采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)和气相色谱与质谱联用技术(gas chromatography with mass spectrometry,GC-MS)分析皇冠梨中梨皮、梨肉、梨汁中的香气成分。结果表明:共鉴定出香气成分56种,3个样...采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)和气相色谱与质谱联用技术(gas chromatography with mass spectrometry,GC-MS)分析皇冠梨中梨皮、梨肉、梨汁中的香气成分。结果表明:共鉴定出香气成分56种,3个样品中均含有酯类物质,其中果皮中最多,果肉居中,果汁最少,分别占香气物质的27.21%、9.63%、0.19%。除此之外还含有正己醛、反式-2-己烯醛、壬醛,且总量分别占果肉样及果汁样中香气物质的4.50%、52.20%,甲基庚烯酮占果皮样及果肉样中香气物质的0.42%、1.48%。其中反式-2-己烯醛具有新鲜的绿叶香味;甲基庚烯酮具有水果香气和新鲜清香香气;壬醛具有玫瑰、柑橘等香气、青味、油脂味;癸醛稀薄时具有果味香,使得皇冠梨具备了独特的怡人风味。此外,皇冠梨果皮中香气成分较为丰富,共检测出33种,其中特有成分14余种,因此,建议在加工皇冠梨果汁、果脯、罐头等产品时,尽量保留果皮,以保留产品独特香气。皇冠梨肉样中检测出香气成分16种,皇冠梨汁样中检测出的香气成分18种,其中特有成分共近20种,适宜加工生产果汁、罐头产品。展开更多
采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)和气相色谱与质谱联用技术(gas chromatography with mass spectrometry,GC-MS)分析金珠果梨中梨皮、梨肉、梨汁中的香气成分,结果表明:共鉴定出香气成分53种。梨皮...采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)和气相色谱与质谱联用技术(gas chromatography with mass spectrometry,GC-MS)分析金珠果梨中梨皮、梨肉、梨汁中的香气成分,结果表明:共鉴定出香气成分53种。梨皮、梨肉、梨汁样品中均含有大量正己酸乙酯、丁酸乙酯、辛酸乙酯,梨皮样、梨肉样及梨汁样中3种酯的总和分别占香气物质的69.42%、30.90%、29.15%。除此之外还含有己烯醛、壬醛、癸醛,且3种醛总含量分占梨皮样、梨肉样及梨汁样中香气物质的10.38%、12.88%、7.13%。这些香气成分可使金珠果梨具有怡人的风味,并使金珠果梨具有自身的典型性风格。此外,金珠果梨果皮香气成分比较丰富,共鉴定出30种,其中特有成分十余种,在加工果汁、果脯、罐头等产品时,尽量保留果皮,以保留产品独特香气。金珠果梨果汁中香气成分共鉴定出30种,其中独特成分15种,因此,适宜加工生产果汁产品。展开更多
To assess the effect of rice straw mulching on changes of antagonistic bacteria and the incidence of wheat sharp eyespot, a multi-year field study was performed to compare unmulched plots and the plots mulched with ri...To assess the effect of rice straw mulching on changes of antagonistic bacteria and the incidence of wheat sharp eyespot, a multi-year field study was performed to compare unmulched plots and the plots mulched with rice straw for two or three years. Bacterial and fungal populations were evaluated in the cultures prepared from the wheat rhizosphere and bulk soils. Rice straw mulching increased the number of pseudomonas colony forming units in wheat rhizosphere and bulk soils. The proportion of total bacteria that were fluorescent pseudomonads was higher in mulched than in unmulched soil. Bacterial isolates antagonistic to Rhizoctonia cerealis were identified using an inhibition zone test. A series of these isolates were typed by partial sequencing of the 16S rRNA gene. Pseudomonads had higher antagonistic activity against R. cerealis than other species, and more than 80% of rhizosphere fluorescent pseudomonads were antagonistic to R. cerealis. The disease indices were lower in the mulched plots than in the unmulched control. These results suggest that rice straw mulching in a rice-wheat rotation increases the number of fluorescent pseudomonads. Additionally, these fluorescent pseudomonads may contribute to the control of wheat sharp eyespot.展开更多
文摘采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)和气相色谱与质谱联用技术(gas chromatography with mass spectrometry,GC-MS)分析皇冠梨中梨皮、梨肉、梨汁中的香气成分。结果表明:共鉴定出香气成分56种,3个样品中均含有酯类物质,其中果皮中最多,果肉居中,果汁最少,分别占香气物质的27.21%、9.63%、0.19%。除此之外还含有正己醛、反式-2-己烯醛、壬醛,且总量分别占果肉样及果汁样中香气物质的4.50%、52.20%,甲基庚烯酮占果皮样及果肉样中香气物质的0.42%、1.48%。其中反式-2-己烯醛具有新鲜的绿叶香味;甲基庚烯酮具有水果香气和新鲜清香香气;壬醛具有玫瑰、柑橘等香气、青味、油脂味;癸醛稀薄时具有果味香,使得皇冠梨具备了独特的怡人风味。此外,皇冠梨果皮中香气成分较为丰富,共检测出33种,其中特有成分14余种,因此,建议在加工皇冠梨果汁、果脯、罐头等产品时,尽量保留果皮,以保留产品独特香气。皇冠梨肉样中检测出香气成分16种,皇冠梨汁样中检测出的香气成分18种,其中特有成分共近20种,适宜加工生产果汁、罐头产品。
文摘采用顶空固相微萃取(headspace solid phase microextraction,HS-SPME)和气相色谱与质谱联用技术(gas chromatography with mass spectrometry,GC-MS)分析金珠果梨中梨皮、梨肉、梨汁中的香气成分,结果表明:共鉴定出香气成分53种。梨皮、梨肉、梨汁样品中均含有大量正己酸乙酯、丁酸乙酯、辛酸乙酯,梨皮样、梨肉样及梨汁样中3种酯的总和分别占香气物质的69.42%、30.90%、29.15%。除此之外还含有己烯醛、壬醛、癸醛,且3种醛总含量分占梨皮样、梨肉样及梨汁样中香气物质的10.38%、12.88%、7.13%。这些香气成分可使金珠果梨具有怡人的风味,并使金珠果梨具有自身的典型性风格。此外,金珠果梨果皮香气成分比较丰富,共鉴定出30种,其中特有成分十余种,在加工果汁、果脯、罐头等产品时,尽量保留果皮,以保留产品独特香气。金珠果梨果汁中香气成分共鉴定出30种,其中独特成分15种,因此,适宜加工生产果汁产品。
基金Supported by the National Key Technology R&D Program of China (No. 2006BAD08A05)the National Special Research Programs for Non-Profit Trades of China (No. nyhyzx3-16)
文摘To assess the effect of rice straw mulching on changes of antagonistic bacteria and the incidence of wheat sharp eyespot, a multi-year field study was performed to compare unmulched plots and the plots mulched with rice straw for two or three years. Bacterial and fungal populations were evaluated in the cultures prepared from the wheat rhizosphere and bulk soils. Rice straw mulching increased the number of pseudomonas colony forming units in wheat rhizosphere and bulk soils. The proportion of total bacteria that were fluorescent pseudomonads was higher in mulched than in unmulched soil. Bacterial isolates antagonistic to Rhizoctonia cerealis were identified using an inhibition zone test. A series of these isolates were typed by partial sequencing of the 16S rRNA gene. Pseudomonads had higher antagonistic activity against R. cerealis than other species, and more than 80% of rhizosphere fluorescent pseudomonads were antagonistic to R. cerealis. The disease indices were lower in the mulched plots than in the unmulched control. These results suggest that rice straw mulching in a rice-wheat rotation increases the number of fluorescent pseudomonads. Additionally, these fluorescent pseudomonads may contribute to the control of wheat sharp eyespot.
