiotic efficacy and macrophage killing of E coli

IntroductionMucosal E coli, increased in Crohn's disease, have an adherent invasive phenotype (AIEC) and replicate within macrophages. AIEC can induce granulomas in vitro and in vivo and treatment leads to...

Biocompatible titania hydrogels with chemically triggered release of a photosensitive dye

5,10,15,20-Tetrakis(4-sulfonatophenyl)porphyrin was entrapped into biocompatible hydrogels formed by self-assembling micelles of the titanium dioxide prepared by hydrolysis of titanium ethoxide modified with triethanolamine (TEA). The materials were characterized by their optical and photosensitive properties. The immobilization led to changes of the absorption spectra of the dye and decreased its molar absorption coefficient. The TiO2 matrix did not degrade the entrapped porphyrin upon u.v. irradiation. The formation of TEA–titanium(IV) chelates facilitated a controlled and triggered release of the immobilized dye from the hydrogels in lactate and citrate buffers. The released dye prolonged the sterility of citrate–phosphate buffer and its illumination with visible light inhibited growth of Aspergillus niger.

Structure and crystallization of sub-elementary fibrils of bacterial cellulose isolated by using a fluorescent brightening agent

The structure and crystallization of carefully isolated sub-elementary fibrils (SEFs) of bacterial cellulose have been investigated using TEM, WAXD, and high-resolution solid-state 13C NMR. The addition of a suitable amount of fluorescent brightener (FB) to the incubation medium of Acetobacter xylinum effectively suppressed the aggregation of the SEFs into the microfibrils, as previously reported. However, this study confirmed for the first time that serious structural change in the SEFs occurs during the removal of excess FB by washing with buffer solutions having pH values higher than 6 or with the alkaline aqueous solution that was frequently used in previous studies. In contrast, the isolation of unmodified SEFs was successfully performed by utilizing a washing protocol employing pH 7 citrate–phosphate buffer solution containing 1% sodium dodecyl sulfate. High-resolution solid-state 13C NMR and WAXD measurements revealed that the SEFs thus isolated are in the noncrystalline state in which the pyranose rings of the almost parallel cellulose chains appear to be stacked on each other. The respective CH2OH groups of the SEFs adopt the gt conformation instead of the tg conformation found in cellulose Iα and Iβ crystals, and undergo significantly enhanced molecular motion in the absence of intermolecular hydrogen bonding associated with these groups. The main chains are also subject to rapid motional fluctuations while maintaining the parallel orientation of the respective chains, indicating that the SEFs have a liquid crystal-like structure with high molecular mobility. Moreover, the SEFs crystallize into cellulose Iβ when the FB molecules that may adhere to the surface of the SEFs are removed by extraction with boiling 70 v/v% ethanol and 0.1N NaOH aqueous solution. On the basis of these results, the crystallization of the SEFs into the Iα and Iβ forms is discussed, including the possible formation of the crystalline-noncrystalline periodic structure in native cellulose.

Adsorption and Stabilization of a Raw Starch Digesting Amylase on Micro Bead Silica Gel 300 A

Aims: To produce a robust starch hydrolyzing enzyme (improved catalytic and noncatalytic properties) by the adsorption of the soluble enzyme on micro bead silica gel. Place and Duration of Study: Department of Life Sciences and Bioengineering, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba-shi Ibaraki-ken, Japan between July 2009 and August 2010. Methodology: Ten types of Micro Bead silica gel with pore sizes ranging from 0.4-100 nm were screened to determine the best support for the immobilization of a microbial raw starch digesting amylase (RSDA). The micro bead which gave the highest yield was selected for further studies. Properties of the immobilized enzyme were compared to the free type to determine the effect of immobilization on catalytic, storage and operational stability. Results: Micro Bead 300 A gave the highest yield and the optimum condition for adsorption of the RSDA was at pH 5, 25°C for 24 h. Optimum pH of the immobilized enzyme shifted from 5 to 4.5 and optimum temperature from 30 to 50°C. The immobilized Research Article British Biotechnology Journal, 2(2): 85-101, 2012 86 amylase retained over 70% of its initial activity after 12 h incubation at 70°C in 0.2 M citrate phosphate buffer pH 5 whereas free enzyme lost 92% initial activity under same conditions. Immobilized enzyme retained 95% activity after 10 batch reactions of 30 min each and 100% activity after storage for 6 weeks at room temperature. Conclusion: Immobilized RSDA was marginally more pH and temperature stable compared to the native type. It also exhibited storage stability and could be re-used repeatedly without considerable desorption during washing. The kinetic and stability features combined with the properties of the support make this process appealing for industrial application.

Development and In-vitro Evaluation of a Contraceptive Vagino-Adhesive Propranolol Hydrochloride Gel.

The objective of the present investigation was to develop and evaluate a contraceptive vagino-adhesive propranolol hydrochloride gel. To achieve this, various mucoadhesive polymers including guar gum (1-4% w/w), sodium alginate (4-7% w/w), xanthan gum (2-5% w/w ), HPMC 4000 (3-5% w/w), Na CMC (4-7% w/w), carbomer 934 and carbomer 940 both in the range of 0.5-2.0% w/w, were dispersed in an aqueous-based solution containing the drug (1.6% w/w). The mucoadhesive properties of the gels were assessed on sheep vaginal mucosa (as model mucosa) in pH 4.5 citrate-phosphate buffer at 37°C. Formulations containing charged functional groups in their polymeric structure, showed higher mucoadhesive strengths in comparison to those composed of neutral polymers. In-vitro drug release profiles of the gels were determined in pH 4.5 citrate-phosphate buffer. Results indicated that, only formulation F13 (containing sodium alginate 6.5% w/w), could release its drug over 12 h, with a burst release at the initial phase followed by a sustained release pattern. This formulation, which showed a good mucoadhesive strength (386.97 ± 9.31 mN), was considered as the final formulation and underwent complementary tests including determination of drug content and duration of mucoadhesion. Its drug content was found to be 101.05 ± 0.106% (n = 3) and it attached to the model mucosa for more than 10 h. In conclusion, formulation F13 was considered as the most desirable formulation as it exhibited appropriate mucoadhesive properties while having the potential of providing an immediate contraceptive effect, followed by a prolonged drug release which is assumed to render longer contraceptive efficacy.

Development of a borondipyrromethene-based Zn2+fluorescent probe: solvent effects on modulation sensing ability

A borondipyrromethene-based Zn(2+) fluorescent probe BODPAQ was designed and synthesized. The chelators in BODPAQ, 2,2'-dipicolylamine (DPA) and 8-aminoquinoline (AQ), coordinate to Zn(2+) in a synergic manner. As a result, BODPAQ displays high Zn(2+) selectivity with a dramatic enhanced emission accompanied by a notable hypsochromic shift due to the binary inhibition effect of PET and ICT mechanisms, enabling the detection of Zn(2+) by both ratiometric and normal turn-on fluorescence methods in acetonitrile. Interestingly, the sensitivity of BODPAQ towards Zn(2+) changes upon varying the compositions of buffer solutions. In 3-morpholinopropanesulfonic acid (MOPS) buffer aqueous solution (50% CH(3)CN), BODPAQ displays the highest sensitivity for Zn(2+), while in citrate-phosphate buffer, BODPAQ shows no response to Zn(2+).

Polydopamine-graft-PEG antifouling coating for quantitative analysis of food proteins by CE

In this paper, firstly the surface plasma resonance (SPR) was used to evaluate the antifouling property of polydopamine-graft-poly(ethylene glycol) (PEG) copolymer coating, and then the quantitative analysis of food proteins (such as hen eggs and milk powder) was investigated by capillary electrophoresis (CE) method using polydopamine-graft-PEG copolymer coated capillary. The great separations of lysozyme, conalbumin and ovalbumin from hen egg white could be achieved in phosphate–citrate buffer (pH 3.20) with an applied voltage of +20 kV in polydopamine-graft-PEG copolymer coated capillary. The range of protein recovery percentage of the three kinds of egg white proteins was 96.67% to 101.02%. According to the quantitative analysis results, the protein content of lysozyme, conalbumin and ovalbumin in hen egg white was 13.268 mg mL−1, 28.360 mg mL−1 and 157.418 mg mL−1, respectively. Whey proteins (β-lactoglobulin A, β-lactoglobulin B and α-lactalbumin) in nonfat milk powder could be separated completely with an applied voltage of −20 kV in sodium tetraborate buffer (pH 8.5). The protein recovery of β-lactoglobulin A, β-lactoglobulin B and α-lactalbumin was in the range of 86.40–94.38%. Finally, the quantitative protein content of β-lactoglobulin A, β-lactoglobulin B and α-lactalbumin in nonfat milk powder was 1.418 mg mL−1, 0.129 mg mL−1, and 0.073 mg mL−1, respectively. Also the egg white proteins could be separated consecutively 25 times without a noticeable loss in separation efficiency using polydopamine-graft-PEG copolymer coated capillary in one day.

Aqueous Extraction of Wheat Germ Oil

In this study, the aqueous extraction of wheat germ oil was examined. The effects of three different buffers and pH on oil extraction yields were evaluated. Preliminary tests carried out at a liquid:solid ratio of 12:1 (v/w) and extraction time of 4 h showed that relatively high oil yields could be obtained at alkaline pH (pH = 8.0). Tris-HCl buffer at pH 8.0 produced the highest oil yield, about 49%. Response surface methodology was used to optimize the processing parameters (liquid:solid ratio and extraction time) to maximize oil yield. Quadratic models with R2 values higher than 0.94 were developed for the three buffer systems: Tris-HCl at pH 8.0, sodium borate (boric acid-NaOH) at pH 8.0, and citrate-phosphate buffer at pH 5.0. In general, oil extraction yield improved with increasing liquid:solid ratio and decreased with prolonged extraction time at pH 8.0. The highest predicted oil extraction yields were similar for Tris-HCl and sodium borate buffers at pH 8.0, about 70%. The verification experiments carried out at the optimum conditions predicted by the models, liquid:solid ratio of 20 (v/w) and extraction time of 0.5 h, resulted in oil yields of 65% and 55% for Tris-HCl and sodium borate buffers, respectively. This study demonstrated the potential of aqueous extraction as a viable technique for recovery of oil from wheat germ. Even though the oil recovery rates achieved in this study were not very high, aqueous extraction of wheat germ oil could be economically feasible because of the higher nutritional and commercial value of wheat germ oil as compared to commodity oils such as soybean oil.

Modified Carbon Nanoball on Electrode Surface Using Plasma in Enzyme-Based Biofuel Cells

Biofuel cells performed similarly to those conventional fuel cells are regarded as one of potential substitute for fossil fuel. Developments of biofuel cells demonstrate the advantages on reduction of greenhouse gas emissions as well as increasing energy security. Enzyme-based biofuel cells is one kind of the biofuel cells, enzyme-based biofuel cells convert chemical energy into electrical energy via specific enzymes as biocatalysts. Glucose oxidase and laccase were immobilized onto carbon paper as bioanode and biocathode, respectively in enzyme-based biofuel cells system. Mediator and enzyme were mixed in phosphate buffer (pH 7) and citrate buffer (pH 5) solutions, respectively. A Nafion membrane117 was inserted to separate the two half cells. The power density with respect to different operating voltages was obtained with a glucose concentration of 10mM. Potassium hexacyanoferrate III and ABTS (2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) as mediators were added to the bioanode and biocathode cell, respectively. Carbon nanoballs were coated on the carbon paper and enormous enhancement of power density was achieved.The power-voltage with the CNB surface modifying by using plasma was with oxygen bubbling in cathode directly in the cell achieved up to 0.114V. The power density was 65.5μW/cm2. The assembled enzyme-based biofuel cells were studied under nitrogen at 37°C in bioanode.

Development and validation of dissolution method for carvedilol compression-coated tablets

The present study describes the development and validation of a dissolution method for carvedilol compression-coated tablets. Dissolution test was performed using a TDT-06T dissolution apparatus. Based on the physiological conditions of the body, 0.1N hydrochloric acid was used as dissolution medium and release was monitored for 2 hours to verify the immediate release pattern of the drug in acidic pH, followed by pH 6.8 in citric-phosphate buffer for 22 hours, to simulate a sustained release pattern in the intestine. Influences of rotation speed and surfactant concentration in medium were evaluated. Samples were analysed by validated UV visible spectrophotometric method at 286 nm. 1% sodium lauryl sulphate (SLS) was found to be optimum for improving carvedilol solubility in pH 6.8 citric-phosphate buffer. Analysis of variance showed no significant difference between the results obtained at 50 and 100 rpm. The discriminating dissolution method was successfully developed for carvedilol compression-coated tablets. The conditions that allowed dissolution determination were USP type I apparatus at 100 rpm, containing 1000 ml of 0.1N HCl for 2 hours, followed by pH 6.8 citric-phosphate buffer with 1% SLS for 22 hours at 37.0 ± 0.5 ºC. Samples were analysed by UV spectrophotometric method and validated as per ICH guidelines.

Biochemical and Molecular Characterization of Secreted α-Xylosidase from Aspergillus niger

α-Linked xylose is a major component of xyloglucans in the cell walls of higher plants. An α-xylosidase (AxlA) was purified from a commercial enzyme preparation from Aspergillus niger, and the encoding gene was identified. The protein is a member of glycosyl hydrolase family 31. It was active on p-nitrophenyl-α-d-xyloside, isoprimeverose, xyloglucan heptasaccharide (XXXG), and tamarind xyloglucan. When expressed in Pichia pastoris, AxlA had activity comparable to the native enzyme on pNPαX and IP despite apparent hyperglycosylation. The pH optimum of AxlA was between 3.0 and 4.0. AxlA together with β-glucosidase depolymerized xyloglucan heptasaccharide. A combination of AxlA, β-glucosidase, xyloglucanase, and β-galactosidase in the optimal proportions of 51:5:19:25 or 59:5:11:25 could completely depolymerize tamarind XG to free Glc or Xyl, respectively. To the best of our knowledge, this is the first characterization of a secreted microbial α-xylosidase. Secreted α-xylosidases appear to be rare in nature, being absent from other tested commercial enzyme mixtures and from the genomes of most filamentous fungi.

Enzymatic synthesis of piceid glycosides by cyclodextrin glucanotransferase

Novel glycosides of piceid (3,4′-5-trihydroxy stilbene 3-O-β-d-glucoside) were produced by the transglycosylation reactions of cyclodextrin glucanotransferase (CGTase) from Bacillus macerans, with piceid (PicG1) and maltodextrin as the acceptor and donor substrates, respectively. The reactions were performed at 40°C with 2.56mM piceid (0.1% w/v) and maltodextrin (5% w/v) in 0.02M citrate phosphate buffer, pH 6.0 containing 5% (v/v) methanol for 6h. Glucose, maltose, sucrose, maltotriose and α-cyclodextrin (α-CD) were also used to analyze their ability to function as donor substrates, for the glycosylation of piceid. Among the different donor substrates used, the maximum transfer efficiency (TE) of glycosylation of piceid was observed for α-cyclodextrin (78.9%) followed by maltodextrin (72.1%). The partially purified piceid glycoside products (PicG2 and PicG3) were identified by mass spectrometry.

Characterization of a Thermostable Family 1 Glycosyl Hydrolase Enzyme from Putranjiva roxburghii Seeds

A 66-kDa thermostable family 1 Glycosyl Hydrolase (GH1) enzyme with β-glucosidase and β-galactosidase activities was purified to homogeneity from the seeds of Putranjiva roxburghii belonging to Euphorbiaceae family. N-terminal and partial internal amino acid sequences showed significant resemblance to plant GH1 enzymes. Kinetic studies showed that enzyme hydrolyzed p-nitrophenyl β-D: -glucopyranoside (pNP-Glc) with higher efficiency (K (cat)/K (m) = 2.27 x 10(4) M(-1) s(-1)) as compared to p-nitrophenyl β-D: -galactopyranoside (pNP-Gal; K (cat)/K (m) = 1.15 x 10(4) M(-1) s(-1)). The optimum pH for β-galactosidase activity was 4.8 and 4.4 in citrate phosphate and acetate buffers respectively, while for β-glucosidase it was 4.6 in both buffers. The activation energy was found to be 10.6 kcal/mol in the temperature range 30-65 °C. The enzyme showed maximum activity at 65 °C with half life of ~40 min and first-order rate constant of 0.0172 min(-1). Far-UV CD spectra of enzyme exhibited α, β pattern at room temperature at pH 8.0. This thermostable enzyme with dual specificity and higher catalytic efficiency can be utilized for different commercial applications.

Screening for Listeria monocytogenes surrogate strains applicable to food processing by ultrahigh pressure and pulsed electric field.

Ultrahigh pressure (UHP) and pulsed electric field (PEF) are emerging processing technologies developed to enhance the safety while maintaining the fresh-like quality of food. For each food and process combination, a pathogen of concern (i.e., target pathogen) must be determined, and a low-risk microorganism that serves as the pathogen surrogate for process validation must be identified. The objective of this study was to identify a surrogate for Listeria monocytogenes for UHP and PEF process validation. Potential surrogates tested include four Lactobacillus spp., a Pediococcus sp., and a Listeria innocua strain. These were compared with nine L. monocytogenes strains, with regard to sensitivity to UHP and PEF processing. For UHP treatment, the strains were suspended in citrate-phosphate buffer (pH 7.0 or 4.5), sweet whey, or acidified whey and pressure processed at 500 MPa for 1 min. For PEF treatment, the strains were suspended in NaCl solution, acid whey, or sweet whey and processed at 25 kV/cm. The lethality of UHP or PEF treatment varied considerably, depending on medium types and pH and the treated strain. Treating the tested microorganisms with UHP inactivated 0.3 to 6.9 log CFU/ml for L. monocytogenes strains and 0.0 to 4.7 log CFU/ml for the potential surrogates. When PEF was employed, populations of tested microorganisms decreased < 1.0 to 5.3 log CFU/ml. L. monocytogenes V7 and OSY-8578 were among the most resistant strains to UHP and PEF treatments, and thus are candidate target strains. Lactobacillus plantarum ATCC 8014 demonstrated similar or greater resistance compared with the target organisms; therefore, the bacterium is proposed as a surrogate of L. monocytogenes for both processes under the conditions specified in the food matrices tested in this study.

Purification and characterization of an antioxidant protein (∼16 kDa) from Terminalia chebula fruit

Terminalia chebula fruit is used as folk medicine in India and Southeast Asia. An antioxidant protein was isolated by bioassay guided fractionation of T.chebula fruit by homogenizing in the citrate phosphate buffer. The isolated protein (TCP-III) obtained from fruit was purified by gel chromatography and preparative HPLC, showed apparent molecular weight of 16kDa by SDS–PAGE and MALDI-TOF/MS analyses. Amino acid sequence obtained by LC–MSE analysis showed homology with the predicted protein fragments of Populus trichocarpa, putative uncharacterized protein fragments from Oryza sativa and with fragments of 17kDa thylakoid lumenal protein from Spinacia oleracea. TCP-III exhibited significant radical scavenging in DPPH, NO, H2O2 and ABTS assays. In addition, TCP-III inhibited oxidation of linoleic acid in β-carotene bleaching assay, reduced ferric ions and chelated ferrous ions. The present finding demonstrates uniquely, for the first time, characterization of an antioxidant protein from T. chebula fruit.