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1.
Pinyi Ma Fanghui Liang Xinpei Li Qingqing Yang Di Wang Daqian Song Dejiang Gao Xinghua Wang 《Food Analytical Methods》2014,7(9):1866-1873
A rapid, sensitive, and selective detection method of nitrite in foods and water was established by surface-enhanced Raman spectroscopy (SERS) based on the diazo reaction of nitrite with p-nitroaniline and 1-naphthylamine in acidic solution. The azo dye (4-(4-nitrophenyldiazenyl)naphthalene-1-aminium, NNA), which was derived from the diazo reaction, was determined by SERS using citrate-coated silver nanoparticles (AgNPs) as SERS substrates. The concentrations of nitrite in samples were finally calculated from the intensities of SERS signals generated by NNA in the testing solutions. By using the present method combined with a portable miniature Raman spectrometer, on-site determination of nitrite could be performed easily and efficiently. The effects of several experimental parameters on the intensity of SERS signals, such as the volume of AgNP solution and the mixing time of AgNPs and NNA, were investigated. The linear range of the method was 0.1–10.0 mg L?1. The limits of detection (LODs) were 0.01, 0.03, and 0.05 mg L?1 at 720, 1,459, and 1,609 cm?1, respectively. The method was applied to the determination of nitrite in real food and water samples, with recoveries in the range of 86.9–103.4 % and relative standard deviations (RSDs) less than 9.64 %. 相似文献
2.
Xiao Liang Hengjia Ni Ross C. Beier Yanni Dong Jingya Li Xiangshu Luo Suxia Zhang Jianzhong Shen Zhanhui Wang 《Food Analytical Methods》2014,7(10):1992-2002
The optimum conditions of an enzyme-linked immunosorbent assay (ELISA) in regard to different monoclonal antibodies (MAbs), assay format, immunoreagents, and several physicochemical factors (pH, salt, detergent, and solvent) were investigated to develop a broad-specific and sensitive immunoassay for detection of sulfonamides in milk samples. Two previously produced broad-specific MAbs, 4D11 and 4C7, and eight structurally different haptens conjugated with bovine serum albumin (BSA) were used as coating antigens in a competitive indirect ELISA (ciELISA). In addition, six hapten-HRP conjugates and the two MAbs were evaluated in a competitive direct ELISA. After optimization, a highly broad-specific and sensitive ciELISA for screening for sulfonamides was obtained based on MAb 4D11 and the BS-BSA heterologous-coating antigen, demonstrating a 50 % specific binding (IC50) for 22 sulfonamides at concentrations below 100 ng mL?1. This is the first report of an immunoassay that is capable of detecting more than 20 sulfonamides based on MAbs. The optimized ciELISA was used to quantify the five sulfonamides, SMZ, SDM, SQX, SMM, and SMX in spiked milk samples. Recoveries of 89–104.6 % and coefficients of variation of 11.9–19.1 % demonstrated the potential of the ciELISA to simultaneously monitor multiple sulfonamides in diluted milk samples without further purification steps. 相似文献
3.
E. J. Llorent-Martínez L. Molina-García A. Ruiz-Medina P. Ortega-Barrales 《Food Analytical Methods》2014,7(10):2177-2183
A high-performance liquid chromatography method with electrospray ionization mass spectrometric detection (HPLC-ESI-MS/MS) for the determination of some of the most important polyphenols present in botanical supplements has been developed. The target analytes were five flavonoids (diosmin, hesperidin, quercetin, rutin and troxerutin) and the flavolignan silybin. The extraction of the analytes from the supplements was carried out by ultrasound-assisted extraction using 100 % dimethyl sulfoxide (or methanol) for 15 min. After centrifugation, 1 μL of the diluted supernatant was injected in the HPLC system and the quantitation was performed by ESI-MS using the negative ionization mode, with methylparaben as internal standard. The validation of the method was performed with recovery experiments, observing recoveries in the range of 85–112 %, and relative standard deviations lower than 10 % for the complete analytical procedure, including the extraction. The limits of detection were in the 2.5–120 μg L?1 range. 相似文献
4.
María Isabel Alarcón-Flores Roberto Romero-González José Luis Martínez Vidal Antonia Garrido Frenich 《Food Analytical Methods》2014,7(10):2095-2106
Phenolic compounds were determined in artichoke (Cynara scolymus), garlic (Allium sativium) and spinach (Spinacia oleracea) using a single method based on simple extraction and ultra-high-performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). Several compounds belonging to different families, such as phenolic acids, isoflavones, flavones and flavonols, were determined. The analytical procedure was validated in all the matrices, obtaining recoveries ranging from 60 to 120 % with reproducibility values (expressed as relative standard deviations (RSDs)) lower than 26 %. Limits of quantification (LOQs) were always equal to or lower than 50 μg/kg, except to kaempferol and its glucosides in spinach (LOQs?=?75 μg/kg). Artichoke showed higher concentration of phenolic compounds (837.2 mg/kg dry weight (DW)) than garlic (26.5 mg/kg DW) or spinach (64.5 mg/kg DW). Apigenin 7-O-glucoside (from 147.0 to 722.7 mg/kg DW) was found to be the major flavonoid in all samples of artichoke investigated, while chlorogenic acid, whose concentration ranged from 37.8 to 734.7 mg/kg DW, is the major phenolic acid in this matrix. Regarding garlic, caffeic acid (from 1.7 to 28.3 mg/kg DW) and quercetin (from 9.0 to 18.9 mg/kg DW) were the compounds detected at higher concentrations, although in general the total content was very low in relation to other matrices. In relation to spinach, ferulic acid was the major phenolic compound, and its concentration ranged from 18.0 to 41.4 mg/kg DW. 相似文献
5.
V. Muriel-Galet G. López-Carballo R. Gavara P. Hernández-Muñoz 《Food and Bioprocess Technology》2014,7(12):3548-3559
Polymer films based on ethylene vinyl copolymers (EVOH) containing a 29 % (EVOH 29) and a 44 % molar percentage of ethylene (EVOH 44), and incorporating ε-polylysine (EPL) at 0 %, 1 %, 5 % and 10 % were successfully made by casting. The optical properties and the amount of EPL released from the films to phosphate buffer at pH 7.5 were evaluated, films showing great transparency and those of EVOH 29 copolymer releasing a greater amount of EPL. The antimicrobial properties of the resulting films were tested in vitro against different foodborne microorganisms and in vivo in surimi sticks. With regard to the antimicrobial capacity tested in vitro in liquid medium at 37 °C and 4 °C against Listeria monocytogenes and Escherichia coli over a period of 72 h, films showed a considerable growth inhibitory effect against both pathogens, more notably against L. monocytogenes, and being EVOH 29 more effective than EVOH 44 films. At 37 °C, total growth inhibition was observed for EVOH 29 films incorporating 10 % EPL against both microorganisms whereas the copolymer EVOH 44 did show total inhibition against L. monocytogenes and the growth of E. coli was reduced by 6.64 log units. At 4 °C, no film was able to inhibit completely bacterial growth. Scanning electron microscopy micrographs showed corrugated cell surfaces with blisters and bubbles, and collapse of the cells appearing shorter and more compact after treatment with EPL. Finally, the films were successfully used to increase the shelf life of surimi sticks. The results show the films developed have a great potential for active food packaging applications. 相似文献
6.
Steven Suryoprabowo Liqiang Liu Juan Peng Hua Kuang Chuanlai Xu 《Food Analytical Methods》2014,7(10):2163-2168
Fast and sensitive screening of antibiotics is a great need in food quality assurance. A monoclonal antibody specific to fluoroquinolones (FQ) was obtained using ciprofloxacin (CPF) derivant as hapten. The antibody was characterized with broad recognition to CPF (100 %), enrofloxacin (ENF, 73.89 %), norfloxacin (73.57 %), nadifloxacin (67.28 %), danofloxacin (53.09 %), pefloxacin (50.26 %), lomefloxacin (35.66 %), enoxacin (12.40 %), and sarafloxacin (3.23 %). Then, an enzyme linked immunosorbent assay (ELISA) was established. The optimized concentrations of coating antigen and antibody were 0.1 and 0.5 μg/ml, respectively. Various parameters including pH values, ionic strength and the concentration of antibody and antigen were optimized for this assay. The ELISA was found to have the best sensitivity in assay buffer of pH 6 and sodium chloride content 1.6 % (m/v) using CPF as tested compound. Fortified milk samples with CPF and ENF (50 and 250 μg/l) and fortified chicken samples (10 and 50 μg/kg) were analyzed with the proposed measure. The ELISA was examined with recovery range of 94–104 % for milk detection and 93–108 % for chicken detection. The coefficient variation data for intra-assay and inter-assay ranged from 4.24 % to 12.16 %. All results indicate the potential extensive application prospects of this ELISA in FQ monitoring for food safety. 相似文献
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8.
Hua Wu Zhiying Wang Yongkang Luo Hui Hong Huixing Shen 《Food and Bioprocess Technology》2014,7(12):3381-3389
The objectives of this study were to investigate quality changes of bighead carp fillets during frozen storage by measuring free fatty acids (FFA), salt extractable protein (SEP) content, Ca2+-ATPase activity, and total sulfhydryl (SH) content and to develop predictive models based on them. FFA increased with the extension of storage time. Meanwhile, SEP content, SH content, and Ca2+-ATPase activity all decreased during storage. A marked inhibition (p?0.05) of FFA formation and SEP content, Ca2+-ATPase activity and SH content decrease was observed during storage of bighead carp fillets at ?30 °C, compared to those stored at ?10 and ?20 °C. Additionally, the relative errors of models based on Ca2+-ATPase and SH were all below 10 %. Thus, the lower frozen temperature can inhibit quality damage effectively, and a reliable estimation of quality changes could be performed by models based on Ca2+-ATPase and SH. 相似文献
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10.
Yungang Shen Shunsheng Chen Rui Du Zhuqing Xiao Yiqun Huang Barbara A. Rasco Keqiang Lai 《Sensing and Instrumentation for Food Quality and Safety》2014,8(4):336-342
Deterioration of deep frying oils used by street vendors is one of the major food safety concerns. Fourier transform infrared (FTIR) spectroscopy coupled with partial least squares (PLS) regression was applied for rapid evaluation of the quality of deep frying oils collected from different street vendors (n = 109) using various frying processes in Shanghai. The levels of free fatty acids (FFA), total polar compounds (TPC), and viscosity of oils were determined with conventional methods and used as reference values for developing PLS models. The FFA (0.07–1.78 mg (KOH)/g) of all tested frying oils were below the maximum allowed value, while 5.5 % of oils had TPC (3.19–54.47 %) above the maximum allowed value (27 %) based upon the related chinese standards. FTIR coupled with PLS regression resulted in less satisfying results for FFA determination (predictability for soybean oils: R2 = 0.709, SEP = 0.14, RPD = 1.83), but showed great promise for rapid determination of viscosity (model predictability: R2 = 0.921–0.945, SEP = 0.68–0.71, RPD = 3.54–3.98) and TPC (predictability for soybean oils: R2 = 0.790–0.931, SEP = 1.89–2.94, RPD = 2.16–3.55) of frying oils from different commercial settings. Developing separated PLS models for shortening and non-shortening oils improved predictability, particularly for the analysis of TPC. 相似文献
11.
Hypnotic effect of GABA from rice germ and/or tryptophan in a mouse model of pentothal-induced sleep
Ji Hyeon Ahn Changkyun Im Joon Ha Park Se Young Choung Seokhoon Lee Jonghun Choi Moo-Ho Won Il-Jun Kang 《Food science and biotechnology》2014,23(5):1683-1688
γ-Aminobutyric acid (GABA), a primary inhibitory neurotransmitter, and tryptophan (Trp), a substrate for melatonin, are found in functional foods and exert hypnotic effects. The hypnotic effects of 3 doses of GABA and a combined-preparation of GABA and Trp (GABA+Trp) were investigated in mice. Hypnotic activity was evaluated using pentothal-induced sleep time testing. Treatments included low, middle, and high doses of GABA and GABA+Trp. Low doses of GABA (low-GABA) and low-GABA+Trp reduced sleep latency and significantly (p<0.05) prolonged the sleep time induced by pentothal, compared with controls, although the melatonin concentration in the serum was not affected. On the other hand, the adenosine A1 receptor (AA1R) immunoreactivity in the suprachiasmatic nucleus of the hypothalamus was significantly (p<0.05) increased after administration of low-GABA and/or low-GABA+Trp, compared to controls. Low doses of GABA and/or Trp cause hypnotic effects that may be related to AA1R activation. 相似文献
12.
Ji Eun Kim Jung Seok Kim Young Cheol Song Jinho Lee Sam Pin Lee 《Food science and biotechnology》2014,23(5):1551-1559
Both γ-poly-glutamic acid (γ-PGA) and γ-amino butyric acid (GABA) were produced from sodium glutamate in a mixed fermentation. A culture broth was obtained using a defined medium including 3% glutamate and Bacillus subtilis HA for 3 days at 42°C, with 1.20×108 CFU/mL viable cells, a 0.46 Pa·sn consistency index, and a 1.94% mucilage content. In a second fermentation using Lactobacillus plantarum K154 at 37°C for 3 days, 1.29% of the remaining glutamic acid in the viscous culture broth was converted to 0.86% GABA. Glutamic acid in the first culture broth fortified with 5% skim milk was completely converted to GABA. The final co-cultured broth had 0.48% GABA, a 0.294% tyrosine content, and viable cells of 1.06×109 CFU/mL (L. plantarum K154) and 5.42×105 CFU/mL (B. subtilis HA). Serial co-culturing of these two bacteria can provide novel ingredients fortified with γ-PGA, GABA, peptides, and probiotics. 相似文献
13.
Moo-Chang Kook Seok-Cheol Cho Junyong Kang Youngju Song Hoon Park 《Food science and biotechnology》2014,23(6):1965-1970
Effect of gamma-aminobutyric acid (GABA) produced by Lactobacillus sakei B2-16 on diet and acute swimming exercise was investigated in rats with high fat diet (HFD)-induced obesity. The body weight gain in the GABA+Exercise group was significantly (p<0.05) lower than in the HFD group. Combined treatment with GABA and exercise decreased the body weight gain by 25.6%, compared to the HFD group. On the other hand, neither GABA supplementation nor exercise alone significantly (p>0.05) influenced reduction in body weight gain, compared to the HFD group. The weights of abdominal and epididymal fat tissues and the liver in the GABA+Exercise group were significantly (p<0.05) lower than in the HFD group. The activity of citrate synthase was significantly (p<0.05) elevated in the soleus muscle by GABA supplementation. GABA contributes to reduction in body weight gain and fat tissue weight by increasing physical activity during exercise. 相似文献
14.
Multivariate curve resolutions (MCR) along with other chemometric techniques are proposed to improve the analysis of Iranian Elettaria cardamomum (E. cardamom) essential oil with gas chromatography-mass spectrometry (GC-MS). In addition, multivariate curve resolution-alternating least squares (MCR-ALS) is used to obtain pure elution and mass spectral profiles for the components present in each chromatographic segment as well as their relative concentrations. This strategy was also used to overcome the problems of baseline offset, asymmetric peaks, retention time shifts, and overlapped and embedded peaks occurring during GC-MS analysis. The analysis of GC-MS data revealed that 42 components exist in the E. cardamom essential oil. However, with the help of MCR and different chemometric methods, this number was extended to 73 components. The most important components of the Iranian E. cardamom are α-terpineol acetate (11.78 %), linalool (10.15 %), nerolidol (8.82 %), α-pinene (8.11 %), geranyl acetate (3.47 %),1,8-cineole (4.25 %), and γ-terpinene (3.88 %). 相似文献
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16.
Yong-Tae Jeong Ju Hye Yang Xian Li Geum Jin Kim Dong Soo Kim Cheorl-Ho Kim Min Kyun Na Hyeun Wook Chang 《Food science and biotechnology》2014,23(5):1695-1701
Hypoglycemic effects of ethylacetate extracts of Anguilla japonica (EMA) muscles in db/db mice were investigated. To understand the mechanism responsible for the hypoglycemic effects of EMA, the effects of EMA on AMP-activated protein kinase (AMPK) activation in L6 myotubes and in vivo using type II diabetic db/db mice were analyzed. In L6 myotubes, the phosphorylation degrees of AMPK and acetyl-CoA carboxylase (ACC) were markedly increased and glucose uptake was significantly (p<0.001) increased by EMA, compared with untretaed L6 myotubes. However, in L6 myotubes, these effects were abolished by compound C, an AMPK inhibitor. Moreover, EMA significantly reduced non-fasting blood glucose and serum insulin levels, and strongly induced AMPK phosphorylation in skeletal muscle tissues of db/db mice. EMA regulates glucose levels in L6 myotubes and in diabetic mice by activation of AMPK. Beneficial effects for diabetes treatment are indicated. 相似文献
17.
María de los Angeles Fernandez Mariela Assof Viviana Jofre María Fernanda Silva 《Food Analytical Methods》2014,7(10):2122-2136
The distinctive aroma of virgin olive oil is attributed to a large number of chemical compounds of different classes such as aldehydes, alcohols, esters, hydrocarbons, ketones, furans, and other volatile compounds that are not yet identified. The aim of the present study lies in the characterization of compound volatile profile of the most representative olive oil cultivars produced in Argentina. The methodology proposed was based on the development of headspace (HS)-SPME/GC-MS with the subsequent analysis of the chemical fingerprints using a discriminant analysis method and a principal component analysis data compression strategy to distinguish olive oils from different varietal origins. Carboxen/polydimethylsiloxane (75 μm) fiber was the most efficient to trap volatile compounds. Optimization of the SPME conditions was also carried out using multivariate methods. To avoid the influence of factors other than the cultivar, olive trees were cultivated under the same agronomic and pedoclimatic conditions; olive fruits were picked at the same stage of ripeness, and their oils were extracted with the same processing system. Volatile fractions from oils of the analyzed cultivars consisted of a complex mixture of more than 40 compounds. Both quantitative and qualitative differences were found among cultivars. The analytical data association with multivariate analysis constitutes a reliable analytical tool with potential ability to discriminate monovarietal extra virgin olive oil from Argentina. 相似文献
18.
A. Zdunek A. Kozioł P. M. Pieczywek J. Cybulska 《Food and Bioprocess Technology》2014,7(12):3525-3535
The nanostructure of polysaccharides is supposed to determine properties such as stiffness or diffusivity of cell walls and their functionality for various tailored properties of food. However, at present, a relation of these nano-properties with sensory texture and firmness remains to some degree unknown. In this work, water (WSP), calcium chelator (CSP) and sodium carbonate (DASP) soluble pectins, hemicellulose and cellulose, extracted from cell walls of two pear cultivars ‘Xenia’ and ‘Conference’ at their harvest times, were studied. An atomic force microscope and image analysis were used to evaluate diameter and branching of the molecules. Sensory texture of ‘Xenia’ was considered as better and its firmness (87 N) was higher than ‘Conference’ (76 N). WSP molecules were present as short molecules with a height of about 0.5 nm for both cultivars. A chain-like and branched CSP fraction had diameter of about 0.3–0.4 nm for both cultivars with a pronounced contribution of molecules with diameter of about 1 nm for ‘Xenia’, which had also higher branching index. DASP revealed similar regular structures for both cultivars however the network was much denser for ‘Xenia’. A rod-like hemicellulose molecules had length of about 20–400 nm and diameter of 1 nm for ‘Xenia’ and 1–4 nm for ‘Conference’. Cellulose diameter for both cultivars was about 23 nm. This study showed that less degraded, thicker and more branched pectin molecules were associated with higher firmness and more favourable texture. Hemicellulose provided a positive contribution to texture when they were thinner and more flexible. 相似文献
19.
Shuang Guan Zhenning Wang Yixuan Huang Guoren Huang Yuekai Guan Wei Jiang Jing Lu 《European Food Research and Technology》2014,239(5):837-845
Punicalagin, mainly isolated from the fruit of Pomegranate (Punica granatum L.), is a natural polyphenolic compound. In the present study, we investigated the negative regulatory effect of punicalagin on acute lung injury (ALI) induced by Lipopolysaccharide (LPS). In the murine model of ALI, the data showed that punicalagin inhibited the production of TNF-α, IL-1β, and IL-6 and decreased protein concentration and myeloperoxidase activity with a single 4 mg/kg dose of punicalagin prior to the administration of intratracheal LPS in the bronchoalveolar lavage fluid. Furthermore, we investigated the effects of punicalagin how to modulate signal transduction. MAPK and NF-κB activation were measured by Western blot and immunocytochemical analysis. The data showed that punicalagin significantly inhibited phosphorylated p38 MAPK protein expression and shocked p65-NF-κB translocation into the nucleus. These results indicated punicalagin may exert negative regulatory effects on ALI partly through suppressing p38 MAPKs or/and NF-κB pathways. This study offered a novel therapeutic strategy for improving clinical effects of acute lung injury (ALI)/acute respiratory distress syndrome and provided more evidence for the health benefits of pomegranate fruits. 相似文献
20.
Heyong Cheng Chao Han Zigang Xu Jinhua Liu Yuanchao Wang 《Food Analytical Methods》2014,7(10):2153-2162
In this study, we reported bromine speciation analysis using a microchip electrophoresis-inductively coupled plasma-mass spectrometry (MCE-ICP-MS)-hyphenated system with sensitivity enhancement by the field-amplified sample injection technique. Satisfactory separation of bromide and bromate within 35 s was achieved in the 1.5-cm separation channel under an electric field of approximately ?260 V cm?1 in the buffer environment of 65 mM NaAc-HAc (pH 8.0). The sensitivities were improved by 12.8 for bromide and 12.0 for bromate by preparing the standards or samples in 3 mM sodium acetate instead of the background electrolyte. The detection limits for Br? and BrO3 ? were 0.18 and 0.22 μg L?1, respectively, and the precisions of the migration time and reproducibilities of peak height and area were all lower than 4 %. Under the optimized conditions, the proposed method was successfully applied for speciation analysis of bromine in bread samples. Recoveries of BrO3 ? and Br? in six bread samples were between 97.2 and 105.2 %. The good agreement between the determined values by the proposed MCE-ICP-MS method and the high-performance liquid chromatography (HPLC)-ICP-MS method was obtained. All results prove its advantages including high sensitivity, high efficiency, and low operation cost, which are beneficial to routine analysis of bromine speciation in environmental, biological, and food fields. 相似文献