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排序方式: 共有256条查询结果,搜索用时 203 毫秒
251.
Detection of pork and lard as adulterants in processed meat: liquid chromatographic analysis of derivatized triglycerides 总被引:4,自引:0,他引:4
T Saeed S G Ali H A Rahman W N Sawaya 《Journal of the Association of Official Analytical Chemists》1989,72(6):921-925
A new method is described for detection of pork and lard as adulterants in processed beef and mutton mixtures. The unsaturated triglycerides in the fat are ozonized and then derivatized. The mixture of derivatized and saturated triglycerides is analyzed by liquid chromatography using a reverse-phase column and a UV detector. Pork fat has larger amounts of triglyceride containing saturated fatty acid at the C-2 position than does the fat of other meat. The ratio of triglyceride containing saturated fatty acid vs triglyceride containing unsaturated fatty acid at the same (C-2) position (SSU/SUS) in a sample is compared with those of pure meats. The presence of pork in the sample causes the ratio to increase compared with ratios for pure beef or mutton. The increase in the SSU/SUS ratio is significant for the addition of 1% pork in beef. In the case of mutton, the addition of 3% pork causes a noticeable change. The method is reliable and is also applicable to samples containing only fat. Processing (heating or cooking) does not affect the ratios. 相似文献
252.
Muhammad Shahzad Zulfiqar A. Saqib Farhan Hafeez Muhammad Bilal Sabaz A. Khan Saeed A. Asad 《Journal of plant nutrition》2016,39(9):1257-1265
The sensitivity of crop genotypes determines the level of growth reduction by salinity. Effect of salinity levels (7.5 and 15 dihydrate m?1) using completely randomized design (CRD) with four replications per treatment were compared on germination, chlorophyll content, water potential, ionic sodium and potassium (Na+, K+) balance, and other growth-related parameters of six wheat genotypes for varietal differences under long-term salinity stress. Chlorophyll contents at flowering stage and yield aspects at maturity of all the wheat genotypes decreased with increasing salinity. The maximum Na+ concentration was observed at 7.5 and 15 dS m?1 in Bhakhar and Saher-2000, respectively, while minimum Na+ concentration was observed for 9476. However, the maximum K+ concentration and water potential was noticed in 9476 at 7.5 dS m?1. Careful selection of salt-tolerant genotypes for field crops is an important perspective especially in the developing countries facing salinity problem. Our results revealed that the wheat genotype 9476 performed best regarding growth and physiological parameters compared to other wheat genotypes. 相似文献
253.
Saeed El-Ashram Fathi Abouhajer Maged El-Kemary Guangping Huang Güngör Dinçel Rashid Mehmood Min Hu Xun Suo 《Veterinary research communications》2017,41(4):263-277
The interactions between gastric microbiota, ovine host, and Haemonchus contortus portray the ovine gastric environment as a complex ecosystem, where all factors play a pertinent role in fine-tuning each other and in haemeostasis. We delineated the impact of early and late Haemonchus infection on abomasal and ruminal microbial community, as well as the ovine host. Twelve, parasite-naive lambs were divided into four groups, 7 days post-infection (dpi) and time-matched uninfected-control groups; 50 dpi and time-matched uninfected control groups were used for the experiment. Six sheep were inoculated with 5000 H. contortus infective larvae and followed for 7 or 50 days with their corresponding uninfected-control ones. Ovine abomasal tissues were collected for histological analysis and gastric fluids were collected for PH value measurements, microbial community isolation and Illumina MiSeq platform and bioinformatic analysis. Our results showed that Haemonchus infection increased the abomasal gastric pH (P = 0.05) and resulted in necrotizing and inflammatory changes that were more severe during acute infection. Furthermore, infection increased the abomasal bacterial load and decreased the ruminal microbiome. A 7-day infection of sheep with H. contortus significantly altered approximately 98% and 94% of genera in the abomasal and ruminal bacterial profile, respectively (P = 0.04–0.05). However, the approximate altered genera 50 days after infection in the ovine abomasal and ruminal microbiome were about 62% and 69%, correspondingly (P = 0.04–0.05) with increase in some bacteria and decrease in others. Overall, these results indicate that Haemonchus infection plays a crucial role in shaping stomach microbial community composition, and diversity. 相似文献
254.
This study describes application of free liquid membrane (FLM) in micro-electromembrane extraction (μ-EME) of Cr(VI) from wastewater samples. Amount of Cr(VI) was quantified by electrothermal atomic absorption spectrometry. The transportation of Cr(VI) across the FLM was explored by electrokinetic migration and ion-exchange process. FLM and acceptor solution types, pH of donor and acceptor solutions, applied electrical potential, as well as FLM thickness were optimized. Presence of an anion exchange carrier (methyl trialkyl-ammonium chloride, Aliquat 336) in FLM facilitated Cr(VI) transportation. The best performance was observed for 1-octanol (containing 5% Aliquat 336) with thickness of 1 mm used as FLM, under applied electrical potential of 75 V, when 0.5 M NaClO4 and 0.1 M HCl were used as the acceptor and donor phases, respectively; and the extraction time was set to 5 min. Linearity was obtained in the working range of 0.5–14.0 ng mL?1 Cr(VI) (R2?>?0.98). The calculated limit of detection was below 0.06 ng mL?1. Application of this method to wastewater samples showed that relative recoveries of the spiked Cr(VI) in the samples were in the range of 73.8–85.1%, based on the standard addition method. 相似文献
255.
Mozhdeh Kakueinezhad Parissa Taheri Seyed Bagher Mahmoudi Saeed Tarighi 《European journal of plant pathology / European Foundation for Plant Pathology》2018,150(2):307-322
Wood-staining fungi, moulds and decay fungi colonize freshly cut wood. Of these, only ophiostomatoid fungi are considered major agents of sapstain on logs and freshly sawn lumber because they can cause permanent staining and discoloration. Sapstain in pine pallets significantly reduces their market value and use in the food industry. The aim of this study was to identify the sapstaining fungi that colonize Scots pine wood used in pallet production. In addition, we evaluated the growth and stain intensity of six isolates of ophiostomatoid fungi on freshly cut Scots pine billets. Fungi were isolated from samples of Scots pine and identified based on morphology and DNA sequence comparisons for three gene regions (ITS, β-tubulin, TEF-1α). A total of 1259 isolates representing 31 fungal species were obtained from the pine samples in Poland during July and September. The isolates represented different ecological and taxonomical groups and belonged to the categories of staining fungi, decay fungi and surface moulds. The most frequently isolated fungi were ophiostomatoid fungi (14 species including an unknown Leptographium sp. and Ophiostoma sp.) and moulds (mainly Trichoderma and Mucor spp.). Of the ophiostomatoid species, Ophiostoma floccosum, O. piceae, O. piliferum and Endoconidiophora pinicola were the predominant species. The results of pine billet inoculation showed that among the six fungal species tested, E. pinicola exhibited the fastest growth in all three directions on the billets. Ophiostoma minus and O. piliferum displayed moderate growth rates in pine billets, while O. floccosum, O. piceae, and Leptographium lundbergii grew very slowly, especially in the tangential and radial directions. The information provided in this paper will help develop more effective control strategies for sapstain prevention in Scots pine. 相似文献
256.
Vermicompost can have an effective role in plant growth and nutrition. It can also reduce the harmful effects of stress caused by environmental factors. This study was a factorial experiment with a completely randomized plot design and three replications. The results showed that the calcium concentration (+40% +39%) of root and calcium (+71% +67%) and potassium contents (+49% +59%) of leaf under conditions of moderate and severe water stress increased under vermicompost treatments at the ratio of 30%. Sodium absorption (?37% ?21%) in moderate and severe conditions was significantly reduced by vermicompost treatment. In moderate and severe water stress, the growth medium of 30% vermicompost significantly enhanced proline (+39%) and soluble protein content (+28%) compared to the control. In conclusion, our results proved vermicompost fertilizer due to its structural properties and components, served to reduce the negative effects of water stress by increasing the absorption of calcium (Ca) and potassium (K), and decreasing sodium (Na) absorption that resulted in increased evaluations for proline and protein content. 相似文献