A new synthetic protocol for coumarin amino acid.

The hydrochloride of the racemic amino acid (2-(7-hydroxycoumarin-4-yl)ethyl)glycine, which can serve as a fluorescent probe in proteins, and two halogen derivatives of it, were synthesized by using a new synthetic protocol in five steps. It is less costly and relatively easy to prepare this kind of fluorescent amino acid with the new synthetic method. Furthermore, it can be applied to synthesize other derivatives of the coumarin amino acid with some specific properties.

Physico-chemical and antioxidant properties of four mango (Mangifera indica L.) cultivars in China.

Four principal mango cultivars (Tainong No.1, Irwin, JinHwang and Keitt) grown in southern China were selected, and their physico-chemical and antioxidant properties were characterized and compared. Of all the four cultivars, Tainong No.

[X-ray diffraction study of high hydrostatic pressure on crystalline structure of different type starches].

Crystalline changes of different type starches after high hydrostatic pressure treated under 300, 450, 600 MPa were studied by X-ray diffraction. Waxy maize (A type, 100% amylopectin), hylon VII (B type, 30% amylopectin) and tapioca starch (C type, 83% amylopectin) were chosen. The results indicated that for waxy maize starch, annealing effect was observed at 300 MPa, disappearance of crystalline structure happened at 450 MPa and retrogradation at 600 MPa.

Inactivation of Bacillus subtilis spores by combining high-pressure thermal sterilization and ethanol.

High-pressure thermal sterilization (HPTS) is a new and promising sterilization technology of foods. Effects of combining HPTS and ethanol treatment on inactivation of Bacillus subtilis spores were investigated. An interesting phenomenon was observed.

Verification of aroma profiles of Jiashi muskmelon juice characterized by odor activity value and gas chromatography-olfactometry/detection frequency analysis: aroma reconstitution experiments and omission tests.

To verify the aroma profile of Jiashi muskmelon previously identified by gas chromatography-olfactometry/detection frequency analysis (GC-O/DFA) and odor activity value (OAV) calculation, the synthetic blends of odorants (aroma models) were prepared and then were compared with the original Jiashi muskmelon juice aroma using quantitative descriptive analysis (QDA) and electronic nose analysis (ENA), respectively. QDA and ENA both indicated that the model solution derived from OAV calculation more closely resembled the original melon juice aroma than that based on DFA data. Omission tests corroborated the significant contribution of five unsaturated aldehydes and alcohols with nine carbon atoms as well as five branched esters, in particular, the "fruity"-smelling ethyl butanoate and the "cucumber-like" (2E,6Z)-nona-2,6-dienal to Jiashi muskmelon overall aroma.

Methyl [13C]glucopyranosiduronic acids: effect of COOH ionization and exocyclic structure on NMR spin-couplings.

Methyl α- and β-D-glucopyranuronides singly labeled with (13)C at C1-C6 were prepared from the corresponding (13)C-labeled methyl D-glucopyranosides, and multiple NMR J-couplings (J(HH), J(CH), and J(CC)) were measured in their protonated and ionized forms in aqueous ((2)H(2)O) solution. Solvated density functional theory (DFT) calculations of J-couplings in structurally related model compounds were performed to determine how well the calculated J-couplings matched the experimental values in saccharides bearing an ionizable substituent. Intraring J(HH) values in both uronide anomers, including (3)J(H4,H5), are unaffected by solution pD, and COOH ionization exerts little effect on J(CH) and J(CC) except for (1)J(C1,H1), (1)J(C4,H4), (1)J(C5,H5), (1)J(C5,C6), and (2)J(C3,C5), where changes of up to 5 Hz were observed.

Effects of high hydrostatic pressure on physicochemical and functional properties of walnut (Juglans regia L.) protein isolate.

Background: Walnut (Juglans regia L.) is a good source of protein that has potential application in new product formation and fortification. The main objectives of this study were to investigate the effects of high hydrostatic pressure (HHP) treatment (300-600 MPa 20 min) on physicochemical and functional properties of walnut protein isolate (WPI) using various analytical techniques at room temperature.

Simultaneous decoloration and deproteinization of crude polysaccharide from pumpkin residues by cross-linked polystyrene macroporous resin.

A novel method for the purification of crude polysaccharide from fermentation broth of pumpkin residues by macroporous resins was developed. Through static adsorption and desorption and adsorption kinetic tests, six resins (AB-8, S-8, HPH480, HPD100, X-5, and D101) with different polarity, diameter, and surface area were studied for simultaneous decoloration and deproteinization of crude polysaccharide, and S-8 was chosen as the best one. Dynamic breakthrough and desorption tests were performed in a glass column packed with S-8 resin, and the resulting adsorption ratios of pigment and protein were 84.

Authentication of edible vegetable oils adulterated with used frying oil by Fourier Transform Infrared Spectroscopy.

The application of Fourier Transform Infrared (FTIR) Spectroscopy to authenticate edible vegetable oils (corn, peanut, rapeseed and soybean oil) adulterated with used frying oil was introduced in this paper. The FTIR spectrum of oil was divided into 22 regions which corresponded to the constituents and molecular structures of vegetable oils. Samples of calibration set were classified into four categories for corn and peanut oils and five categories for rapeseed and soybean oils by cluster analysis.

[Study on the effect of high hydrostatic pressure treatment on the secondary structure of mushroom polyphenoloxidase by SRCD and FTIR].

The secondary structure of the mushroom polyphenoloxidase treated by the high hydrostatic pressure (HHP) was analyzed by the synchrotron radiation circular dichroism (SRCD) and Fourier transform infrared spectroscopy (FTIR). The alpha-helix content of mushroom PPO was decreased after HHP treatment, which indicated that the secondary structure of PPO was changed. There was a discrepancy of the result of the secondary structure content between untreated or HHP-treated mushroom PPO analyzed by SRCD and FTIR spectra, and this discrepancy may be due to the different determination temperature, the concentration of the PPO solution and the spectra analysis method etc.

Identification of aroma-active compounds in Jiashi muskmelon juice by GC-O-MS and OAV calculation.

To identify aromatic compounds in Jiashi melon juice, gas chromatography-mass spectrometry-olfactometry (GC-MS-O) analysis was used. Odor activity values (OAVs) were also calculated on the basis of the qualitative and quantitative analysis of volatile compounds. Results showed that 42 volatiles were identified, among which 4 compounds, namely, diethyl carbonate, isophorone, 2-butoxyethyl acetate, and menthol, were identified or tentatively identified for the first time as volatiles in melon fruit.

Effects of high hydrostatic pressure on color of spinach purée and related properties.

Background: Changes in instrumental color parameters, chlorophyll a and b, activity of chlorophyllase, Mg-dechelatase, peroxidase and polyphenol oxidase, total phenolic compounds and pH of spinach purée were assessed after high hydrostatic pressure (HHP) (200, 400 and 600 MPa for 5, 15 and 25 min) treatments at room temperature.

Results: HHP treatments induced a better retention of visual green color (-a* and L* values) and chlorophyll contents of spinach purée. As for chlorophyll degradation-related enzymes, the results indicated that chlorophyllase activity decreased at all pressures; however, Mg-dechelatase activity was dramatically activated after HHP treatment at 400 and 600 MPa.

Effect of ultrahigh hydrostatic pressure on the activity and structure of mushroom (Agaricus bisporus) polyphenoloxidase.

High hydrostatic pressure (HHP, treatment pressure ≤700 MPa) is approved to be the most successful commercial nonthermal processing due to its minimal modifications in nutritional and sensory quality. However, for some pressure stable enzymes such as PPO, this unique technology can hardly inactivate them at treatment pressure below of 700 MPa. This study investigated the effects of ultrahigh hydrostatic pressure (UHHP, treatment pressure >700 MPa) on the activity of Agaricus bisporus mushroom polyphenoloxidase (PPO) both in the phosphate buffer and in the mushroom puree, and on the structure of the enzyme by means of circular dichroism (CD), fluorescence emission spectra, and sulphydryl group detection.

Troglitazone induced apoptosis via PPARγ activated POX-induced ROS formation in HT29 cells.

Objective: In order to investigate the potential mechanisms in troglitazone-induced apoptosis in HT29 cells, the effects of PPARγ and POX-induced ROS were explored.

Methods: [3- (4, 5)-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, Annexin V and PI staining using FACS, plasmid transfection, ROS formation detected by DCFH staining, RNA interference, RT-PCR & RT-QPCR, and Western blotting analyses were employed to investigate the apoptotic effect of troglitazone and the potential role of PPARγ pathway and POX-induced ROS formation in HT29 cells.

Results: Troglitazone was found to inhibit the growth of HT29 cells by induction of apoptosis.

Reduction of diazinon and dimethoate in apple juice by pulsed electric field treatment.

Background: Organophosphorus pesticides (OPPs) are widely used in agricultural production in China, and residues of OPPs in agro-products and foods have become a public health concern. Chronic exposure to OPPs can result in potential immunosuppressive effects, cytotoxicity and mutagenicity. Pulsed electric fields (PEFs) have the potential to be used as an alternative to conventional techniques of food production.

The pathways for the removal of acrylamide in model systems using glycine based on the identification of reaction products.

The reaction between acrylamide and glycine was studied in the aqueous model system heated at 150°C. The main reaction products were identified as C5H10N2O3, C8H15N3O4, C7H12N2O5 and C10H17N3O6 using HPLC-MS/MS, IT-TOF and NMR. Both of the critical intermediates were identified as glyoxylic acid and iminodiacetic acid.

Effect of sonication on eliminating of phorate in apple juice.

The degradation of phorate in apple juice by sonication was investigated in the present study. Results showed that sonication was effective in eliminating phorate in apple juice, and the ultrasonic power and sonication time significantly influenced the degradation of phorate (p<0.05).

Methyl 2-acetamido-2-deoxy-β-D-glucopyranoside dihydrate and methyl 2-formamido-2-deoxy-β-D-glucopyranoside.

Methyl 2-acetamido-2-deoxy-β-D-glucopyranoside (β-GlcNAcOCH(3)), (I), crystallizes from water as a dihydrate, C(9)H(17)NO(6)·H(2)O, containing two independent molecules [denoted (IA) and (IB)] in the asymmetric unit, whereas the crystal structure of methyl 2-formamido-2-deoxy-β-D-glucopyranoside (β-GlcNFmOCH(3)), (II), C(8)H(15)NO(6), also obtained from water, is devoid of solvent water molecules. The two molecules of (I) assume distorted (4)C(1) chair conformations. Values of φ for (IA) and (IB) indicate ring distortions towards B(C2,C5) and (C3,O5)B, respectively.

Effects of high-pressure carbon dioxide on proteins and DNA in Escherichia coli.

Protein changes in Escherichia coli, when subjected to high-pressure carbon dioxide (HPCD) at 10 MPa and 3 °C for 5-75 min, were assessed using the Bradford method, 2D electrophoresis (2-DE) and liquid chromatography-electrospray ionization-MS-MS (LC-ESI-MS-MS). The changes in DNA in E. coli under the same conditions were also investigated by using flow cytometry with propidium iodide and acridine orange, agarose gel electrophoresis (AGE) and the comet assay.

The degradation of chlorpyrifos and diazinon in aqueous solution by ultrasonic irradiation: effect of parameters and degradation pathway.

In this paper, elimination of two types of organophosphorus pesticides (OPPs), chlorpyrifos and diazinon spiked in aqueous solution by ultrasonic irradiation was investigated. Results showed that chlorpyrifos and diazinon could be effectively and rapidly degraded by ultrasonic irradiation, and the degradation of both pesticides was strongly influenced by ultrasonic power, temperature and pH value. Furthermore, two and seven products for the degradation of chlorpyrifos and diazinon formed during ultrasonic irradiation have been identified by gas chromatography-mass spectrometry, respectively.

Aggregation and homogenization, surface charge and structural change, and inactivation of mushroom tyrosinase in an aqueous system by subcritical/supercritical carbon dioxide.

The subcritical/supercritical carbon dioxide (SS CO(2)) has gained considerable attention in green chemistry industry for its advantage as nontoxic, nonflammable, and inexpensive. The effects of SS CO(2) treatments on aggregation and homogenization, surface charge, secondary and tertiary structure, and activity of mushroom tyrosinase in an aqueous system were investigated using a number of methods including dynamic light scattering (DLS), zeta potential measurement, circular dichroism (CD) spectropolarimeter, and spectrofluorometer. With a treatment time of 20 min, three treatment temperatures (35, 45, and 55 °C) and four pressures (5, 8, 12, and 15 MPa) had been selected.

Optimization of extraction process by response surface methodology and preliminary structural analysis of polysaccharides from defatted peanut (Arachis hypogaea) cakes.

In this work, response surface methodology was used to determine optimum conditions for extraction of polysaccharides from defatted peanut cake. A central composite design including independent variables, such as extraction temperature (x(1)), extraction time (x(2)), and ethanol concentration (x(3)) was used. Selected response which evaluates the extraction process was polysaccharide yield, and the second-order model obtained for polysaccharide yield revealed coefficient of determination of 97.

Analysis of Escherichia coli cell damage induced by HPCD using microscopies and fluorescent staining.

Cellular damage of Escherichia coli (E. coli) induced by high pressure carbon dioxide (HPCD) at 37-57°C and 10-30 MPa for 5-75 min was investigated using scanning electronic microscopy (SEM), transmission electronic microscopy (TEM), confocal laser scanning microscopy (CLSM), and fluorospectrophotometer (FSM). HPCD-induced alterations in the morphology and the intracellular organization of E.

Acceleration of precipitation formation in peach juice induced by high-pressure carbon dioxide.

Peach juice was treated by high-pressure carbon dioxide (HPCD). HPCD-induced acceleration of precipitation formation in peach juice was observed. Particle size distribution (PSD), pH, zeta-potential, protein and total phenols, pectin methylesterase (PME) activity, pectin and calcium, and viscosity in juice, contributing to the precipitation formation, were studied.

High hydrostatic pressure inactivation of total aerobic bacteria, lactic acid bacteria, yeasts in sour Chinese cabbage.

This study investigated the inactivation of total aerobic bacteria (TAB), lactic acid bacteria (LAB), yeasts in sour Chinese cabbage (SCC) treated by high hydrostatic pressure (HHP). The pressure level ranged from 200 to 600 MPa and the treatment time were 10-30 min. All samples were stored at 4, 27 and 37 degrees C for 90 days.