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1.
Food Chem ; 311: 125953, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31855769

RESUMO

Flubendiamide, a ryanoid family insecticide, has been linked to elevated adipogenesis. However, the influence on adipogenesis of chlorantraniliprole, another widely-used ryanoid-class insecticide in agriculture, remains unknown. Therefore, the influence of chlorantraniliprole on adipogenesis was studied in 3T3-L1 cells. Chlorantraniliprole enhanced TG content and upregulated the expression of C/EBPα, PPARγ, and ACC, three key adipogenic regulators. Chlorantraniliprole decreased the phosphorylation of AMPK, while it had no influence on the expression of endoplasmic reticulum stress regulators. The influence of chlorantraniliprole on adipogenesis was abolished by AMPKα activation. Collectively, the results indicate that chlorantraniliprole enhances adipogenesis through the AMPKα pathway, but not the ER stress-mediated pathway.

2.
J Food Sci ; 84(12): 3601-3607, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31730276

RESUMO

Sturgeon meat has been found to be suitable as surimi raw materials. The present study determined the modori phenomenon in sturgeon surimi gels and identified its relationship with cathepsins. In all heat-treated gels (25 to 90 °C, at 5 °C intervals), the 40 °C-incubated sturgeon surimi gel showed the weakest gel properties and water-holding capacity (P < 0.05), a rough protein gel network under SEM, and the highest protein solubility and trichloroacetic acid-soluble peptides content (P < 0.05). SDS-PAGE indicated that the myosin heavy chain band of sturgeon surimi gels was almost completely degraded at 40 °C. Moreover, the highest cathepsin L activity was observed in 40 °C-treated sturgeon surimi gels (P < 0.05). Our results suggested that the modori phenomenon in sturgeon surimi gels occurred at 40 °C, which was partially attributed to cathepsin L, thereby allowing for the better exploitation and utilization of sturgeon surimi.

3.
Food Chem Toxicol ; 134: 110791, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31476344

RESUMO

Previous research has shown that deltamethrin, a Type-II pyrethroid, increases fat accumulation in adipocytes and Caenorhabditis elegans. The underlying mechanisms on how deltamethrin promotes fat accumulation, however, are unknown. The aim of the current study was therefore to determine the possible mechanisms through which deltamethrin increases fat accumulation in mouse 3T3-L1 adipocytes and C. elegans. Deltamethrin (10 µM) significantly increased fat accumulation, and the expression of adipogenic regulators, such as CCAAT/enhancer-binding protein (C/EBPα) and fatty acid synthase (FAS). Deltamethrin significantly decreased the phosphorylation of AMP-activated kinase α (AMPKα), while it increased protein expression of endoplasmic reticulum (ER) stress markers in 3T3-L1 adipocytes and C. elegans. The activation of AMPK with 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) or the inhibition of ER stress with 4-phenylbutyrate (4-PBA) abolished the effects of deltamethrin on adipogenesis. Further study reveals that 4-PBA recovered the decreased AMPK phosphorylation induced by deltamethrin. These results suggest that deltamethrin promotes adipogenesis through an ER stress-AMPKα mediated pathway.

4.
J Environ Sci Health B ; 54(8): 693-701, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31271109

RESUMO

Di-n-butyl phthalate (DBP) is one of the primary PAEs (phthalate acid esters) pollutants. DBP can be absorbed by plants and threaten human health via the food chain. Some DBP-degrading bacteria have been successfully isolated from the environment (water, soil, etc.). However, only a few DBP-degrading plant endophytes have been isolated. In this study, an endophytic bacterium, Bacillus amyloliquefaciens subsp. strain JR20, which was found capable of degrading DBP, was isolated from garlic chive. We found that strain JR20 metabolized 89.74% of DBP at a 5 mg/L concentration within 4 d in liquid mineral salts medium (MSM). The optimized conditions for maximum removal of DBP were as follows: DBP concentration, 5 mg/L; pH, 7-8; temperature, 30-40 °C. The colonization of strain JR20 significantly improved the degradation rate of DBP in the roots, stems and leaves of leafy vegetables.


Assuntos
Bacillus amyloliquefaciens/metabolismo , Cebolinha-Francesa/microbiologia , Dibutilftalato/metabolismo , Verduras/microbiologia , Bacillus amyloliquefaciens/genética , Bacillus amyloliquefaciens/isolamento & purificação , Biodegradação Ambiental , Endófitos/isolamento & purificação , Endófitos/metabolismo , Poluentes Ambientais/metabolismo , Concentração de Íons de Hidrogênio , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Temperatura Ambiente , Verduras/metabolismo
5.
Food Funct ; 10(7): 3890-3897, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31187836

RESUMO

Gelatin was extracted from the swim bladder of Amur sturgeon with hot water at 50 °C with acceptable yield (76.54%) and it showed type I collagen features. The degree of hydrolysis reached 70.42%, and 26.55% of collagen peptides (380.76 Da) survived, after simulating digestion, absorption and peripheral blood circulation in vitro. In situ single-pass intestinal perfusion showed that the AMW of the collagen peptides was about 1100 Da in the intestine and they were mainly absorbed in the jejunum (61.11%). A 12-month feeding experiment using rats demonstrated that gelatin improved the histological structure, increased the thickness of the dermis (18.45%) and the density of collagen fibers (22.17%), and decreased the ratio of type III to type I collagen (43.44%) of chronologically aged skin at 3.85 g per kg bw per d. Moreover, the antioxidant enzyme activities in skin were significantly enhanced, while the malondialdehyde content was reduced by 31.99%. These results provided new insights into the development of new nutraceuticals and functional foods for the anti-skin-aging effect.

6.
Food Chem ; 295: 320-326, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174764

RESUMO

This research focused on the effects of l-arginine (l-Arg) and l-histidine (l-His) on the heat-induced aggregation of fish myosin. l-Arg/l-His increased the pH of the myosin solution from 6.82 to 8.74 and 7.24, respectively, and decreased the turbidity, aggregate size, shear modulus, and breaking force. The incorporation of l-Arg/l-His decreased the surface hydrophobicity during setting, but increased it during the two-step heating. The heat-induced aggregation of myosin was suppressed by both amino acids, with the inhibitory effect being greater for l-Arg than l-His. On one hand, the change in the pH played a critical role in suppressing the heat-induced aggregation of myosin. On the other hand, the characteristics of l-Arg/l-His themselves, such as net charges and particular R-groups, were another main contributor to aggregation suppression. Particularly, l-Arg/l-His could interact with exposed aromatic residues of myosin, and the interactions may dominate and overwhelm the burial of aromatic residues during two-step heating.


Assuntos
Arginina/química , Proteínas de Peixes da Dieta/química , Histidina/química , Miosinas/química , Animais , Cyprinidae , Proteínas de Peixes da Dieta/metabolismo , Géis/química , Temperatura Alta , Interações Hidrofóbicas e Hidrofílicas , Miosinas/metabolismo
7.
Mar Drugs ; 17(6)2019 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-31181804

RESUMO

Zinc-binding peptides from oyster (Crassostrea gigas) have potential effects on zinc supplementation. The aim of this study was to prepare efficient zinc-binding peptides from oyster-modified hydrolysates by adding exogenous glutamate according to the plastein reaction and to further explore the zinc absorption mechanism of the peptide-zinc complex (MZ). The optimum conditions for the plastein reaction were as follows: pH 5.0, 40 °C, substrate concentration of 40%, pepsin dosage of 500 U/g, reaction time of 3 h and l-[1-13C]glutamate concentration of 10 mg/mL. The results of 13C isotope labelling suggested that the addition of l-[1-13C]glutamate contributed to the increase in the zinc-binding capacity of the peptide. The hydrophobic interaction was the main mechanism of action of the plastein reaction. Ultraviolet spectra and scanning electronic microscopy (SEM) revealed that the zinc-binding peptide could bind with zinc and form MZ. Furthermore, MZ could significantly enhance zinc bioavailability in the presence of phytic acid, compared to the commonly used ZnSO4. Additionally, MZ significantly promoted the intestinal absorption of zinc mainly through two pathways, the zinc ion channel and the small peptide transport pathway. Our work attempted to increase the understanding of the zinc absorption mechanism of MZ and to support the potential application of MZ as a supplementary medicine.


Assuntos
Técnicas de Química Analítica/métodos , Absorção Intestinal/efeitos dos fármacos , Ostreidae/química , Peptídeos/química , Peptídeos/farmacologia , Zinco/química , Zinco/metabolismo , Animais , Disponibilidade Biológica , Quelantes/química , Hidrolisados de Proteína/química
8.
Food Funct ; 10(4): 1940-1947, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30874277

RESUMO

Vitexin, a bioactive compound isolated from hawthorn leaf extracts, has been reported to exhibit many biological activities, such as anticancer, antioxidation, and adipogenesis inhibition activities. The current study explored the effects of vitexin on high fat diet (HFD)-induced obesity/adipogenesis in male C57BL/6J mice and 3T3-L1 adipocytes, as well as the underlying mechanisms thereof. Vitexin significantly mitigated HFD-induced body weight gain and adiposity. Vitexin also partially normalized serum, hepatic lipid contents, and decreased adipocyte size induced by the HFD. Consistently, there were significant effects of vitexin on important regulators of lipid metabolism, including AMP-activated protein kinase-α (AMPKα), CAATT element binding protein-α (C/EBPα), and fatty acid synthase (FAS) in white adipose tissue. Moreover, vitexin significantly inhibited fat accumulation in 3T3-L1 adipocytes, and this was totally abolished by compound C (an AMPKα inhibitor). These results suggest that vitexin may prevent HFD-induced obesity/adipogenesis via the AMPKα mediated pathway.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Fármacos Antiobesidade/administração & dosagem , Apigenina/administração & dosagem , Obesidade/tratamento farmacológico , Células 3T3-L1 , Proteínas Quinases Ativadas por AMP/genética , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Dieta Hiperlipídica/efeitos adversos , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/etiologia , Obesidade/genética , Obesidade/metabolismo , Transdução de Sinais/efeitos dos fármacos
9.
J Agric Food Chem ; 67(33): 9178-9186, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-30835107

RESUMO

Chicoric acid is a dicaffeoyl ester with many bioactivities, including antioxidation, antidiabetes, and anti-inflammation. A previous study reported that chicoric acid extended the lifespan in Caenorhabditis elegans; however, the mechanism behind the effect of chicoric acid on the extended lifespan remains unknown. Consistent with the previous report, chicoric acid (25 and 50 µM) extended the maximum lifespan compared to the control (17.5 ± 3.3 and 15.6 ± 5%, respectively; p < 0.001 for both). The declines of the pumping rate and locomotive activity, two indicators of aging, were delayed by chicoric acid. Moreover, chicoric acid enhanced resistance to oxidative stress in C. elegans. It was further determined that the extended lifespan by chicoric acid was in part via aak-2 [a homologue of adenosine monophosphate (AMP)-activated protein kinase] and skn-1 (a homologue of nuclear factor erythroid 2-related factor 2). The current findings suggest that chicoric acid has the potential to be used as an anti-aging bioactive compound.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/crescimento & desenvolvimento , Ácidos Cafeicos/farmacologia , Proteínas de Ligação a DNA/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Succinatos/farmacologia , Fatores de Transcrição/metabolismo , Animais , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ligação a DNA/genética , Feminino , Longevidade/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/genética , Fatores de Transcrição/genética
10.
Molecules ; 24(4)2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30781435

RESUMO

This study investigated the effects of α-tocopherol (α-TOH) on the physicochemical properties of sturgeon surimi during 16-week storage at -18 °C. An aliquot of 0.1% (w/w) of α-TOH was added into the surimi and subjected to frozen storage, and 8% of a conventional cryoprotectant (4% sorbitol and 4% sucrose, w/w) was used as a positive control. Based on total viable count, pH and whiteness, α-TOH exhibited a better protection for frozen sturgeon surimi than cryoprotectant during frozen storage. According to soluble protein content, carbonyl content, total sulfhydryl content, and surface hydrophobicity, α-TOH and cryoprotectant showed the same effects on retarding changes of proteins. The results of breaking force, deformation, gel strength, water-holding capacity and microstructure of sturgeon surimi indicated that the gel properties of frozen sturgeon surimi were retained by α-TOH. Our results suggest that α-TOH is an attractive candidate to maintain the quality of sturgeon surimi during frozen storage.


Assuntos
Crioprotetores/farmacologia , Peixes/metabolismo , Congelamento , alfa-Tocoferol/farmacologia , Animais , Produtos Pesqueiros/análise , Produtos Pesqueiros/microbiologia , Conservação de Alimentos/métodos , Armazenamento de Alimentos/métodos , Compostos de Sulfidrila/metabolismo
11.
Molecules ; 23(11)2018 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-30424524

RESUMO

Flubendiamide, a ryanoid class insecticide, is widely used in agriculture. Several insecticides have been reported to promote adipogenesis. However, the potential influence of flubendiamide on adipogenesis is largely unknown. The current study was therefore to determine the effects of flubendiamide on adipogenesis utilizing the 3T3-L1 adipocytes model. Flubendiamide treatment not only enhanced triglyceride content in 3T3-L1 adipocytes, but also increased the expression of cytosine-cytosine-adenosine-adenosine-thymidine (CCAAT)/enhancer-binding protein α and peroxisome proliferator-activated receptor gamma-γ, two important regulators of adipocyte differentiation. Moreover, the expression of the most important regulator of lipogenesis, acetyl coenzyme A carboxylase, was also increased after flubendiamide treatment. Further study revealed that 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) or A769662, two Adenosine 5'-monophosphate (AMP)-activated protein kinase α activators, subverted effects of flubendiamide on enhanced adipogenesis. Together, these results suggest that flubendiamide promotes adipogenesis via an AMPKα-mediated pathway.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Adipogenia/efeitos dos fármacos , Benzamidas/farmacologia , Sulfonas/farmacologia , Células 3T3-L1 , Adipócitos/citologia , Animais , Diferenciação Celular/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Camundongos , Triglicerídeos/metabolismo
12.
Food Funct ; 9(8): 4135-4142, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30019729

RESUMO

In this study, with grass fish bones as the substrate, after flavourzyme treatment, and fermentation with Leuconostoc mesenteroides, a fermentation solution with a high content of soluble calcium was obtained. High performance liquid chromatography and GC-MS analysis indicated that free calcium (11.29 mmol L-1) in the fermentation solution was composed of calcium lactate (3.89 mmol L-1), calcium acetate (6.21 mmol L-1), calcium amino acids and small peptide calcium. Animal experiments show that the fermentation solution of grass fish bones could promote the growth and development of calcium-deficient rats. Complex organic calcium could be well absorbed and utilized by rats so that serum calcium, alkaline phosphatase levels, femur weight and other indicators in calcium-deficient rats could be returned to normal levels. The fermentation solution of grass fish bones can avoid the waste of aquatic proteins and fish bone calcium, and it exhibited high calcium bioavailability. Therefore, the fermentation solution of grass fish bones might be used as a new efficient calcium supplement.


Assuntos
Osso e Ossos/química , Cálcio/farmacocinética , Carpas , Fosfatase Alcalina , Ração Animal/análise , Animais , Densidade Óssea , Cálcio/administração & dosagem , Cálcio/sangue , Cálcio/química , Dieta/veterinária , Fermentação , Manipulação de Alimentos , Leuconostoc mesenteroides/fisiologia , Masculino , Fósforo/sangue , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
13.
J Agric Food Chem ; 66(19): 4820-4826, 2018 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-29701967

RESUMO

Insulin and an antacid [Mg(OH)2] were co-encapsulated inside calcium alginate microgels (diameter = 280 µm) using a vibrating nozzle injector. Confocal microscopy indicated that insulin was successfully encapsulated inside the microgels and remained inside them after they were exposed to simulated gastric conditions. Localized fluorescence intensity measurements indicated that the internal pH of the antacid-loaded microgels was around pH 7.4 after incubation in acidic gastric fluids but below the limit of detection (pH < 4) in the antacid-free microgels. After incubation in small intestine conditions, around 30% of the insulin was released from the antacid-loaded microgels over a 2 h period. Encapsulation of insulin within the antacid-loaded microgels increased its biological activity after exposure to simulated gastric conditions. In particular, the encapsulated insulin significantly increased Akt phosphorylation at both Thr308 and Ser473 in L6 myotubes when compared to free insulin.


Assuntos
Antiácidos/química , Diabetes Mellitus/tratamento farmacológico , Composição de Medicamentos/métodos , Insulina/química , Intestino Delgado/efeitos dos fármacos , Substâncias Protetoras/química , Administração Oral , Antiácidos/administração & dosagem , Diabetes Mellitus/metabolismo , Combinação de Medicamentos , Géis/química , Humanos , Concentração de Íons de Hidrogênio , Insulina/administração & dosagem , Intestino Delgado/metabolismo , Substâncias Protetoras/administração & dosagem
14.
J Sci Food Agric ; 97(5): 1412-1419, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27378532

RESUMO

BACKGROUND: Because proteases play an important role in the fermentation of fish sauce, the purification and characterisation of an extracellular protease from the halophilic archaeon Halogranum rubrum was investigated. RESULTS: The molecular mass of the protease was estimated to be approximately 47 kDa based on sodium dodecyl sulfate-polyacrylamide gel electropheresis (SDS-PAGE) and native-PAGE analysis. The optimum conditions for catalytic activity were pH 8.0 and 50°C. The protease showed alkaline stability (pH 7.0-10.0). The protease also exhibited novel catalytic ability over a broad range of salinity (NaCl 0-3 mol L-1 ). Calcium ion enhanced the proteolytic activity of the enzyme. The Km and Vmax values of the purified protease for casein were calculated to be 4.89 mg mL-1 and 1111.11 U mL-1 , respectively. The protease was strongly inhibited by ethylenediamine tetraacetic acid (EDTA) and phenylmethanesulfonyl fluoride (PMSF). Meanwhile, the protease was stable in the presence of Triton X-100, isopropanol, ethanol or dithio-bis-nitrobenzoic (DTNB), but was inhibited by sodium dodecyl sulfate (SDS), dimethyl sulfoxide (DMSO) or methanol. MALDI -TOF/TOF MS analysis revealed that the protease shared some functional traits with protease produced by Halogranum salarium. Furthermore, it exhibited high hydrolytic activity on silver carp myosin protein. CONCLUSION: The protease is an alkaline and salt-tolerant enzyme that hydrolyses silver carp myosin with high efficiency. These excellent characteristics make this protease an attractive candidate for industrial use in low-salt fish sauce fermentation. © 2016 Society of Chemical Industry.


Assuntos
Euryarchaeota/enzimologia , Peptídeo Hidrolases/química , Animais , Carpas , Estabilidade Enzimática , Produtos Pesqueiros/análise , Concentração de Íons de Hidrogênio , Hidrólise , Peso Molecular , Miosinas/química , Peptídeo Hidrolases/isolamento & purificação , Cloreto de Sódio/química
15.
Food Sci Biotechnol ; 25(1): 21-26, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-30263231

RESUMO

Changes in white shrimp (Litopenaeus vannamei) protein during thermal denaturation were studied using Raman spectroscopy and isotopic H/D exchange. Denaturation of shrimp protein began after heating for 10 min at 50°C. A decrease in the percentage of α-helices accompanied by an increase in the percentage of ß-sheets occurred while the total percentage of disordered structures increased. With extension of the exchange time, the relative intensity of the O-D bond increased, accompanied by a higher relative O-D bond intensity for heated shrimp, compared with unheated shrimp. H/D exchange revealed a higher rate of deuteration kinetics in heated shrimp than for unheated shrimp, especially during the first 2 h, consistent with water loss from denatured white shrimp protein. Physical property changes in muscle tissue can be caused by changes in hydrogen bonding and hydrophobicity during thermal processes.

16.
Food Chem ; 166: 473-8, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25053082

RESUMO

Sea urchin gangliosides have been proved to contain neuritogenic activities, which related to their molecular compositions. This study reports a method utilizing reversed-phase chromatography coupled to mass spectrometry for structure investigation and molecular species determination of the monosialogangliosides from sea urchin Strongylocentrotus nudus. Two types of sulfated and nonsulfated monosialogangliosides were isolated from the sea urchin ovary. In MS(2) spectra of both nonsulfated monosialoganglioside and sulfated monosialoganglioside, 2-6 linked sialic acids were identified by the characteristic fragments of (0,4)A2-CO2 and (0,2)A1. Fragment ions at m/z 139.1 and m/z 169.1 of nonsulfated monosialoganglioside might be characteristic for 8-sulfated sialic acid residue. Retention time of the molecules was effectively used in the characterization of unknown molecules, and molecules that differ in mass by only 0.04 Da were easily differentiated.


Assuntos
Cromatografia de Fase Reversa/métodos , Gangliosídeos/análise , Ouriços-do-Mar/química , Animais , Feminino , Ácido N-Acetilneuramínico/análise , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
17.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 32(6): 1354-8, 2015 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-27079113

RESUMO

Penicillin is a kind of ß-lactam drug which has been applied in the clinical treatment firstly in the world, and it has still been widely used at present. The synthesis and regulation mechanism of Penicillium chrysogenum, which is used to produce penicillin, has been studied quite maturely, but its proteomics research started relatively late and fewer reports were published. This paper reviews the synthesis and application of penicillin, transformation of Penicillium chrysogenum, and the research progress of its proteomics. On this basis, the study highlights the advantages of proteomics in the research of protein expression.


Assuntos
Penicilinas/biossíntese , Penicillium chrysogenum/metabolismo , Proteoma , Proteômica
18.
Food Chem ; 146: 423-8, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24176362

RESUMO

In this paper, we examined the role of chitosan in the removal of off-flavours from radish anthocyanin-rich pigments and studied the mechanisms of the process. Four radish glucosinolates (glucoraphenin, dehydroerucin, glucobrassicin, and glucoerucin) were identified by LC-MSn from root extracts and dehydroerucin was found to be the major glucosinolate in red radish roots. Application of chitosan with 76%, 83% or 89% deacetylation in radish extracts attributed to 26%, 35% or 43% adsorption rate for glucosinolates, and 28%, 26% or 22% for anthocyanins, respectively. HS-SPME/GC-MS analysis demonstrated that the concentration of volatile compounds decreased by 70%, resulting in the loss of odorous compounds. The changes in chitosan spectra before/after adsorption and after desorption at 1590 and 3360cm(-1) and at broad bands from 2600 to 2000cm(-1) suggest that the dominant adsorption mechanisms of glucosinolates on chitosan may be electrostatic attractions, including hydrogen bonds and charge neutralisation.


Assuntos
Antocianinas/análise , Quitosana/química , Glucosinolatos/química , Raphanus/química , Extração em Fase Sólida/métodos , Adsorção , Manipulação de Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Glucosinolatos/isolamento & purificação , Odorantes/análise
19.
J Chromatogr A ; 1208(1-2): 239-41, 2008 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-18804768

RESUMO

A precise analytical assay was developed and validated for the determination of Pacific oyster glycogen using ion chromatography. The Pacific oyster glycogen was quantified by the determination of glucose-6-phosphate (Glc-6-P), which was derived from glucose that was hydrolyzed from glycogen. Glc-6-P, adenosine triphosphate, and adenosine diphosphate were separated by ion chromatography. The method was validated over the curve range 0.5-100mg/L for the abovementioned analytes. The recoveries were between 95% and 102%. The relative standard deviations (RSDs, c=10mg/L, n=9) were less than 4.37%. Unlike a traditional method, this validated method was inexpensive and stable.


Assuntos
Cromatografia por Troca Iônica/métodos , Crassostrea/química , Glucose-6-Fosfato/análise , Glicogênio/análise , Animais
20.
J Agric Food Chem ; 55(8): 3083-8, 2007 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-17381105

RESUMO

A simple method was developed for the determination of biogenic amines in aquatic food products using a reverse-phase high-performance liquid chromatography with postcolumn automatic o-phthalaldehyde derivatization and fluorescence detection. The linearity, repeatability, and recovery of the method for seven amines (tyramine, putrescine, cadaverine, histamine, agmatine, spermidine, and spermine) were evaluated. This optimized method was applied to detect biogenic amines in squid and white prawn during refrigerated storage. Sensory analysis, pH value, and total volatile base nitrogen value were combined to evaluate the freshness quality of these two raw materials. Agmatine and cadaverine in squid, cadaverine, and putrescine in white prawn were the most obviously changed amines during the storage at two different temperatures, and these biogenic amines could be the effective quality indicators for the freshness of the raw aquatic materials.


Assuntos
Aminas Biogênicas/análise , Cromatografia Líquida de Alta Pressão/métodos , Crustáceos/química , Decapodiformes/química , Animais , Temperatura Baixa , Conservação de Alimentos , Reprodutibilidade dos Testes
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