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The carotenoid pattern of four yellow- and four white-fleshed potato cultivars (Solanum tuberosum L.), common on the German market, was investigated using HPLC and LC(APCI)-MS for identification and quantification of carotenoids. In each case, the carotenoid pattern was dominated by violaxanthin, antheraxanthin, lutein, and zeaxanthin, which were present in different ratios, whereas neoxanthin, beta-cryptoxanthin, and beta,beta-carotene generally are only minor constituents. In contrast to literature data, antheraxanthin was found to be the only carotenoid epoxide present in native extracts. The total concentration of the four main carotenoids reached 175 microg/100 g, whereas the sum of carotenoid esters accounted for 41-131 microg/100 g. Therefore, carotenoid esters are regarded as quantitatively significant compounds in potatoes. For LC(APCI)-MS analyses of carotenoid esters, a two-stage cleanup procedure was developed, involving column chromatography on silica gel and enzymatic cleavage of residual triacylglycerides by lipases. This facilitated the direct identification of several potato carotenoid esters without previous isolation of the compounds. Although the unequivocal identification of all parent carotenoids was not possible, the cleanup procedure proved to be highly efficient for LC(APCI)-MS analyses of very low amounts of carotenoid esters. 相似文献
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Dietmar E Breithaupt Ursula Wirt Ameneh Bamedi 《Journal of agricultural and food chemistry》2002,50(1):66-70
Liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCIMS) was employed for the identification of eight lutein monoesters, formed by incomplete enzymatic saponification of lutein diesters of marigold (Tagetes erecta L.) by Candida rugosa lipase. Additionally, the main lutein diesters naturally occurring in marigold oleoresin were chromatographically separated and identified. The LC-MS method allows for characterization of lutein diesters occurring as minor components in several fruits; this was demonstrated by analysis of extracts of cape gooseberry (Physalis peruviana L.), kiwano (Cucumis metuliferus E. Mey. ex Naud.), and pumpkin (Cucurbita pepo L.). The assignment of the regioisomers of lutein monoesters is based on the characteristic fragmentation pattern: the most intense daughter ion generally results from the loss of the substituent (fatty acid or hydroxyl group) bound to the epsilon-ionone ring, yielding an allylic cation. The limit of detection was estimated at 0.5 microg/mL with lutein dimyristate as reference compound. This method provides a useful tool to obtain further insight into the biochemical reactions leading to lutein ester formation in plants. 相似文献
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Shahabeddin Safi Ameneh Khoshvaghti Seyed Reza Jafarzadeh Mahmoud Bolourchi Iradj Nowrouzian 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2009,38(4):471-476
Background: The California mastitis test (CMT) and somatic cell count (SCC) are commonly used for diagnosis of subclinical mastitis in cattle. Acute phase proteins (APPs), as alternative biomarkers of mastitis, may increase in concentration in the absence of macroscopic changes in the milk, or may precede the onset of clinical signs. Objective: The aim of this study was to compare the accuracy of APPs measured in milk and in serum with bacterial culture for the diagnosis of bovine subclinical mastitis. Methods: One hundred and seventy‐five Holstein cows were randomly selected from 7 dairy farms. Quarter milk and serum samples were taken from all cows. Milk samples were analyzed using a CMT and SCC, and for haptoglobin (MHp) and amyloid A (MAA) concentrations, and were also submitted for bacterial culture. Serum samples obtained concurrently were analyzed for haptoglobin (SHp) and amyloid A (SAA). Two‐sample Wilcoxon (Mann–Whitney) test was used to compare SCC, MAA, MHp, SAA, and SHp concentrations between culture‐positive and culture‐negative animals. Receiver‐operating characteristic analysis was used to assess the performance of each test using bacterial culture as the reference method. Results: MAA concentration was the most accurate of the 5 tests, with a sensitivity of 90.6% and specificity of 98.3% at concentrations >16.4 mg/L. MAA and MHp had significantly larger areas under the curve than the respective serum proteins, SAA and SHp. Conclusions: The results suggest that measuring haptoglobin and amyloid A in milk is more accurate than serum analysis for the diagnosis of subclinical mastitis in Holstein cows. 相似文献
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Ameneh Moridi Ali Akbar Moosavi Abdolmajid Ronaghi 《Journal of plant nutrition》2013,36(20):2745-2756
In order to study the effect of water deficit stress (WDS), plant growth promoting rhizobacteria (PGPR)-enriched and non-enriched vermicompost tea(VT) and vermiwash(V) on the growth and nutrients uptakes of maize, a greenhouse experiment was conducted. The two-factor experiment was set up in a completely randomized design with three replications. The factors included: 1) liquid organic fertilizers (LOFs) with five levels (control, VT, V, vermicompost tea enriched with bacterium (VTB) and vermiwash enriched with bacterium (VB)) and 2) WDS with three levels (Field Capacity (FC), 80% FC and 60% FC(. At each irrigation interval, the volume of the used LOFs was equivalent to 60% of the volume of water required for 60% FC. At 60% FC, shoot dry matter (SDW), shoot N, P, Zn, Cu, and Fe uptake significantly decreased compared with those of FC and 80% FC, whereas shoot K uptake significantly increased. At all WDS levels, application of LOFs led to increase in SDW and shoot nutrients uptake. The highest amount of studied traits was obtained in VTB and VT treatments. Generally, VT treatments were more effective than V. Furthermore, PGPR-enriched LOFs were more effective than non-enriched ones. Application of LOFs may be considered as a practical approach for amplifying drought tolerance and reducing the risk of water scarcity in maize cultivation. 相似文献
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