神农架富锶植物资源调查研究

目的 对当地的富锶植物资源进行采样分析, 研究神农架林区富锶植物的分布规律。方法 针对神农架地区含锶水源分布特点, 采集水源周边常见植物并分析其锶含量水平。采用湿法消化及火焰原子吸收法对采集的样品进行锶含量检测。结果 所有检测的109种不同植物样品中, 有38种植物的锶含量高于1.0 μg/g, 如: 红菜苔、木耳菜、苋菜、小白菜和空心菜等叶菜类蔬菜具有较高的含锶量。此外, 地皮菜、猪苓和枇杷叶具有极高的富锶能力。采自于松柏镇清泉村、神农架矿泉水厂水源地以及塔坪村的植物, 大部分都具有较高的锶含量, 而龙沟村一组和大九湖国家湿地公园的植物含锶量较低。结论 生长在富锶水源附近或富锶地区(如神农架矿泉水厂水源地、塔坪村)的植物大部分都有较高的锶含量, 如银杏叶、猪苓中分别含锶2.740 μg/g、10.570 μg/g。而未经富锶水浇灌或生长在含锶量较低的水源附近(如龙沟村一组、大九湖国家湿地公园)的植物中锶含量相对较低, 除黄花菜外锶含量普遍低于1.0 μg/g。研究结果对推动神农架地区富锶产品开发及产业发展具有重要意义。     

河北省包装饮用天然泉水中三种无机物的检测

目的抽样检测河北省包装饮用天然泉水中偏硅酸、锶和锂的含量,分析这三项指标是否适合作为其界限指标。方法在河北省6个设区市的流通环节采样47份包装饮用天然泉水,采用国标方法进行检验。结果抽检的47份样品中均检测到了锶,检出率为100.0%,其中31份样品锶含量≥0.2 mg/L,16份样品锶含量≥0.15mg/L但0.2 mg/L;有28份样品检测到偏硅酸,检出率为59.6%(28/47),其中2份样品含量≥25 mg/L、2份含量≥13 mg/L,其余样品均13 mg/L;样品中均未检出锂。47份样品中,分别有27和33份样品的标签上标示了锶和偏硅酸的界限指标值,其中4份样品锶含量及29份样品偏硅酸含量的检测值与产品标签上标示值不符。结论河北省包装饮用天然泉水中普遍含锶,其含量稳定,适合作为界限指标;抽检样品中偏硅酸检测值与标签标示值符合率较低,如果企业产品标准选择其作为界限指标,应根据终产品实际检测结果来确定,并在标签上按产品标准标示;抽检产品中均未检出锂,锂不适合作为界限指标。     

塑料厂区DEHP的污染及蔬菜安全评价

邻苯二甲酸二(2-乙基己基)酯(DEHP)具有致畸致癌的作用,对塑料附近农田蔬菜进行了采样调查,应用GC/MS联机检测技术检测了12种蔬菜样品中DEHP的浓度水平。结果表明,按照EPA提出的人体每天限制剂量(RfD)为20μg/kg体重,则塑料工业区蔬菜DEHP含量已经超出安全标准。蔬菜不同品种累积DEHP的能力大不相同,其中冬瓜、茄子、毛豆、小白菜累积DEHP含量较高,为重污染蔬菜品种;番茄、小辣椒、丝瓜累积DEHP含量较低,在塑料厂周边农田种植和食用相对较安全。     

云南某县蔬菜中有机磷类和氨基甲酸酯类农药残留调查

目的调查云南某蔬菜种植大县蔬菜中有机磷类和氨基甲酸酯类农药残留状况。方法在云南省某蔬菜种植大县3个乡镇的6个自然村中,抽取424户农户,对每一户中主要负责农业生产的农民进行面对面询问的问卷调查,并对调查对象家中当天的待食用蔬菜进行采样,共766份,用PR-12N农药残留快速检测仪检测蔬菜样品中的有机磷类和氨基甲酸酯类农药残留。结果在过去一年内,有130户农户(占调查对象的31.18%)使用过问卷中列出的21种禁限用农药中的至少一种。使用人数最多的禁限用农药为杀虫脒,其次为甲胺磷、克百威、氧化乐果、地虫硫磷等。557份自留地蔬菜样品中阳性样品(即有机磷类和氨基甲酸酯类农药残留超标的样品)34份(6.10%);51份大田样品中阳性样品有7份(13.73%);158份农户从市场上购买的蔬菜样品中阳性样品有20份(12.66%)。结论三种来源的蔬菜样品均检测出有机磷类和氨基甲酸酯类农药残留超标(阳性),从市场上买来的蔬菜样品的检出率高于自留地蔬菜样品的检出率。     

大麦品种和制麦过程对麦芽含脂量的影响

脂类物质影响啤酒泡沫稳定性并对啤酒老化有重要作用.啤酒中脂类物质的浓度和性质取决于原料的组成和酿造过程.本文研究了大麦品种和制麦过程对麦芽含脂量的影响.采用意大利的四种春大麦和一种冬大麦作为样品,进行微型制麦和分析.本研究旨在确认大麦品种对麦芽含脂量及制麦过程中脂肪酸（FA）含量变化的影响.采用主成分分析（PCA）建立不同样品之间的关系,同样也对大麦的含脂量和制得麦芽品质的相关性进行了评估.数据显示制麦过程中大麦转化为麦芽时总脂含量显著下降;不同大麦品种的脂肪酸含量和脂肪酸图谱均不同.大麦含脂量和制得麦芽质量的相关性确认了脂类的负面影响.     

富硒大豆中蛋白提取工艺优化及HPLC-MS联用测定硒代蛋氨酸

根据Box-Behnken试验设计原理和响应面分析法确定了富硒大豆中硒蛋白提取的最佳工艺;在此条件下,获取可溶性硒蛋白中的硒代氨基酸,并采用高效液相色谱-质谱联用技术对富硒大豆可溶性蛋白中的硒代蛋氨酸进行定性定量分析。结果表明,液料比11∶1（mL/g）、提取温度 44 ℃、提取时间96 min时,可溶性硒蛋白的提取率可达到76.03%。对4 种自行种植的富硒大豆中可溶性蛋白分析可知：硒-L-蛋氨酸中硒含量与可溶性蛋白中硒含量、富硒大豆中总硒量呈正相关;实验范围内硒代蛋氨酸相对于可溶性蛋白中硒含量最高可达28.46%;说明富硒大豆中不仅含有硒代蛋氨酸,还存在其他形态的硒代氨基酸,有待于进一步研究探索。对大豆进行富硒种植,不仅能提高大豆中含硒总量,而且能通过大豆的生物代谢将其转化成安全无毒营养的有机硒。     

可追溯宁夏大米土壤中硒的本底分布情况及其含量评价

为了满足人们对健康的追求,研究从宁夏稻米种植区土壤中微量元素硒含量的本底状况及含量评价展开。以宁夏回族自治区粮食作物耕作区的基本农田为调查采样的目标区域,通过原子分光光度法对土壤中微量元素硒进行检测分析,比较了全土壤中平均含量、不同行政区土壤以及不同土壤类型中微量元素硒含量的差别。结果表明:所采集的土壤样品中,不同行政区土壤样品中硒含量差别不大,而不同土壤类型中硒含量有差别且西部土壤含硒量较高,其中局部地区达到中硒土壤上限。     

农作物镉污染与公路交通关系研究

农产品重金属污染已越来越为社会关注,为探明农作物、土壤和大气等镉污染与公路交通的关系,按不同采样距离采集高速、国道、省道和县级公路两侧农作物和土壤样品,检测Cd含量,并对高速公路路口、生活区和风景区空气自动监测站PM2.5和PM10样品中的Cd含量进行检测分析.结果表明,农作物Cd含量受公路交通影响的情况并不明显,所有监测农作物Cd含量均未超过绿色食品标准的限量规定;农作物中Cd的直接源头土壤和大气也未表现出受公路交通影响的趋势,所有采样点土壤Cd含量均在绿色食品标准的限量范围内,也无距路侧采样距离不同而发生变化的规律;高速公路出口附近PM2.5或PM10样品中Cd含量与生活小区或风景区相比无显著差异.     

甘肃省市售浆水中亚硝酸盐含量测定

了解甘肃省市售浆水中亚硝酸盐的含量。方法 对GB 5009.33—2010《食品中亚硝酸盐与硝酸盐的测定》方法做了改进,省略了沉淀蛋白质的步骤；并按照改进的方法测定了采集于2013年4月至8月的62份浆水样品中亚硝酸盐的含量。结果 62份样品中亚硝酸盐含量均低于2 mg/kg,平均亚硝酸盐含量为0.64 mg/kg；含菜浆水亚硝酸盐含量高于不含菜浆水。结论 依据GB 2762—2012《食品中污染物限量》中规定的蔬菜及其制品、腌渍发酵蔬菜中亚硝酸盐最大量为20 mg/kg,62份样品中亚硝酸盐含量均未超标。     

重庆市江津区含硒稻谷碾减率与硒损失关系探究

收集了江津区7个乡镇的19种含硒稻米,探究了碾磨加工对稻米中硒含量的影响。结果表明,不同品种的糙米中硒含量存在显著性差异(P<0.05),渝香203、旌1优华珍、Q香优100及晶两优510对硒富集能力较强。受稻米品种和种植环境的影响,不同稻米碾减率、米糠硒含量及碾磨过程中的硒损失情况不同,渝香203和旌1优华珍的米糠中硒含量较高,最高可达0.82mg/kg,可作为加工过程中产生的富硒副产物被广泛利用。所有测试样品均表现为随碾磨时间的延长,稻米碾减率增大,加工精度越高,硒的损失率越大,最高损失率可达44.39%。贾嗣镇种植的旌1优华珍和晶两优510、白沙镇种植Q香优100及中山镇种植的渝香203在碾磨加工过程中硒的损失量较小,累计碾磨80s后,一级精米中硒含量仍可达到富硒水平。     

A Preliminary Investigation of Naturally Occurring Aluminum in Grains,Vegetables, and Fruits from Some Areas of China and Dietary Intake Assessment

An investigation of the naturally occurring aluminum contents in grains, fruits and vegetables locally planted in some areas of China was conducted, and the aluminum dietary intake from the investigated food was estimated. A total of 2,469 samples were collected during 2013 to 2014 and tested for aluminum content using ICP‐MS method. The results showed that although 77.6% of the samples contained aluminum less than 5 mg/kg, significant variations of aluminum contents were observed in different food groups. Generally, the aluminum contents were found to be relatively high in dried grains and fresh vegetables, and low in fresh fruits. The mean value of aluminum contents in grains was 6.3 mg/kg, with wheat being the highest, followed by soybean and corn. The fresh vegetables had an average aluminum content of 4.7 mg/kg, with leafy vegetables being the highest, followed by bulb and stem vegetables. Most varieties of fresh fruits were low in aluminum, with the mean of 1.3 mg/kg. Based on the food consumption data from the China National Nutrient and Health Survey, the average weekly dietary intake of naturally occurring aluminum from the investigated foods was estimated to be 0.62 mg/kg bw for the general population and 0.55 to 1.00 mg/kg bw for different age groups. Grains and vegetables were the main contributors to the overall intake. Evaluated against the provisional tolerable weekly intake (PTWI) of 2 mg/kg bw, the dietary naturally occurring aluminum intake from the investigated foods was considered to be no safety concern.     

京郊主要蔬菜产品器官硝酸盐与亚硝酸盐含量分析与评价

对京郊52种蔬菜产品,以及同一种类不同品种、同一品种产品的不同部位的硝酸盐、亚硝酸盐和VC含量等进行测定。结果表明：供试蔬菜产品器官的硝酸盐含量在不同种类、品种及其不同部位间存在明显差异。以蔬菜鲜质量器官中硝酸盐含量均值计算,根菜类(420.66mg/kg)＞叶菜类(281.24mg/kg)＞茎菜类(279.54mg/kg)＞果菜类(176.54mg/kg)＞花菜类(157.93mg/kg);同种蔬菜品种间的硝酸盐含量相差1.13～5.48倍;产品器官不同部位的硝酸盐含量也有较大差异,如结球叶菜硝酸盐含量外叶＞中叶＞内叶,叶柄＞叶片,黄瓜果实顶部、基部＞中部,果肉＞果心,萝卜根皮＞根肉。各供试蔬菜产品器官的亚硝酸盐含量多在1mg/kg以下,个别蔬菜种类如茼蒿可达6.74mg/kg,不同蔬菜种类、品种和部位间亚硝酸盐含量差异不如硝酸盐含量差异明显。果菜类、叶菜类和花菜类蔬菜产品器官的VC含量普遍较高,如辣椒可达146.56mg/100g,但品种间VC含量差异不显著。由此可见,目前京郊蔬菜产品器官中的硝酸盐和亚硝酸盐含量多在安全范围内,但仍建议消费者科学合理进行蔬菜种类搭配以保障人体健康。     

Nitrate and nitrite quantification from cured meat and vegetables and their estimated dietary intake in Australians

High dietary nitrate and nitrite intake may increase the risk of gastro-intestinal cancers due to the in vivo formation of carcinogenic chemicals known as N-nitroso compounds. Water and leafy vegetables are natural sources of dietary nitrate, whereas cured meats are the major sources of dietary nitrite. This paper describes a simple and fast analytical method for determining nitrate and nitrite contents in vegetables and meat, using reversed-phase HPLC-UV. The linearity R² value was >0.998 for the anions. The limits of quantification for nitrite and nitrate were 5.0 and 2.5 mg/kg, respectively. This method is applicable for both leafy vegetable and meat samples. A range of vegetables was tested, which contained <23 mg/kg nitrite, but as much as 5000 mg/kg of nitrate. In cured and fresh meat samples, nitrate content ranged from 3.7 to 139.5 mg/kg, and nitrite content ranged from 3.7 to 86.7 mg/kg. These were below the regulatory limits set by food standards Australia and New Zealand (FSANZ). Based on the average consumption of these vegetables and cured meat in Australia, the estimated dietary intake for nitrate and nitrite for Australians were 267 and 5.3 mg/adult/day, respectively.     

Folate Content and Composition of Vegetables Commonly Consumed in China

Abstract: Folate deficiency increases the risk of chronic diseases, including neural tube defects (NTDs) in infants, megaloblastic anemia, cardiovascular disease, and some cancers in adults. China is the most NTDs prevalent area in the world. Folate deficiency in China can be reduced by proper supply of fresh leafy green vegetables but little is known about the folate content and vitamers in the vegetables commonly consumed by Chinese population. The purposes of this study were first to analyze most commonly consumed important vegetables that contribute to folate intake in the Chinese population and second to estimate the significance of selected vegetables as a source of dietary folate intake. Folate content and vitamers forms in vegetables were analyzed using a valid liquid chromatography method. Monoenzyme treatment was used for leafy green and some fruit vegetables, and dienzyme treatment for some root vegetables. Total folate content in commonly consumed vegetables ranged from 14.78 to 145.54 μg/100 g in edible portion with an average of 61.99 μg/100 g. The highest folate content (>140 μg/100 g) was found in pak choi and spinach. Total folate contents in leafy vegetables, fruit vegetables, and root vegetables were in the range of 17.22 to 145.54 μg/100g, 18.14 to 86.04 μg/100g, and 14.78 to75.81 μg/100g, respectively. The considerable variations in folate content were found in different types of vegetables commonly consumed by Chinese population. Leafy vegetables are a better source of folate than fruit and root vegetables commonly consumed by Chinese population. Practical Application: Data from this research would facilitate to accurately establish the actual folate intake by Chinese population. Our folate composition data on vegetables can be incorporated into the national food databases. Availability of such data is essential for estimating folate intake and defining an optimal level for fortification program in China.     

不同利用方式对几种根茎类蔬菜亚硝酸盐含量的影响

以山药、胡萝卜、莲藕为实验材料,研究不同贮藏条件、烹饪方法和熟菜保存方式下3种根茎类蔬菜中亚硝酸盐含量的变化。结果表明：无论常温还是低温贮藏,贮藏7d内,3种根茎类蔬菜的亚硝酸盐含量均呈现先增加后降低的趋势,虽然常温贮藏的亚硝酸盐含量高于低温贮藏,但两者均小于4mg/kg。不同烹饪加工可显著降低3种蔬菜的亚硝酸盐含量,煮制、炒制、烤制加工方式的亚硝酸盐含量降幅分别为70%～83%、66%～80%和33%～55%,其中胡萝卜的亚硝酸含量降幅最大,莲藕的最小。低温和常温保存的熟菜,菜体中亚硝酸盐含量随时间延长而增加,保存到48h时,3种菜体的亚硝酸盐含量均小于4mg/kg,且低温远低于常温(前者最大为1.03mg/kg,后者最大为1.98mg/kg),参照食用的亚硝酸盐标准,低温(4℃)和常温(20℃)保存的熟制根茎类蔬菜食用安全期均达48h,且煮制和炒制加工的熟菜优于烤制。     

Determination of nitrates by a novel ion chromatographic method: occurrence in leafy vegetables (organic and conventional) and exposure assessment for Italian consumers

A novel ion chromatographic method to detect nitrates in vegetables was developed, and the nitrate contents in green salad (a mixture of endive and prickly lettuce), lettuce, chicory, rocket and spinach were determined from Italian markets in 1996 -2002. These leaf vegetables were included because they are currently supposed to provide most of the nitrate intake in the typical Italian diet. The highest content of nitrate was detected in chicory (6250 mg kg -1 ) and rocket (6120 mg kg -1 ), which are consumed in large quantities in some regions of Italy. Green salad and lettuce contained less nitrate (highest values = 4200 and 3300 mg kg -1 , respectively), but because they are consumed more generally, they provided 60% of the total intake of nitrates. Only a few samples were above the legal limits, with seasonal variation. A significantly higher nitrate content was found in organically grown green salad and rocket than in those conventionally produced. These data indicate that the average intake of nitrates from leafy vegetables is below the acceptable daily intake, i.e. 3.7 mg nitrate ion kg -1 body weight day -1 , but the total intake should be monitored to protect groups at risk, such as children and vegetarians.     

Nitrate and nitrite levels in commonly consumed vegetables in Hong Kong

Levels of nitrate and nitrite in 73 different vegetables, a total of 708 individual samples grouped into leafy, legumes, root and tuber, and fruiting vegetables, which are traded mainly in Hong Kong, were measured. Where available, five samples of each vegetable type were purchased from different commercial outlets during the winter of 2008 and summer of 2009. Levels of nitrate and nitrite were determined by ion chromatography and flow injection analysis, respectively. Nitrate and nitrite levels of all samples ranged <4–6300 and <0.8–9.0 mg?kg^?1, respectively. Nitrate concentrations for the different groups, in descending order, were leafy?>?root and tuber?>?fruiting and legume vegetables. More than 80% of vegetables had mean nitrate concentrations less than 2000?mg?kg^?1, but mean nitrate concentrations of three types of leafy vegetables, namely Chinese spinach, Shanghai cabbage and Chinese white cabbage, were >3500?mg?kg^?1. On the other hand, nitrite concentrations were generally low –?<1?mg?kg^?1 on average. Nitrate in vegetables (i.e. Chinese flowering cabbage, Chinese spinach and celery) can be reduced significantly (12–31%) after blanching for 1–3?min, but not after soaking.     

2001—2017年我国部分地区蔬菜中砷和重金属累积特征及膳食暴露风险

目的 探讨我国部分地区蔬菜中砷和重金属的累积特征,并分析潜在膳食暴露风险。方法 搜索论文数据库,收集2001—2017年发表文献中蔬菜铜(Cu)、铅(Pb)、镉(Cd)、铬(Cr)、砷(As)及汞(Hg)含量的数据,分析我国根茎类、叶菜类及茄果类蔬菜中As和重金属的污染特性,并采用美国环保署推荐的健康风险评价模型评估蔬菜中砷和重金属的膳食暴露风险。结果 3类蔬菜中Cu、Pb、Cd、Cr、As和Hg均呈非正态分布,变异系数均<10%。根茎类、叶菜类及茄果类蔬菜中Cd、As、Hg的含量均差异有统计学意义(P<0.05),叶菜类和茄果类蔬菜中Pb-Cr含量差异有统计学意义(P<0.05),但3类蔬菜中Cu含量均差异无统计学意义(P>0.05)。根茎类蔬菜中Pb、As和Hg的含量较高,叶菜类蔬菜中Cd含量较高。根茎类和叶菜类蔬菜中Pb-Cd及根茎类蔬菜中Pb-Cr相关性均较强(P<0.01)。3类蔬菜中Cu、Cd、Cr和As污染指数均在安全范围内,而根茎类和叶菜类蔬菜中的Pb和Hg均存在不同程度的污染,但基本属于轻度污染。根茎类和茄果类数值中As和重金属对成人和儿童的风险值均<1.0,但叶菜类蔬菜中Pb对成人和儿童的风险值的第95百分位数分别是1.780和2.020,表明叶菜类蔬菜中的Pb存在潜在的人体非致癌风险。结论 中国蔬菜中Cu、Cd、Cr、As和Hg整体污染较轻,但叶菜类蔬菜中Pb污染应引起重视。     

蔬菜对多环芳烃的吸收富集特性及清洗剂筛选

研究蔬菜在浸毒暴露下对多环芳烃（PAHs）的吸收特性及优选降解蔬菜中PAHs的最佳清洗剂。选取番茄、辣椒、茄子、黄瓜、白萝卜、豆角、油麦菜作为实验样本,分别在500 μg/kg的PAHs溶液浸毒2、4 h,检测蔬菜果皮等暴露部分和果瓤中PAHs含量,分析不同蔬菜对PAHs的富集特性;比较不同蔬菜中PAHs平均含量的变异系数,筛选均一试验材料,通过进一步实验确定蔬菜适宜的浸毒处理条件。应用8种清洗剂处理浸毒蔬菜,以5种PAHs降解效果为评价标准,优选最佳清洗剂。浸毒处理后,多数蔬菜表现出果皮等暴露部分对PAHs富集能力比果瓤强,并且随PAHs环数增加,向内迁移能力下降;通过比较PAHs含量变异系数得出,除油麦菜外,其它蔬菜均变现内外含量变化不一致,果瓤平均含量数据波动大;以油麦菜为试材,通过进一步试验确定浸毒条件为PAHs溶液浓度500 μg/kg,浸毒时间60 min。不同清洗剂处理对油麦菜中5种PAHs降解效果整体表现为轻质PAHs>重质PAHs,其中果蔬清洗剂和臭氧水降解效果最差,超声波清洗仅对轻质PAHs具有良好降解效果,降解率可达72.72%;优选清洗剂处理共7组且均为氧化剂处理,其中800 mg/L的Fenton （nH₂O₂：nFeSO₄=8∶1）试剂降解效果最好,对油麦菜中轻质PAHs平均降解率为79.29%,重质PAHs为59.07%。通过探究蔬菜对PAHs的富集特性及对比不同清洗处理对PAHs的降解效果,为有效控制污染及消费者挑选合理、高效清洗剂提供理论指导。     

常见蔬菜的黄酮含量及烹饪对其含量的影响

本实验目的在于了解我国辽宁省地区常见蔬菜的黄酮类物质含量及黄酮类物质在不同烹饪方式下的变化情况,为进一步估算膳食中黄酮类物质的摄入水平提供依据。结果表明,叶菜中黄酮类物质含量较高,花、果类和根、茎类次之。萝卜缨、韭菜、芹菜中黄酮类物质含量较高,分别达到39.18,36.26和32.20mg/100g。经过烹饪后,大部分蔬菜中黄酮类物质含量均有所增加,其中,中火炒制的烹饪方式使蔬菜中的黄酮含量增加得较为显著,增加幅度在12.11%～166.38%之间。增加绿叶蔬菜的摄入量,可获得充足的黄酮类物质,采用中火炒制的烹饪方式有利于黄酮类物质的释放。