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排序方式: 共有326条查询结果,搜索用时 421 毫秒
1.
Anna Rizzolo Patrizia Lombardi Maristella Vanoli Stefano Polesello 《Journal of separation science》1995,18(5):309-314
Capillary GC/sensory analysis was used to judge if dynamic headspace on sliced pulp and on intact fruit, and solvent extraction could collect the “character impact” and the “contributory” aroma compounds in peaches. Capillary GC/sensory data showed that the headspace techniques selectively recovered the “contributory” volatile compounds, which are strictly related to the characteristic odor of the various peach cultivars, whereas solvent extraction better quantified the “character impact” compounds (lactones). 相似文献
2.
几种常见水果的微量元素分析 总被引:1,自引:0,他引:1
运用原子吸收分光光度法测定了几种常见水果中部分微量元素含量。其中榴莲的Mg、Zn、Cu、K含量位于四种水果之首。美国提子中Ca含量最高,芒果中Fe含量最高。以上差别具有统计学意义。六种元素的回收率为90%-106.5%。连续6次测定样品,变异系数(CV)为0.96%。 相似文献
3.
光谱电化学法测定水果中抗坏血酸的研究 总被引:7,自引:2,他引:7
本文采用平行入射式光谱电化学装置,对水果中的抗坏血酸进行测定并寻找了最佳的测定条件。方法简便快捷,可消除背景干扰。线性范围1.0×10^-5-1.0×10^-4mol/L,检测下降为4.0×10^-6mol/L,回收率高,结果满意。 相似文献
4.
A new chemical method is reported for the determination of total fluoride in complex liquids and suspensions, such as fruit juices, urine, serum and blood. It is based on the formation of the A1F radical in a graphite furnace afterin situ oxygen-assisted ashing of the untreated sample. The absorbance of this radical is measured at 227.45 nm. The method is relatively easy to use and provides a low detection limit (14 ng/ml) and reasonable reproducibility (5–10%). 相似文献
5.
The composition of volatile compounds produced by fruit during growth and post-harvest storage and ripening has been studied and the different headspace methods compared. Static and dynamic headspace sampling have been compared and evaluated according to their capacity to collect and concentrate volatiles from the atmosphere surrounding the fruits, and FID, MSD, and organoleptic detection have been compared. The results emphasize that the headspace sampling procedure selected is crucial to the performance of subsequent analysis. 相似文献
6.
D. T. Asilbekova 《Chemistry of Natural Compounds》2003,39(5):442-445
Lipids from fruit pulp of the sweet red pepper (Capsicum annuum, Solanaceae) were characterized. The principal components of the lipids from pepper fruit pulp were neutral lipids with predominance of triacylglycerines (55.8%). The polar lipids contained sulfoquinovosyldiacylglycerines and phosphotidylglycerines. The fatty-acid compositions of the neutral lipids, glycolipids, and phospholipids were determined. 相似文献
7.
果蝇 ( Tephritidae)对水果生产有严重的危害 .热带果蝇寿命较长 ,具有很强的迁徙能力和繁殖能力 .因此开展果蝇生物防治和控制措施的相关研究具有重要的意义 [1,2 ] .Baker等 [3]发现性成熟的雌B.dorsalis果蝇 ,性腺分泌物中包含有螺环缩酮化合物 2 ,8-二甲基 - 1 ,7-二氧杂螺 [5 ,5 ]十一烷 ( 1 ) .Bactrocera Latifrons( Hendel)果蝇的雄性腺体分泌物中也存在螺环缩酮 1 [4 ] ,另外在 rove甲虫腹梢分泌物中也分离出 1 [5] ,螺环缩酮不仅作为性信息素组分存在于许多果蝇腺体中 ,而且作为结构单元存在于许多复杂的有强烈生理活性的天然… 相似文献
8.
M. T. Lafuente J. L. Tadeo 《International journal of environmental analytical chemistry》2013,93(1-2):99-108
Abstract The determination of imazalil and prochloraz fungicide residues has been carried out by HPLC with an UV detector at 204 nm and by GLC with an electron capture detector (ECD). In both cases fungicide residues were extracted with hexane/acetone (90:10, v/v) after pH adjustment and purified by a liquid-liquid partitioning process. When HPLC was used for prochloraz and imazalil analysis, it was necessary to eliminate the interfering substances with a further clean-up process. This was also required when samples with low residue levels were analyzed by GLC. Recovery was always higher than 70%. The detection limit was 0.04 ppm for the HPLC method and 0.02 for the GLC method. Imazalil and prochloraz residues in “Washington Navel” oranges and “Hernandina” clementine fruits, dipped in a 1000 ppm fungicide solution, are reported. 相似文献
9.
Ethanol determination in frozen fruit pulps: an application of quantitative nuclear magnetic resonance
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Wilian da Silva Nunes Caroline Silva de Oliveira Glaucia Braz Alcantara 《Magnetic resonance in chemistry : MRC》2016,54(4):334-340
This study reports the chemical composition of five types of industrial frozen fruit pulps (acerola, cashew, grape, passion fruit and pineapple fruit pulps) and compares them with homemade pulps at two different stages of ripening. The fruit pulps were characterized by analyzing their metabolic profiles and determining their ethanol content using quantitative Nuclear Magnetic Resonance (qNMR). In addition, principal component analysis (PCA) was applied to extract more information from the NMR data. We detected ethanol in all industrial and homemade pulps; and acetic acid in cashew, grape and passion fruit industrial and homemade pulps. The ethanol content in some industrial pulps is above the level recommended by regulatory agencies and is near the levels of some post‐ripened homemade pulps. This study demonstrates that qNMR can be used to rapidly detect ethanol content in frozen fruit pulps and food derivatives. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
10.
建立了气相色谱-质谱法(GC-MS)同时测定鲜水果中对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、乙萘酚、4-苯基苯酚和联苯醚5种保鲜剂的分析方法。鲜水果样品经乙醚超声提取、浓缩后,活性炭柱净化,选择离子模式(SIM)下测定,外标法定量。在优化条件下,5种保鲜剂的线性范围为0.2~4.0 mg/L,相关系数(r2)大于0.991,联苯醚的检出限为0.05 mg/kg,其余4种保鲜剂的检出限均为0.1 mg/kg。5种保鲜剂的加标回收率为80.4%~104.5%,相对标准偏差(RSD)为1.2%~6.4%。该方法简便、快速、试剂价廉易得,且能消除鲜水果样品中色素等杂质的干扰,具有较高的准确度和精密度,适用于鲜水果中上述5种防腐保鲜剂残留量的测定。 相似文献