Effect of different drying methods on the amino acids,α-dicarbonyls and volatile compounds of rape bee pollen

The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed vacuum drying(PVD),freeze drying(FD),infrared drying(IRD),hot-air drying(HAD)and sun drying(SD)on free amino acids(FAAs),α-dicarbonyl compounds(α-DCs)and volatile compounds(VOCs)in rape bee pollen(RBP)were determined.The results showed that FD significantly released the essential amino acids(EAAs)compared with fresh samples while SD caused the highest loss.Glucosone was the dominantα-DCs in RBP and the highest loss was observed after PVD.Aldehydes were the dominant volatiles of RBP and SD samples contained more new volatile substances(especially aldehydes)than the other four drying methods.Comprehensively,FD and PVD would be potential methods to effectively reduce the quality deterioration of RBP in the drying process.

Preparation of lactic acid bacteria compound starter cultures based on pasting properties and its improvement of glutinous rice flour and dough

The effects of 5 lactic acid bacteria(LAB)fermentation on the pasting properties of glutinous rice flour were compared,and suitable fermentation strains were selected based on the changes of viscosity,setback value,and breakdown value to prepare LAB compound starter cultures.The results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice flour.In particular,the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice flour.Moreover,the gelatinization enthalpy of the fermented samples increased significantly.For frozen glutinous rice dough stored for 28 days,the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough,and the freezable water content was lower than that of control dough.These results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry,which has significance for its application.

Corrosion resistance of Mg-Al-LDH steam coating on AZ80 Mg alloy:Effects of citric acid pretreatment and intermetallic compounds

In this study,the effects of intermetallic compounds(Mg_(17)Al_(12)and Al_(8)Mn_(5))on the Mg-Al layered double hydroxide(LDH)formation mechanism and corrosion behavior of an in-situ LDH/Mg(OH)_(2)steam coatings on AZ80 Mg alloy were investigated.Citric acid(CA)was used to activate the alloy surface during the pretreatment process.The alloy was first pretreated with CA and then subjected to a hydrothermal process using ultrapure water to produce Mg-Al-LDH/Mg(OH)_(2)steam coating.The effect of different time of acid pretreatment on the activation of the intermetallic compounds was investigated.The microstructure and elemental composition of the obtained coatings were analyzed using FE-SEM,EDS,XRD and FT-IR.The corrosion resistance of the coated samples was evaluated using different techniques,i.e.,potentiodynamic polarization(PDP),electrochemical impedance spectrum(EIS)and hydrogen evolution test.The results indicated that the CA pretreatment significantly influenced the activity of the alloy surface by exposing the intermetallic compounds.The surface area fraction of Mg_(17)Al_(12)and Al_(8)Mn_(5)phases on the surface of the alloy was significantly higher after the CA pretreatment,and thus promoted the growth of the subsequent Mg-Al-LDH coatings.The CA pretreatment for 30 s resulted in a denser and thicker LDH coating.Increase in the CA pretreatment time significantly led to the improvement in corrosion resistance of the coated AZ80 alloy.The corrosion current density of the coated alloy was lower by three orders of magnitude as compared to the uncoated alloy.

Understanding changes in volatile compounds and fatty acids of Jincheng orange peel oil at different growth stages using GC-MS

Jincheng orange(Citrus sinensis Osbeck)is widely grown in Chongqing,China,and is commonly consumed because of its characteristic aroma contributed by the presence of diverse volatile compounds.The changes in aroma during the development and maturation of fruit are indicators for ripening and harvest time.However,the influence of growth stages on the volatile compounds in Jincheng orange remains unclear.In addition,volatiles originate from fatty acids,most of which are the precursors of volatile substances.On this basis,gas chromatography-mass spectrometry(GC-MS)was performed to elaborate the changes in volatile constituents and fatty acids as precursors.This study tested proximately 60 volatiles and 8 fatty acids at 9 growth and development stages(AF1-AF9).Of those compounds,more than 92.00%of total volatiles and 87.50%of fatty acids were terpenoid and saturated fatty acids,respectively.As shown in the PCA plot,the AF5,AF6,and AF9 stages were confirmed as completely segregated and appeared different.In addition,most of the volatiles and fatty acids first increased at the beginning of the development stage,then decreased from the AF6 development stage,and finally increased at the AF9 maturity stage.Moreover,the highest contents of terpenoid,alcohols,aldehydes,ketones,and saturated fatty acids in Jincheng orange peel oil were d-limonene,linalool,octanal,cyclohexanone,and stearic acid during development stages,respectively.Our results found that the growth stages significantly affected the volatile constituents and precursors in Jincheng orange peel oil.

CATIONIC RING-OPENING POLYMERIZATION OF TETRAHYDROFURAN WITH KEGGIN-TYPE HETEROPOLYCOMPOUNDS AS SOLID ACID CATALYSTS

Three Keggin-type heteropolyanions, namely H3PMo12O40-13H2O, （NH4）3PMo12O40·4H2O and H3PW12O40·13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of the counter-cation （H＋, NH4＋） and the peripheral atoms （Mo, W） on the polymerization were investigated. It has been found that when the protons of H3PMo12O40·13H2O were replaced by the ammonium cations the polymerization rate decreased dramatically. Whereas, when the peripheral atoms （Mo） were replaced by their homologous （W）, the polymerization rate increased twofold. As for the viscosity average molecular weight （My） of polymer products, it was found that the high molecular weight （7930） was obtained by using H3PW12O40·13H2O. The molecular weight （My） obtained by H3PMo12O40·13H2O and （NH4）H3PMo12O40·13H2O was 6470 and 6810, respectively.

Evaluation of Protein Concentration, Amino Acid Profile and Antinutritional Compounds in Hempseed Meal from Dioecious and Monoecious Varieties

Hempseed meal from three dioecious and three monoecious varieties has been evaluated for content and quality of the protein and for the concentration of antinutritional compounds. Hemp seeds were obtained from plants grown in two experimental fields for two consecutive years (2011-2012). For all the varieties, hempseed meal resulted in a rich source of protein (34% mean content) with an amino acid profile extremely rich in arginine and slightly poor in lysine. Differences between dioecious and monoecious varieties were observed in the content of antinutritional compounds. They were more concentrated in monoecious varieties in comparison with those dioecious. The concentration of phytic acid in hempseed meal deserves attention in both groups, being 63 and 75.4 g·kg-1 of dry matter in dioecious and monocieous varieties, respectively. The results show that, besides the recognized value of hemp oil, also the hempseed cake could find application in animal feed as a substitute of other cakes (soybean, rapeseed). From this point of view, the dioecious varieties showing lower contents of antinutritional compounds with respect to the monoecious varieties would be preferred.

Corrosion inhibition of α,β-unsaturated carbonyl compounds on steel in acid medium

Corrosion inhibition of three α,β-unsaturated carbonyl compounds on N80 steel at high temperature and in concentrated acid medium was evaluated, and the inhibition mechanism was investigated. The results proved that both cinnamaldehyde and benzalacetone had an evident anticorrosion effect and could reduce the corrosion of steel effectively in acid medium, α,β-unsaturated carbonyl compounds with a benzene ring structure had good adsorption on steel surface. The experiments proved that polymerization of α,β-unsaturated carbonyl compounds on the steel surface at a high temperature and in concentrated acid medium resulted in a good corrosion inhibiting effect, which was attributed to the structures of α,β-unsaturated carbonyl compounds.

The Promotion Effect of Low-Molecular Hydroxyl Compounds on the Nano-Photoelectrocatalytic Degradation of Fulvic Acid and Mechanism

A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natural water bodies,and its influence mechanism was proposed.A TiO_2 nanotube arrays(TNAs) material is served as the photoanode.Methanol,ethanediol,and glycerol were chosen as the representative of LMHCs in this study.The adsorption performance of organics on the surface of TNAs was investigated by using the instantaneous photocurrent value.The adsorption constants of FA,methanol,ethanediol,and glycerol were 43.44,19.32,7.00,and 1.30,respectively,which indicates that FA has the strongest adsorption property.The degradation performance of these organics and their mixture were observed in a thin-layer reactor.It shows that FA could hardly achieve exhausted mineralization alone,while LMHCs could be easily oxidized completely in the same condition.The degradation degree of FA,which is added LMHCs,improves significantly and the best promotion effect is achieved by glycerol.The promotion effect of LMHCs in the degradation of FA could be contributed to the formation of a tremendous amount of hydroxyl radicals in the NPEC process.The hydroxyl radicals could facilitate the complete degradation of both FA and its intermediate products.Among the chosen LMHCs,glycerol molecule which has three hydroxyls could generate the most hydroxyl radicals and contribute the best effective promotion.This work provides a new way to promote the NPEC degradation of FA and a direction to remove humus from polluted water.

Effects of Microencapsulated Compound Acidifier on Acidity and Development of Gastrointestinal Tract in Weaning Piglets

The effects of different types of compound acidifiers （encapsulated and non-encapsulated） in maize-soybean basic diets on acidity and development of the gastrointestinal tract in weaning piglets were investigated in this study. 64 28-day-old weaned Landrace x Yorkshire hybrid piglets with average weight of （7.00 ±0.10） kg were selected and grouped into four treatments with four pigs （ half boars and half sows） in each repeat of four repeats in each treatment based on single-factor test design principles, and the pre-test period was 3 days but the test period was 35 days. The results showed that compared with acid-free diet group, encapsulated compound acidifier could reduce pH of stomach and intestinal in weaning piglets significantly （P 〈 0.01 ）, while Test group 1 could also increase the relative weight of stomach and intestinal in piglets significantly （P 〈 0.05 ）. Compared with non-encapsulated acidifier, encapsulated compound acidifier could greatly decrease pH in jejunum and ileum of weaning piglets （ P 〈 0.05） or relative weight of stomach in piglets （ P〈0.05）, while Test group 1 could also enhance the relative weight of intestinal in piglets significantly （ P 〈0.01 ）. In addition, encapsulated compound acidifiers significantly increased the ratio between the villus height and crypt depth of jejunum （ P 〈0.01 ）. Accordingly, the microencapsulated compound acidifier in diets of weaning piglets can promote the development of gastrointestinal tracts for piglets by reducing pH of gastrointestinal tracts.

The Condensation of Aromatic Aldehydes with Acidic Methylene Compounds in Water

The condensation of aromatic aldehydes with acidic methylene compounds such as malononitrile, methyl cyanoacetate, cyanoacetamide, 5,5-dimethyl-1,3-cyclohexanedione, bartbituric acid and 2-thiobarbituric acid proceeded very efficiently in water in the presence of triethylbenzylammonium chloride (TEBA) and the products were isolated simply by filtration.

Silica sulfuric acid:A versatile reagent for oxathioacetalyzation of carbonyl compounds and deprotection of 1,3-oxathiolanes

Oxathioacetalyzation of carbonyl compounds with 2-mercaptoethanol and deprotection of the obtained 1,3-oxathiolanes is easily performed in the presence of silica sulfuric acid （SSA）. All reactions were performed under mild and completely heterogeneous reaction conditions in good to high yields.

Synthesis and antitumor activities of structure-related small molecular compounds of gambogic acid

Through simplifying the complicated skeleton of the natural product gambogic acid, two series derivatives of chromone and xanthone were synthesized and examined for their antitumor activities against several cancer cells in vitro by MTT method. The results showed that appropriate introduction of prenyl group to the small molecular compounds could elevate their antitumor activities. The structure–activities relationship of synthesized compounds certified that the bridgecore in gambogic acid was very important for keeping its antitumor activities.

Syntheses,Crystal Structures and Antibacterial Activities of 5-Chloro-3-methyl-1-phenyl-1H-pyrazole-4-carboxylic Acid and Its Copper(Ⅱ) Compound

The title compounds 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carboxylic acid（C11H9Cl N2O2, HL）（1） and [Cu（L）2（H2O）]（2） were prepared and structurally characterized by elemental analysis, IR and single-crystal X-ray diffraction. Compound 1（C11H9Cl N2O2） crystallizes in the monoclinic system, space group P21/n with a = 7.249（3）, b = 20.515（10）, c = 7.249（3）,β= 96.30°, V = 1071.6（9） ？3, Z = 4, Mr = 236.65, Dc = 1.467 g/cm3, F（000） = 488, GOOF = 1.029, μ= 0.341 mm-1, the final R = 0.0736 and w R = 0.1966 for 1500 observed reflections with I 〉 2σ（I）. Compound 2（C22H18Cl2Cu N4O5） crystallizes in the monoclinic system, space group P21/c with a = 7.2931（6）, b = 24.548（2）, c = 13.2726（11）, β= 99.4040（10）°, V = 2344.2（3） ？3, Z = 4, Mr = 552.84, Dc = 1.566 g/cm3, F（000） = 1124, GOOF = 1.050, μ= 1.201 mm-1, the final R = 0.0376 and w R = 0.1000 for 3626 observed reflections with I 〉 2σ（I）. 1 and 2 are connected through hydrogen bonding interactions to generate 2D and 3D supramolecular structures, respectively. Moreover, the preliminary antibacterial activities of 1 and 2 against the gram positive bacteria（S. aureus, C. albicans and B. subtilis） and gram negative bacteria（E. coli and P. aeruginosa） have been tested by using the microdilution method, and the results indicate that 2 is more active than 1 against the tested bacteria.

Synthesis and Evaluation of Nicotinoylamino Acid Compounds as Radiosensitizer

Nicotinoylamino acid compounds 4, 5, 9a, 9b, 9c, 10a and 10b were synthesized with nicotinoyl chloride or nicotinoyl azide as acetylating agents of amino acid esters or amino acids. The compounds were tested for their radiosensitizing activity in Leukemia cell line（L1210） and compared with nicotinamide; among them, compounds 9a and 9c showed significant radiosensitizing effects, the sensitizer enhancement ratio（SER） was 1.64 and 1.58, respectively, while nicotinamide did not show good radiosensitizing effect under the same conditions. Compound 9c was alone tested for radiosensitization in LA 795 cell-bearing T-739 mice, or hyperthermia and breathing carbogen（5%CO2＋95%O2） were together tested for radiosensitization. The results showed that radiation-induced growth delay was enhanced by 9c alone or by the combination of hypertheimia and carbogen. The tumor-bearing mice were irradiated locally by total 10 Gy, and the tumors grew to three times that of the original volume in an average of 5.8 d. The mice were given i.p. compound 9c at 1000 mg/kg 60 min before irradiation and treated at 43 ℃ for 30 min after irradiation or treated with breathing carbogen for 5 min before radiation or with hyperthmia（43 ℃） for 30 min after irradiation; the time required for the tumor to grow to three times the orginal volume was in an average of 12.9 and 13 d, respectively.

Syntheses, Crystal Structures, Magnetic and Luminescent Properties of Ni(Ⅱ), Cd(Ⅱ) and Pb(Ⅱ) Coordination Compounds Constructed from 5-Fluoronicotinic Acid

Five coordination compounds, namely [Ni2(5-Fnic)2(H2 O)4](1), [Ni(5-Fnic)(μ-5-Fnic)(H2 biim)]n(2), {[Cd((μ-5-Fnic)2(H2 O)2]×4,4’-bipy}n(3), [Pb2(μ-5-Fnic)2(μ3-5-Fnic)2(H2 O)2]n(4), and [Pb(5-Fnic)2(4,4’-bipy)(H2 O)](5), have been constructed hydrothermally using 5-FnicH(5-FnicH = 5-fluoronicotinic acid), H2 biim(H2 biim = 2,2’-biimidazole), 4,4’-bipy(4,4’-bipy = 4,4’-bipyridine), NiCl2×6 H2 O, CdCl2×H2 O and PbCl2. The products were isolated as stable crystalline solids and were characterized by IR spectra, elemental analyses, thermogravimetric analyses(TGA), and single-crystal X-ray diffraction analyses. Structures of 1~5 range from discrete 0 D monomers(1 and 5) to 1 D coordination polymers(2 and 4) and 2 D metal-organic network(3). A broad structural diversity of 1~5 is guided by the type of the metal(Ⅱ) node and the introduction of auxiliary ligands. The magnetic(for 2) and luminescent(for 3~5) properties were also investigated and discussed.

Melt Synthesis and Characterization of Poly(L-lactic Acid) Chain Linked by Multifunctional Epoxy Compound

High molecular weight（Mw） poly（L-lactic acid）s（PLLAs） were synthesized using multifunctional epoxy compound（Joncryl-ADR4370） as chain extender. The products were characterized by gel permeation chromatography（GPC） and spectroscopy（1HNMR and FTIR）. The results indicated that the Mw of PLLA increased with the increasing of the ratio of epoxy compound and the extending of reaction time. The highest Mw of PLLA reached 360 000 g/mol when the ratio of epoxy compound was 1.5 wt%. However, the reactants turned to cross-linking when the ratio of epoxy compound was over 1.5 wt%. Differential scanning calorimetry（DSC） measurements demonstrated that the glass transition（Tg） and melting temperatures（Tm） of products increased slightly as the increase of the molecular weight. Analysis of the hydrolytic degradation in vitro showed that the branched PLLA possessed the quicker degradability than that of the linear PLLA.

Analysis of the Fatty Acids and Phenolic Compounds in a Cereal-Based Fermented Food (Tarhana)

Tarhana is a Turkish home-made fermented food product. The mixture of wheat flour, yoghurt, yeast, cooked vegetables, salt, and spices is fermented for 1 - 7 days. Tarhana is sun dried and ground for preparation of instant Tarhana powder. Color, phenolic compounds and fatty acid composition were determined for home-made Tarhana, collected from 4 cities in the Thrace Region of Turkey. Color and phenolic content were significantly different (P < 0.05). These differences were due to the variation of ingredients used at different locations. The major unsaturated fatty acids were oleic (C18:1, 16.41% - 57.69%), and linoleic acids (C18:2, 9.74% - 56.31%). Palmitic (C16:0, 16.90% - 37.66%) and stearic acids (C18:0, 0.65% - 11.34%) were the main saturated fatty acids. This study suggested that Tarhana soup is a good source of unsaturated fatty acids. Antioxidant properties of phenolic compounds and their effect on peroxidation of lipids in Tarhana should be tested in future studies.

Syntheses, Crystal Structures and Luminescent and Magnetic Properties of Cerium(Ⅲ) and Zinc(Ⅱ) Coordination Compounds Constructed from 3,5-Dibromobenzoic Acid

Two coordination compounds, namely [Ce（3,5-Br2BC）3（3,5-HBrzBC）]n （1） and [Zn（3,5-Br2BC）2（phen）] （2, 3,5-HBr2BC = 3,5-dibromobenzoic acid, phen = 1,10-phenanthroline）, were assembled. Single-crystal X-ray diffraction studies show that compound 1 possesses a ID chain coordination network, which is further extended into a 3D supramolecular architecture via Br..＇Br and Br＇＂O halogen bonding. Compound 2 consists of a mononuclear molecule, which is assembled to a 3D supramolecular framework through C-H..-O hydrogen bond, π-π stacking interactions and Br..π halogen bonding. Luminescent and magnetic properties of both compounds have also been studied.

Structures and Properties of Two Pb^Ⅱ Compounds and Theoretical Study of 2,4-Oxybis（benzoic acid）

Two Pb^Ⅱ coordination polymers [Pb（oba）（2,2′-bipy）]·1.5H2O（1） and [Pb（oba）（phen）]（2）（H2oba = 2,4-oxybis（benzoic acid）, 2,2′-bipy = 2,2′-bipyridine, phen = 1,10-phenanthroline） were synthesized by hydrothermal reactions and characterized by single-crystal X-ray diffraction, thermogravimetric analyses, IR spectroscopy and elemental analysis. Structures of compounds 1 and 2 are similar. Compounds 1 and 2 show 1D wavy chains, which are further connected through aromatic π-π stacking interactions to expand into 2D wavelike networks. The crystal structure of 2,4-oxybis（benzoic acid） ligand（3） was obtained, and its full geometry optimization was carried out by using DFT methods at the B3LYP/6-31G（d） level. The calculated data show that the bond distances and bond angles were very close to the experimental data. The values of the frontier orbital energies indicate that this configuration is stable. Moreover, the solid-state fluorescence properties of 1-3 have also been investigated.

Characteristics of physico-chemical properties, volatile compounds and free fatty acid profiles of commercial set-type Turkish yoghurts

Ten most popular brands of commercial Turkish set-type yoghurts were collected from local retail outlets in Hatay, Turkey for two separate periods, and analyzed for basic nutrients, physico-chemical properties, volatile aroma compounds and free fatty acid profiles to compare their differences among the yoghurt products. The results showed that there were significant differences (P<0.05, 0.01, or 0.001) and variations in physico-chemical indices, volatile aroma compounds and volatile free fatty acid profiles among the yoghurt brands, which ultimately influence the flavor quality of the product. Acetaldehyde was predominant volatile compound in yoghurts, which followed by acetone, acetoin, diacetyl and ethanol. The level of diacetly was inversely related to titratable acidity, acetaldehyde and ethanoic acid. From ketones with high carbones 2-undecanone and 2-pentadecanone were higher than 2-butanone, 2-nanonane and 2-tridecanone. These ketones are related to fat content of yoghurt. Among short chain free fatty acids, ethanoic (acetic) acid was the most abundant in yoghurts, followed by hexanoic, octanoic and butanoic acids. These differences in detected chemical compositions of volatile compounds and free fatty acids would be applicable to predict flavor, nutritional value, quality control or shelf-life of the commmercial set-type Turkish yoghurts.