Comparison of Headspace Solid-Phase Microextraction with Simultaneous Steam Distillation Extraction for the Analysis of the Volatile Constituents in Chinese Apricot

Volatile constituents in fully mature fruits of apricot （Prunus armeniaca L.） cultivar Xinshiji were extracted using headspace solid-phase microextraction （HS-SPME） and simultaneous steam distillation extraction （SSDE） and then analyzed using capillary gas chromatography and gas chromatography-mass spectrometry. A total of 70 components were identified by HSSPME, including 20 esters, 19 hydrocarbons, 5 alcohols, 5 ketones, 4 acids, 4 lactones, 3 aldehydes, and 10 miscellaneous components, with the esters being the dominant constituent. On the basis of the odor unit values, it is believed that the following compounds probably contributed to the fresh apricot odor： hexyl acetate, β-ionone, butyl acetate, （E）-2-hexenal, linalool, limonene, γ-decalactone, and hexanal. A total of 49 components were also detected by SSDE, including 13 hydrocarbons, 9 alcohols, 7 aldehydes, 9 esters, 4 ketones, 4 lactones, 2 acids, and 1 miscellaneous component, of which the monoterpene alcohols were the dominant constituents. It could be judged from the odor unit values that the following compounds were the major contributors to boiled apricot aroma： β-ionone, linalool, hexyl acetate, γ-dodecalactone, γ- decalactone, （E）-2-hexenal, hexanal, γ-octalactone, phenylacetaldehyde, butyl acetate, limonene, α-terpineol, and δ-decalactone. The results show that HS-SPME is a simple, rapid, and solvent-free method, which is an alternative to the classical SSDE.

Plasma-Induced Degradation of Polypropene Plastics in Natural Volatile Constituents of Ledum palustre Herb

Polypropene （PP） plastics can be effectively degraded by natural volatile con- stituents from Ledum palustre catalyzed by atmospheric air dielectric barrier （DBD） plasma. The electron spin resonance （ESR） result indicates that the volatile constituents produce radicals in aerobic condition energized by power sources such as light, UV, plasma and so on. The degradation is a novel chemically oxidative way and it is initiated by a series of radical reactions. Lots of active cud oxidative species, radicals, products cud high euergy electromagnetic field in plasma aggravate the degradation process. The results about PP maximum tensile strength （Crbmax） confirm this conclusion. PP plastic heavily loses its extensibility, mechanical integrity and strength in a short time after suffering a synergetic treatment of the herb extract and air DBD plasma with no toxic residues left. The components of herb extract keep almost unchanged and may be reused. This study offers a new approach to manage and recycle typical plastics.

ANALYSIS OF VOLATILE CONSTITUENTS OF CHINESE MEDICINAL HERBS BY FLASH DISTILLATION/CAPILLARY GAS CHROMATOGRAPHY/MASS SPECTROMETRY

In present work,the volatile constituents of Curcuma longa L.,A.lancea (Thunb.) DC.,Foeniculum vulgare Mill,and Cinnamomun cassia Presl.have been analyzed by flash distillation/capillary gas chro-matography/mass spectrometry.The results are consistent with those obtained by conventional steam distillation extraction method.The optimum condition of flash distillation has been studied.The experimental results showed that this new technique proved to be a simple,rapid and efficient tool for microanalysis of volatile constituents of Chinese medicinal herbs.

Content determination of saponins and HS-GC/MS analysis of volatile components in Chinese Shizhu Panax of different growth years

HPLC and headspace-gas chromatography-mass spectrometry(HS-GC-MS)were used to investigate the content of saponins and volatile components in Chinese Shizhu Panax of different growth years.82 components were isolated from Chinese Shizhu Panax,69 components of them were successfully identified.They mainly contained monoterpenes,alkanes and sesquiterpenoids,of which sesquiterpenoids were the main components.The results indicated that the content of saponins in Chinese Shizhu Panax of different growth years was dissimilar and diverse.The content of total saponins can be enriched when properly prolonging the growth years of Chinese Shizhu Panax.However,the content of ginsenosides can reach the level in the fifth year according to Chinese Pharmacopoeia.The volatile components in Chinese Shizhu Panax of different growth years also differ in content,type and proportion of compounds to a certain degree.

Rosa x alba:source of essential minerals and volatile oils

Rosa x alba is cultivated almost exclusively for the production of aromatic water and fruits widely used as ingredients in some traditional food preparations sold commercially.Results of the proximate and elemental analyses revealed that flowers exhibited higher moisture content while the dry matter content was higher in leaves.Total fat and ash was higher in fruits when compared with leaves and flowers.All studied organs were found to be rich in essential mineral such as K,Ca,P and Mg.Qualitative and quantitative analysis of the volatile oils revealed different composition patterns between organs.Linalool and geraniol were found as major constituents of the leaf oil whereas 2-phenethyl alcohol and eugenol were the major constituents of the floral oil.In contrast,fruits showed very distinct composition and alkanes/alkenes were found to have the major contribution.The present composition could justify the traditional use of Rosa x alba which could be considered as a potential source of essential minerals and volatile constituents.

益母草中挥发性组分的酶提取及分析

The cellulase was used for extracting the volatile constituents of the Leonurus japonicus Houtt.The effects of the pH,the amounts and the fineness of cellulase were discussed.The average yield obtained was 4.05%.16 chemical components were identified by gas chromatography-mass spectrometry (GC-MS)method.The cellulase extraction (CE)method was made a camparison with distillation extraction (DSE)method.

The Flavor and Antioxidant Activity Change Pattern of Shrimp Head Paste During Fermentation

To study the changes of volatile compounds and antioxidant activity of fast fermented shrimp head paste during the fermentation processing,Penaeus vannamei boone head was used as the raw material,and compound starter was added for fermen-tation.During the 14 days of fermentation,the changes of free amino acids,volatile flavor compounds and main components were determined by SPME-GC-MS and electronic nose.The oxidation-resistance changes of water extract at different fermentation stages were evaluated.The results showed that the total free amino acids increased from original 2320 to 5640 mg(100 mL)^(−1).SPME-GC-MS analysis found that aldehydes,pyrazine compounds increased from 10.80%,1.94%to 24.35%,13.63%respectively during the fermentation process.The HO·scavenging ability of shrimp head paste increased from 52%to 86%.Our results showed that the shrimp paste produced from shrimp head fermentation could obtain good flavor and possess certain antioxidant activity of aquatic fermented condiment.