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31.
《Food Control》2015
Classification of heat load applied to milk requires the detection of parameters appropriately related to the intensity of the heat treatment. Current analytical methods based on heat-induced changes in the protein component of milk have been directed either to determine the amount of protein-derived products arised from heat treatments or to evaluate the extent of thermal denaturation of milk proteins. Lately, a new analytical strategy has been developed according to the occurrence of three major whey proteins, namely bovine serum albumin (BSA), beta-lactoglobulin (βlg) and alfa-lactalbumin (αla), normally soluble at pH 4.6 in raw milk, in the pH 4.6 insoluble protein fraction recovered from heat-treated milk. The results have shown that pH 4.6 insoluble BSA, βlg and αla, as detected by ELISA in milk, can be regarded as thermal markers suited for either dairy process control or regulation purposes. 相似文献
32.
《Food Control》2015
Tree nut allergies are considered an important health issue in developed countries. To comply with the regulations on food labeling, reliable allergen detection methods are required. In this work we isolated almond-specific recombinant antibody fragments (scFv) from a commercial phage display library bypassing the use of live animals, hence being consistent with the latest policies on animal welfare. To this end an iterative selection procedure employing the Tomlinson I phage display library and a crude almond protein extract was carried out. Two different almond-specific scFv (named PD1F6 and PD2C9) were isolated after two rounds of biopanning, and an indirect phage ELISA was implemented to detect the presence of almond protein in foodstuffs. The isolated scFvs demonstrated to be highly specific and allowed detection of 40 ng mL−1 and 100 ng mL−1 of raw and roasted almond protein, respectively. The practical detection limit of the assay in almond spiked food products was 0.1 mg g−1 (110–120 ppm). The developed indirect phage ELISA was validated by analysis of 92 commercial food products, showing good correlation with the results obtained by a previously developed real-time PCR method for the detection of almond in foodstuffs. The selected phage clones can be affinity maturated to improve their sensitivity and genetically engineered to be employed in different assay formats. 相似文献
33.
34.
Seon-Gyun?Rho Choon-Hyoung?KangEmail author 《Korean Journal of Chemical Engineering》2003,20(3):517-521
The factors affecting the back-extraction efficiency of Bovine Serum Albumin (BSA, 65kDa, pI 4.9) solubilized in an AOT reverse
micellar solution, prepared by the injection method, to an excess aqueous phase were investigated. In particular, effects
of pH, the type of salt and its concentration in the excess aqueous phase were examined. Furthermore, by comparing CD spectra
of the back-extracted BSA with the feed BSA, the structural changes of the protein during the extraction process were determined.
The addition of 1:1 salt such as KCl or NaCl to the aqueous phase resulted in a 100% recovery of the protein to the aqueous
phase at a pH higher than its isoelectric point pI. This high efficiency of the back-extraction might be due to the change
in the interactions between the protein and micellar aggregates driven by the added salt. For 1 : 2 salts like MgCl2 or CaCl2, BSA was back extracted with lower than 20% extraction efficiency. Maximum efficiencies were achieved at about pH=7 and pH=8
for monovalent and divalent salts, respectively. From the C D spectra of back-extracted BSA, it was observed that denaturation
of BSA was not significant during the extraction process. 相似文献
35.
制备聚丙烯(PP)接枝聚丙烯酸中空纤维荷电膜,对膜表面的流动电位进行了分析,并用这种接枝膜对牛血清白蛋白(BSA)的吸附性能进行了研究.结果表明:接枝膜对BSA的截留率相对未改性前有明显提高;PP膜表面呈现正电位,而接枝膜随接枝率的增加,负电性逐渐增加;由于接枝膜表面接枝链与BSA分子的相互作用。使BSA对接枝膜的吸附有如下规律:pH=3〉pH=4.7〉pH=8. 相似文献
36.
吸附树脂的制备及吸附蛋白质的研究 总被引:1,自引:0,他引:1
本文用醇钠活化球状聚乙烯醇颗粒,Williamson醚化法制得了大孔径的吸附树脂。以牛血清白蛋白(BSA)为模型蛋白,研究了蛋白质在多孔吸附树脂表面的吸附行为。通过测定蛋白质的吸附等温线,并用线性最小二乘法对曲线进行拟合,发现蛋白质在疏水吸附树脂的吸附等温线可用Langmuir方程描述。 相似文献
37.
The progress in atom transfer radical polymerization (ATRP) provides an effective means for the design and preparation of functional membranes. Polymeric membranes with different macromolecular architectures applied in fuel cells, including block and graft copolymers are conveniently prepared via ATRP. Moreover, ATRP has also been widely used to introduce functionality onto the membrane surface to enhance its use in specific applications, such as antifouling, stimuli-responsive, adsorption function and pervaporation. In this review, the recent design and synthesis of advanced functional membranes via the ATRP technique are discussed in detail and their especial advantages are highlighted by selected examples extract the principles for preparation or modification of membranes using the ATRP methodology. 相似文献
38.
Utilization of Electrospun Polystyrene Membranes as a Preliminary Step for Rapid Diagnosis 下载免费PDF全文
Recent advances in clinical practice drive deoxyribonucleic acid (DNA) as an important class of biomarker. Monitoring the change in their concentration suggests the initiation and/or progression of various disorders. However, low quantity of DNA biomarkers in body fluids requires a delicate isolation methodology that provides efficient separation and easy handling. This study describes a newer‐generation separation technology relying on electrospun fibers of sub‐micrometer diameter of a commodity polymer for DNA biomarkers in simulative serum. Fibrous polystyrene membranes are prepared by electrospinning and they are subjected to post‐modification with Au. The composite membranes may provide a convenient environment for the removal of bovine serum albumin (BSA) from BSA and DNA mixtures. The eluent can be used as an efficient tool for detection of DNA biomarkers associated with diagnosis of numerous life‐threatening diseases.
39.
Jun Wang Na Ding Zhaohong Zhang Shixian Wang Ying Guo Bin Liu Yuanyuan Zhang Xiangdong Zhang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(4):538-546
BACKGROUND: In order to effectively damage some biomolecules under ultrasonic irradiation, a mixed TiO2/SiO2 powder with high catalytic activity and selectivity was used as a sonocatalyst. RESULTS: The mixed TiO2/SiO2 powder heat treated at 450 °C for 30 min was adopted as a sonocatalyst and the damage to BSA molecules under ultrasonic irradiation was assessed. In addition, the effects of such variables as molar ratio of TiO2 and SiO2, treatment temperature and time, ultrasonic irradiation time, catalyst amount, solution acidity, ionic nature and strength, ultrasonic irradiation power and D2O concentration on the damage to BSA molecules were studied by means of UV‐visible and fluorescence spectra. The results showed that the degree of damage was aggravated by an increase in ultrasonic irradiation time, catalyst amount, solution acidity, ultrasonic irradiation power and D2O concentration, but was reduced by an increase in ionic strength. CONCLUSION: The results indicated that the mixed TiO2/SiO2 powder displayed higher activity and selectivity compared with nano‐sized TiO2 and SiO2 powders during the sonocatalytic damage of BSA. The extent of the damage decreased in the order TiO2/SiO2 > nano‐sized TiO2 > nano‐sized SiO2. These results are of great significance for applying sonocatalytic methods to treat tumours. Copyright © 2008 Society of Chemical Industry 相似文献
40.
A simple and fast method for the TMS derivatization of phenolic acids in a closed vial using microwave irradiation followed by GC/MS analysis is proposed. A full factorial design was used to investigate the effects of two independent variables, namely, time and power of microwave irradiation, on the yield of silylation reaction. The optimal conditions were tested against the classical heating derivatization procedure. No significant differences were found between the classical heating and microwave-assisted derivatization. Chromatographic separation of the nine phenolic acids examined was achieved in 16 min. The mass spectral fragmentation patterns of the derivatives obtained by the proposed method were identical to those from the classical heating. Four different batches of brewer’s spent grain were extracted and analyzed for the total phenolic acid content. Significant differences between the batches of spent grains were found for all analytes. The total phenolic acid content varied between 2688 and 4884 μg/g. 相似文献