内蒙古地区市售蔬菜中农药残留状况调查

目的 了解内蒙古地区市售蔬菜中农药残留状况,为蔬菜监管、标准制修订及风险评估提供科学依据。方法 2019—2020年春季（3-4月）和秋季（9-10月）,在内蒙古自治区12个盟市采集市售蔬菜样品各20份,按照《国家食品中化学污染物及有害因素监测工作手册》中的方法对9种杀虫剂、13种杀菌剂及二硫代氨基甲酸酯类（以CS2计）农药残留含量进行检测;依据《食品安全国家标准食品中农药最大残留限量GB 2763—2019》对蔬菜中农药残留情况进行评判价。结果 480份蔬菜中,9种杀虫剂、13种杀菌剂、二硫代氨基甲酸酯类（以CS2计）检出率分别为11.04%(53/480)、34.79%(167/480)、27.71%(133/480),超标率分别为3.33%(16/480)、1.46%(7/480)、2.29%(11/480),农药残留超标的蔬菜主要为芹菜、韭菜、白菜、菠菜。结论 内蒙古地区12盟市市售蔬菜中存在农药残留及超标现象,有高毒与剧毒农药检出;且存在单种蔬菜中杀菌剂农药共残留情况,建议相关部门加强农药生产与使用的监管。     

ICP-AES法快速测定青菜中14种元素的含量

研究了微波消解样品,电感耦合等离子体原子发射光谱(ICP-AES),快速测定青菜中K、Na、Ca、Mg、Fe、Mn、Cu、Zn、Pb、Cd、Cr、Ba、As、Ni等14种常量元素和微量元素。方法操作简便,分析速度快,结果令人满意,该方法也可用于农副产品中上述元素的同时测定。     

Effect of water cooking on free phytosterol levels in beans and vegetables

Plant sterols (phytosterols) are known to decrease plasma cholesterol, mainly the atherogenic LDL cholesterol. In an earlier study, the thermal stability of phytosterols in vegetable oils was reported. The aim of this present work was to investigate the potential effect of cooking (30 min in boiling water), for eight plant products (broad bean, celery, cabbage, courgette, carrot, cauliflower, onion, pepper), on the free phytosterol level. Sitosterol was the most abundant sterol, followed by campesterol. After cooking, the level of total sterols was higher in all vegetables than that before cooking, if dry matter is considered. Acid hydrolysis (active for glycosylated phytosterols) yielded a higher sterol value than alkaline hydrolysis alone (active for esterified phytosterols). This indicated that studied vegetables contained appreciable amounts of steryl glycosides. Their cooking induced higher values of free phytosterols. Cooked vegetables could give better protection against cardiovascular diseases thanks to higher phytosterol levels.     

广东省蔬菜水果中有机磷农药残留监测与评价

目的掌握广东省蔬菜、水果中有机磷农药的残留状况,为政府部门采取有效预防措施提供依据。方法自2001年起每年在全省各监测网点抽检各类新鲜蔬菜、水果,采用气相色谱仪和气相色谱质谱联用仪,参考GB/T 5009.20—2003《食品中有机磷农药残留量的测定》等分析方法进行检测。结果连续7年的监测共获得47400个检验数据,蔬菜、水果中有机磷的检出率和超标率分别为10.1%和8.0%,2001-2007年间,甲胺磷、甲基对硫磷、久效磷等国家禁止在蔬菜水果中使用的高毒高残留的有机磷农药还在普遍使用。结论广东省各地农产品中有机磷农药残留检出率和超标率变化趋势不明显,有机磷农药在蔬菜水果中的使用较为普遍。     

Availability of essential trace elements in Indian cereals,vegetables and spices using INAA and the contribution of spices to daily dietary intake

Indian diet is primarily vegetarian and consists of various cereals and vegetables along with spices, often used in the preparation of curries. The nutritive potential of each ingredient, in terms of trace element contents, has been evaluated using instrumental neutron activation analysis (INAA). Four minor (Na, K, P and Cl) and 16 trace elements (Br, Co, Cr, Cs, Cu, Fe, Hg, Mn, Mo, Rb, Sb, Sc, Se, Sr, Th and Zn) have been determined in six cereals, nine vegetables and 20 spices and condiments, including two betel leaves. None of the carbohydrate-rich cereals or potato was rich in any of the essential elements but leafy vegetables showed higher contents of Fe and other nutrients. Fe/Zn is well correlated with Fe contents in cereals and spices. Out of various spices, cinnamon was most enriched in Fe, Co, Cr, Na, K, P and Zn, whereas turmeric and curry leaves were found to be particularly rich in Se. Cumin and mustard seeds were rich in Cu. Some environmental contaminants, such as Hg, Cr, Br and Th, were also present in significant amounts. An attempt has been made to evaluate the contribution of essential elements (Cr, Cu, Fe, Mn, P, Se and Zn) in spices to the daily dietary intake (DDI) through an Indian vegetarian diet. For a typical mixture of six commonly used spices, contributions of Cr, Fe, Mn and Zn, were found to be 7.5% of DDI in each case.     

硫氰酸根离子电极的研究与应用

通过合成水杨醛缩4-氨基安替比林Schiff碱金属配合物,并以此为载体研究该电极对阴离子的电位响应特性,同时采用紫外光谱技术和交流阻抗研究电极的响应机理。发现以水杨醛缩4-氨基安替比林合铜（[Cu（Ⅱ）-SAMT]）为载体的离子选择性电极对硫氰酸根离子呈现优良的电位响应和反Hofmeister选择性序列：SCN^-〉Sal^-〉ClO4^-〉NO3^-〉Cl^-〉Br^-〉I^-〉SO3^2-〉No2^-〉SO4^2-。在pH=4．0的磷酸盐缓冲体系中,硫氰酸根离子在1．0×10～1．0×10^-6 mol／L浓度范围内呈近能斯特响应,斜率为-55．64mV／pSCN^-（26℃）,检测下限为6．3×10^-7 mol／L。并将电极应用于蔬菜中硫氰酸盐的测定,结果比较满意。     

晋南野菜和蔬菜硝酸盐、亚硝酸盐和维生素C含量分析

目的对山西南部的10种野菜和4种常食用蔬菜的硝酸盐、亚硝酸盐和维生素C含量进行测定。方法硝酸盐含量测定采用镉柱法;亚硝酸盐含量测定采用盐酸萘基乙二胺法;维生素C含量测定采用2,6-二氯酚靛酚滴定法。结果苜蓿、黄瓜和西红柿的硝酸盐含量低于轻度污染水平,亚硝酸盐含量低于亚硝酸盐含量的限量标准,维生素C的含量较低,属于一级蔬菜,可以安全生食;马齿苋、荠菜、蒲公英的硝酸盐含量低于中度污染水平,亚硝酸盐含量低于或相当于亚硝酸盐含量的限量标准,维生素C的含量高或较高,属于二级蔬菜,不宜生食,可盐渍和熟食;苣荬菜、车前草、苦菜、胡萝卜的硝酸盐含量过高,低于重度污染水平,不宜生食和盐渍,可以熟食;藜菜、菠菜、白蒿、地肤的硝酸盐含量高于1234mg/kg,属于高度污染水平,亚硝酸盐含量超过或相当于亚硝酸盐含量限量标准,维生素C的含量高或极高,不宜食用或限量食用。结论大多数供试野菜的各个指标含量均高于栽培蔬菜。     

Phenolic compound profile of selected vegetables frequently consumed by African Americans in the southeast United States

The phenolic composition of vegetables commonly consumed by African Americans in the southeast United States was analyzed with HPLC–MS. The vegetable samples included collard greens, mustard greens, kale, okra, sweet potato greens, green onion, butter beans, butter peas, purple hull peas, rutabagas, eggplant, and purslane. Five compounds out of total 29 peaks detected from the 12 samples – caffeic acid, ferulic acid, quercetin, kaempferol, and isorhamnetin – were identified. No gallic acid, p-coumaric acid, myricetin, luteolin, apigenin, hesperetin, naringenin, or flavanols was detected. The major flavonoids were isorhamnetin, quercetin and kaempferol. Isorhamnetin was found in kale, mustard greens, and purslane. The content ranged from 2.8 to 23.6 mg/100 g fresh edible part. Quercetin was found in collard greens, mustard greens, kale, okra, sweet potato greens, purple hull peas, and purslane. The content ranged from 1.3 to 31.8 mg/100 g with the highest content in kale and lowest content in purslane. Kaempferol was found in collard greens, mustard greens, kale, sweet potato greens, green onion, and purslane. The content ranged from 1.1 to 90.5 mg/100 g. Caffeic acid was only found in sweet potato greens. Ferulic acid was found in collard greens, mustard greens, kale, okra, purple hull peas, and purslane. Although some peaks were found in eggplant, butter beans, butter peas and rutabagas, these peaks were not identified due to lack of reference compound and no flavonoid or phenolic acid was quantified in these samples. The results suggest that these indigenous vegetables among African Americans are good sources of the phenolic compounds, which can be useful for the prevention of cardiovascular and other chronic diseases.     

Monitoring of pesticide residues in Egyptian fruits and vegetables during 1997

A total of 2318 domestic samples of different types of fruits and vegetables were collected from eight Egyptian local markets in six different regions of the country. All samples were examined for residues of 54 pesticides, including organophosphorus, organonitrogen, organohalogen and certain pyrethroides. However, dithiocarbamates were analysed in only 318 samples. Overall, 81.5% of the samples had no detectable pesticide residues. Of the contaminated samples, 18.5% contained detectable residues and 1.9% exceeded their maximum residue limits (MRLs). Root and leafy vegetables showed the lowest contamination rates (1.9 and 4.7%, respectively), slightly exceeding the MRLs in leafy vegetables. However, fruit samples showed a slightly higher proportion of contamination than vegetables (29 and 14.3%, respectively). Fruit also exhibited a higher level of violation than vegetables (2.3 and 1.9%, respectively). The contamination and violation rates were lower than the percentages recorded in previous years' monitoring studies. Dicofol and dimethoate were the most frequently occurring pesticide residues at 5.1 and 5.0%, respectively. Dimethoate showed higher violation levels (0.69%). However, dicofol showed a slight violation rate (0.09%) which indicates good agricultural practices for dicofol use. Dithiocarbamates residues were found in 21 of the 318 samples analysed, which when expressed as a percentage contamination was 6.6%, and only one sample exceeded the MRL.     

Carotene content of some common (cereals,pulses, vegetables,spices and condiments) and unconventional sources of plant origin

This study provides new data on the the total carotenoids and β-carotene content of commonly consumed cereals, pulses, vegetables, spices and condiments. Separation of carotenoids by HPLC showed that β-carotene is the predominant carotenoid in all the foods studied. Cereals and pulses appear to be poor sources of provitamin A precursors. Among the vegetables studied pumpkin, ridge gourd, green chillies, tomato, green peas, field beans and French beans are not only inexpensive but are better sources of β-carotene (20–120 mg/100 g). Among the spices and condiments, red chilli (1310 mg/100 g) and Smilax (2136 mg/100 g), which are regularly used in Indian recipes are good sources of provitamin A precursors. The study also identified unconventional sources like Gulmohar, Peltiforum ferruginum,Lucern and Spirulina as rich sources of β-carotene. Considering that Indian diets predominantly consist of cereals and pulses, choosing appropriate combinations of cereals and pulses will contribute significantly to overall vitamin A intakes. Together with our earlier efforts, the present study has generated a database of β-carotene contents of Indian plant foods, which could be of help in the elimination of vitamin A deficiency.