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ABSTRACT: Large amounts of fresh seed epicarp of Nelumbo nucifera Gaertn. (FSENN) are discarded in China without any utilization. The aim of this study was to identify the flavonols found
in a fraction of an extract of FSENN, and to measure their levels and investigate antioxidant properties. Glycosylated flavonols
in fraction 2 (Fr2) from the extract of FSENN and their aglycones were identified by HPLC-ESI–MS2 (negative mode), and six glycosylated and one aglycone flavonols in Fr2 were found. We also quantified flavonol aglycones
(myricetin, quercetin, kaempferol and isorhamnetin) using HPLC method. The result showed that the quercetin content (10.2mg/g
of dry fraction) was higher than that of other aglycones. Antioxidant properties of Fr2 were evaluated in vitro by a number
of methods including 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, the β-carotene bleaching method, and hydroxyl
radical and hydrogen peroxide scavenging ability using the chemiluminescence method. This antioxidant potential in terms of
IC50 values was 5.48, 40±0.14 and 0.62±0.05μg (dry Fr2)/mL on DPPH radicals, hydroxyl radicals and hydrogen peroxide, respectively.
The Fr2 also exhibited antioxidant property in the β-carotene bleaching assay. In total, it possesses high levels of flavonol
compounds with high antioxidant potential, and it is beneficial for the treatment or prevention of a variety of diseases and
has nutraceutical potential.
KeywordsSeed epicarp (Nelumbo nucifera Gaertn.)-Flavonols and flavonol glycosides-Flavonol contents-HPLC-ESI-MS2
-Antioxidant
European Food Research and Technology 04/2012; 231(3):387-394. · 1.57 Impact Factor
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ABSTRACT: Isoquinoline alkaloids from leaves of Nelumbo nucifera (N. nucifera) were extracted using supercritical CO2. The effects of the parameters such as the dynamic extraction time, temperature, pressure, various modifiers, and flow rate
of the modifier on the yield of nuciferine and the ratio of total isoquinoline alkaloids to the total extract were investigated.
Nuciferine content of the extract was determined by high-performance liquid chromatography (HPLC). The results indicated that
the yield of nuciferine increased with increases in the dynamic extraction time, pressure, temperature, and flow rate of the
modifier. The highest nuciferine yield of 325.54μg/g was obtained when the extraction was carried out for 2h at 70°C under
30MPa, with 10% (v/v) diethylamine and 1% (v/v) water in methanol as the modifier which kept a flow rate of 1.2mL/min. The
ratio of total isoquinoline alkaloids to the extract was 49.85% at the highest nuciferine yield. Five kinds of isoquinoline
alkaloids extracted from N. nucifera leaves were identified by high-performance liquid chromatography combined with ion trap/time-of-flight mass spectrometry
(LC/MS-ITTOF). They were Dehydronuciferine, N-nornuciferine, O-nornuciferine, Nuciferine, and Roemerine in the order of retention
time.
KeywordsSupercritical fluid extraction (SFE)-Isoquinoline alkaloids-
Nelumbo nucifera (N. nucifera)-High-performance liquid chromatography (HPLC)-High-performance liquid chromatography-ion trap/time-of-flight mass spectrometry (LC/MS-ITTOF)
European Food Research and Technology 04/2012; 231(3):407-414. · 1.57 Impact Factor
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ABSTRACT: The major purpose of this study was to determine the effect of procyanidins extracted from the lotus seedpod (LSPC) on the nitric oxide (NO) system in the hippocampus and cerebral cortex in cognitively impaired aged rats. Using the Morris water maze, aged-unimpaired (AU) and aged-impaired (AI) rats were chosen from aged rats. All aged rats exhibited elevated inducible nitric oxide synthase (iNOS) activities and decreased neuronal nitric oxide synthase (nNOS) activities in the both brain regions. The changes were more pronounced in the brain of AI rats, especially in the hippocampus. Furthermore, AI rats greatly lowed the percentage of change of hippocampal nNOS activity in the presence of protein kinase inhibitors or phosphatase inhibitor, which meant that AI animals existed in a hardly modified nNOS dephosphorylated state in hippocampus. LSPC supplementation [50, 100 mg/kg of body weight (BW), per os (p.o.)] for 7 weeks significantly decreased iNOS activities and improved hippocampal nNOS phosphorylation status in AI animals. These results suggested that changes in the NO system may involve in the ameliorative effects of LSPC on cognitive deficits in AI animals.
Rejuvenation Research 02/2011; 14(1):33-43. · 3.83 Impact Factor
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Jiqu Xu,
Shuang Rong, Bijun Xie,
Zhida Sun,
Qianchun Deng,
Hailei Wu,
Wei Bao,
Di Wang,
Ping Yao,
Fenghong Huang,
Liegang Liu
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ABSTRACT: The major purpose of this study was to determine the effects of procyanidins extracted from the lotus seedpod on cAMP-response element-binding protein phosphorylation in hippocampus and cerebral cortex in cognitively impaired aged rats. Based on Morris water maze, aged unimpaired and aged impaired rats were chosen from aged rats. Comparing with young and aged unimpaired animals, aged impaired rats exhibited significant reduction in hippocampal but not cortical cAMP-response element-binding phosphorylation states as well as brain-derived neurotrophic factor messenger RNA and protein expressions, which were accompanied by decreased phosphorylation states of hippocampal extracellular signal-related kinase (42/44) and calcium calmodulin kinase IV. Lotus seedpod supplementation (50 and 100 mg/kg body weight intragastric administration) for 7 weeks significantly reversed all these declines happened in hippocampus except calcium calmodulin kinase IV phosphorylation levels. These results suggested that lotus seedpod might enhance cAMP-response element-binding-dependent transcription through the activation of extracellular signal-related kinase signalling pathway, which might contribute to its ameliorative effects on cognitive deficits in aged impaired animals.
The Journals of Gerontology Series A Biological Sciences and Medical Sciences 09/2010; 65(9):933-40. · 4.60 Impact Factor
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ABSTRACT: The alleviative effect of procyanidins extracted from the lotus seedpod (LSPC) on oxidative stress in various tissues was evaluated by determining the activities of the antioxidant enzymes and the content of reduced glutathione (GSH) in heart, liver, lung, kidney, skeletal muscle, and serum in aged rats. Aging led to antioxidant deficit in various tissues in this study, which is confirmed by remarkable increased lipid peroxidation, whereas the change patterns of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and GSH were diverse in various tissues of aged rats. LSPC treatment (50 and 100 mg/kg body weight) modified the activity of SOD, CAT, and GPx as well as GSH content alteration in these tissues, which reversed the age-related antioxidant deficit in aged rats. However, the regulatory patterns on the activities of these enzymes and GSH content by LSPC treatment were different according to the tissues in aged rats.
The Journals of Gerontology Series A Biological Sciences and Medical Sciences 03/2010; 65(3):236-41. · 4.60 Impact Factor
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ABSTRACT: The major purpose of this study was to determine the effect of procyanidins extracted from the lotus seedpod (LSPC) on the learning and memory impairments in cognitively impaired aged rats. Based on Morris water maze performance compared with young female rats, aged unimpaired (AU) and aged impaired (AI) rats were chosen from aged female rats. LSPC supplementation (50, 100 mg/kg BW, p.o.) for 7 weeks significantly improved learning and memory impairments in AI animals in the Morris water maze test, as evaluated by shortened escape latency and swimming distance. Aged rats had significantly declined antioxidant defense capacities and significantly increased lipid peroxidation and protein oxidation levels in hippocampus and cerebral cortex than young rats. Further, AI group had higher protein oxidation level compared with AU group. LSPC (50, 100 mg/kg BW, p.o.) significantly reversed the decline of antioxidant defense capacities and significantly reduced lipid peroxidation and protein oxidation levels in hippocampus and cerebral cortex of AI rats. In addition, LSPC significantly restored acetylcholine (ACh) contents and acetylcholinesterase (AChE) activities in hippocampus and cerebral cortex of AI animals. The results of this study suggest that LSPC may play a useful role in the treatment of cognitive impairment caused by Alzheimer's disease and aging.
European neuropsychopharmacology: the journal of the European College of Neuropsychopharmacology 09/2009; 19(12):851-60. · 3.68 Impact Factor
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ABSTRACT: The major purpose of this study was to determine the effect of procyanidins extracted from the lotus seedpod (LSPC) on the learning and memory impairments induced by scopolamine (1 mg/kg, i.p.) in mice. The capacities of memory and learning were evaluated by the Morris water maze and the step-down avoidance test. LSPC (50, 100, 150 mg/kg BW, p.o.) significantly reversed scopolamine-induced learning and memory impairments in the Morris water maze test, as evaluated by shortened escape latency and swimming distance. In the step-down avoidance test, LSPC (50, 100, 150 mg/kg BW, p.o.) treatment significantly reduced the number of errors and shortened latency compared with that of scopolamine. In addition, LSPC was also found to inhibit acetyl cholinesterase (AChE) activity. These results of this study suggest that LSPC may play a useful role in the treatment of cognitive impairment caused by AD and aging.
Phytotherapy Research 04/2009; 23(12):1742-7. · 2.09 Impact Factor
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ABSTRACT: We investigated the effects of lotus seedpod proanthocyanidins (LSPC) administration by oral gavage for 3 months on body weight, learning and memory deficits using Y-maze test, oxidative stress and antioxidative enzyme activity in brain and serum of the senescence-accelerated mice (SAMP8) and the senescence-resistant mice (SAMR1). Mice of each group were weighed weekly. Brain was obtained from SAMP8 and SAMR1 (the control mouse for SAMP8) at 6 months of age and serum was available from SAMP8 and SAMR1 at 3, 4, 5 and 6 months of age. The results of body weight showed that 90mg/kg LSPC administration significantly increased body weight at 5.5 and 6 months of age in SAMP8 when compared with control SAMP8 of the same age. Y-maze test indicated that learning and memory abilities of mice were deteriorated significantly at 6 months of age in SAMP8 compared with age-matched SAMR1, but were remarkably improved after LSPC (60, 90, 120mg/kg body weight) administration beginning at 3 months of ages. Malondialdehyde (MDA), nitric oxide (NO) and nitric oxide synthase (NOS) exhibited significant increases mostly at 5 and 6 months of age in SAMP8. Glutathione (GSH), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities decreased significantly mostly at 5 and 6 months of age in SAMP8. LSPC (60, 90, 120mg/kg body weight) administration beginning at 3 months of ages decreased MDA, NO content and lowered NOS activity in the brain and serum of SAMP8. Furthermore, LSPC significantly increased GSH level and augmented GPx, SOD activity in the brain and serum of SAMP8. These results suggest that an age-related increase in brain tissue vulnerability to oxidation and deterioration in learning and memory abilities in SAM that can be modified by LSPC, most likely through the ability of LSPC to scavenge oxygen free radicals and to stimulate antioxidant enzyme activity.
Behavioural Brain Research 12/2008; 194(1):100-7. · 3.42 Impact Factor
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ABSTRACT: BACKGROUND: To contribute towards understanding the relationship of structure and bioactivity, a protein-bound acidic polysaccharide named TPC3-1 was isolated and purified from low-grade green tea (Camellia sinensis L.). The homogeneity and weight average molecular weight of TPC3-1 was determined by agarose gel electrophoresis and high-performance gel permeation chromatography. The monosaccharide and amino acid composition of TPC3-1 were analysed by gas chromatography and an amino acid analyser. The molecular structure of TPC3-1 was characterised by Fourier transform infrared spectroscopy, 13C nuclear magnetic resonance spectroscopy and atomic force microscopy.RESULTS: Based on the data obtained, the average peak molecular weight of TPC3-1 was about 120 kDa. TPC3-1 was composed of L-arabinose, D-ribose, D-xylose, D-glucose and D-galactose with a molar ratio of 4.9:2.2:3.1:1.8:1.0. Fifteen amino acids were identified as components of the polymer. The TPC3-1 molecule was found to have an anomeric carbon sign of both and β configurations and high-branched chains. The network structure of TPC3-1 was observed.CONCLUSION: The tea polysaccharide TPC3-1 was an acid protein-bound polysaccharide with an image of network structure. The results presented here will facilitate further study of the relationship between the chemical structure and biological role of tea polysaccharide. Copyright © 2008 Society of Chemical Industry
Journal of the Science of Food and Agriculture 09/2008; 88(14):2523 - 2528. · 1.44 Impact Factor
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ABSTRACT: Volatile compounds of fresh blood orange juice were analyzed by solid phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS) and the aroma active compounds were identified by olfactometry. The volatile compounds were extracted by headspace solid phase microextraction (HS-SPME) using a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber for 40 min at 40 degrees C. The analysis was carried out using an HP 6890N GC equipped with an HP-5 column (30 m x 0.25 mm x 0.25 microm ) directly connected to an HP 5975 series mass selective detector and a sniffing port (ODP2, Gerstel) using helium as carrier gas. Compound identifications were made by the comparison of the mass spectra, retention times, retention indices (I(R)) and odor of the volatile components in the extracts with those of the corresponding reference standards. Forty-six compounds were identified by GC-MS and I(R). The major components of the juice were limonene (86.36%), linalool (3.69%), beta-myrcene (1.79%), octanal (1.32%) and valencene (1.27%). GC-MS-olfactometry analysis was performed to determine 34 compounds with aroma activity, of which 23 compounds were identified. The major contributors to orange juice aroma activity are ethyl butanoate, octanal, gamma-terpinene, 4-acetyl-1-methyleyclohexene, decanal, (-)-carvone, geranyl acetate, valencene. These compounds of strong aroma intensity represent 7.22% of the total volatile compounds. Other four unknown compounds (I(R), <800; I(R) = 1020, 1143, 1169, separately) are also the major contributors to the overall aroma.
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui 07/2008; 26(4):509-14.
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ABSTRACT: This paper describes the binding of Calcofluor, a fluorescent probe, to oat beta-glucan in buffer solutions. The binding equilibrium constant (K), the total number of binding sites per beta-glucan molecule (N), and the average binding number of Calcofluor per beta-glucan molecule (n) were determined by UV spectroscopic method. The results indicate that the association of Calcofluor and beta-glucan is driven by both enthalpy and entropy and that the process involves hydrogen bonding, van der Waals forces, and hydrophobic interaction. Higher buffer concentration and NaCl facilitate the binding of Calcofluor to beta-glucan. The adsorption isotherm fits a Langmuir model quite well.
Journal of Agricultural and Food Chemistry 03/2008; 56(3):1131-7. · 2.82 Impact Factor
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ABSTRACT: Aflatoxin B(1) (AFB(1)), which is commonly found in agricultural commodities, is one of the most potent carcinogenic mycotoxins. To ensure food safety, rapid and low-cost immunological methods have been applied to detect AFB(1) worldwide. A key step in these immunological methods is coupling AFB(1) to carrier proteins; AFB(1) is usually deviated to AFB(1)-oxime and coupled to carrier proteins to form the AFB(1)-oxime-protein conjugate. In the current research, AFB(1) was directly coupled with cationized bovine serum albumin (cBSA) using a method based on Mannich-type principles. The coupling effects were investigated with different initial molar ratios of AFB(1) to cBSA. The conjugate molar ratio was 6.4:1 when the initial molar ratio was 40:1. The cationized proteins and their conjugates were identified by UV-Vis and FT-IR spectra, which showed the characteristic bands of the ethylendiamine group and AFB(1), respectively. After BALB/c mice were immunized with AFB(1)-cBSA, a quicker immunological response and a similar sensitivity of antisera against AFB(1) were observed, compared with immunization by AFB(1)-oxime-BSA. This suggests that the Mannich-type reaction might be an alternative method of preparation for AFB(1)-protein.
Journal of Immunological Methods 01/2008; 328(1-2):79-88. · 2.20 Impact Factor
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ABSTRACT: The degradation mechanism of cyanidin 3-rutinoside in the presence of (-)-epicatechin and litchi pericarp polyphenol oxidase (PPO) was investigated using several model systems. The enzymically generated (-)-epicatechin o-quinone could induce cyanidin 3-rutinoside degradation. The results obtained in this study allowed us to propose a pathway for cyanidin 3-rutinoside degradation in the presence of (-)-epicatechin and litchi pericarp PPO. First, enzymatic oxidation of (-)-epicatechin produced the corresponding o-quinone, and then cyanidin 3-rutinoside and (-)-epicatechin competed for (-)-epicatechin o-quinone, resulting in degradation of cyanidin 3-rutinoside and regeneration of (-)-epicatechin. Moreover, the results of kinetic studies indicated this competition was influenced by both (-)-epicatechin concentration and cyanidin 3-rutinoside concentration in the model system.
Journal of Agricultural and Food Chemistry 11/2007; 55(22):9074-8. · 2.82 Impact Factor
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ABSTRACT: Hydrophobins are a family of small, moderately hydrophobic proteins with eight cysteine residues arranged in a conserved pattern. A full-length cDNA, designated Po.hyd, corresponding to a hydrophobin gene of Pleurotus ostreatus was obtained in our previous work. The Po.hyd gene contains a 333 bp open reading frame (ORF), which is interrupted by two typical classI introns. There was no consensus signal for a polyA tail detected in the 3'untranslated region. However, an analogous T- or TG-rich motif was observed that probably influence the formation of the mRNA 3' end. We assign the putative Po.HYD protein to the classI hydrophobins since its sequence arrangement and hydropathy pattern has a high consensus to other known class I hydrophobins. Northern analysis showed that the Po.hyd gene was abundantly expressed throughout the fruiting process (from primordium to mature fruiting body) but silenced during vegetative growth of the mycelium. Southern blot analysis showed Po.hyd to be a single copy gene in the genome of dikaryotic strain likely to locate at the same locus within the two parental genomes.
Journal of Basic Microbiology 09/2007; 47(4):317-24. · 1.27 Impact Factor
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ABSTRACT: Polyphenol oxidase (PPO) from litchi (Litchi chinensis Sonn.) pericarp was characterized using (-)-epicatechin, which was the major endogenous polyphenol in litchi pericarp as a substrate. The optimum pH for PPO activity with (-)-epicatechin was 7.5, and the enzyme was unstable below pH 4.5 and stable in the pH range of 6.0-8.0. Residual activities of PPO were 86.25, 86.31, and 80.17% after 67 days of incubation at 4 degrees C at pH 6.0, 7.5, and 8.0, respectively. From thermostability studies, the Ki value increased with temperature and the results suggested that the enzyme was unstable above 45 degrees C. Moreover, the results also provided strong evidence that the denaturalization temperature of PPO was near 70 degrees C. The inhibition studies indicated that l-cysteine and glutathione were strong inhibitors even at low concentrations while NaF inhibited moderately. In addition, the results also indicated that the inhibition mechanisms of thiol groups were different from those of halide salts.
Journal of Agricultural and Food Chemistry 09/2007; 55(17):7140-3. · 2.82 Impact Factor
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ABSTRACT: The antioxidant activities of three parts (peel, juice, and seed) and extracts of three pomegranate varieties in China were investigated by using a chemiluminescence (CL) method in vitro. The scavenging ability of pomegranate extracts (PEs) on superoxide anion, hydroxide radical, and hydrogen peroxide was determined by the pyrogallol-luminol system, the CuSO4-Phen-Vc-H2O2 system, and the luminol-H2O2 system, respectively. DNA damage preventing the effect of PE was determined by the CuSO4-Phen-Vc-H2O2-DNA CL system. The results showed that the peel extract of red pomegranate had the best effect on the scavenging ability of superoxide anion because its IC50 value (4.01 +/- 0.09 microg/mL) was the lowest in all PEs. The seed extract of white pomegranate could scavenge hydroxide radical most effectively of the nine extracts (the IC50 value was 1.69 +/- 0.03 microg/mL). The peel extract of white pomegranate had the best scavenging ability on hydrogen peroxide, which had the lowest IC50 value (0.032 +/- 0.003 microg/mL) in the nine extracts. The seed extract of white pomegranate (the IC50 value was 3.67 +/- 0.03 microg/mL) was the most powerful on the DNA damage-preventing effect in all of the PEs. Also, the statistical analysis indicated that there were significant differences (at P < 0.05) among the extracts of the different varieties and parts in each system.
Journal of Agricultural and Food Chemistry 05/2007; 55(8):3134-40. · 2.82 Impact Factor
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ABSTRACT: Tea polysaccharide conjugate is one of the main bioactive constituents of tea (Camellia sinensis L.). The chemical composition and preliminary toxicological evaluation of a tea polysaccharide conjugate was investigated to determine the possibility of using it for human consumption. Chemical analysis of tea polysaccharide conjugate showed that the tea polysaccharide conjugate was a nonstarch protein bounded acidic polysaccharide. The protein, neutral sugar, and uronic acid content of the tea polysaccharide conjugate was 3.5%, 44.2%, and 43.1%, respectively. The contents of iron, magnesium, zinc, and selenium in the tea and its polysaccharide conjugate were measured by inductively coupled plasma-optical emission spectrometry (ICP-OES). Results showed that the contents of four elements in tea polysaccharide conjugate were much higher than that of tea power. Especially, the content of iron in tea polysaccharide conjugate was increased 5.9 times. The tea polysaccharide conjugate, when fed to mice, was found to have no toxicity to the liver, kidney, heart, thymus, or spleen of the mice and none of the mice died throughout the period of the experiment. There was no significant difference between the thymus index, spleen index, and liver index of the mice from the test and control groups (P>0.05). On the basis of the study, the tea polysaccharide conjugate may be classified either as a very low toxicity substance, that is, GHS Category 5 (globally harmonized system), or as unclassified when orally administrated to mice. It might be a candidate of dietary supplements besides the bioactivities as a polysaccharide.
Journal of Agricultural and Food Chemistry 03/2007; 55(6):2256-60. · 2.82 Impact Factor
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ABSTRACT: The aim of this study was to investigate the effects of sea buckthorn procyanidins (SBPC) on healing of acetic acid-induced lesions in the rat stomach and its possible mechanism. The sea buckthorn procyanidins (SBPC) were extracted with 60% alcohol/H2O from sea buckthorn bark and purified by macropore adsorption resin column, with a purity of >96%. The chemical character of SBPC was analyzed by reverse phase high-performance liquid chromatography/mass spectrometry (HPLC/MS). Chronic gastric ulceration was induced by injecting acetic acid into the subserosa of stomach. Different concentrations of SBPC were orally administrated to gastric ulcers rats. After treatment 7d and 14d, rats were sacrificed respectively. The healing of the acetic acid induced ulcerations was measured by ulcer index (UI). The level of epidermal growth factor (EGF) in plasma was determined; the expression of epidermal growth factor receptor (EGFR) and proliferating cell nuclear antigen (PCNA) around ulcer was detected by immunohistochemical method. SBPC was found to reduce the size of the ulcers at day 7 and 14 in a dose-dependent manner. Compared with the control, the UI of SBPC group was significantly lower (p< 0.01) and the level of EGF in the plasma of SBPC group increased significantly (p< 0.01), meanwhile the expression of EGFR and PCNA around ulcer in high-dose SBPC stomach were enhanced (p< 0.05). The results implied that SBPC plays an important role in healing of acetic acid-induced gastric lesions possibly by the acceleration of the mucosal repair.
Asia Pacific Journal of Clinical Nutrition 01/2007; 16 Suppl 1:234-8. · 1.13 Impact Factor
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ABSTRACT: The antimicrobial effect of konjac glucomannan (KGM) edible ûlm incorporating chitosan (CHI) and nisin at various ratios or concentrations was studied. This activity was tested against pathogenic bacteria, namely, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus. Mechanical and physical properties were determined, and the results indicated that the blend film KC2 (mixing ratio KGM 80/ CHI 20) showed the maximum tensile strength (102.8 ± 3.8 MPa) and good transparency, water solubility, and water vapor transmission ratio. Differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy were used to characterize the structural change of the blend films; and the results showed that strong intermolecular hydrogen bonds occurred between CHI and KGM. Incorporation of nisin at 463IU per disk of film for the selected KC2 was found to have antimicrobial activity against S. aureus, L. monocytogenes, and B. cereus. The mean value of inhibition zone diameter of the CHI-N series and the KC2-N series were higher than the KGM-N series at each corresponding concentration and with significant difference (P < 0.05), however, there was no significant difference in the antimicrobial effect between CHI and KC2 incorporating nisin. At all these levels, the blend ûlm KC2-nisin had a satisfactory appearance, mechanical and physical properties, and antimicrobial activity. Therefore, it could be considered as a potential “active” packaging material.
Journal of Food Science 03/2006; 71(3):C174 - C178. · 1.66 Impact Factor
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ABSTRACT: Surfactants were used to disperse oat beta-glucan. Atomic force microscopy (AFM) images of the resulting samples revealed a distribution of extended chainlike molecules and allowed, for the first time, direct visualization of single oat beta-glucan molecules with cross-sectional heights of about 0.44 nm. The number-average contour length (L(n)) and root-mean-square end-to-end distance ((R(ee)2)(1/2)) measured from the AFM images were 938 and 912 nm, respectively. The calculated persistence length (L(p)) was 526 nm. The weight-average molecular weight (M(w)) calculated from single beta-glucan molecules was 4.43 x 10(5). Samples without surfactant showed a strong tendency to form aggregates. The sample concentration, reserving time, and calcofluor as well as freezing could affect the formation of aggregates. These aggregates were visualized by both AFM and confocal scanning laser microscopy. The shape of the aggregates changed from small dots with diameters of approximately 20-50 nm to microfibrils over 3 microm long with the increasing of the concentration of oat beta-glucan from 10 to 100 microg/mL. The particle size distribution obtained by a laser particle size analyzer was 926 nm, which confirmed the size of oat beta-glucan molecules obtained from AFM images.
Journal of Agricultural and Food Chemistry 03/2006; 54(3):925-34. · 2.82 Impact Factor
