肉制品中苯并[a]芘的控制措施

肉类是人们补充营养物质的重要食物之一, 我国是肉制品生产及消费大国。近年来, 随着国民食品消费需求的转变, 肉制品的安全问题受到人们越来越多的关注。肉制品在热加工过程中易发生美拉德反应以及脂肪热解等现象, 进而产生大量苯并[a]芘等有害物质, 因此探索肉制品中有害物质生成的减控手段成为肉制品安全加工的要点。苯并[a]芘是世界公认的致癌物之一, 还具有强致畸性和致突变性, 严重威胁着消费者的身体健康, 并阻碍肉制品品质的提升。近些年来关于肉制品中苯并[a]芘的减控方法的研究日益增多。本文就肉制品中苯并[a]芘的产生途径及控制措施进行综述, 以期为解决肉制品中苯并[a]芘的污染问题提供一定的理论依据, 进而促进肉制品行业的绿色安全发展。     

卷烟主流烟气中苯并[a]芘的测定方法研究

确立了一种简单、快速且精密度和准确度都较高的分析卷烟主流烟气苯并[a]芘的方法,并应用于不同牌号的市售卷烟样品的检测.该方法是用甲醇溶液提取主流烟气中的苯并[a]芘,提取液用SPE C18固相萃取小柱净化后,以环己烷洗脱后浓缩,在高效液相色谱上用Inertsil ODS-PC18柱分离,荧光检测器检测.     

二甲亚砜提取—冷冻离心净化测定食品中苯并[a]芘及苯并[e]芘

建立以二甲基亚砜作为提取溶剂,冷冻离心提取净化食品中的苯并[a]芘和苯并[e]芘,高效液相色谱—荧光法检测的方法。替代传统的固相萃取小柱净化方式,能更快速、高效、准确检测食品中苯并[a]芘和苯并[e]芘的含量。2种目标物在0.5~1 000 ng/mL范围内呈现良好线性关系,在1~100 ng/g添加量下,回收率为89.0%~91.3%,相对标准偏差为1.19%~1.29%;仪器检出限为0.01 ng/mL,植物油脂方法检出限为0.05 ng/g,肉制品和动物油脂方法检出限为0.02 ng/g。该方法测定动植物油脂和肉制品中的苯并[a]芘和苯并[e]芘方便、快捷,适用于批量化检测。     

Protective effects of lupeol against benzo[a]pyrene induced clastogenicity in mouse bone marrow cells

Fruits and vegetables contain a variety of ingredients that exhibit chemopreventive effects against an array of xenobiotics. In the present study, the antigenotoxic potential of lupeol, a triterpene, and mango pulp extract (MPE) was evaluated in Swiss albino mice. Benzo[a]pyrene (B[a]P), a well-known mutagen, was given at a single dose of 100 mg/kg body weight intraperitoneally. Pretreatment with lupeol (1 mg/animal) and MPE (1 mL, 20%) was given through oral intubation for 7 days prior to B[a]P administration. Animals from all the groups were killed at sampling time of 24 h and their bone marrow tissue was analyzed for chromosomal damage and micronuclei induction. In B[a]P-treated animals a significant induction of chromosomal aberration and micronuclei was recorded, with a decrease in mitotic index. In lupeol- or MPE-supplemented groups, a significant decrease in B[a]P-induced clastogenicity was recorded. The incidence of aberrant cells and micronuclei was found to be reduced by both lupeol and MPE when compared to the B[a]P-treated group. The anti-cytotoxic effects of lupeol or MPE were also evident, as observed by significant increase in mitotic index. Thus, results of the present investigation revealed that lupeol and MPE have protective effects against B[a]P-induced clastogenic changes in Swiss albino mice.     

内标校准液相色谱荧光法测定食用油中苯并（a）芘

采用内标苯并（b）屈校正,建立了正相固相净化-反相液相色谱-荧光分光光度法测定食用油中苯并（a）芘的方法。正相Plus Silica固相萃取柱作为净化柱,反相C18柱作为分离柱。以苯并（b）屈作为内标,测定了苯并（a）芘的校正因子。使用本方法,苯并（a）芘在液态食用油和固态食用油中的检出限分别为0.01和0.03μg/kg。苯并（a）芘在不同食用油回收率在83%～108%之间,方法的日内精密度和日间精密度分别小于7.7%和13.2%。     

卷烟主流烟气中苯并[a]芘分离纯化方法的研究

我们在文献基础上采用SPE柱分离纯化卷烟主流烟气中的B[a]P,对比了C₁₈反相柱和Si正相柱的分离纯化效果,并优化了C₁₈反相柱的纯化条件,以求取得较好的分离纯化效果。      

Cytotoxic effects of 7-O-butyl naringenin on human breast cancer MCF-7 cells

The effect of 7-O-butyl naringenin (BN), a chemically synthesized derivative of naringenin, was tested on the proliferation of human breast cancer MCF-7 cells. BN inhibited the proliferation of MCF-7 cells in dosedependent manner (IC₅₀: 67.5±2.1 μM), resulting in an increase in the sub-G1 phase cell population. BN induced the generation of intracellular reactive oxygen species (ROS), which were reduced by pretreatment with N-acetylcysteine (NAC). BN also increased the phosphorylation of stress-activated protein kinase/c-Jun NH₄-terminal kinase 1/2 (SAPK/JNK1/2), c-Jun, and p38. However, the phosphorylation of extracellular-regulated kinase 1/2 (Erk1/2) was decreased in BN-treated cells. Pretreatment of cells with the specific inhibitors SP600125 and SB203580 diminished the BN-induced activation of SAPK/JNK1/2 and p38, respectively. These results indicate that the BN-induced cytotoxicity of MCF-7 cells is mediated by the generation of ROS as well as through the p38, SAPK/JNK1/2, and c-Jun activation signaling pathways. BN may therefore possess chemotherapeutic potential as an anti-proliferative agent.     

纳豆脂肽对人乳腺癌细胞MCF-7的作用

目的:研究纳豆脂肽对人乳腺癌细胞MCF-7的作用。方法:通过酸沉、有机溶剂提取以及活性炭吸附等方法从纳豆发酵液中提取纳豆脂肽。MTT法测定纳豆脂肽对MCF-7细胞增殖的影响;流式细胞仪检测纳豆脂肽对MCF-7细胞凋亡和周期的影响。结果:纳豆脂肽对人乳腺癌细胞MCF-7的增殖有显著抑制作用且抑制率随纳豆脂肽浓度的增加而上升,其IC50为3.68μg/mL。纳豆脂肽可以影响MCF-7细胞的凋亡率,并将细胞周期阻滞在S期。结论:纳豆脂肽能显著抑制体外培养的人乳腺癌细胞MCF-7的增殖,引起人乳腺癌细胞MCF-7的凋亡。      

Analysis of benzo[a]pyrene content from smoked food products in Korea

The content of benzo[a]pyrene (BaP) was evaluated from 100 smoked food products commonly consumed in Korean market with HPLC. Analysis method for BaP content on smoked food products was evaluated and validated. For validation, the efficiency of saponification time and solid phase extraction cartridges were evaluated. During 1–4 h of saponification, recovery of BaP was ranged from 90.17 to 98.87%. Among the 5 tested cartridges including florisil, silica gel, and alumina cartridges (acidic, basic, and neutral), the most efficient cartridge was florisil cartridge and the recovery of BaP was 98.87%. Limit of detection and limit of quantification was 0.03 and 0.09, respectively. As a result of BaP content analysis from smoked food products, the average BaP content was 0.45 μg/kg and the highest content of BaP was 2.87 μg/kg detected in smoked salmon product.     

Determination of the level of benzo[a]pyrene in fatty foods and food supplements

A routine method was developed for the quantification of benzo[a]pyrene (BaP) in edible oils and food supplements. BaP is often taken as an indicator of the presence of polycyclic aromatic hydrocarbons. The method consists of on-line liquid chromatography clean-up followed by injection to an HPLC system with fluorescence detection. The method has good performance characteristics and gave good results in proficiency tests. From 2002 to 2004, about 1350 samples of oils and food supplements were analysed using this method to test the level of BaP. About 20% of the edible oils contained more than 1.2 µg kg^-1 BaP (which is the limit applied by the Dutch Food and Consumer Product Safety Authority until 1 April 2005, and includes measurement uncertainty). In the case of food supplements, more then 30% contained too high levels of BaP, ranging from 1.2 to 135 µg kg^-1.     

Determination of benzo[a]pyrene in some Spanish commercial smoked products by HPLC-FL

In order to investigate the levels of the potently carcinogenic benzo[a]pyrene (BP), 31 samples of smoke foods were analysed. The samples tested included five samples of meat products, three samples of cheese and 22 samples of fish. A liquid chromatographic method was developed using a fluorescence detector. BP was found in 74% of the samples analysed. The levels varied from not detected to 2.46 mug/kg. Only one sample showed a BP level above 1 mug/kg, the maximum level that the EU intends to set for smoked foods.     

Determination of benzo[a]pyrene in camellia oil via vortex-assisted extraction using the UPLC-FLD method

In this paper, vortex-assisted extraction using the ultraperformance liquid chromatography analysis method was performed to determine benzo[a]pyrene in camellia oil. Optimum results were obtained when 0.5 g of oil sample was used followed by vortex-assisted extraction for 10 min with 25 mL of acetonitrile. Chromatographic separation was performed on an Agilent ZORBAX Eclipse Plus C₁₈ column (2.1mm×100mm, particle size 1.8 μm). The optimum mobile phase comprised 70% acetone and 30% water. The detection limit of benzo[a]pyrene was 0.2 μg/kg. The recoveries were in the range of 81.0–97.0%. The proposed method was simple and fast, and it provided high throughput in the determination of benzo[a]pyrene in an oil matrix sample.     

中红外光谱模型用于烤肉中苯并[a]芘的快速检测和评估

目的：实现烤肉制品中苯并[a]芘含量的快速检测。方法：提出一种基于中红外光谱模型的苯并[a]芘含量检测方法,利用中红外光谱采集了120个烤肉样品的原始光谱,采用标准正态变量转换法、多元散射校正、一阶导数、二阶导数对原始光谱进行预处理,并通过主成分分析评价了光谱的预处理效果,以8∶2的比例将原始光谱数据分为训练集和验证集建立了烤肉制品评价模型。结果：基于中红外光谱数据建立的模型的训练集决定系数、验证集决定系数、训练集均方根误差以及验证集均方根误差分别为0.995 1、0.995 7、0.164 4 μg/kg和0.116 3 μg/kg,训练集样本经过建模后,其残差较小,最大值为0.406,总残差和趋于零。结论：该模型的预测能力强,准确度高,能够较好反映实际的烤肉中苯并[a]芘的含量,可以实现烤肉制品的无损快速检测,在烤肉制品行业中有实际应用价值。     

碱炼对菜籽油苯并芘脱除及脱色效果的研究

苯并α芘(BaP)是致癌性最强的多环芳烃,因其亲油性而容易集聚于油脂中。本试验以菜籽油为原料,研究碱炼脱酸过程中加碱量、碱炼时间、碱炼温度和超碱量对脱除菜籽油中苯并芘及脱色效果的影响。结果表明,在碱炼时间40 min、碱液浓度8°Bé、超碱量0.2%、碱炼温度80℃的工艺条件下,菜籽油中BaP的脱除率达52%,其含量由10.1μg/kg降低至4.8μg/kg,菜籽油色泽由R5、Y40降至R4、Y30。合理的碱炼脱酸条件对于兼带脱除油脂中BaP及脱色是有效的。     

Beneficial effects of different tea flowers against human breast cancer MCF-7 cells

Tea is a popular beverage with health benefits. The enriched tea polyphenols including catechins have been reported to perform anti-cancer, anti-oxidant, anti-inflammatory and anti-bacterial activity. In this study, we compared the levels of catechins and caffeine in tea flowers from six different species of Camellia japonica, Camellia tenuifolia, Camellia oleifera, 2 savoury Camellias and Camellia sinensis. C. sinensis detected a variety of catechins, while only (+)-catechin and (−)-epicatechin can be detected by the isocratic HPLC system in other tea flowers. The total catechin content was also lower in these tea flowers. In addition, the water extract of tea flowers was used to test the biological functions including anti-proliferative and apoptotic effects in human breast cancer MCF-7 cells. The water extract of C. sinensis remained most active among six different species using both MTT assays and the cleavage analysis of apoptosis-related molecules, PARP and Bid. The major bioactivity of C. sinensis comes from (−)-epigallocatechin-3-gallate and (−)-epigallocatechin, not detected in other five species. Interestingly, we found that C. tenuifolia still had potent bioactivity. It is likely that bioactive molecules other than catechins exist in C. tenuifolia.     

三嗪基磁性纳米粒子富集和测定粮油中苯并(a)芘

目的 建立测定谷物和油脂中苯并(a)芘含量的超高效液相色谱荧光检测法。方法 采用三嗪基共价层状网络修饰的磁性纳米粒子功能材料作为固相萃取吸附剂,样品经正己烷提取, 提取液经吸附剂净化, Waters BEH C18柱（100 mm×2.1 mm,1.7 μm）进行色谱分离, 采用超高效液相色谱法测定, 外标法定量,建立了超高效液相色谱荧光检测谷物和油脂中苯并(a)芘的方法。考察了样品溶液的pH、吸附剂用量、吸附时间、重复使用次数、洗脱剂种类和用量等影响富集萃取效率的因素。结果 在 0.5?~20.0 ng/mL 范围内, 苯并(a)芘线性关系较好,线性相关系数(R2)为0.9998,该方法的检出限和定量限分别为0.15和0.5 μg/kg,回收率为79%-90%,相对标准差小于3.53%。结论 制备的吸附剂对苯并(a)芘具有良好的吸附能力,可循环使用,该方法灵敏、简单、节省成本,并成功应用于粮油中痕量苯并(a)芘检测。     

Differential effects of polyphenols-enriched extracts from hawthorn fruit peels and fleshes on cell cycle and apoptosis in human MCF-7 breast carcinoma cells

This study was to investigate the anticancer effects of the peel polyphenolic extract (HPP) and flesh polyphenolic extract (HFP) from hawthorn fruit in human MCF-7 breast cancer cells. It was found that the polyphenol and flavonoid contents of HPP were significant higher than that of HFP. Both HPP and HFP inhibited cell growth in a dose-dependent manner with the IC₅₀ of 88.6 μg/mL and 175.5 μg/mL, respectively, suggesting that HPP was more effective against MCF-7 cells than HFP. Flow cytometric analysis revealed that both HPP and HFP mediated the cell-cycle arrest at the S-phase, and also dose-dependently led to apoptosis of MCF-7 cells via the mitochondrial pathway, as evidenced by the activation of caspase-3 and caspase-9 and the elevation of intracellular ROS production. All these findings indicate that hawthorn fruit, especially its peel, is an excellent source of natural chemopreventive agents in the treatment of breast cancer.     

Optimization of the peroxy acid treatment of alpha-methylnaphthalene and benzo[a]pyrene in sandy and silty-clay sediments

The majority of polycyclic aromatic hydrocarbons (PAHs) released to the environment come from anthropogenic sources involving the incomplete combustion of organic compounds. Several techniques are available for the degradation of PAHs. Among the abiotic/biotic processes used to degrade PAHs, an alternative strategy utilizing a primary chemical oxidative step to be combined with a biological was created. The degradation of alpha-methylnaphthalene and benzo[a]pyrene using an advanced oxidation process was optimized over a period of 24 h by varying the ratio of acetic acid to hydrogen peroxide, the compounds that form peroxy acids. The optimization process was performed using sandy and silty-clay sediment types. Gas chromatography equipped with a flame ionization detector was used to determine the varied rates of degradation depending on acetic acid:hydrogen peroxide ratios and the characteristics of the sediment sample. Reduction of 20-90% of alpha-methylnaphthalene and benzo[a]pyrene was observed when 2-5 mL of hydrogen peroxide was used, respectively. A peracetic acid solution (e.g., a commercial form of acetic acid and hydrogen peroxide) was used to compare the results from the peroxy acid experiments. In all the experiments, peracetic acid was more reactive than the combination of acetic acid and hydrogen peroxide. Acetic acid, deionized water, and hydrogen peroxide served as controls and demonstrated minimal degradation over the time course study. Therefore, the use of a peroxy acid process to target electron dense pollutants may have a great utility.