The objective of the study was to research the aroma profile of volatile compounds in garlic subspecies originating from Latvia, and compare them with the aroma composition of garlic grown in the region of Midi-Pyrene...The objective of the study was to research the aroma profile of volatile compounds in garlic subspecies originating from Latvia, and compare them with the aroma composition of garlic grown in the region of Midi-Pyrenees （France）. It was established that hard-neck garlic tends to contain more diallyl disulfide （DADS）, the main decomposition product of allicin. Compared to the hard-neck subspecies, the content of allyl mercaptan, one of the major compounds producing the strong odor detectable after ingestion of garlic, was significantly lower in the soft-neck garlic clones. The amount of cyclic compound 3-vinyl-1,2-dithiin differed considerably with higher contents in the soft-neck subspecies. The results also demonstrate the soft-neck garlic as a more suitable subspecies for long-term storage. In general, the results show no significant difference in the content of DADS and the total content of other flavor compounds between hard-neck and soft-neck garlic grown in the region of Midi-Pyrenees and Latvia. However, comparing garlic subspecies originating from France and Latvia by the content of allyl mercaptan, 1,2-dithiolane and 3-vinyl-1,2-dithiin, a considerable proportional difference of these volatiles was determined. Also, a significant difference was established in the content of DADS between the white garlic variety ＂Blanc de Lomagne＂ （France, region of Midi-Pyrenees） and white garlic grown in other countries. The results of this study suggest the suitability of solid phase microextraction （SPME） and gas chromatography （GC） methods for quality control of garlic originating from France.展开更多
This paper investigated the feasibility of sonication as an advanced treatment method for drinking water production and used comprehensive indexes of water quality to examine its efficiency. Results show that sonicati...This paper investigated the feasibility of sonication as an advanced treatment method for drinking water production and used comprehensive indexes of water quality to examine its efficiency. Results show that sonication significantly reduces the toxicity of water. Sonication with 5 W/L at 90 kHz lasting for 30 rain decreases the water SUVA and the disinfection byproduct formation potential （DBPFP） by 38.7% and 27. 2% respectively. Sonication also decreases the UV254 by more than 50% through destroying unsaturated chemical bonds. Higher sound intensity and higher frequency benefit the reduction of TOC and UV254. Besides, sonication significantly increases the affinity of organics with granular activated carbon （ GAC ） , and thus the hybrid sonication-GAC method reduces the water TOC, COD, UV254, and DBPFP by 78.3%, 69.4%, 75.7%, and 70.0% respectively. Therefore, sonication and the hybrid sonication-GAC metbod are proposed as advanced treatment methods for drinking water.展开更多
Biological and synthetic surfactants were compared in terms of their ability to reduce interfacial tension, change the thermodynamic characteristics of a pre-conditioned surface, and to modify the rheological properti...Biological and synthetic surfactants were compared in terms of their ability to reduce interfacial tension, change the thermodynamic characteristics of a pre-conditioned surface, and to modify the rheological properties of their respective formulations at two different temperatures. Both classes of suffactants were able to reduce the inteffacial tension of their formulations to a similar level. However, the biosurfactants were more effective than the synthetics surfactants. Biosurfactants also altered the surface properties of stainless steel, rendering it hydrophilic. Microbial adhesion to stainless steel conditioned with biosurfactants was found to be thermodynamically unfavorable for all microbial strains tested. A linear relationship between shear stress and shear rate was obtained across a range of experimental conditions for all surfactant mixtures, indicating that all formulations behaved as Newtonian fluids.展开更多
文摘The objective of the study was to research the aroma profile of volatile compounds in garlic subspecies originating from Latvia, and compare them with the aroma composition of garlic grown in the region of Midi-Pyrenees （France）. It was established that hard-neck garlic tends to contain more diallyl disulfide （DADS）, the main decomposition product of allicin. Compared to the hard-neck subspecies, the content of allyl mercaptan, one of the major compounds producing the strong odor detectable after ingestion of garlic, was significantly lower in the soft-neck garlic clones. The amount of cyclic compound 3-vinyl-1,2-dithiin differed considerably with higher contents in the soft-neck subspecies. The results also demonstrate the soft-neck garlic as a more suitable subspecies for long-term storage. In general, the results show no significant difference in the content of DADS and the total content of other flavor compounds between hard-neck and soft-neck garlic grown in the region of Midi-Pyrenees and Latvia. However, comparing garlic subspecies originating from France and Latvia by the content of allyl mercaptan, 1,2-dithiolane and 3-vinyl-1,2-dithiin, a considerable proportional difference of these volatiles was determined. Also, a significant difference was established in the content of DADS between the white garlic variety ＂Blanc de Lomagne＂ （France, region of Midi-Pyrenees） and white garlic grown in other countries. The results of this study suggest the suitability of solid phase microextraction （SPME） and gas chromatography （GC） methods for quality control of garlic originating from France.
基金Sponsored by the National High Technology Research and Development Program of China(Grant No.2007AA06Z339)the National Science Foundation for Post-doctoral Scientists of China(Grant No.2006AA06Z306)
文摘This paper investigated the feasibility of sonication as an advanced treatment method for drinking water production and used comprehensive indexes of water quality to examine its efficiency. Results show that sonication significantly reduces the toxicity of water. Sonication with 5 W/L at 90 kHz lasting for 30 rain decreases the water SUVA and the disinfection byproduct formation potential （DBPFP） by 38.7% and 27. 2% respectively. Sonication also decreases the UV254 by more than 50% through destroying unsaturated chemical bonds. Higher sound intensity and higher frequency benefit the reduction of TOC and UV254. Besides, sonication significantly increases the affinity of organics with granular activated carbon （ GAC ） , and thus the hybrid sonication-GAC method reduces the water TOC, COD, UV254, and DBPFP by 78.3%, 69.4%, 75.7%, and 70.0% respectively. Therefore, sonication and the hybrid sonication-GAC metbod are proposed as advanced treatment methods for drinking water.
文摘Biological and synthetic surfactants were compared in terms of their ability to reduce interfacial tension, change the thermodynamic characteristics of a pre-conditioned surface, and to modify the rheological properties of their respective formulations at two different temperatures. Both classes of suffactants were able to reduce the inteffacial tension of their formulations to a similar level. However, the biosurfactants were more effective than the synthetics surfactants. Biosurfactants also altered the surface properties of stainless steel, rendering it hydrophilic. Microbial adhesion to stainless steel conditioned with biosurfactants was found to be thermodynamically unfavorable for all microbial strains tested. A linear relationship between shear stress and shear rate was obtained across a range of experimental conditions for all surfactant mixtures, indicating that all formulations behaved as Newtonian fluids.
