Abstract:The study was to investigate the poisoned situation of accumulation of paralytic shellfish poison of 10 species of shellfish bred in the coastal water of Shenzhen so as to identify the indicator species of shellfish whose content of the poison can indicate the situation of pollution of water by the poison.Using the biological method(AOAC,15th Ed.,1990),the content of the poison in the samples was determined.Chalmys nobilis and Perna viridis were found to have relatively stronger capability of accumulating PSP than other 8 species of shellfish and Chalmys nobilis accumulated more PSP than Perna viridis.The investigation suggests that the indicator species of PSP in Shenzhen are Chalmys nobilis and Perna viridis,and sometimes the content of PSP in them exceeds the safety limit of related standard within a year.This research provides scientific basis for the effective supervision and management.

Abstract:Objective To understand the current situation of foodborne diseases prevalence and food contaminants in food in China. Methods Following the Tenth-five Years Plan, Food Safety Key Technology Program started up, the National Surveillance Network for Food Contamination and foodborne diseases have been strengthened and consummated. During the last three years, the surveillance regions have been extended to 16 provinces, which covered about 65.58 percent Chinese populations. There were 36 chemical contaminants, 10 food additives and 6 foodborne pathogens in 29 various food commodities were detected and analyzed. Results The contamination of arsenic and mercuric have basic controlled, but the lead and cadmium contamination seriously. The average levels of lead in fresh milk products and preserved eggs exceed the National Limits, and higher levels in sea food and swine kidney product. The diet intakes of lead in Chinese population, especially in 2 years young children, are higher than the ADI recommended by WHO. Seven of the ten kind food additives were over added in some food products. The result of the risk assessment indicated that all the limits of food additives set in the National Standards on Food Additives are safe. The chloropropanols levels detected in export natural fermented soy sauce products meet with China Industry Standard and Europe limits,but the higher levels were found in the individual regional markets. The residues of the highness toxicity pesticides were detected, especially, the tea products were seriously contaminated by the pyrethroid and orangophosphorus pesticides. National Surveillance Network for Foodborne Diseases has been developed. The data of foodborne diseases were collected and analyzed. There are 46.4% cases reported caused by foodborne pathogens, 24.1% by chemical contaminants and 14.7% by the toxic animal or plant foods. The main foodborne pathogens, such as Salmonella, Vibrio parahaemolyticus, Listeria monotocygenes, E.coli O157:H7, Campylabacter and Enterbacter sakazakii were isolated from various food especially meat and seafood products. Among hundreds Salmonella isolates from food, 20% of them are multiple antimicrobial resistant. A multiple antimicrobial resistant strain of Salmonella typhimurium was fund. The charaterization of antimicrobial resistant is quite similar to Salmonella typhimurium DT104. Conclude The results will be scientifically contributed for controlling the chemical and microbial hazards in food and their impact for human health, as well as for revising of food hygiene legislation and criteria in China.

Abstract:Objective Headspace solid-phase microextraction (HS-SPME) was used as a clean-up and pre-concentration procedure for the simultaneous determination of organochlorine pesticides(OCPs)in pork samples. Method Two stable isotopic compounds, 13C labeled mirex and 13C labeled hexachlorobenzene, were used as internal standard. Gas chromatographic analysis with mass spectrometry (GC-MS) facilitates sensitive detection of the selected pesticides. Several parameters controlling SPME were studied and optimised: choice of SPME fiber, extraction temperature, extraction time, desorption time, desorption temperature and content of salt. Result Under optimal conditions, detection limits obtained were in the range of 1 to 100 ng/g depending on pesticide. Good recoveries (range from 90% to 120% in most cases) were achieved. Conclision The result showed that the HS-SPME/GC-MS method is suitable for the analysis of multi-residue OCPs in pork sample.

Abstract:A technique for simultaneous determination of 13 phenoxy acid herbicide residues in soybean was developed.Phenoxy acid herbicides were extracted with acetonitrile-50 mmol/L HCl(volume ratio was 7 3),followed by liquid-liquid partition with n-hexane.The soybean extract was further cleaned up by anion exchange column and derivatized with pentafluorobenzyl bromide.The resulting esters were determined by gas chromatography equipped with electron capture detector.The pre-treatment method was critically examined.Recoveries of two fortified levels(0.01 and 0.1 mg/kg)were above 70%.and the coefficients of variation were less than 20%.It showed that this method can meet the requirements of multi-residue analysis in the inspection of import/export soybean commodities.

Abstract:为研究不同发育期雌性大鼠暴露于大豆异黄酮(soy isoflavones,SIF)对生殖系统的影响,并确定敏感期及有害作用剂量,在孕鼠妊娠第12～18天灌胃给予SIF(胎儿期暴露),母鼠分别在仔鼠出生后第5～10天和第15～20天灌胃给予SIF(新生儿期暴露和婴儿期暴露),仔鼠在出生后第25～30天灌胃给予SIF(青春前期暴露)。SIF的剂量分别为0(对照)、10、50、100、150、200mg/kgBW。观察雌性仔鼠生殖系统发育指标的近期和远期(出生后70d)改变。对近期的影响:(1)胎儿期暴露:100、150、200mg/kgBWSIF组肛殖距(anogenital distance,AGD)显著增大,200mg/kgBWSIF组阴门开张时间(Vaginal opening,VO)提前,150、200mg/kgBWSIF组出生后第14天的卵巢/体重比显著增加;(2)新生儿期暴露:150、200mg/kgBWSIF组出生后第11天的子宫/体重比和卵巢/体重比显著增加,200mg/kgBWSIF组动情周期延长;(3)婴儿期和青春前期暴露于SIF对生殖系统发育各指标无明显影响。对远期的影响:胎儿期、新生儿期、婴儿期和青春前期暴露于SIF对出生后70天的各指标亦无明显影响。150mg/kgBWSIF可对仔代雌性大鼠表现出明显的不良作用,胎儿期和新生儿期是大豆异黄酮生殖毒性的两个敏感期。

Abstract:为了解北京市春季蔬菜中硝酸盐污染及居民硝酸盐暴露情况,于2006年3-5月从北京市16个菜市场采集应季蔬菜7大类26个品种341份样品,用国标法(GB/T5009.33—2003)分析蔬菜中的硝酸盐含量。随机抽取北京市15岁以上常住居民152户428人,以记账法对居民日常蔬菜摄入量进行调查,结合蔬菜硝酸盐含量的检测结果,进行居民蔬菜硝酸盐暴露量评估。叶菜类硝酸盐含量最高(3156.94±1425.62mg/kg),茄果类的含量最低(172.36±148.08mg/kg),硝酸盐含量依次为叶菜类>根茎类>葱蒜类>瓜类>豆菜类>花菜类>茄果类,但同一类蔬菜不同品种的硝酸盐的含量差别较大;同一品种的蔬菜中硝酸盐含量差别也很大。居民每日通过蔬菜摄入的硝酸盐量为328.21mg(以中位数计),比WHO/FAO的ADI值(300mg/d)高9.4%。北京市春季蔬菜的硝酸盐污染较严重,居民仅由蔬菜摄入的硝酸盐量已经高于ADI值,因此需要加强监督管理,以保护居民健康。

Abstract:In order to get information about L.hongkongensis contamination in fish,1097 samples of various species of fish including grass carp(247),bighead carp(248),other freshwater fish(431)and marine fish(171)were collected from five coastal provinces,Zhejiang,Guangxi,Guangdong,Hebei and Fujian in China within the period from August to October 2005.L.hongkongensis was isolated solely from freshwater fishes(7.69% of grass carp(19/247),0.81% of bighead carp(2/248)).The organism was not found in marine fishes.It is concluded that L.hongkongensis needs to be particularly monitored in the market of fresh water fishes.

Abstract:The purpose of this study is to establish an appraisal index system of affecting factors that helps pursue quantitative graded management in food services,and investigate the pursuing tactics,According to the reports of food sanitation supervision from some districts in Guangdong Province and our own experience,a questionnaire was designed and distributed to personnel in charge of supervision and management of food safety to collect their opinions.The personnel were chosen randomly with stratified sampling method from municipal administive organs and food service firms that had passed the assessment for graded management.The data collected were analyzed by credibility analysis,descriptive analysis,major component analysis and factor analysis.Ten factors and 60 indexes affecting the effect of graded management were defined.The 10 factors are:attention by leadership,estimation standardization,estimation management,estimation justness and method,pursuing mechanism,management after estimation,pursuing guarantee,standard requirement and operation,burden of business and approving degree by consumers.Colligating the above results,tactics for pursuing graded management of food services were formed.The study provided scientific basis for pursuing quantitative graded management in food services.

Abstract:为研制抗微囊藻毒素(Microcystins,简称MC)的特异性单克隆抗体,用MC-KLH偶联物免疫6～8周龄雌性BalB/c小鼠,取脾细胞与小鼠骨髓瘤细胞Sp2/0融合,经过3～4次亚克隆建立稳定分泌抗MC的杂交瘤细胞株。将杂交瘤细胞注射入BalB/c小鼠腹腔,生产出抗MC的单克隆抗体。得到了抗微囊藻毒素单克隆抗体细胞株,命名为G5,抗体亚类为IgG2a,亲和力常数2.9×10-11mol/L,分子量150KD,加标回收率在81.5%～125.0%之间,与其他结构类似物的交叉反应率<1%。筛选出的抗微囊藻毒素单克隆抗体具有较好的特异性。

Abstract:为了解广东省食品中食源性致病菌的污染状况和污染水平。按国家监测网的工作手册进行了食源性致病菌的检测和菌密度测定,应用RiboPrinterMicrobial Characterization System检测分离菌株的基因指纹图谱,纸片法作药敏试验。在监测的10类2265份食品中,共分离出76株沙门菌、75株单核细胞增生性李斯特菌、161株副溶血性弧菌、2株空肠弯曲菌、2株O157∶H7大肠杆菌。5种食源性致病菌的检出率为13.95%。部分分离的菌株基因指纹图谱分析的结果是:58株沙门菌分属于22个血清型,25株单核细胞增生性李斯特菌分属于11个RP基因型,55株副溶血性弧菌分属于14个RP基因型。药敏试验结果显示,沙门菌、副溶血性弧菌、O157∶H7大肠杆菌均有多重耐药株,单核细胞增生性李斯特菌对抗生素产生耐药性的比例较低。沙门菌、单核细胞增生性李斯特菌和副溶血性弧菌阳性样品中的几何平均菌密度分别为265、96CFU/g和93MPN/100g。5种食源性致病菌对广东省食品的污染普遍存在。肉类食品和水产品的污染尤为严重,政府相关部门应尽快对畜牧养殖业抗生素的使用进行科学指导,并制定相关的法规进行监督和约束。

Abstract:The present study was to investigate the chemopreventive effect of green tea on the precancerous lesion of colorectal cancer in rats based on a series of biomarkers.Twenty four Wistar rats were randomly divided into 3 groups,8 rats for each.Rats in the positive control group were subcutaneously injected with a carcinogen(DMH)from the second week,once a week for 10 weeks.Animals in tea-drinking group were given the same treatment as the positive control group and received 2% green tea as drinking water during the whole study.Rats in the negative control group were subcutaneously injected with the same volume of saline.Rats in the positive control group and the negative control group received tap water as drinking water during the whole study.The results showed that tea-drinking significantly reduced the number of aberrant crypt foci(ACF),the putative precancerous lesions of colorectal cancer(P<0.05).The number of silver-stained nucleolar organizer dots per nucleus(AgNORs)and labeling index(LI)of proliferating cell nuclear antigen(PCNA)of intestinal mucosa in the tea-drinking group were also significantly reduced as compared with those in the positive control group(P<0.05).In addition,tea-drinking inhibited the expression of Bcl-2 protein and induced the expression of Bax protein.In conclusion,green tea had a chemoprophylactic effect on the precancerous lesions of colorectal cancer.The possible mechanisms may be the inhibition of cell preliferation and induction of apoptosis.

Abstract:为建立直接测定铁强化酱油中NaFeEDTA含量的简易方法,在酸性(pH≤0.5)条件下,NaFeEDTA中的铁完全解离成游离的Fe3 ,以TritonX-100作增溶剂,在胶束条件下,Fe3 与硫氰酸钾反应生成红色配合物,最大吸收波长为λmax=490nm。酱油中NaFeEDTA浓度在20.0～200.0μg/10ml范围与吸光度之间呈线性关系,相关系数为0.9998;检出限为2.0μg/10ml,测得该配合物的表观摩尔吸光系数(εNaFeEDTA)为1.7×104L/(mol.cm)。试样中的非强化的铁及颜色背景的干扰采用差减法校正扣除,试样加标回收率为98.5%～107.9%,相对标准偏差(RSD)为1.4%～5.1%。该法适用于实验室和现场测定,全部操作过程时间仅需2～5min,实测结果与卫生部推荐方法对比相一致。

Abstract:为建立同时测定食品中砷、汞微量酸微波消解-原子荧光光谱法,采用1ml硝酸 0.5ml过氧化氢 6ml水的微波消解体系,用0.5g抗坏血酸 1g硫脲为As5 预还原剂,消解液无需赶酸,直接用原子荧光光谱仪同时测定。砷在0～200ng/ml、汞在0～40ng/ml范围内线性关系良好,相关系数均大于0.9995。方法的检出限砷0.12ng/ml、汞0.04ng/ml。检测国家标准物质GBW08508米粉、GBW08513茶树叶,相对标准偏差砷3.94%,汞3.22%,平均回收率砷96.1%;汞93.6%。该方法试剂用量少,污染小,简便、快速、准确,能满足各类食品中砷、汞检测。

Abstract:To achieve good internal quality control in a food microbiology laboratory,the contents and modes of internal technical verifications and the methods to implement were summed up and discussed.The discussion was made in terms of five aspects,i.e.personnel,equipment and environment,verification of strain and culture medium,confirmation of methods and process control.The modes and technical basis for performing technical verifications of elements in a food microbiology laboratory were presented.Internal technical verification is an important integral part of quality assurance for a laboratory and should be performed regularly in a planned way.

Abstract:为了掌握广西酵米面食物中毒流行病学特点及其规律,为有效开展防制酵米面食物中毒提供科学依据和方法,对1996-2005年广西酵米面食物中毒的有关资料进行统计分析。1996-2005年广西共报告11起酵米面中毒,中毒77人,死亡50人,病死率64.94%。中毒地点主要发生在广西西北部的巴马、隆林、凌云等8个山区县的农户,中毒原因系食用制作后贮存多日被椰毒假单胞菌污染的酵米面所致。调查结果显示,酵米面食物中毒是危害广西西北部山区村民身体健康的严重公共卫生问题。做好宣传教育,使村民养成良好的饮食卫生习惯,改变食用制作后贮存多日的酵米面习俗,是防止酵米面食物中毒的有效办法。

Abstract:为了保障市民的饮食安全,摸清市场销售水产品的甲醛含量状况,于2003年11月-2006年3月,对宁波市市售或即将进入市场的208份鲜冻水产品和84份干品或加工品用水蒸汽蒸馏-乙酰丙酮法进行了甲醛定量检测。结果表明大部分水产品甲醛值正常,在10mg/kg以下,但部分产品甲醛含量高,银鱼1300.0～2045.2mg/kg,丁香鱼863.0～1310.4mg/kg,龙头鱼、鳕鱼、鱿鱼加工品、海捕虾及虾米亦有较高的甲醛值。由于水产品中既有人为添加又有天然存在甲醛的现象,所以在监管中应根据具体情况加强监督。

Abstract:The legislation framework of food fortification in Australia was described in detail.Meanwhile,issues about food vehicle(s),the levels of the added nutrients in food and related risk assessment in mandatory and voluntary fortifications were also discussed.Some suggestions and recommendations were put forward to improve our policy and regulations on food fortification.