云南省常见野生食用菌镉含量调查分析

目的:对云南省常见的野生食用菌中镉含量进行调查,为食物资源的开发和综合利用提供参考依据。方法:定点采集野生食用菌品种,按GB/T 5009.15-2003《食品卫生检验方法理化部分食品中镉的测定方法》石墨炉原子吸收光谱法进行分析。结果:对36种172件新鲜野生食用菌进行检测,最高镉含量检出值为1.66 mg/kg(小黑鸡枞菌,昆明),55.8%的样品镉含量低于0.2 mg/kg。结论:云南野生食用菌镉含量偏高,其原因可能与云南省有着丰富的矿产资源有关,也可能与云南省经济日益发展,环境污染日趋加重有关,具体需待进一步的调查。     

Nitrate in vegetables: estimation by HPLC

Over the past fifty years the development of high-tech farming has led to excessive amounts of fertiliser being applied to soil. Some research aspects of this abuse are described in relation to the uptake of nitrate into vegetables. In order to monitor this problem a high precision HPLC method capable of rapid throughput has been evolved. Using this HPLC method the results over a twelve month period are presented and compared with the existing standards now legally enforced in Switzerland and Holland.     

高氮施肥区蔬菜硝酸盐及亚硝酸盐调查

目的了解高氮施肥区蔬菜硝酸盐及亚硝酸盐污染情况。方法于2011年7—10月选择沙颍河上游地区每月采样,共采集27种、136个蔬菜样品检测硝酸盐、亚硝酸盐含量并进行初步的健康风险评估。结果 8—9月蔬菜硝酸盐含量较高,10月最低;9月蔬菜亚硝酸盐含量最高,7—8月较低,10月最低;7—10月份6类蔬菜亚硝酸盐含量超标(4.00mg/kg)率为41.67%,10月均达标。蔬菜硝酸盐健康风险指数除10月外均1;亚硝酸盐健康风险指数均1。结论该区域蔬菜硝酸盐和亚硝酸盐蓄积水平较高,且硝酸盐存在一定的健康风险。     

4种药食兼用野菜的微量元素含量分析

用火焰原子吸收光谱法测定了石家庄地区茵陈、地肤、车前和苦菜中Fe、Mn、Cu、Zn等微量元素的含量,结果表明:4种野菜中的Fe、Zn含量均较高,Cu/Zn比值较低,具有很好的食用和医疗价值,尤其是茵陈4种微量元素含量均较丰富,具有很高的开发利用价值。     

Antioxidant activity and polyphenol content in edible wild fruits from Nepal

Abstract

Fifteen fruits commonly used by the ethnic population in Nepal were studied for the antioxidant activity and total polyphenol content (TPC). Among them, Terminalia bellirica, Terminalia chebula, Phyllanthus emblica and Spondias pinnata were the most potent antioxidants as compared with vitamin C based on the 1,1-diphenyl-2-picryl hydrazyl radical assay. These fruits also contained high TPCs. Spondias pinnata, Pyrularia edulis, Melastoma malabathricum, Cipadema bacifera and Choerospondias axillaries fruits were evaluated for the first time. Moreover, Spondias pinnata was found to be more potent (16% radical scavenging activity at 5 μg/ml) than vitamin C (5% radical scavenging activity at 5 μg/ml). Antioxidant activity showed correlation to TPC with the correlation coefficients (R²) as 0.7189 and 0.7246 for the methanol and water extracts, respectively. This study suggests that a number of these fruits may have the potential to confer beneficial health effects due to their antioxidant activity and TPC.     

Determination of antioxidant activity and antioxidant compounds in wild edible mushrooms

The methanolic extracts of dried Agaricus bisporus, Polyporus squamosus, Pleurotus ostreatus, Lepista nuda, Russula delica, Boletus badius, and Verpa conica were analyzed for antioxidant activity in different systems including reducing power, free radical scavenging, superoxide anion radical scavenging, total antioxidant activity, and metal chelating activities. Those various antioxidant activities were compared to standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and α-tocopherol. The percentage inhibition methanolic extracts of dried Russula delica, Boletus badius, Agaricus bisporus, Polyporus squamosus, Pleurotus ostreatus, Lepista nuda and Verpa conica at 100 μg/mL concentrations on peroxidation in linoleic acid system were 99.7%, 99.2%, 98.8%, 98.4%, 98.3%, 97.9% and 97.7%, respectively, and greater than those 400 μg/mL of α-tocopherol, BHA and BHT (77%, 85%, and 97%). Among methanolic extracts from seven wild edible mushrooms, the reducing power of Russula delica and Verpa conica were excellent, and were 1.32 and 1.22 at 200 μg/mL, respectively. Methanolic extract from Verpa conica, Boletus badius and Russula delica proved to be better at scavenging O₂⁻ than other mushroom species. The scavenging effects of methanolic extracts from mushroom species and standards on the DPPH radical decreased in the order of BHA>α-tocopherol>Lepista nuda>Russula delica>Polyporus squamosus>Pleurotus ostreatus>Agaricus bisporus>Verpa conica>Boletus badius and were, at the concentration of 180 μg/mL, 97.4, 95.4, 91.3, 86.1, 82.8, 81.3, 77.5, 75.7 and 68.7, respectively. The metal scavenging effect of extract of the mushroom species and standards decreased in the order of Verpa conica>Lepista nuda>Russula delica>Boletus badius>Polyporus squamosus>BHT>Pleurotus ostreatus>Agaricus bisporus>BHA>α-tocopherol. On the other hand, total phenolic compounds, α-tocopherol, and β-carotene were determined in the methanolic extracts of dried Agaricus bisporus, Polyporus squamosus, Pleurotus ostreatus, Lepista nuda, Russula delica, Boletus badius, and Verpa conica.     

Pro- and antioxidant effects and cytoprotective potentials of nine edible vegetables in southwest Nigeria

Antioxidant and cytoprotective activities of boiled, cold, and methanolic extracts of nine edible vegetables in Southwest Nigeria were evaluated in the 1,1-diphenyl-2-picrylhydrazyl free radical assay and hemagglutination assay in bovine erythrocytes, respectively. Crassocephalum rubens showed the highest antioxidant activity (56.5%), Solanum americanum and Vernonia amygdalina exhibited moderate antioxidant activity (26.0-37.5% and 14.8-36.2%, respectively), Solanum macrocarpon, Telfaria occidentalis, Amaranthus hybridus, and Jatropha tanjorensis produced weak activity (1.6-15.8%, 1.6-7.7%, 2.8-6.62%, and 10.7-12.1%, respectively), while Celosia argentea and Talinum triangulare were pro-oxidants. It was also shown that extracts from all the vegetables are pro-oxidants at high concentrations of either 1 or 5 mg/mL or both. On the other hand, the studies on the cytoprotective effect showed that all the plant extracts demonstrated a very low hemagglutination titer value between 0.32 and 5.56 except S. americanum methanolic extract, which had a titer of 50.0. These results indicated correlation between the antioxidant properties and the hemagglutination values of these plant extracts; however, the membrane stabilizing capacity of the extracts supports the plants' antioxidant activity.     

The use of wild edible plants in the Jordanian diet

In Jordan, large numbers of wild edible plants are widely distributed throughout the country and consumed in various ways. In this study 56 wild edible plants used in local meals were surveyed to determine the plant parts used, the detailed methods of their preparation and preservation as well as their uses. The study showed that the plants used are either eaten raw, cooked by boiling in water, frying in fat or baking to be served as dishes such as stew, turnovers, stuffed and rolled vegetable foods or as cold or hot drinks for certain occasions and seasons. The study also showed that some of these plants are preserved by sun drying to be used out of season for cooking in main dishes, or as spices and appetizers.     

Nutritional quality of some wild leafy vegetables in South Africa

Wild vegetables play an important role in the diet of inhabitants of different parts of the world. Among the wild vegetables of South Africa are Chenopodium album, Sonchus asper, Solanumnigrum and Urtica urens. The leaves of these plants were analysed for their nutritive value, anti-nutritive components and polyphenolic contents. The protein contents of their leaves ranged between 13.25% and 26.44%, while the fibre and mineral (ash) contents were 16.08–23.08% and 13.0–27.75%, respectively. U. urens contained the highest concentrations of calcium, potassium, phosphorus and zinc. A high level of iron was observed in S. asper. These values were found to be comparable with or higher than those of commonly used vegetables such as spinach, lettuce and cabbage. The total phenolic contents ranged between 4.58 and 10.53 mg/g. In terms of anti-nutritional principles, all the vegetables had comparatively lower concentrations of phytate, alkaloids and saponins. Considering the amount of available mineral elements in the vegetables, these plants could be valuable and important contributors to the diets of the people in South Africa.     

Antioxidant capacity and mineral contents of edible wild Australian mushrooms

Five selected edible wild Australian mushrooms, Morchella elata, Suillus luteus, Pleurotus eryngii, Cyttaria gunnii, and Flammulina velutipes, were evaluated for their antioxidant capacity and mineral contents. The antioxidant capacities of the methanolic extracts of the dried caps of the mushrooms were determined using a number of different chemical reactions in evaluating multi-mechanistic antioxidant activities. These included the Trolox equivalent antioxidant capacity, ferric ion reducing antioxidant power, and ferrous ion chelating activity. Mineral contents of the dried caps of the mushrooms were also determined by inductively coupled plasma-optical emission spectroscopy. The results indicated that these edible wild mushrooms have a high antioxidant capacity and all, except C. gunnii, have a high level of several essential micro-nutrients such as copper, magnesium, and zinc. It can be concluded that these edible wild mushrooms are good sources of nutritional antioxidants and a number of mineral elements.     

云南野生食用蕈中的微量元素分析

用原子吸收分光光度法分析了５种云南野生食用蘑菇中Ｃａ、Ｍｇ、Ｚｎ、Ｃｕ、Ｃｏ、Ｋ、Ｍｎ和Ｆｅ的含量，根据实验结果，讨论对人体健康的关系。     

分光光度法测定野菜中铁的含量

野菜植物无污染、无农药残毒、营养丰富,具有特殊风味,并且很多野菜还有医疗保健作用。用分光光度法直接测定野菜中铁的含量,方法简便快速准确,对指导人们合理食用野菜进行补铁及进一步开发野菜提供了可靠的理论依据。     

The polyphenol content and antioxidant activities of the main edible vegetables in northern Vietnam

Oxidized low-density lipoprotein (LDL) is considered a risk factor in atherosclerosis, and polyphenols are the potential agents to inhibit the oxidation of LDL. We determined the polyphenol contents and the antioxidant activities of commonly consumed vegetables in Vietnam and assessed the quantity of the polyphenol intake from vegetables in the current Vietnamese diet. The polyphenol contents in 30 kinds of vegetables was determined by the Folin-Ciocalteu method. The antioxidant activities of vegetables were evaluated by measuring the oxidation of LDL and the reduction of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. In this study, some herbs and edible wild vegetables possessed high contents of polyphenols and antioxidant activities. Among green vegetables, sweet potato leaves showed both a high polyphenol content and antioxidant activity. The mean polyphenol daily intake of the Vietnamese was a 595 mg catechin equivalent. Water spinach, a kind of green vegetable, contributed the highest amount (45%) of the total polyphenol intake, followed by other green vegetables. Neither herbs nor edible wild vegetables contributed significantly to the total polyphenol intake due to their low consumption. Green vegetables are therefore considered very important sources of polyphenol intake for the Vietnamese.     

Antioxidant and cytotoxic activity of the wild edible mushroom Gomphus clavatus

The fruiting bodies of the edible mushroom Gomphus clavatus (Family Gomphaceae) were collected from the wild and extracted with solvents of increasing polarity. Crude extracts were evaluated for their total phenolic content, their antioxidant capacity, and their cytotoxic activity against MCF-7 and PC-3 cancer cell lines. Concerning total phenolics and antioxidant activity, the methanol extract showed the most potent radical scavenging activity with inhibition of 45.5% of 1,1-diphenyl-2-picrylhydrazyl at 3?mg/mL. Further chemical investigation of the methanol extract led to the isolation and identification of nine compounds, among them four ergosterol derivatives. Concerning cytotoxicity, the dichloromethane (DCM) extract showed the most interesting activity, with half-maximal inhibitory concentration (IC(50)) values of 55.3 and 49.0?μg/mL in the MCF-7 and PC-3?cell lines, respectively. Further investigation of the DCM extract lead to the identification of methyl esters of fatty acids and the isolation of four fatty acids and three ergosterol derivatives. Ergosterol peroxide (compound 6) was one of the most active constituents, with IC(50) values of 35.8?μM and 30.6?μM for MCF-7 and PC-3?cells, respectively, suggesting that the cytotoxic activity of the crude extract could be at least partly attributed to the presence of ergostan derivatives. Those findings suggest that G. clavatus can be considered as a medicinal food with antioxidant and chemopreventive activities.     

Phytoestrogens in common herbs regulate prostate cancer cell growth in vitro

Prostate cancer is an important public health problem in the United States. Seven phytoestrogens found in common herbal products were screened for estrogen receptor binding and growth inhibition of androgen-insensitive (PC-3) and androgen-sensitive (LNCaP) human prostate tumor cells. In a competitive 3H-estradiol ligand binding assay using mouse uterine cytosol, 2.5 M quercetin, baicalein, genistein, epigallocatechin gallate (EGCG), and curcumin displaced > 85% of estradiol binding, whereas apigenin and resveratrol displaced > 40%. From growth inhibition studies in LNCaP cells, apigenin and curcumin were the most potent inhibitors of cell growth, and EGCG and baicalein were the least potent. In PC-3 cells, curcumin was the most potent inhibitor of cell growth, and EGCG was the least potent. In both cell lines, significant arrest of the cell cycle in S phase was induced by resveratrol and EGCG and in G2M phase by quercetin, baicalein, apigenin, genistein, and curcumin. Induction of apoptosis was induced by all of the 7 compounds in the 2 cell lines as shown by TUNEL and DNA fragmentation assays. Androgen responsiveness of the cell lines did not correlate with cellular response to the phytoestrogens. In conclusion, these 7 phytoestrogens, through different mechanisms, are effective inhibitors of prostate tumor cell growth.     

Carotenoid concentrations in vegetables and fruits common to the Costa Rican diet

The intake of vegetables and fruits has been shown to reduce the risk of multiple diseases in many different populations. Various components of these foods have been investigated to explain the protective effects. Carotenoids, a class of phytochemicals found in these foods, have been investigated for links between their oxidative, provitamin A, and cellular properties and disease risk reduction. Many nutrition-based studies employ dietary questionnaires to estimate intakes for associations with disease. Reliable assessments of the components of these foods are necessary for accurate quantification of intake. While databases have been published, they vary greatly due to differences in methodology, growth conditions, and handling. In addition, data relevant to foods grown and consumed in Latin America and Costa Rica are scarce. In this paper, we employ a quality-controlled method for analyzing foods to obtain data on vegetables and fruits that are common to the Costa Rican diet. The data is presented in tables and compared to databases from the United States and Europe.