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ObjectiveOn the basis of sensory evaluation， the changes of volatile components in gecko before and after processing were compared， and the odor correction effect of different processing methods of gecko was discussed. MethodRaw products， fried yellow products， vinegar processed products， wine processed products， talcum powder scalding products and white wine sprayed products after scalding talcum powder of gecko were prepared， and 10 odor assessors were invited to evaluate the 6 samples in turn by sensory evaluation. Headspace solid-phase microextraction-gas chromatography-mass spectrometry （HS-SPME-GC-MS） and relative odor activity value （ROAV） were used to analyze the key odor components， and multivariate statistical methods were used to analyze the difference of volatile components between raw and processed products of gecko. Taking water-soluble extract and protein contents as internal indicators， sensory evaluation score and content ranking of differential components as external indicators， and assigning a weight of 0.25 to them respectively， the comprehensive scores of raw products and processed products of gecko were calculated to evaluate the odor correction effect of each processing method. ResultThe average sensory evaluation scores of the raw products， fried yellow products， vinegar processed products， wine processed products， talcum powder scalding products and white wine sprayed products after scalding talcum powder of gecko were 1.6， 5.2， 6.2， 6.1， 7.2 and 8.0， respectively. ROAV results showed that key components affecting odor of gecko were 2-ethyl-3，5-dimethylpyrazine， isovaleraldehyde， trimethylamine， 1-octen-3-ol， n-octanal， nonanal， 2-methylnaphthalene， γ-octanolide， 2-heptanone and phenol. Principal component analysis （PCA） significantly distinguished raw products from processed products. Orthogonal partial least squares-discriminant analysis （OPLS-DA） results showed that there were 16， 13， 16， 16， 16 differential components between raw products， fried yellow products， vinegar processed products， wine processed products， talcum powder scalding products and white wine sprayed products after scalding talcum powder of gecko. Among these differential components， there were 4 common components， namely， the contents of different odor components （2-methylnaphthalene and 2-ethyl-p-xylene） decreased， while the contents of different flavor components （2-decanone and 2，3，5-trimethylpyrazine） increased. The comprehensive scoring results showed that the odor correction effect of each processed products was in the order of talcum powder scalding products>wine processed products>vinegar processed products>fried yellow products>white wine sprayed products after scalding talcum powder. ConclusionTalcum powder scalding is a better method to improve the odor of gecko， and it can provide an experimental basis for the processing of gecko to correct the odor.
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ObjectiveTo analyze the quality changes of Platycladi Semen before and after the deterioration of moth-eaten and rancidity during storage. MethodFour types samples of Platycladi Semen， including normal， moth-eaten， oxidative rancidity and hydrolytic rancidity， were determined for volatile components， odor， and taste based on headspace solid phase microextraction/gas chromatography-mass spectrometry （HS-SPME/GC-MS） and electronic sensory techniques such as electronic nose and electronic tongue. Volatile components were identified by searching the database and manual comparison， the odor and taste were determined by the response values of the electronic nose and electronic tongue sensors， and the difference between samples before and after deterioration was studied by multivariate statistical analysis. ResultA total of 85 compounds were identified in Platycladi Semen samples. Compared with the normal samples， the number of volatile compounds in samples after hydrolytic rancidity decreased by 5， the number of volatile compounds in samples after moth-eaten and oxidative rancidity increased by 1 and 21， respectively. Aldehydes and acids accounted for majority of types. Among them， the contents of N-hexanoic acid， hexanal and propionic acid in the samples of oxidative rancidity reached 11.49%， 10.21% and 7.52%， which became the key indicators of rancidity. There was significant variance among the odor components corresponding to W1W， W2W and W1S sensors by electronic nose analysis. It was indicated that the value of sourness in deteriorated samples generally increased by mean of electronic tongue analysis. Compared with normal samples， the moth-eaten samples had changed slightly and rancidity samples had changed significantly especially oxidative rancidity samples of volatile components， odor and taste by multivariate statistical analysis. ConclusionIn terms of Platycladi Semen， the oxidative rancidity caused by nature storage for 12 months has the greatest impact on the quality. Therefore， it should be mainly to prevent oxidative rancidity to ensure the quality of Platycladi Semen.
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Objective: To screen a processing method suitable for deodorizing of Periplaneta americana (PA) through subjective and objective evaluation combined with changes in volatile components, and explore the mechanism of deodorization. Methods: Raw, vinegar-processed, wine-processed, wheat bran-processed products of PA were prepared respectively. Volunteer sensory evaluation combined with electronic nose system was used to evaluate the odor difference between raw and processed products to screen a better processed product. HS-SPME-GC-MS and ROAV were used to analyze the key odorous components of PA. The peak area normalization method combined with multivariate statistical analysis were used to analyze the difference of volatile components between raw and processed products to explore the mechanism of processing. Results|| Volunteer scores showed that the average scores of raw, vinegar-processed, wine-processed, wheat bran-processed products were 3.38, 1.25, 2.88, and 3.04, respectively. The results of the electronic nose showed that the Euclidean distance between the raw and vinegar-processed, wine-processed, wheat bran-processed products were 7.34, 3.77 and 1.60, respectively, but the direction of scatter of vinegar-processed product was opposite to that of wine-processed product and wheat bran-processed product, suggesting that the mechanism of deodorization may be different. Vinegar processing was determined as the optimum method for deodorizing by comprehensive analysis of subjective and objective evaluation data. The key odor components of PA were 3-methyl butanal, hexanal, nonyl aldehyde, heptaldehyde, decyl aldehyde, phenyl acetaldehyde, (E,E)-2,4-nonadienal, 2-pentylfuran, (+)-limonene, and myristic aldehyde. The PCA result of volatile components showed that four kinds of processed products can be clearly distinguished, and there were differences in volatile components and content. There were seven differential chemical components between raw and vinegar-processed products, including hexanal, palmitic acid, oleic acid, acetic acid, ethyl oleate, ethyl palmitate, and ethyl linoleate. The content of vinegar-processed products was lower than that of raw products, especially the key odorous component hexanal. Conclusion: The vinegar processing is a better method to improve the odor of PA, and its mechanism may be associated with reducing odorous components such as hexanal.
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The aim of the present work was to optimize the main experimental variables of a procedure using HS-SPME/GC-MS as the analytical methodology to establish the profile of the volatile compounds present in aerial parts of Hedeoma multiflorum Benth. The influence of the type of fiber, equilibrium time, extraction time and extraction temperature on the composition of the volatile compounds was determined using response surface methodology (RSM), and the parameters of the models were corroborated by multiple linear regressions. The results showed that the regression models generated adequately explained the data variation and represented the relationships between the parameters and their responses. The optimal analysis conditions from the contour plots were established (DVB/CAR/PDMS fiber, with a 10 min equilibrium time, 10 min extraction time, and 40°C). Under these conditions, 41 volatile components in the whole plant were determined, which represents more than those reported using hydrodistillation.
El objetivo del presente trabajo fue optimizar las principales variables experimentales de un procedimiento HS-SPME/GC para establecer el perfil de compuestos volaÌtiles presentes en la parte aeÌrea de Hedeoma multiflorum Benth. Se determinoÌ la influencia de las variables tipo de fibra, tiempo de equilibrio, tiempo de extraccioÌn y temperatura de extraccioÌn sobre la composicioÌn de los volaÌtiles, utilizando una met odologiÌa de superficie de respuesta (RSM) y los paraÌmetros del modelo se corroboraron por regresioÌn lineal muÌltiple. Los resultados demostraron que los modelos de regresioÌn generados explican adecuadamente la variacioÌn de los datos y representaron significativamente las relaciones reales entre los paraÌmetros y sus respuestas. Las condiciones oÌptimas de anaÌlisis fueron establecidas (DVB/CAR/PDMS, con un tiempo de equilibrio de 10 minutos, un tiempo de extraccioÌn de 10 minutos y trabajando a 40°C). Utilizando esta metodologiÌa, se determinaron 41 componentes volaÌtiles en planta entera, maÌs que los reportados mediante hidrodestilacioÌn.
Subject(s)
Hedeoma , Solid Phase Microextraction/methods , Volatile Organic Compounds/chemistry , Gas Chromatography-Mass Spectrometry/methodsABSTRACT
Objective: Headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze the characteristic volatile compounds from 18 heat-clearing herbs. Method: HS-SPME was used to extract the volatile components from different heat-clearing herbs,and the chemical compositions were analyzed by GC-MS. The GC was performed at the injector temperature of 250℃,the high-purity helium was used as the carrier gas at a constant column flow of 1.0 mL·min-1 with no split sampling. The solvent delay time was 3 min. Mass spectrum conditions included electron bombardment ion source,electron bombardment energy of 70 eV,ion source temperature of 230℃,quadrupoles temperature of 150℃,and scanning range of m/z 29-370.The volatile components were confirmed according to NIST2013 database,and the relative content percentage of each component was calculated by peak area normalization method. PCA was used to detect clustering and discuss the characteristics of volatile compounds of 18 heat-clearing herbs. Result: A total of 328 volatile compounds were detected in 18 heat-clearing herbs,including alkanes,unsaturated hydrocarbon,alcohols,aldehyde,ketones,esters,furan and other unknown compounds. The number and relative content of volatile components in different heat-clearing herbs varied dramatically. Several important characteristic volatile compounds,such as l-camphor,torreyol,caryophyllene oxide,globulol and 2,4-cycloheptadien-1-one,2,6,6-trimethyl,were detected in the 18 heat-clearing herbs by principal component analysis. Conclusion: Heat-clearing herbs contains rich volatile components,which are the main contributors to the formation of unique aroma of herbs,as well as the main active substances.
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Objective A headspace-solid phase microextraction-gas chromatography-mass spectrometry method (HS-SPME-GC-MS) was adopted for analyzing the volatile components of different parts of Clausena lansium in Hainan Province. Methods Five different fibers were investigated and optimized. Other five experimental parameters such as volume of water, extraction temperature, equilibrium time, extraction time, and salt concentration had been evaluated and optimized by means of the orthogonal design with L16(45) table. Finally, the volatile components of C. lansium leaves, pericarps, and seeds in Hainan were analyzed and identified by GC-MS combined with retention index (RI). Results The optimum extraction conditions were as follows: a 50/30 μm DVB/CAR/PDMS fiber, 10 mg sample powders, 2.0 mL water, 0.2 g NaCl, extraction temperature 80 ℃, equilibrium time 30 min, extraction time 60 min. A total of 83 chemical components were identified from leaves, 96 from pericarps, and 106 from seeds, representing the relative contents of 95.24%, 92.15%, and 95.92% of the total composition. The highest contents were sesquiterpenes in all of the parts, but there were obviously different both in components and contents. Conclusion The HS-SPME-GC-MS method is rapid and sensitive, with a small sample size, without any organic solvents. GC-MS combined with RI has improved the accuracy of analysis and identification. The results may provide experimental basis for further exploitation of C. lansium in Hainan. This method can be used to perform enrichment analysis of the components with high-boiling point and micro-components, which can comprehensively and scientifically characterize and evaluate the quality of Chinese materia medica.
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Objective:To analyze and evaluate the quality control of Radix Aucklandiae in Xianglian preparation and develop a new quality control method for the preparation through standard testing and exploration study on 127 batches of samples .Methods:Ac-cording to the mandatory method , Radix Aucklandiae was identified by TLC .In the exploratory research , the volatile compounds in Xianglian preparation was analyzed by SPME/GC-MS, and the GC-MS fingerprints of volatile compounds in Xianglian preparation with different dosage forms were established .The contents of costunolide and dehydrocostuslactone in Xianglian preparation were determined by UPLC.Results:According to the current quality standard , all the batches of samples met the standard with the qualified rate of 100%.The composition of volatile compounds in different dosage forms was similar , while the relative contents were quite different . The contents of costunolide and dehydrocostuslactone in Xianglian preparation were different .Conclusion: The exploratory research provides reference for the further revision of drug standard and monitoring quality of the preparation .
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The search for chemical markers for determining honey authenticity as a complementary tool for melissopalynological method is an important issue in the study of honeys from different botanical origins. The objective of this study was to determine the volatile compounds in tevo (Retanilla trinervia [Gillies & Hook] Hook & Arn [Fam. Rhamnaceae]) honey as one of the most relevant honeys from central Chile. For the identification and quantification of volatile compounds, Solid-Phase Microextraction and Gas Chromatography with Mass Spectrometry (SPME-GC-MS) was performed. A total of 28 out of 103 volatile compounds were found common to the five tevo honeys analyzed. Nevertheless, these compounds are common in unifloral honey of different floral sources from other countries. These results represent the first record in the identification of volatile compounds in tevo honey and would indicate that tevo honey does not present specific volatile compounds that allow its clear differentiation from other unifloral honey.
La búsqueda de marcadores químicos para determinar la autenticidad de la miel como una herramienta complementaria al análisis melisopalinológico es un tema importante en el estudio de las mieles de diferentes orígenes botánicos. El objetivo de este estudio fue determinar los compuestos volátiles en miel de tevo (Retanilla trinervia [Gillies & Hook] Hook & Arn [Fam. Rhamnaceae]), una de las mieles más relevantes de Chile Central. La identificación y cuantificación de compuestos volátiles se llevó a cabo mediante Microextracción en Fase Sólida y Cromatografía de Gases con Espectrometría de Masas (SPME-CG-MS). Un total de 28 de los 103 compuestos volátiles identificados en las cinco mieles de tevo analizadas se encontraron en común para ellas. Sin embargo, estos compuestos son comunes en la miel monofloral de diferentes fuentes florales de otros países. Estos resultados representan los primeros avances en la identificación de compuestos volátiles en la miel de tevo e indicarían que la miel de tevo no presenta compuestos volátiles específicos que permitan su clara diferenciación respecto a otras mieles monoflorales.
Subject(s)
Honey/analysis , Rhamnaceae/chemistry , Volatile Organic Compounds/chemistry , Chile , Gas Chromatography-Mass Spectrometry , Solid Phase MicroextractionABSTRACT
Objective To find out the impact of SHI-1 cells on VOCs in the headspace, and to assess the feasibili-ty of VOCs analysis in leukemia patients or with other tumors in the differential diagnosis by determing VOCs in the headspace of acute mononuclear leukemia cells(SHI-1). Methods The air samples from the headspace of SHI-1, Human macrophages cells and medium control were collected by syringes, and then determined by means of solid phase microextraction-gas chromatography/mass spectrometry ( SPME-GC/MS ) in order to have a better under-standing of the concentration distributions and changes of VOCs in SHI-1 cells' headspace. Results Using Mann-Whitney U test, we found that eight kinds of VOCs were different among them. They were 2,4-dimethyl heptanes, 4-methyl octane, chloroform, benzene, 3,7-dimethyl dodecanese, hexanol, cyclohexanol, cetane. And alkane, benzene were significantly higher than the control group ( P<0.05 ) , alcohol decreased significantly ( P<0.05 ) . Conclusion SHI-1 cells have an impact on the concentration distributions of VOCs in their headspace. The most outstanding VOCs are alkanes, alcohol and benzene compared with the blank control group. They may be potential markers characteristic of leukemia cells.