水果、蔬菜中11种有机磷农药残留的快速测定

目的：建立一种快速测定水果、蔬菜中常见有机磷农药残留的超高效液相色谱串联质谱的方法。方法：称取5.00 g样品用10.00 ml乙腈为提取溶剂,经氯化钠盐析提取。吸取5.00 ml提取液经PSA和活性碳粉基质分散净化,无水硫酸镁脱水,吸取4.00 ml净化液蒸干,用乙腈＋水（1＋1）洗脱、定容,过0.20μm滤膜后上机测定。结果：11种有机磷农药在4 min内全部出峰完毕,检出限均≤0.010 mg/kg,在0.010-0.200 mg/kg范围内线性关系良好（r≥0.995）,回收率62.2%-115.1%,RSD1.53%-22.0%。结论：该方法具有检出限低、检测快速（从样品处理到上机仅需约1.5 h）、定量准确,检测成本低等特点,符合国内外农药残留检测的要求。

海南省集约化种植园中谷物、蔬菜和水果中重金属累积程度及健康风险

集约化种植园中植物有害元素的累积会危及人类健康.本研究共采集海南省典型集约化种植园中谷物、蔬菜和水果样品673份.分析了7种重金属(Cu、Pb、Zn、Cr、Cd、As和Hg)的分布特征,并采用单因子指数和内梅罗指数进行污染物评价.同时,结合中国营养学会推荐的日常膳食摄入量,分析重金属的膳食暴露风险.结果表明,673件农作物的Cu、As和Hg含量均低于国家食品限量标准,Pb、Zn、Cr和Cd的超标率分别为2.67%、3.71%、2.53%和3.71%.6类农作物的重金属综合污染程度表现为:叶类蔬菜>薯类>非叶类蔬菜类>豆类>水果>谷类.其中,叶类蔬菜中Cr的风险系数(HQ)显著高于其它类型农作物,并且大于1,表明通过叶类蔬菜摄入重金属具有潜在健康风险.薯类、非叶菜蔬菜类、豆类、水果类和谷类农作物的危害指数(HI)较低,表明这几类农作物更适合集约化生产模式.

Pesticide Residues and Government Regulation in China─Evidence from Pesticide Residues in Fruits and Vegetables

China is a big producer and exporter of fruits and vegetables,and pesticide residues are an important factor affecting the quality and safety of fruits and vegetables and their export trade.In this paper,we analyzed the pesticide residue data on fruits and vegetables in 32 major Chinese cities between 2012—2019,the export data of Chinese fruits and vegetables and the role of pesticides in foodborne diseases.The results showed that pesticide residues in fruits and vegetables(PRFV)partial excess of maximum residue standard(MRL)and residues of banned pesticide were still widespread in China.By comparing the standards of pesticide residues in the European Union and China and addressing the agricultural situation in China,this paper analyzed the main causes of PRFV in China and put forward some policy suggestions for strengthening government regulation of pesticide application in agricultural products.

Vegetable/fruit, smoking, glutathione S-transferase polymorphisms and risk for colorectal cancer in Taiwan

AIM: To investigate the colorectal cancer risk associated with polymorphic GSTM1, GSTT1 and GSTP1 and the effect of diet and smoking.METHODS: With consents, genotypes of the genes were determined using PCR methods for 727 cases and 736sex and age-matched healthy controls recruited at a medical center in the Northern Taiwan. Nurses who were blind to the study hypothesis conducted interviews with study participants for the information of socio-demographic variables, diet and smoking.RESULTS: There was no significant association between GSTM1 genotypes and the disease. Men, not women, with GSTT1 null genotype were at significant risk of colorectal cancer, but limited to rectal tumor, and in men aged 60 years and less. The corresponding association with the GSTP1 with G allele compared to GSTP1 A/A genotype was at borderline significance. Compared to men with GSTT1 present and GSTP1 A/A combined, men with both GSTT1 null and GSTP1 with G allele genotypes were at significant risk (odds ratio (OR) = 1.91, 95% confidence interval (CI) = 1.21-3.02), also limited to the rectal tumor and younger men. The beneficial effects of vegetable/fruit intake on colorectal cancer were much higher for men with GSTT1 present (OR = 0.32, 95%CI = 0.20-0.50) or GSTP1 A/A genotypes (OR = 0.40, 95%CI = 0.25-0.64).These effects remained significant for women. But, the greatest protective effect from vegetable/fruit intake for women was observed in those with GSTT1 null or GSTP1 with G allele genotypes. In addition, non-smoking men benefitted significantly from combined effect of higher vegetable/fruit intake and GSTT1 present or GSTP1 A/A genotypes with OR = 0.17 and 0.21 respectively.CONCLUSION: This study suggests that the GSTT1 gene can modulate the colorectal cancer risk and vegetable/fruit-related colorectal cancer risk, particularly in men of no smoking history.

Determination of Forechlorfenuron Residue in Fruits and Vegetables by QuEChERS Extraction and HPLC-MS/MS

[Objective] A quick extraction method of QuEChERS-HPLC-MS/MS was established to determine forechlorfenuron in fruits and vegetables. [Method] Fruits and vegetables were extracted with 0.1% acetic acid of acetonitrile solution and pu- rified by QuEChERS, and then forechlorfenuron residues were determined by HPLC- MS/MS. [Result] The limits of detection （LODs） and low determination limit （LOQ） for the forechlorfenuron was 1.0 vg/kg and 5.0 pg/kg in fruits and vegetables, re- spectively. Regression equations of these hormones had a good linear relationship （FF〉0.999） within 2.0-100.0 vg/L. The average recoveries of forechlorfenuron was in the range of 72.0-115. 0% with the coefficients of variation between 1.5% and 9.8% at the spiked levels of 10.0-500.0 μg/kg. [Conclusion] The method can be applied for the determination of the forechlorfenuron in fruits and vegetables.

Learning Retention in Undergraduate Biology Using a Hands-on Practical ＂Enzyme Detection from Vegetables and Fruits＂

The purpose of this research was to study learning retention in undergraduate biology students on the topic of enzyme properties by using simple enzyme activity from vegetables and fruits. A hands-on practical was developed to simplify detection of enzyme activity of amylase, protease and lipase on starch agar, dry whole milk agar, and trihutyrin agar, respectively. The subjects of the study were 24 senior undergraduates who studied in the Program of General Science, Faculty of Science, Srinakharinwirot University, Bangkok, in three semesters during 2007 - 2008. The basic concepts of enzymes, e.g., substrate specificity, how to detect enzymes and optimal enzyme conditions, were taught before the practical. The first enzyme, protease, was used in the second semester of 2007, and then changed to be lipase and protease in the first and second semesters of 2008, respectively. Ten open-ended questions were used to assess students in all semesters. In agreement with the constructivist learning model, it was demonstrated that students had learning retention and applied their prior knowledge to other enzyme experiments.

Colors of vegetables and fruits and the risks of colorectal cancer

AIM To investigate the relationship between the colors of vegetables and fruits and the risk of colorectal cancer in Korea.METHODS A case-control study was conducted with 923 colorectal cancer patients and 1846 controls recruited from the National Cancer Center in Korea. We classified vegetables and fruits into four groups according to the color of their edible parts(e.g., green, orange/yellow, red/purple and white). Vegetable and fruit intake level was classified by sex-specific tertile of the control group. Logistic regression models were used for estimating the odds ratios(OR) and their 95% confidence intervals(CI).RESULTS High total intake of vegetables and fruits was strongly associated with a reduced risk of colorectal cancer in women(OR = 0.32, 95%CI: 0.21-0.48 for highest vs lowest tertile) and a similar inverse association was observed for men(OR = 0.60, 95%CI: 0.45-0.79). In the analysis of color groups, adjusted ORs(95%CI) comparing the highest to the lowest of the vegetables and fruits intake were 0.49(0.36-0.65) for green, and 0.47(0.35-0.63) for white vegetables and fruits in men. An inverse association was also found in women for green, red/purple and white vegetables and fruits. However, in men, orange/yellow vegetables and fruits(citrus fruits, carrot, pumpkin, peach, persimmon, ginger) intake was linked to an increased risk of colorectal cancer(OR = 1.61, 95%CI: 1.22-2.12).CONCLUSION Vegetables and fruits intake from various color groups may protect against colorectal cancer.

Determination of Pesticides Residues in Some Fruits and Vegetables Imported to Iraq

A study was carried out in the laboratories of the National Center for Pesticides Control/State Board for Plant Protection / Ministry of Agriculture in 2010-2011. The aim was to determine the residues of some pesticides in fruits and vegetables imported to Iraq from neighboring countries （Jordan, Syria, Turkey and Iran）. Two types of fruits （apples and oranges） and two types of vegetables （tomatoes and cucumber） were selected for the purpose of this study. These fruits and vegetables are the most agricultural products imported for human consumption in Iraq. Samples were taken from different border points and from local markets. Extraction, clean up and analysis were then processed. The results indicated the presence of small amounts of residues of certain pesticides such as Deltamethrin and Abamectin and Thiamethoxam in some samples. However, these amounts were less than the limit allowed internationally. No indication was observed for the presence of other pesticides residues such as Bifenthrin Trticonazol and Imidacloprid ... etc. in the samples analyzed. Therefore, there is a need to continuity of inspection on pesticides residues in agricultural products imported to Iraq in order to prevent the entry of contaminating materials and secure human safety.

Prevalence of Fruit and Vegetable Intake and Associated Factors Among Secondary School Children in Mongolia

The objectives of this study were to assess the prevalence of students＇ fruit and vegetable intake and its associated factors among adolescents in Mongolia. Data for this analysis were from the 2010 Mongolia Global School-Based Health Survey （GSHS）. The GSHS administered a self-report questionnaire to a nationally representative sample （N = 5,328） of 7th-llth grade school children. Chi-square analyses and multivariate logistic regressions were performed to determine the prevalence and to predict the fruit and vegetable intake from associated factors. Only 7.0% of students met WHO＇s recommendation of eating fruits and vegetables S or more times per day. There was a significant association between gender and fruit and vegetable intake （P = .016）. There was a significant relationship between living condition and fruit and vegetable intake （P =.029）. Students who lived in apartment were more likely to have adequate fruit and vegetable intake than those who lived in ger in the khashaa. To be effective, educational interventions should be implemented as early as possible.

A Mew Technique to Rapidly Test Agrochemicai Residues In Fruits and Vegetables

Extraction of AchE, relationship between substrate and enzyme concentration, and inhibition effects of the agrochemicals to AchE are discussed in this paper. Through the re-search, the proper AchE concentration for hydrolysis of 1 ml 1mmol/L substrate and I50 val-ues of the agrochemicals to AchE are decided. It is proved that Asch-DTNB method is a rapid test tool for agrochemical residues in fruits and vegetables.A rapid test card has been developed with sensitivity of 0.05mg/L.

Biotransformation of nitro-polycyclic aromatic compounds by vegetable and fruit cell extracts

Extracts from various vegetables and fruits were investigated for their abilities to reduce nitro-polycyclic aromatic hydrocarbons （NPAHs）. The extracts from grape and onion exhibited an interesting selectivity, yielding corresponding hydroxylamines or amines as major products under mild conditions of 30 ℃ and pH 7.0. Grape extracts reduced the 4-nitro-l,8-naphthalic anhydride with the highest conversion rate （〉99%） and the highest ratio of hydro- xylamine to amine （95：5）. In contrast, the onion extracts reduced 4-nitro-l,8-naphthalic anhydride with a conversion rate of 94% and a ratio of hydroxylamine to amine of 8：92. The thiol-reducing agent, 13-mercaptoethanol, and metal cations, Ca2＋ and Mg2＋, greatly increased the reductive efficiency. This work provides an alternative strategy for biotransformation of nitro-polycyclic compounds.