Advanced Materials Research Vols. 554-556

Abstract: In this paper, the volatile compounds of the belly meat and red meat of cultured grass carp in different seasons were identified by SPME(solid phase micro-extraction)-GC (gas chromatography)-MS (mass spectrometry). The results showed that SPME was effective to analysis of the volatiles in grass carp meat. According to GC-MS, 26, 44, 41 and 26 volatile compounds were detected in belly meat of grass carp in spring, summer, autumn and winter respectively; 48, 46, 43 and 53 volatile compounds were detected in red meat of grass carp in spring, summer, autumn and winter respectively. The volatile components are mostly carbonyl compounds and alcohols, the respective relative contents are above 90%. The relative content of the volatile compounds of cultured grass carp in different seasons has the significance difference by ANOVA. Seasons have great effect on the volatile compounds of grass carp meat and the impact on red meat is smaller than belly meat The study will enrich the theoretical knowledge of flavor chemistry and provide an effective solution to the current situation of low proportion of fish processing.

Abstract: Objective : Codonopsis tangshen Oliv.is a kind of traditional Chinese medicinal materials high medicinal purposes value and wide application.It had important meanding to analyze its volatile oil consitituent on expanding its utilization and increasing the added value.Methods:The volatile compounds of Codonopsis tangshen Oliv. were isolated with steam distillation,and identified by capillary GC／MS and the relative contents of the constitons were detemined by area normalization method. Rusults: 60 volatile components were identified and determined，accounting for98.51％ of the total area of the peaks.Conclusion: The main volatile compounds are :Decanoic acid 2-monoglyceride,Furfural,Isopentyl alcohol,Palmitic acid,eugenol methyl ether,Di-sec-butyl ether,Hydroperoxide, 1-methylhexyl,Hexanoic acid ,2,4,5-trimethyl-1,3-Dioxolane ,Propasol solvent P,Hexyl alcohol ,cis-Isosafrole ,2-Hexenal ,Cajeputol.

Abstract: Short-chain triglycerides i.e. the low calorie oil was produced by transesterification with soybean oil and glycerol triacetate using sodium methoxide as catalyst. The reaction conditions were optimized and the yield reached 73.14 % under this conditions. The calorific values of the soybean oil and the product were measured and the value for the later was 32 450 J/g which was approximately 71 % of the former.

Abstract: The aroma compoumds of Muscat Hamburg dry white wines from three different wine regions, made with the same brewing technology, were determined by head space solid phase microextraction coupled with gas chromatography mass spectrometry (HS-SPME-GC/MS), with grapes harvested in 2010 from Tianjin Hangu, Heibei Changli and Shandong Pingdu regions as raw materials. Total 58 volatile compounds were identified and 23 componds were quantified. The results show that the wines from Hangu regions contained relatively high levels of terpenes and esters, and lower contents of higher alcohols,which contributed to the wines rich floral and fruity aromas and sweet, musky flavors.

Abstract: The flavor compounds in paprika sausage were investigated by using gas chromatography mass spectrometry (GC-MS) in this study. By comparing with NIST mass spectral database, 11 flavor compounds including caryophyllene, 9, 12-Octadecadienoic acid, 4-Heptyn-2-ol, were identified. The obtained results could be used to establish the method analyzing the flavor ingredients in low temperature-heated meat product.

Abstract: The physical and sensory properties of the steamed bread with different refrigerated processes (frozen steamed bread, pre-steamed steamed bread, proofed-frozen dough, fermented-frozen dough, frozen dough and cold storage dough technology) were compared with fresh steamed bread. The specific volume, spread ratio, whiteness and the parameters from texture profile analysis (TPA) were used to evaluate the physical properties. The results showed that technology of cold storage dough was the best for the steamed bread. Technology of frozen dough and frozen steamed bread were better technology. Technology of pre-steamed steamed bread, proofed-frozen dough and fermented-frozen dough which were used in the industry of bread commonly were not fit for steamed bread.

Abstract: A commercial electronic tongue (ET) with specific sensors was applied on taste distinction and physicochemical characterization of seven kinds of sweet sauces. The response signals of ET sensors were analyzed by Principal Component Analysis (PCA) and Discriminant Factor Analysis (DFA). Meanwhile, these signals were transformed into the four relative taste scores (sourness, saltiness, umami and sweetness) by macro operation, followed by comparing with the corresponding four physiochemical indexes (total acids, sodium chloride, amino nitrogen and reducing sugars) which were determined by the methods in GB/T. The results show that ET can be used to distinguish different kinds of sweet sauces according to overall taste. Moreover, the intensity order of taste scores that obtained from ET is basically matched with the sequence of the corresponding physicochemical indexes, which proves that ET technique can be an effective approach to monitor and guarantee the quality of sweet sauce on line.

Abstract: Amino acid hydrolysates were obtained from dried clamworm of Perinereis aibuhitensis by acid hydrolysis method. Maillard reaction products(MRPs) were prepared with the amino acid hydrolysates and glucose and sucrose respectively. Volatile constituents from the two kinds of MRPs were separated and identified by gas chromatography–mass spectrometry(GC/MS). The results indicate that 120 components were identified from MRPs of Perinereis aibuhitensis, Some of which are flavor compounds such as ketones, aldehydes, esters, and organic acids etc., taking up approximately 8 percent of the MRPs.

Abstract: Density functional theory (DFT) calculations were performed on seven magnesium surfaces of Mg(100), Mg(010), Mg(001), Mg(110), Mg(101), Mg(011) and Mg(111). The electronic state density was analyzed. The stabilities of the seven surfaces were established. The results indicated that the surface energies are in the range of 0.4610 to 1.0940 J/m², which correspond to the Mg(001) and Mg(101) surfaces respectively. These data agree well with the available experimental result. In addition, it was found that the lower surface energy corresponds to more evenly distributed density of state (DOS), more number of DOS peaks but less height of it.

Abstract: Adopting BYLP method in Density Functional Theory (DFT), we make theoretical study on the ozonide-orthophenylphenol, parachlorophenol, orthobenzoquinone and parabenzoquinone in the two reaction routes of phenol oxidizing into benzoquinone with ozone. We get the geometric configuration of molecules, charge distribution of atoms, thermodynamical properties and frontier orbit energy. Natural Bond Orbital(NBO)charge calculation shows that compared with orthobenzoquinone and parabenzoquinone molecules, phenol, orthophenylphenol and parachlorophenol molecules have stronger reactivity and they are more likely to have electrophilic substitution reaction. Thermodynamic properties indicate that phenol is easy to have oxidation reaction and produce orthophenylphenol which is easily to oxidize into orthobenzoquinone no matter at low temperature, room temperature or high temperature. Another reaction pathwaycalculation shows that in thermodynamics, phenol will not easily ozonize into parachlorophenol; while parachlorophenol will easily ozonize into parabenzoquinone. Frontier orbit energy calculation shows that phenol, orthophenylphenol, and parachlorophenol show similar stability. Orthobenzoquinone and parabenzoquinone have the strongest stability.