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941.
Biljana Škrbić Jelena Cvejanov Nataša Đurišić-Mladenović 《Polycyclic Aromatic Compounds》2013,33(4-5):348-361
The levels of 16 EPA polycyclic aromatic hydrocarbons (PAHs) were investigated in samples of sugar beets and their products representative for a beet sugar factory located in the central part of Vojvodina, the main agricultural region in Serbia. The sum of the detected PAHs ranged from 51 pg g ?1 ww for molasses to 391 pg g ?1 ww for dried sugar beet pulp. The concentration of benzo(a)pyrene (BaP) for all sample types was about or less than 100 pg g ?1 ww, which is far less than the existing Serbian and EU tolerances set for some foodstuffs. The Serbian intake of BaP via total sugar consumption that ranged from 70–85 g per capita day ?1 , was assessed to be from 0.029 to 0.035 ng kg ?1 b.w. day ?1 . Furthermore, the toxic equivalency factor (TEF) approach was used to estimate the carcinogenicity of PAH mixture found in analyzed samples. 相似文献
942.
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944.
我国人多地少,森林资源相对匮乏,林纸一体化不能完全解决原料短缺问题,而同时我国非木材纤维原料很丰富,加强非木材纤维原料制浆造纸意义重大。以苇浆生产线备料和蒸煮工段为例,采用先进和清洁生产的工艺技术和设备,可以最大限度地实现物质和能量的综合循环使用,符合制浆造纸行业清洁生产评价指标体系和循环经济的要求。本文重点介绍了芦苇原料备料和蒸煮工段的清洁生产技术方案。 相似文献
945.
946.
Maria Balcerek Katarzyna Pielech‐Przybylska Piotr Patelski Ewelina Sapińska Mirosława Księżopolska 《Journal of food science》2013,78(5):S770-S776
In this study, an evaluation of intermediate products of plum processing as potential raw materials for distillates production was performed. Effects of composition of mashes on ethanol yield, chemical composition and taste, and flavor of the obtained spirits were determined. The obtained results showed that spontaneous fermentations of the tested products of plum processing with native microflora of raisins resulted in lower ethanol yields, compared to the ones fermented with wine yeast Saccharomyces bayanus. The supplementation of mashes with 120 g/L of sucrose caused an increase in ethanol contents from 6.2 ± 0.2 ÷ 6.5 ± 0.2% v/v in reference mashes (without sucrose addition, fermented with S. bayanus) to ca. 10.3 ± 0.3% v/v, where its highest yields amounted to 94.7 ± 2.9 ÷ 95.6 ± 2.9% of theoretical capacity, without negative changes in raw material originality of distillates. The concentrations of volatile compounds in the obtained distillates exceeding 2000 mg/L alcohol 100% v/v and low content of methanol and hydrocyanic acid, as well as their good taste and aroma make the examined products of plum processing be very attractive raw materials for the plum distillates production. 相似文献
947.
Giovana Domeneghini Mercali Débora Pez JaeschkeIsabel Cristina Tessaro Ligia Damasceno Ferreira Marczak 《Food chemistry》2013
Degradation kinetics of monomeric anthocyanins in acerola pulp during thermal treatment by ohmic and conventional heating was evaluated at different temperatures (75–90 °C). Anthocyanin degradation fitted a first-order reaction model and the rate constants ranged from 5.9 to 19.7 × 10−3 min−1. There were no significant differences between the rate constants of the ohmic and the conventional heating processes at all evaluated temperatures. D-Values ranged from 116.7 to 374.5 for ohmic heating and from 134.9 to 390.4 for conventional heating. Values of the free energy of inactivation were within the range of 100.19 and 101.35 kJ mol−1. The enthalpy of activation presented values between 71.79 and 71.94 kJ mol−1 and the entropy of activation ranged from −80.15 to −82.63 J mol−1 K−1. Both heating technologies showed activation energy of 74.8 kJ mol−1 and close values for all thermodynamic parameters, indicating similar mechanisms of degradation. 相似文献
948.
《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(5):737-747
This work describes a novel Fe3O4@SiO2@polyaminoquinoline magnetic nanocomposite and its application in the pre-concentration of Cd(II) and Pb(II) ions. The parameters affecting the pre-concentration procedure were optimised by a Box–Behnken design through response surface methodology. Three variables (extraction time, magnetic sorbent amount and pH) were selected as the main factors affecting the sorption step, while four variables (type, volume and concentration of the eluent, and elution time) were selected as main factors in the optimisation study of the elution step. Following the sorption and elution of analytes, the ions were quantified by flame atomic absorption spectrometry (FASS). The limits of detection were 0.1 and 0.7 ng ml?1 for Cd(II) and Pb(II) ions, respectively. All the relative standard deviations were less than 7.6%. The sorption capacities of this new sorbent were 57 mg g?1 for Cd(II) and 73 mg g?1 for Pb(II). Ultimately, this nanocomposite was successfully applied to the rapid extraction of trace quantities of these heavy metal ions from seafood and agricultural samples and satisfactory results were obtained. 相似文献
949.
《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(11):1851-1857
Graphene oxide nano-sheet was modified with dithizone as a novel sorbent for selective pre-concentration and determination of Cd(II) and Pb(II) in food. The sorbent was characterised by various analytical methods and the effective parameters for Cd(II) and Pb(II) adsorption were optimised during this work. The high adsorption capacity and selectivity of this sorbent makes the method capable of fast determinations of the Cd(II) and Pb(II) content in complicated matrices even at μg l?1 levels using commonly available instrumentation. The precision of this method was < 1.9% from 10 duplicate determinations and its accuracy verified using standard reference materials. Finally, this method was applied to the determination of Cd(II) and Pb(II) ions in common food samples and satisfactory results were obtained. 相似文献
950.
结合生产实际对影响河内白曲酸性蛋白酶活力的因素进行分析和工艺改进。结果表明,以麸皮为主要原料,加入5%的豆粕,入房水分为52%~56%,培养温度32℃~37℃,控制好起温并及时排潮,可明显提高白曲的酸性蛋白酶活力。 相似文献