叶菜中有机磷农药多组分残留的快速分析

为提高蔬菜中有机磷农药的检测水平,建立了新鲜叶菜样品中37种有机磷农药残留的分析方法。对试样用乙腈一次性提取,凝胶色谱柱净化预处理,毛细管气相色谱法分离,火焰光度检测器的磷滤光片(FPD(P))检测,外标法定量。该方法分离效果良好,重现性好,灵敏度、精密度高,杂质干扰少。所检测的37种有机磷农药的最低检出量在3.36×10-11(甲胺磷)～5.652×10-10g(磷胺)之间,当青菜试样中有机磷农药的添加浓度为0.05～2.0mgkg时,方法回收率在54.57%～112.64%之间。最低检测限和方法添加回收率均符合农药残留分析的要求。本方法操作简便,重现性好,杂质干扰少,测定结果可靠,灵敏度高,无论是进行多组分有机磷快速定量检测,或是突发性有机磷中毒检测均具有较好的适用性。     

How natural dietary antioxidants in fruits, vegetables and legumes promote vascular health

Oxidative stress disturbs the normal redox state within the human body, and thus may trigger many human chronic diseases including cardiovascular disease. Antioxidant properties of some bioactive components in plant-based foods have been proposed to be capable of controlling such disturbances. This hypothesis has initiated a great number of laboratory studies devoted to the understanding of the role of natural antioxidants in cardio-health promotion. This review summarizes these studies with an emphasis on major natural antioxidants found in three categories of plant-based foods (fruits, vegetables and legume) and mechanisms that these antioxidants may use in promoting cardio-health. Since different food categories possess different bioactive compounds with various antioxidant capacities, specific foods, when consumed together, may produce synergistic antioxidant interactions and in turn have more positive physiological effects on cardio-health than when consumed alone. This review also highlights research on antioxidant synergisms. We recommended strategically selecting foods that provide multiple levels of protection against the development of cardiovascular diseases.     

臭氧在果蔬保鲜和农残降解上的应用

臭氧是一种强氧化剂，它可以杀灭果蔬上的微生物，去除果蔬释放的乙烯，抑制果蔬的呼吸作用，延长果蔬的保鲜期。臭氧还可以降解果蔬上的农药残留。尽管可能会对某些果蔬的品质造成损伤，但具有高活性、高渗透性和无毒降解产物的特点的臭氧在果蔬采后处理上有着巨大的应用潜力。     

天津地区果蔬农药施用状况的调查

目的调查天津农民在种植水果蔬菜过程中的农药施用状况。方法对全年随机抽取的3360名农户进行问卷调查，内容涉及施用农药的种类、频次、施药间隔及安全间隔期等。结果2005年天津市施用于水果、蔬菜的农药种类共计140种，以有机磷类杀虫剂为主，占20．7％；按施药频次排序，前10位主要为低毒低残留农药，其中有机磷类杀虫剂一遍净（吡虫啉）施用频次最多，占全年总频次的15．3％；全年总违规施药率为1．59％，四季农药违规施用率差异有统计学意义（P〈0，01），第三季度违规施用率最高，为2．57％；部分调查果蔬中施药次数违规率较高．其中苹果中氰戊菊酯的施药次数违规率高达95．8％。结论国家明令禁止的农药违规施用率明显好转，但部分农药的施药次数及安全间隔期违规现象比较严重。     

Residues of organochlorine pesticides in vegetables marketed in Greater Accra Region of Ghana

Residual levels of organochlorine pesticides (OCPs) were determined in 240 samples of vegetables collected from selected markets from Greater Accra region of Ghana in July 2010 to February 2011. The determination was done using gas chromatography with electron capture detector (GC-ECD). The compounds targeted were lindane, heptachlor + its epoxide, endrin, dieldrin, o,p′-DDE, p,p′-DDE, o,p′-DDD, o,p′-DDT and p,p′-DDT. The results indicated that all the vegetables sampled had some levels of one or more OCPs in them. Residues of pesticides were found in 71.9% of all the vegetable samples analyzed indicating high incidence of these xenobiotics in the vegetables from the markets and 31.48% samples were above the maximum residue levels (MRLs). The most frequently found and abundant pesticides were the metabolites of DDT (o,p′-DDE, p,p′-DDE and o,p′-DDD), followed by lindane and then o,p′-DDT. The residue levels and the detection rate of the OCPs indicate that, vegetables from supermarket had higher OCPs levels, followed by roadside grocery stores and open markets. The results recommend the need for regular monitoring of a greater number of samples for long periods for pesticide residues especially in fruits and vegetables to protect consumers’ health.     

The effect of preparation method and typicality of colour on children’s acceptance for vegetables

This research aimed to investigate if children’s acceptance for vegetables was influenced by preparation method or typicality of colour. Sweet potato, cauliflower and beans were tested using different cooking methods and using typically or an atypically coloured vegetable. Children’s acceptance was measured among a group of 104 five-and-six year olds. A trained sensory panel determined the vegetable samples sensory characteristics. Background information for children was collected from parents. Preparation method affected acceptance for cauliflower and beans, with baked/stir fried samples accepted less than boiled samples. A high odour intensity and the presence of a browned flavour were found to lower acceptance. Differences in texture and flavour characteristics imparted by different boiling times, as well as small differences observed in sweetness or bitterness, did not affect acceptance. Atypical colour had a positive influence on expected preference but not on acceptance upon tasting. Familiarity, variety in the number of vegetables liked, and reported liking of target vegetables was associated with higher acceptance. Preparation method was more important for acceptance for children who liked fewer vegetables than those who liked many vegetables.     

2004-2007年肇庆市食品中食源性致病菌监测与分析

目的了解肇庆市食品中食源性致病菌的污染状况和污染水平,初步确定高危食品的种类,为食源性疾病的监测提供科学的依据。方法按全国食品污染物监测网的工作手册,2004-2007年采集4个监测点的5大类食品(生肉、熟肉、水产品、生吃水产品和生吃蔬菜)共计325份,对沙门菌、单核细胞增生李斯特菌、大肠杆菌O157∶H7和副溶血性弧菌4种食源性致病菌进行监测分析。结果325份食品样品中,检出致病菌27株(8.31%)。其中沙门菌16株(4.92%),单核细胞增生李斯特菌10株(3.08%),大肠杆菌O157∶H7未检出,80份水产品中检出副溶血性弧菌1株(1.25%)。生肉的污染情况最为严重,检出率为11.35%,其次是熟肉,检出率为9.68%;水产品的检出率为5.45%,生食水产品的检出率为4.00%,生食蔬菜的检出率为2.56%。结论沙门菌和单核细胞增生李斯特菌对肇庆市食品的污染普遍存在。生肉、熟肉的污染尤为严重,是重要的高危食品。     

胶体金试纸与气相色谱法检测毒死蜱结果相符率比较

目的通过研究胶体金法与气相色谱法在检测毒死蜱中的应用,证实胶体金试纸条在检测蔬菜中毒死蜱残留的可靠性。方法对比胶体金试纸半定量法和气相色谱定量法检测毒死蜱的结果。结果胶体金试纸条检测阴性样品得出的结果与气相色谱的结果符合率为100%,添加的阳性样品符合率也达到100%。添加的界限值样品的回收率达到96%。结论与气相色谱法相比较,胶体金试纸检测毒死蜱操作简便、观察直观、快速、省时,其特异性、敏感性较高,可作为蔬菜采摘前毒死蜱农药残留自我检测的手段。并可以此为基础建立一个不同于以前的毒死蜱监管模式。     

Research on factors allowing a risk assessment of spore-forming pathogenic bacteria in cooked chilled foods containing vegetables: a FAIR collaborative project

Vegetables are frequent ingredients of cooked chilled foods and are frequently contaminated with spore-forming bacteria (SFB). Therefore, risk assessment studies have been carried out, including the following: hazard identification and characterisation — from an extensive literature review and expertise of the participants, B. cereus and C. botulinum were identified as the main hazards; exposure assessment — consisting of determination of the prevalence of hazardous SFB in cooked chilled foods containing vegetables and in unprocessed vegetables, and identification of SFB representative of the bacterial community in cooked chilled foods containing vegetables, determination of heat-resistance parameters and factors affecting heat resistance of SFB, determination of the growth kinetics of SFB in vegetable substrate and of the influence of controlling factors, validation of previous work in complex food systems and by challenge testing and information about process and storage conditions of cooked chilled foods containing vegetables. The paper illustrates some original results obtained in the course of the project. The results and information collected from scientific literature or from the expertise of the participants are integrated into the microbial risk assessment, using both a Bayesian belief network approach and a process risk model approach, previously applied to other foodborne hazards.