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11.
Two wheat genetic lines (responsive and non-responsive to elevated CO2) grown under ambient and free-air CO2 enrichment (FACE) conditions were compared using fuzzy chromatography mass spectrometry (FCMS) metabolite fingerprinting. A more comprehensive survey of the changes in their chemical composition was made on selected samples using ultra-high-performance liquid chromatography (UHPLC) metabolomic profiling with high resolution accurate mass/tandem mass spectrometry (HRAM/MSn). Principal component analysis (PCA) of the metabolite fingerprints showed four clusters for the two genetic lines (responsive and non-responsive) and the two CO2 levels (ambient and elevated) in score plots. Metabolite profiling of representative samples for each of the four clusters identified 25 and 16 compounds from negative and positive data, respectively, including amino acids, saccharides, phenolic acids, flavonoids, and lipids. Loading plots demonstrated that some saccharides and lipids were responsible for discriminating between not only two genetic lines but also two CO2 levels. Analysis of free amino acids (not bound) showed a clear pattern of reduced concentration for both lines with elevated CO2. After acid hydrolysis, the responsive line 6 (41% increase in yield) showed the same pattern observed for free amino acids, but the non-responsive line 5 (6% increase in yield) showed different trends in concentrations of amino acids with elevated CO2. 相似文献
12.
Quinoa (Chenopodium quinoa) and kiwicha (Amaranthus caudatus) are nutritious pseudocereals that originate from the Andean region. The aim of this research was to study the effect of germination and the subsequent kilning on the phenolic compounds and proximate composition in selected Peruvian varieties of quinoa (“Chullpi”) and kiwicha (“Oscar Blanco”). The germination process was carried out for 24, 48 and 72 h at 22 °C, and the kilning was performed with samples germinated for 72 h by drying the seeds at 90 °C for 5 min. Both processes increased the protein content of the samples. However, lipid content was reduced during germination. On the other hand, germination and kilning clearly increased the concentration of total phenolic compounds in both quinoa and kiwicha. Germination for 72 h either with or without kilning process resulted in a significant (p < 0.05) increase in the total content of phenolics compared to untreated materials, which was especially due to coumaric acid and a kaempferol tri-glycoside in quinoa and caffeoylquinic acid in kiwicha. Based on the results, germination and kilning may improve the nutritional quality of the Andean grains, encouraging the usage of the processed grains as ingredients in functional products for people with special gluten-free or vegetarian diets. 相似文献
13.
建立了使用Waters UPLC Xevo TQ超高效液相色谱串联质谱仪检测水产品中4种硝基呋喃代谢物的分析方法。匀浆后的样品在酸性环境下水解,并用2-硝基苯甲醛衍生16h,经磷酸氢二钾提取,LMS固相萃取小柱净化后,在三重四极杆多反应监测模式下进行测定。方法采用同位素内标法定量,四种代谢物的检出限(LOD)均低于0.25μg·kg-1,线性范围在0.5μg·L~(-1)到10μg·L~(-1)间,相关系数大于0.99。在0.5、1.0和5μg·kg-1浓度下分别进行添加回收试验(n=5),回收率在75.2%~123.3%之间,相对标准偏差(RSD)小于9.4%。 相似文献
14.
[目的]研究不同大蒜制品中锗元素含量的差别。[方法]采用马弗炉灰化样品,火焰原子吸收光谱法测定以金乡紫皮蒜为原料加工而成的黑蒜、蒜蓉辣酱、脱水蒜片、蒜粉、糖醋蒜5种制品中锗的含量。[结果]试验表明,黑蒜中锗含量为1.384 mg/g,蒜蓉辣酱中锗含量为0.784 mg/g,脱水蒜片中锗含量为0.913 mg/g,蒜粉中锗含量为0.956 mg/g,糖醋蒜中锗含量为0.827 mg/g。5种蒜制品中均含有锗元素,其含量由多到少依次为黑蒜、蒜粉、脱水蒜片、糖醋蒜、蒜蓉辣酱。[结论]研究可为大蒜及大蒜制品的开发利用提供参考依据。 相似文献
15.
石墨炉原子吸收光谱法测定新资源食品中的硒含量 总被引:1,自引:0,他引:1
建立一种简便、快速、准确的食品中硒的测定方法;检测新资源食品芝麻叶、野生四叶参、野生菜葛根、野生葛花及桑蚕蛹中的硒含量。用1mg·mL-1硝酸镍为基体改进剂,加入体积分数为0.1%TritonX-100和0.5%硝酸(1∶1),以改善样液的表面张力。用HITACHIZ-5000型石墨炉原子吸收光谱仪及全自动进样方法进行硒含量测定。石墨炉采用光控升温方式,硒的灰化温度按程序升温方式进行,程序升温分为干燥、灰化、原子化和净化。该方法的测定限为18.6μg/L,精密度为3.26% ̄9.29%(RSD),加标回收率为92.1% ̄108.8%。该方法具有测定简便、快速和准确等特点,可作为食品中硒含量测定的良好方法。 相似文献
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17.
以分蘖葱头为试材,采用超声波-微波协同法提取有机硫化合物,进行分蘖葱头有机硫化合物工艺优化试验,并利用气相色谱-质谱联用仪对提取物组分进行分离鉴定,以期为进一步研究和开发分蘖葱头功能组分提供参考依据。结果表明:最佳提取工艺为微波温度55℃、料液比1∶8 g·mL-1、协同时间6 min、搅拌转速300 r·min-1、超声波功率500 W,该条件下有机硫化合物得率为0.2771%±0.0023%。该条件得到15种有机硫化合物,含量较高的是噻吩类39.0678%±0.0043%,其次是三硫化合物14.1570%±0.0071%和硫醚类7.3872%±0.0052%,其中含量相对较高的有机硫化合物为2,4-二甲基噻吩、3,5-二乙基-1,2,4-三硫杂环戊烷、二烯丙基二硫醚。 相似文献
18.
《Communications in Soil Science and Plant Analysis》2012,43(4):471-492
Abstract A method employing fusion of soil clay samples with lithium metaborate (1:5 ratio) in a furnace at 1050°C for 1 hr. subsequent dissolution of the fused sample in 4% HNO3. and elemental analysis for Si, Al, Fe, Ca, Mg, K, and Ti by atomic absorption spectrometry was compared with the X‐ray fluorescence (XRF) fused disc technique for analysis. Duplicated analyses were performed on 15 clay samples from soils of the southern U.S and three API reference samples. The mean total percent recovery by this method was excellent (100.14 ± 2.85). Elemental oxide quantities in terms of SiO2. Al2O3, Fe2O3, MgO, CaO and K2O determined by atomic absorption/flame emission (AA/FE) spectroscopy were in good agreement with values measured by x‐ray fluorescence (XRF) on the same subsamples (r = 0.89* to 0.98**). but somewhat more variable on subsamples seperated from different pretreatments (r = 0.70* to 0.97** ). The method, which has also been tested on 36 additional clay samples from a variety of Kentucky soils with total percent recoveries ranging from 96.5 ‐ 103.5%. demonstrated no bias due to mineralogy with respect to mixed, montmorillonitic. and siliceous classes. This technique presents numerous advantages over other elemental analysis techniques utilizing fusion, dissolution, or XRF spectroscopy with respect to time, effort and cost. With the introduction of inductively‐coupled plasma (ICP) emission spectroscopy. efficiency can be additionally improved. 相似文献
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20.
采用微波消解-原子荧光法对广东竹丝鸡肉中有毒有害元素砷的含量进行抽样检测分析。结果表明:该方法检出限为0.067μg/L,回收率为95.7%~101.2%;竹丝鸡肉中砷的检出率为100%,平均残留量为0.041 mg/kg,符合我国无公害畜禽肉中砷的限量标准,并达到了我国绿色食品中砷限量标准。 相似文献