Abstract:To enhance the laboratory ability of quality control and method validation in the determination of natural occurring PCDD/Fs, dl-PCBs and their analoguesin milk, thereference material was prepared and certificated. MethodsThe milk samples were homogenized, packed and cryodesiccated, then the PCDD/Fs and dl-PCBs were analyzed by high resolution gas chromatography/high resolution mass spectrometry using isotope dilution and internal standard quantization techniques. Afterthe homogeneity and stabilitytest, the certification was conducted with 5 qualified laboratories. ResultsThe 10 bottles of milk samples were randomly selected and were tested for the cross-sample homogeneity, and PCDD/Fs and dl-PCBs in milk samples were homogeneous. The stabilities of the PCDD/Fs and dl-PCBs in milk samples were tested over one year at room temperature and the levels were stabilized.ConclusionThe natural reference material of PCDD/Fs and dl-PCBs in milk was first prepared and certificated and was intended to be used for quality control and method validation in the determination of PCDD/Fs, dl-PCBs and their analoguesin milk samples.

Abstract:To investigate the β-Lactamases activities in pasteurized milk in China based on an enzyme thermistor (ET) biosensor.MethodsCertain amount of penicillin G was incubated with the milk sample for 3 h, then an aliquot of the mixture was directly injected into the ET system to give a signal corresponding to penicillin G remained. The amount of β-lactamase was calculated by the penicillin G consumed during incubation. 106 pasteurized milk samples collected from 13 provinces were tested. ResultsThe linear range of this method was 4-20 U/ml with LOQ and LOD of 2 and 4 U/ml, respectively. The total detection rate was 3.8%. 47 pasteurized milk products collected in Beijing showed negative results containing β-lactamase lower than 2 U/ml (LOD). 59 products collected from 12 other provinces contained β-lactamase lower than 4 U/ml, among which 4 products were within the range of 2 to 4 U/ml.ConclusionLow levels of β-lactamase were detected in 106 milk samples collected from 13 provinces in China, and it was suggested that the illegal use of β-lactamase was almost eliminated in China.

Abstract:To investigate the skin antiaging efficacy of plant antioxidant blend based on the concept of non-animal testing.MethodsHaCaT keratinocyte cell line were induced oxidation damage by ultraviolet irradiation and treated with resveratrol, procyanidins and two substances blend respectively. The quantitative measurement including cell viability, ROS, SOD, cell cycle and cell apoptosis were detected by MTT assay, fluorescein labeling and ELISA method. The ocular irritation of eye cream formula containing plant material were assessed by combination of CAMVA and BCOP testing. Clinical efficacy was evaluated in terms of chronoaging and photoaging features including skin hydration, elasticity and color by non-invasive methods on 25 female volunteers after 60 days of treatment. ResultsResveratrol-procyanidins blend antioxidant could significantly relieve HaCaT cell oxidative lesion induced by UV. The SOD level in test group were significantly higher than radiation group (P<0.001). All ROS fluorescence intensity, apoptosis cell and the percentage of S-phase cell in cell cycle were obviously decreased in test group (P<0.001). The antioxidant ability of blend are better than resveratrol and procyanidins. The clinical test of volunteers after alternative combination evaluation of its safety, which showed that skin moisturization, TEWL, elasticity and color had significantly improved. ConclusionSpecific plant antioxidant blend by resveratrol and procyanidins could effectively reduce skin oxidative stress and improve function.

Abstract:To evaluate the burden of nontyphoidal Salmonella infection in Guangzhou and provide information for strategies of foodborne diseases surveillance.MethodsBased on the active surveillance system established in nine hospitals from six districts, a 12-month population-based household survey in three districts, as well as national notifiable disease reporting system (NNDRS), attendance rates of patients with diarrhea, stool sampling rate, laboratory testing rate for Salmonella, sensitivity of testing method, and positive case reporting rate were calculated and adjusted by pyramid model ratio and uncertainty analysis to yield the burden ratio and make a comparison between active and passive surveillance. Then the local actual annual incidence of nontypoidal Salmonella infection was estimated and analyzed according to the foodborne diseases epidemiological burden pyramid model. ResultsThe average attendance rate of patients with diarrhea was 23.91%; stool sampling rate, laboratory testing rate for Salmonella, sensitivity of the stool culture method and positive case reporting rate of the active surveillance hospitals were 38.34%, 28.24%, 87.5% and 42.98% respectively, extrapolating rates of hospitals around the city as 38.34%, 28.24%, 47.5% and 20.94%. Accordingly, it was estimated that the actual annual incidence rate of nontyphoidal Salmonella infection was 508.5 cases (95%CI:347.5-802.5) per 100 000, with 64 586 (95%CI:44 136-101 921) as emerging cases, while the reported cases from NNDRS was only 171 and the annual incidence rate was 1.3 cases per 100 000. Among different age groups, the incidence of under 5 years was estimated as the highest (3 583.2 per 100 000), while age group from 15 to 24 years the lowest (23.5 per 100 000).ConclusionIt was the first time that the pyramid model was used on specific foodborne pathogen burden analysis in China, based on data from local surveys, indicating that active surveillance would help improve the stool sampling, laboratory test for Salmonella, sensitivity of the stool culture method, and positive case reporting, and the pyramid model would help gain effective and robust estimate of disease burden. According to the estimate, nontyphoidal Salmonella infection was a major public health problem in Guangzhou in terms of disease burden, which was higher than that of the U.S, with the highest incidence occurred in the age group younger than 5 years. The findings highlighted the necessity to carry out further investigations on risk factors and to implement effective intervention measures on Salmonella infection.

Abstract:To investigate the influence of Momordica charantia extract (MCE) on the immune function of BALB/c mice. MethodsA total of 200 female BALB/c mice were randomly divided into negative control group (distilled water), positive control group (cyclophosphamide) and three dosage group (1.11,3.33,0.00 g/kg BW), and the mice were administered intragastrically for 30 days, the effects of MCE on humoral immunity, cellular immunity and nonspecific immunity of BALB/c mice were observed. ResultsThe IgA levels of the middle and high-dose group of MCE compared with the negative control group were significantly higher (P<0.05), the IgG levels of the low dose group were significantly higher than the control group (P<0.05), andthe IL-6, IL-4 levels of the low dose group was significantly higher (P<0.05) compared with the negative control group. Other indicators compared with the negative control group was not statistically significant (P＞0.05).ConclusionUnder the dosage in this study, MCE had some regulatory effects on immune function of BALB/c mice, especially for humoral immunity and cellular immunity. However, there was no significant effects on non-specific immune.

Abstract:To develop a real-time PCR method for detection of duck, chicken and pork in raw meat products and to investigate the component in lamb and beef slices sold in Beijing.MethodsSpecific primers and probes were synthesized and real-time PCR method was developed. The specificity and sensitivity was tested by artificially spiked duck, chicken and pork into other meat.86 samples of lamb or beef slices were collected from Beijing markets and the detection of duck, chicken and pork was carried out. ResultsThe real-time PCR in this study showed good specificity for duck, chicken and pork. No cross-reaction was observed with other meat within Ct 30.The detection limit was 0.1% of duck, chicken or pork DNA in meat mixtures. 30 of total 86 lamb or beef slices samples were positive for duck, chicken or pork in this study. The adulteration rate of lamb slices was higher than that of beef slices, and samples collected from farmer’s markets was significantly higher than supermarkets and restaurants samples.ConclusionThe method developed in this study was specific for the detection of duck, chicken or pork mixed in raw lamb or beef products. The results of the study showed that some lamb or beef slices were mixed with duck, chicken or pork in Beijing.

Abstract:An ultra high performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS) method was developed for the determination of α-solanine and α-chaconine in potato tuber.MethodsThe sample was extracted with 5% acetic aicd and purified with C₁₈ SPE column(600 cc). The extraction was separated on a waters BEH HILIC column (100 mm ×2.1 mm,1.7 μm) using 88% acetonitrile with 10 mmol/L ammonium acetate as mobile phase at 0.3 ml/min. The detection was performed with waters Xevo TQ-S using postive electrospray ionization (ESI⁺) mode and multiple-reaction monitoring (MRM) mode.ResultsThe results showed that the linear range for α-solanine was 0.5-500 ng/ml. The LOQ for α-solanine was 0.7 and 0.35 μg/kg for α-chaconine. The method showed good accuracy with RSD<10% (n=6) and recovery>80%.ConclusionThis method is fast, simple and has good reproducibility. It is suitable for α-solanine and α-chaconine determination in potato tuber and crisps.

Abstract:A modified QuEChERS method for simultaneous determination of 109 pesticide residues in potato using gas chromatography coupled with mass spectrometry was established and validated.MethodsThe pesticide residues were extracted from the potato samples with acetonitrile, and purified by dispersion solid phase extraction (d-SPE) using N-propyl ethlene diamine (PSA) as the adsorbent. The GC-MS analysis was carried out under selected ion monitoring mode and the quantification was performed using the external standard calibration. ResultsThe limits of quantification (LOQ) for 109 pesticide were in the range of 0.001-0.010 mg/kg. The recoveries were between 72.7% and 118.7% with the RSD of 1.1%-17.3%. When using electron impact (EI) mode, most pesticides exhibited matrix enhancement effects in potato matrix. To ensure an accurate determination, the matrix-matched calibration was used for quantitation. The established method was successfully applied to the potato samples provided by European proficiency test in fruits and vegetables organized by European Union Reference Laboratory for Residues of Pesticides in Fruits and Vegetables, and 13 pesticides were detected with the concentration in the range of 0.002-1.669 mg/kg with the Z-scores in the range of -1.00 to 1.00.ConclusionThe method was simple, sensitive, accurate and suitable for the fast screening test for multi-residue pesticides in potato.

Abstract:The pretreatment methods for determination of dichlorvos and trichlorfor in pickled foods were developed using ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). MethodsSamples were ultrasonically extracted with acidified acetonitrile and cleaned up with dispersivesolid phase extraction (d-SPE) or gel-permeation chromatography (GPC) respectively. The extract components were separated and gradient eluted on a BEH C₁₈ column with acetonitrile-0.1% formic acid solutions, and external standard calibration was used for quantification. ResultsThe linearity was satisfying within certain range of concentration, and the coefficients of determination (r) were above 0.999 for dichlorvos and trichlorfor. The limits of detection (LODs) and the limits of quantitation (LOQs) were 1.0 and 2.0 μg/kg for d-SPE cleanup, 0.5 and 1.0 μg/kg for GPC cleanup, respectively. The recoveries of the spiked samples at the levels of 2,0, 20, and 40 μg/kg ranged from 81.7% to 104.2% for d-SPE cleanup, and from 72.4% to 89.8% for GPC cleanup, with the relative standard deviations (RSDs)less than 7.8%. There was no significant difference between the results obtained by the two kinds of cleanup.ConclusionThe proposed method is rapid, simple, sensitive and specific enough for the supervision of the illegal use of dichlorvos and trichlorfor in pickled foods. Dichlorvos was detected in 1 out of 8 pickled foods collected from local market.

Abstract:A gas chromatography-tandem mass spectrometry GC-MS/MS method for the detection of 18 phthalates PAEs in white spirits was developed. MethodsThe samples were spiked with isotope internal standards, adjusted by alcohol concentration, and finally extracted with toluene. The supernatant were determined by GC-MS/MS. ResultsThe calibration curves of 18 phthalates obtained were linear with correlation coefficients above 0.991. It was effective in the determination of phthalates in white spirits. The limits of detection were 3.1-150.0 μg/L and the limits of quantification were 9.9-500.0 μg/L. The recoveries were 98.5%-119.8% with the RSD of 0.6%-15.6% at different spiking levels. ConclusionThe method improved the specificity for PAEs detection in white spirits and was applicable for multi-component PAEs detection.

Abstract:To improve the ability of rapid detection and tracing the infectious source of food poisoning outbreak with molecular biological technology.MethodsRapid detection of 10 fecal samples and 6 food samples were carried out with real-time fluorescent PCR. A total of 39 fecal samples and 8 food samples were detected by culture, isolation and identification method. Virulence gene of invA was detected by PCR. Homologous relationship among strains from local region and other regions was analyzed with PFGE and MLST genotyping technique respectively. ResultsSalmonella was detected in 10 fecal samples and 6 food samples with real-time fluorescent PCR. Thirty-one strains of Salmonella enteritidis were finally isolated and identified in 39 fecal samples and 8 food samples. Homology among those 31 strains was proved by PFGE, which suggested that the strains from food samples and clinical samples were from the same origin. Homology among the isolates and prevalent strains in other regions was also shown with MLST genotyping results. Virulence gene of invA in all isolates was testified by PCR. ConclusionTimeliness and accuracy of strain identification during food poisoning incident could been improved by real-time fluorescent PCR. Combination of PFGE and MLST genotyping techniques was of great significance to trace homologous relationship among strains in local region and other regions, and to understand their epidemiological characteristics.

Abstract:Circumstance and problems of changes of registration in health foods were analyzed to provide basic data for CFDA, and to provide guidance for applicants. MethodsThe quantities and change types etc. of changes registered by SFDA were analyzed from 2009-2012. The reasons of registration refused were summarized. ResultsTotal 445 changes of registration were registered from 2009 to 2012. Mainly types were change of name, specification, property right, guarantee period and quality standard. The common problem of product name was that proposed name is not fit for the regulation related. The primary reason refused was unqualified sample-test and self-test reports.ConclusionCircumstances of changes of registration are mainly related with the market factors. CFDA is suggested to push forward management reform of change of registration timely.

Abstract:Role and obligation, as well as deficiency and misbehavior in knowledge,attitude and practice, of the consumers were analyzed in this paper. Suggestions and measures on how to promote the consumers to play an active and enthusiastic role were put forward from the viewpoint of consumer education and legal system construction.

Abstract:To understand the status of claims and tolerances for nutrition labeling of infant formula in current Chinese market, and to provide scientific data for the revision of national food safety standard The Labeling of Prepackaged Foods for Special Dietary Uses. MethodsThe declarations of energy and nutrients on the labels of 21 different brands of milk-based infant formula were recorded, and the contents were measured with the national standard methods and compared with the declared value. Meanwhile, the international literatures were consulted for exploration of foreign management. ResultsThe energy, 30 essential nutrients and 5 selectable nutrients of 21 samples were tested and compared. It was in line with Chinese and international practice that the contents of energy and nutrients were declared with numerical value while setting the tolerance range as≥80%. ConclusionThe results would be adopted to revise the labeling requirements in the revision of The Labeling of Prepackaged Foods for Special Dietary Uses.

Abstract:To investigate the extraction of lead under different conditions and evaluate the risk of lead exposure by drinking tea.MethodsTea samples with certain concentration of lead were selected after screening, and extracted under the condition of daily use and more extreme conditions. The lead extraction was determined by AAS. The effect of different extraction conditions were investigated, including temperature, soaking time, ratio of tea and water, completeness of tea sample and washing. ResultsExtraction rate of trace lead in green tea was not significantly changed after soaking 5-30 min in water under 60-100 ℃. The highest extraction rate was found when the ratio of tea and water was 1∶30.The extraction rate in tea powder was higher than that in complete tea sample. The extraction rate reduced when soaking times increased. The extraction rates were in the range of 3.5%-6% for different green tea. The highest extraction rate was found in dark tea (12%).ConclusionThe lead intake from tea water was far below the lead amount in tea, according to the daily tea drinking habits.

Abstract:Using extra virgin olive oil, mix olive oil, soybean oil and sunflower seed oil as frying oil, and French fries and chicken wings as raw materials, the quality changes of the four kinds of edible oil were observed after repeated frying.MethodsAcid value, carbonyl value, polar components and sensory evaluation were used to detect the quality changes of the edible oil. ResultsThe acid values and carbonyl values in all kinds of edible oil were positively correlated with the times of frying. The quality changes of all kinds of edible oil were different. The quality change after chicken wings frying was great than that of potato frying.ConclusionFour kinds of edible oil had a trend of deterioration after repeated frying, but the overall quality change of extra virgin olive oil was at the lowest level among these four kinds of edible oil indicating that it was the best choice for frying oil.

Abstract:The GB 28050-2011 National food safety standards general principles for prepackaged food nutrition label (in short General Principles) was officially implemented since Jan. 1^st 2013, and this survey was aimed to understand the status of the nutrition labeling of prepackage food in supermarkets in Tangshan. MethodsThe survey was designed and analyzed according to General Principles. All 7 categories of prepackage foods were investigated in a Tangshan supermarket. Results885 food items were investigated, and 734(82.9%) items were labeled. The top three labeling categories were:beverages (50 items, 100%), milk and dairy products (80 items, 98.9%), meat products (98 items, 90.7%). The worst labeling category was seasoning (123 items, 65.4%). Energy and core nutrients were labeled on 718 items (97.8%), of which 696 items (96.9%) were qualified. Among the food with nutrition label, 78 items (10.6%) carried nutrition claims, and 76 (97.4%) of them were qualified. 55 items (7.5%) carried functional claims, and 53 (96.4%) of them were qualified. ConclusionCurrent General Principles was effectively promoted in practice, the labeling rate and qualified rate of all food nutrition labels requiring mandatory labeling reached 80%, except for food seasonings.

Abstract:To assess the risk of microbial contamination of edible icefrom catering industry in the Beijing market.Methods63 samples of edible ice was packed in a sterile sampling bag and the process of testing was completedwithin 2 hours. Aerobic plate count, Coliforms, Salmonella, Shigella and Staphylococcus aureus were detected using national standard methods. ResultsSalmonella, Shigella and Staphylococcus aureus were not detected in all samples. The number of aerobic plate count and Coliforms of edible ice from chain restaurants and coffee shops was low, and higher in drinks and desserts shops.ConclusionResults showed that these edible ice was safe. Drinks and desserts shops need to strictly carry out hygienic practices.

Abstract:To understand the condition of cadmium contamination in main food, and to assess the risk of dietary exposure to cadmium in Jinan. MethodsSurveillance on cadmium contents in wheat, rice, aquatic products, livestock and poultry, vegetable, egg and dairy products was conducted in Jinan from 2011 to 2012. According to the average food intake of Shandong residents and the cadmium PTMI 25 μg/kg BW in food established by JECFA in 2010, the point assessment method was applied to assess resident exposure risk. Results441 food specimens were tested. The average cadmium contents were 49.39 μg/kg, the cadmium contents level at the 50th percentile (P50) was 13.40 μg/kg, and P95 was 118.20 μg/kg. The total detection rate was 90.02% and the violation rate was 0.91%. The cadmium contents in wheat, rice and vegetables were all detected but the detection rate of dairy products was the lowest. The cadmium contents in aquatic products was the highest withthe average cadmium contents of 206.43 μg/kg. The monthly average cadmium intake from main food in Jinan was estimated to be 8.83 μg/kg BW, accounted for 35.32% of PTMI. Aquatic products, wheat and vegetable were the higher contributors and their contribution were 46.43%, 32.62% and 9.51%, respectively. These three foods contributed more than 80% to the total dietary cadmium exposure. ConclusionThe level of dietary cadmium exposure from main food in Jinan was within safety limit, so the risk of dietary intake of cadmium was not obvious. However, more attention should be paid to cephalopods and shellfish.

Abstract:Food safety problems are so prevalent that it is most likely to trigger intensive emotional reaction among general public. This paper is to discuss the major difference in reception pattern between laypersons and experts thereby illustrating the importance of incorporating social science findings in the food safety risk communication strategies. Several practice propositions are also made to improve the effectiveness of current risk communication work.

Abstract:To analyze the epidemiological characteristics of food poisoning events in Beijing, and to provide scientific basis for prevention and control.MethodsThe data of food poisoning events in Beijing from 2010 to 2012 were analyzed using descriptive epidemiologic method. ResultsThere were 85 food poisoning events reported in Beijing, resulting in 1 268 cases and 1 death. The incidence of food poisoning had a seasonal peak during July to September. Microorganism caused the largest percentage of food poisoning events (41.18%) and the most common pathogen was vibrio parahaemolyticus. Poisonous Plant caused the largest percentage of food poisoning cases (42.19%) and the main plant involved was haricot beans. Most poisoning events occurred in catering canteens and food services, which accounted for 40.00% and 30.59% of totals events. ConclusionMicroorganism food poisoning and haricot beans poisoning were the most important agents for food poisoning in Beijing, and the prevention and control measures should be focused on the food service including catering canteens and restaurants. Health education on prevention and control of food poisoning should be targeted at the high-risk population.

Abstract:With the development of modern analytic technology, an increasing number of arsenic forms were identified. The toxicity of arsenic was closely related to its chemical form. Determination of total arsenic in food was not enough for food safety analysis, and there was an urgent need to establish appropriate analysis methods for different arsenic forms in food. Consulting relevant literature, arsenic form in food such as seafood, rice, feed, livestock and poultry meat products, edible fungus and commonly used pre-treatment, separation and detection methods was summarized.

Abstract:Genistein has a variety of biological activities, such as estrogen, anti-tumor, prevent osteoporosis, anti-oxidation, lipid-reduction, anti-atherosclerosis and other physical activity. It has become a hot spot for worldwide in recent years. This review focuses on the anti-tumor activity of genistein derivatives, in order to facilitate its research and applications, and provide the basis for molecular design for the purpose of anti-tumor prodrug.