蔬菜中叶绿素及叶绿素铜盐钠抗诱变活性测定

本实验在测定莴巨叶，油菜，青椒，茱萸，芹菜中的叶绿素含量的同时，采用Ａｆｍｅｓ标准平板掺入法测定了以上蔬菜提取液中叶绿素的抗诱变活性及叶绿素铜钠盐的抗诱变活性，结果表明：抗诱变活性的大小依次为莴苣叶，油菜，青椒，茱萸，芹菜，抗诱变活性的大小与叶绿素的含量有关，叶绿素铜钠盐有抗诱变的作用，有一定的应用价值。     

凉拌菜有拌法

大多数维生素遇热容易被破坏,受热越厉害,破坏越严重。而凉拌菜营养丰富,质地脆嫩,色泽诱人,爽口不腻,深受人们喜爱。能够用来凉拌的蔬菜很多,如黄瓜、菠菜、油菜、水萝卜、莴苣、芹菜、青椒、西红柿等。但在制作时必须注意以下几个问题:     

蔬菜的抗致突变活性和叶绿素含量

最近由Graham等进行的对结肠癌、直肠癌患者的饮食习惯的流行病学研究结果说明,在其它饮食相同时,癌患者比非癌患者新鲜蔬菜消费量要低。他们考虑吲哚化合物可能是致癌的活性因子。Lai氏曾报告小麦的叶和根的水提取物在Ames试验中能选择性抑制需代谢激活的致癌物的致突变活性。最近的研究说明在蔬菜中叶绿素、维生素E和葫萝卜素均有对致突变物的抑制作用,而叶绿素是主要的因素。作者用Ames法对西红柿、黄瓜、芹菜、菠菜、莴苣叶、土豆、绿芥菜、葫萝卜、洋白菜,香菜,硬花甘兰,布鲁塞尔芽菜等蔬菜汁进行了     

叶绿素及其衍生物抗诱变作用研究进展

叶绿素及其衍生物抗诱变作用研究进展吕晓华综述王瑞淑张立实审校食物中的非营养成分（ｎｏｎ－ｎｕｔｒｉｅｎｔ），如叶绿素、类黄酮、香辛料、多酚类化合物等，是相对于蛋白质、脂肪、碳水化合物、维生素和矿物质等营养素而言的。它们在食物中含量虽少，但对人体的生理...     

不同季节蔬菜中类黄酮物质含量的差异

目的研究不同季节蔬菜中类黄酮物质含量的变化规律,丰富食物成分数据库。方法改进现有的类黄酮物质HPLC检测方法 ,测定天津当地不同季节的52种蔬菜样品中槲皮素、杨梅黄酮、玉米黄酮、坎二菲醇、芹菜配基含量。结果在52种蔬菜中,春夏季节类黄酮含量较高的有香芹叶、土豆、球茎甘蓝、大蒜、茴香、白洋葱,秋冬季节类黄酮含量较高的有香芹叶、土豆、大蒜、球茎甘蓝,含量均超过20mg/100g鲜重。受季节影响变化幅度较大的蔬菜包括莴苣叶、圆茄子、菠菜、蒜苔、卷心菜和香菜。结论不同季节多数蔬菜中类黄酮物质含量差异有显著性,一般春夏季节含量高于秋冬季节。     

西红柿是最好的防晒食品

除了防晒霜、太阳镜这些保护措施外,很多食物也具有防晒功能。"夏天应尽量少吃感光蔬菜。"医学专家指出,芹菜、莴苣、油菜、菠菜、香菜、小白菜、芥菜、白萝卜等蔬菜内含有光敏性物质,吃完后立刻     

食物中非营养成分的生物学效应研究进展

食物中的非营养成分，如叶绿素，类黄酮，香辛料，含硫化合物，胰蛋白酶抑制剂等，在食物中含量虽少，但作用比较复杂，其中许多物质有抗氧化，抗诱变，抗肿瘤等重要的生物学效应，本文仅简单介绍非营养成分在食物中的分布，存在形式及生物学效应的研究，并初步探讨其发挥作用的可能机理。     

巧烹下脚料

在日常生活中,一些蔬菜叶及根茎经常被弃之,如白菜、菠菜,人们习惯吃其茎叶,而不懂得烹调菜根;莴苣、芹菜则吃其茎而弃去叶.据营养学家研究分析,白菜根、菠菜根所含的铁与胡萝卜素比其茎叶高,莴苣叶所含的维生素C是茎的十几倍,而芹菜叶则含有大量的胡萝卜素和维生素C.     

蔬中娇娘：莴苣

莴苣，别名莴笋、青笋、莴苣笋，有“蔬中娇娘”的美誉。莴苣叶的营养价值比莴苣还高，但遗憾的是人们在食用时常把它丢弃。莴苣食用清脆爽口，可生拌，也可煸炒。     

有些菜吃了不能晒太阳

专家提示:芹菜、莴苣、油菜、菠菜、苋菜、小白菜等为光敏性蔬菜,易诱发日光性皮炎。许多人为了减肥而长期吃素,可是若在紫外线照射强烈的情况下吃多了光敏性蔬菜,对日光敏感者就极易得上日光性皮炎。解放军304医院皮肤性病科主任邹先彪博士介绍说,菜市场上     

肥城市居民饮食与食管疾病关系

目的探讨各种主食、副食、蔬菜及其营养成分与食管炎症、增生、早期癌间的关联。方法在食管癌高发区肥城市1个乡镇3304名40～69岁人群中，将内镜检查正常者作为对照组，将用碘染色内镜和活检病理诊断方法确诊的炎症、增生、早期癌患者分为3组，采用多项式Logistic回归分析饮食与食管疾病的关联，将OR作为关联强度的指标。结果肉类是早期癌的危险因素，大豆、鱼类、油类、芹菜、茄子、芸豆、青椒、脂肪、粗纤维素、灰分、钙能降低其危险性；小麦、油类、热量是食管增生的危险因素，韭菜、莴苣具有预防作用；油类、热量是食管炎症的危险因素。结论在食管癌高发区，饮食及其含有的营养成分与食管疾病具有重要关系。     

Microbial load, prevalence and antibiograms of salmonella and Shigella in lettuce and green peppers

Background

Human food borne infections traditionally are acquired through the ingestion of foods of animal origin. Fresh fruits and vegetables are major vehicles for the transmission of the food-borne infections. In Ethiopia, there is a tradition of consuming raw vegetables, particularly lettuce and green pepper, without adequate treatment. The objective of this study was to investigate the microbial load of fresh lettuce and green pepper, used as salad vegetables, and to assess the prevalence and antibiotic resistance of Salmonella and Shigella spp. isolated from lettuce and green pepper.

Methods

A total of eighty samples of lettuce and green peppers were purchased from different outlets in Addis Ababa and analyzed for their load of various microbial groups and flora analysis was conducted following standard microbiological methods. The presence of Salmonella and Shigella and their antibiotic resistance was also determined.

Results

Over 90% of the vegetable samples had aerobic mesophilic counts of ≥ log 6 cfu/g. Ninety seven percent of the lettuce and 58% of the green pepper samples had enterobacteraceae counts of ≥ log 5 cfu/g. Coliforms were encountered at counts ≥ log 4 cfu/g in 48% and 35% of lettuce and green pepper samples, respectively. Over 80% of vegetable samples harbored staphylococci with counts ranging from log 4 to log 6 cfu/g. More than 88% of lettuce and 18% of green pepper samples had yeast and mold counts ≥ log 4 cfu/g. The aerobic mesophilic flora of the vegetable samples was dominated by Bacillus and Micrococcus spp. Salmonella and Shigella were isolated from eight (10%) and 24 (30%) samples, respectively. All of the Salmonella and 97% of Shigella isolates showed resistance to penicillin. Ampicillin resistance was observed in 42% of Salmonella and 79% of Shigella isolates. Multiple drug resistance was seen in 8 and 24 isolates of Salmonella and Shigella isolates, respectively.

Conclusion

The majority of lettuce and green pepper samples had high microbial load and multiple drug resistant pathogens were also isolated from some samples. As lettuce and green pepper, when used as salad vegetables, do not get any further heat treatment, thorough washing and considerably longer exposure of the vegetables to food grade chemicals is recommended to kill pathogens and significantly reduce the microbial load.     

某些蔬菜与水果的抗氧化活性观察

在本研究中,以TBAS生成的阻断率(TBASI)为指标,测定了豇豆、韭菜、茄子、香蕉、桃、油菜、四季豆、柿子椒、土豆、芹菜、葡萄、苹果、黄瓜、番茄的抗氧化活性,并同时用化学发光法测定了清除超氧化物自由基(O(?))的活性。其主要结果为:1.煮沸前以豇豆、韭菜、茄子、香蕉、油菜与四季豆的抗氧化活性较高,黄瓜、葡萄与番茄的抗氧化活性较低。煮沸20min后葡萄、香蕉与茄子的抗氧化活性较高;黄瓜与番茄的抗氧化活性较低。2.煮沸后茄子、豇豆、韭菜、四季豆与土豆的抗氧化活性与煮沸前相比显著下降,而葡萄的抗氧化活性反而显著增加。3.TBASI与清除(O(?))的活性两指标似无平行关系。4.在所测样品中,以茄子清除(O(?))的活性最高;豇豆和柿子椒次之;而黄瓜、葡萄、番茄、桃最低。     

哈尔滨市售蔬菜中有机磷和拟除虫菊酯农药的残留量

目的了解哈尔滨市蔬菜中有机磷农药、拟除虫菊酯类农药的残留情况,为政府相关部门制订政策提供依据。方法于2007年5—10月,从哈尔滨市10个主要农贸市场和5个超市采集大辣椒、小辣椒、黄瓜、西红柿、豆角、菠菜、油菜、大头菜、花菜和白菜菜样各15件,采用气相色谱法检测其农药的残留情况。结果共检测出4种有机磷农药(甲胺磷:0.003 1～0.048 8mg/kg;敌敌畏:0.001 5～0.052 7mg/kg;氧化乐果:0.003 9～0.3449mg/kg;水胺硫磷:0.0026～0.0869mg/kg)和3种拟除虫菊酯类农药(氯氰菊酯:0.018 1～0.324 5 m/kg;氰戊菊酯:0.024 7～0.024 8 mg/kg;溴氰菊酯:0.039 4～0.044 1 mg/kg)残留,甲拌磷、乐果、甲基对硫磷均未检出残留。农药残留超标率由高至低依次为氧化乐果(24.00%)>甲胺磷(20.67%)>水胺硫磷(4.67%)。氧化乐果在10种蔬菜中均有检出,氯氰菊酯在9种蔬菜中检出,敌敌畏和甲胺磷分别在7种蔬菜中检出。结论本次调查的蔬菜中普遍存在有机磷、拟除虫菊酯类农药的残留。     

66种蔬菜、水果抗氧化活性的比较研究

目的 :　比较不同蔬菜、水果的抗氧化活性。方法 :　采用 FRAP法 ( ferric reduc-ing/antioxidantpower assay)对 3 6种蔬菜、3 0种水果的抗氧化活性进行了测定比较 ,并且分析了其抗氧化活性与维生素 C含量的关系。结果 :　 3 6种蔬菜中 ,抗氧化活性以藕最强 ,姜、油菜、豇豆、芋头、大蒜、菠菜等次之 ,芹菜、山药和生菜最弱 ;3 0种水果中 ,抗氧化活性以山楂最强 ,冬枣、番石榴、猕猴桃、桑葚、草莓、玛瑙石榴等次之 ,白兰瓜、京欣一号西瓜和柿子最弱 ;不同蔬菜、水果中维生素 C所占的抗氧化活性差异很大。结论 :　一些蔬菜、水果的抗氧化活性较强 ,有效成分值得进一步研究开发     

Bioavailability of 1-nitropyrene from model coal fly ash and its uptake by alveolar macrophages

Alveolar macrophage cultures exposed to coal fly ash vapor-coated with 1-nitropyrene were used as a model system to study the bioavailability and the uptake of a nitroaromatic hydrocarbon from coal combustion emissions. Initially, 1-nitropyrene-coated fly ash and uncoated fly ash were examined for cytotoxicity using rabbit alveolar macrophages and for mutagenicity in the Salmonella typhimurium plate incorporation assay. The results were compared to determine the effects of vapor deposition. The distribution and recovery of 1-nitropyrene from macrophage cultures treated with coated fly ash were determined by using a reverse-phase high-performance liquid chromatography-fluorescence method. 1-Nitropyrene alone was not very toxic, nor did vapor deposition of 1-nitropyrene onto coal fly ash significantly affect the toxicity of the fly ash. Most toxicity resulted from the original, uncoated fly ash particles. 1-Nitropyrene after being coated onto the particles was bioavailable in agar and aqueous culture medium. The coated fly ash showed mutagenic activity when the particles were tested directly; the uncoated fly ash did not show mutagenic activity. 1-Nitropyrene recovery from alveolar macrophage cultures exposed to the coated fly ash diminished as cell number increased. The rate of 1-nitropyrene loss was 2.7 ng/10(6) macrophages for medium and 4.1 ng/10(6) macrophages for the whole culture. The mutagenic activity recovered from these macrophage cultures also decreased with increasing cell number.     

Effect of benzyl butyl phthalate on physiology and proteome characterization of water celery (Ipomoea aquatica Forsk.)

This study examined the effect of benzyl butyl phthalate (BBP), a phthalate ester (PAE) and an endocrine disruptor, on water celery, Ipomoea aquatica Forsk., one of the most popular leaf vegetables in Taiwan. After 28 days of cultivation, treatment with 100 mg L⁻¹ BBP retarded plant growth and decreased biomass and number of mature leaves and caused the accumulation of proline in leaves of water celery, but the concentrations of chlorophyll a and b in the leaves remained constant. 2-D gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the proteome of leaf tissue revealed five protein spots with up- and down-regulated expression. The predicted protein XP_001417439 was down-regulated, which explained inhibition of plant growth, and the proteina XP_001417040, calreticulin, GAI-like protein 1, and (-)-linalool synthase were up-regulated, which indicates interference with the cell cycle and protein synthesis, as well as dwarfism of water celery. BBP is a stressor on the growth of water celery, and proteome analysis revealed the up- and down-regulation of genes involved in plant growth with BBP treatment.     

几种中草药及绿茶抗香烟焦油的致突变作用

为了深入研究开发利用中药资源，本实验用人外周血淋巴细胞的非程序ＤＮＡ合成试验（ＵＤＳ试验），对几种中草药及绿茶抗香烟焦油的致突变作用进行了研究。结果表明，白花蛇舌草、半枝莲、绿茶、茶多酚及犀黄丸均有不同程度的抗突变作用。先提取香烟焦油凝聚物后，再加１２５ｇ／Ｌ的白花蛇舌草，１２５ｇ／Ｌ的半枝莲，７８ｇ／Ｌ的绿茶，２５ｇ／Ｌ的茶多酚及３２５ｇ／Ｌ的犀黄丸就可以明显地对抗香烟焦油凝聚物对淋巴细胞ＤＮＡ的损伤作用；将中草药及绿茶先注入香烟内，再提取香烟凝聚物（内含中草药或绿茶），结果显示以上各浓度的中草药及绿茶同样能保护淋巴细胞的ＤＮＡ，且保护作用较前者更强。这一结果与其他抗突变试验结果基本一致。     

Vegetable consumption and carotenoids in plasma and adipose tissue in Malaga,Spain

OBJECTIVE: To study relationships between habitual dietary intake, adipose tissue concentrations of alpha-carotene, beta-carotene and lycopene, and plasma concentrations of alpha- and beta-carotene. DESIGN: Cross-sectional study including assessment of food habits by a food frequency questionnaire and 48-hour recall and determination of carotenoid concentrations in adipose tissue and plasma. SUBJECTS: 51 women (mean age of 62 years) from the control group of the European Community Multicentre Study on Antioxidants, Myocardial Infarction, and Breast Cancer (EURAMIC), Málaga, Spain. RESULTS: In adipose tissue, beta-carotene was correlated with consumption of green pepper (r = 0.36; p < 0.05) and lycopene with total fruit/vegetable intake (r = 0.28; p < 0.05), green pepper (r = 0.31; p < 0.05), and carrot (r = 0.25; p < 0.10). In plasma, beta-carotene was correlated with total fruit/vegetable intake (r = 0.29; p < 0.10), lettuce (r = 0.34; p < 0.05), tomato (r = 0.26; p < 0.10), and lycopene with total fruit/vegetable intake (r = 0.27; p < 0.10). Age-, BMI- and waist circumference-adjusted regression coefficients for the regression of logn-transformed adipose and plasma concentrations on consumption of specific fruits and vegetables (per 100 g/day) were calculated. In adipose tissue, coefficients were: 1.50 (p < 0.05) for alpha-carotene/carrot; 1.90 (p < 0.10) and 0.51 (p < 0.10) for beta-carotene/green pepper and lettuce; 2.02 (p < 0.05), 1.25 (p < 0.05) and 0.18 (p < 0.05) for lycopene/green pepper, carrot and total fruit/vegetable intake. In plasma, coefficients were 1.14 (p < 0.05) and 0.21 (p < 0.05) for beta-carotene/lettuce and total fruit/vegetable intake. CONCLUSIONS: Consumption of fruit and vegetables could be linked directly to carotenoid concentrations in adipose tissue and plasma. Although associations with individual food items are related to their carotenoid contents, the absorption and distribution of carotenoids needs more attention to improve their usefulness as biomarkers of exposure.     

Antimutagenic activity of vegetable and fruit extracts against in-vitro benzo(a)pyrene

About 80% of the juices from twenty vegetables and fruits showed antimutagenic activity when tested in the presence of the mutagen and carcinogen benzo[a]pyrene using the Ames' Salmonella/microsome assay. In a standardized test system juices from raw celeriac, broccoli, red cabbage, carrots, green, peppers, lettuce, asparagus, apricots, red-currants, gooseberries, raspberries, and pineapple showed more than 50% inhibition. Leek, kohlrabi, cucumber, zucchini, French beans, fennel leaves, rhubarb, and sweet cherries were less effective. No antimutagenic activity was detected in onions, Chinese cabbage, radish, and white cabbage. Cooking considerably reduced the antimutagenic activity of celeriac, leek, broccoli, French beans, carrots, asparagus, cherries, and pineapple, but was ineffective or only moderately effective with kohlrabi, zucchini, cucumber, fennel leaves, lettuce, apricots, red-currants, gooseberries, and raspberries.