茴香中总多酚和总黄酮含量及其抗氧化活性研究

测定茴香体外抗氧化活性,并分析茴香中总多酚与总黄酮含量与抗氧化活性的关系。结果表明,茴香乙酸乙酯部位和正丁醇部位具有体外抗氧化活性。其中,乙酸乙酯部位清除DPPH自由基和ABTS+自由基的能力（IC50分别为（37.67±0.21）、（24.88±0.07）μg/mL）比正丁醇部位的清除能力（IC50分别为（47.48±0.18）、（34.19±0.19）μg/mL）强,且具有显著性差异（p<0.05）,而正丁醇部位对铁离子的还原能力（TEAC值为（569.9±0.69）μmol/g）比乙酸乙酯部位的还原能力（TEAC值为（281.23±4.73）μmol/g）强,且具有显著性差异（p<0.05）。乙酸乙酯部位清除DPPH和ABTS自由基的能力强可能与其总黄酮含量高有关,正丁醇部位还原铁离子的能力好与其总多酚含量高有关。      

Pesticide residues in the total diet in England and Wales, 1966-1967. I. Organisation of a total diet study

The organisation of a total diet sampling scheme is described, including the basis on which it was designed and the manner in which it was carried out. Twenty colleges or institutions, widely distributed in England and Wales, co-operated in preparing the samples for analysis for pesticide residues. the samples were separated into 7 food groups for analytical purposes.     

Screening of 70 medicinal plant extracts for antioxidant capacity and total phenols

The total phenolic content and related total antioxidant capacity of 70 medicinal plant infusions was analyzed. Infusions were prepared in common way in which teas are prepared for human consumption. The total phenolics were measured by Folin–Ciocalteau assay. The total antioxidant capacity was estimated by Ferric Reducing/Antioxidant Power (FRAP) assay. To make practical comparison of relative antioxidant potential of phenolics extracted from selected medicinal plants, the phenol antioxidant coefficient (PAC) was calculated for each infusion. The total phenolic content of medicinal plant infusions ranges from 9 to 2218 mg/L. The FRAP range from 0.06 to 25 mM/L. There was significant linear correlation between total phenolic content and FRAP. According to their antioxidant capacity, 70 medicinal plant extracts can be divided in five groups: (a) very low FRAP (<1 mM/L) n = 9; (b) low FRAP (1–5 mM/L), n = 37; (c) good FRAP (5–10 mM/L), n = 15; (d) high FRAP (10–20 mM/L), n = 8; and (e) very high FRAP (>20 mM/L), n = 1 medicinal plant extract. The PAC was ranging from 1.1 to 3.9 (average 2.4). The best results were obtained for Melissae folium infusions: high phenolic concentration, very high FRAP (>20 mM/L) and PAC > 3. The effect of infusion time and infusion temperature on the phenolic content, FRAP, and free radical scavenging ability was tested. DPPH radical scavenging ability of Melissae folium phenolics was similar to (+)-catechin but not as good as for quercetin. Compared to Trolox and vitamin C, Melissae folium phenolics were more efficient free ABTS radical scavengers. The results indicate that Melissae folium infusions could be an important dietary source of phenolic compounds with high antioxidant capacity comparable with red wine or beverages like tea.     

Pesticide residues in the total diet in England and Wales, 1966-1967. II. Organochlorine pesticide residues in the total diet

Details are given of the methods of analysis used for the determination of the Organochlorine pesticide residues in each of the food groups into which the total diet samples were divided. the results obtained for each food group and the calculated result for the total diet are given and comparison is made between the observed daily intakes and the acceptable daily intakes recommended by F.A.O. and W.H.O.     

Nutrients and chemical residues in an Egyptian total mixed diet

A mixed diet composite (EGYPT-DIET95) was prepared to represent the intake of Egyptian urban adults. Proximate analyses and assays for selected toxic elements, as well as organic chloro compounds, were carried out on this composite using well established methods and certified RMs (reference materials). The analysis of the composite diet demonstrates its usefulness for assessment of daily intakes. Calculated daily intakes of toxic substances were compared with the Acceptable Daily Intake of Codex Alimentarius (1984). The amounts of mercury and nitrates in Egyptian total-diet samples are of health concern.     

Intake and bioaccessibility of total polyphenols in a whole diet

The knowledge of dietary intake of polyphenols and their bioaccessibility in the human gut are key factors in assessing their significance in human health. The aim of this work was to estimate the amount of total polyphenols consumed in a whole diet (Spanish Mediterranean diet) and their intestinal bioaccessibility. Total polyphenols were determined, as the sum of the polyphenols present in methanol:acetone:water extracts (extractable polyphenols) of plant foods and condensed tannins and hydrolysable polyphenols (non-extractable polyphenols) in the corresponding residues. The polyphenols intestinal bioaccessibility was estimated by an in vitro gastrointestinal model where food polyphenols are released by enzyme digestion and colonic fermentation. The mean daily intake of polyphenols in the Spanish diet was estimated between 2590 and 3016 mg/person/day. The amount of non-extractable polyphenols was almost double that of extractable polyphenols. It was estimated that about 48% of dietary polyphenols are bioaccessible in the small intestine, while 42% become bioaccessible in the large intestine.     

Evaluation of antioxidant activity and total phenols index in persimmon vinegars produced by different processes

The total phenols index (TPI) and antioxidant activity of persimmon vinegars produced by different processes were evaluated. A novel extraction method was designed and optimised for this purpose with respect to the type and concentration of solvent and ultrasonication time. The best extraction conditions found were the use of 80% ethanol and 25 min of ultrasonication. Antioxidant capacity was determined by the oxygen-radical absorbance capacity of fluorescein (ORAC-FL) and 2,2′-diphenyl-1-pycrylhydrazyl (DPPH) free-radical assays. The antioxidant activities were the same in the fruit and the vinegar, except in the ORAC assay, which showed a significant decrease during the acetification process. The results showed that using the wild yeast strain native to the persimmon produced vinegars with higher antioxidant activity than that of an inoculated alcoholic fermentation. Finally, a comparison between our vinegars and other commercial examples was made. The TPI and antioxidant activity values of persimmon vinegars were always higher than those obtained from white and red-wine vinegars. The antioxidant activity and total phenols of the final product indicate that persimmon vinegar is a competitive product in the market.     

深圳市部分市售禽类制品二噁英污染水平研究

目的了解深圳市部分市售禽类制品(鸡肉、鸭肉、鸡蛋、鸭蛋)中17种二噁英污染情况。方法于2004年12月至2008年10月期间,随机采集深圳市市售的26份禽类样品,参照美国国家环保局EPA1613方法,采用索式抽提装置和FMS自动纯化系统分别对样品进行提取和净化,采用同位素稀释技术,用高分辨气相色谱/高分辨双聚焦磁式质谱联用(HRGC/HRMS)的超痕量有机分析技术平台,对样品中的二噁英进行定量分析检测。结果禽肉中PCDD/Fs含量(pgWHO-TEQ/g脂肪)范围是0.03～1.61,平均含量为0.50;禽蛋中PCDD/Fs含量范围是0.22～5.66,平均含量为1.43。其中有1份鸡肉和1份鸡蛋中二噁英含量超过欧盟执行标准,含量分别为1.61和5.66。结论本次调查的禽类制品中二噁英平均含量低于欧洲标准,但个别样品存在二噁英污染现象。     

Intake of polychlorinated biphenyls (PCB) in the total diet

The content of six selected indicator polychlorobiphenyl (PCB) congeners (nos 28, 52, 101, 138, 153, and 180) in 159 samples of total diet obtained from 20 different people has been determined by capillary gas chromatography. The congeners most frequently found were nos 138 and 153. The mean daily intake of the sum of the three congeners 138, 153, and 180 was 2.3 micrograms/person. This value compares favourable with a value calculated from PCB content of selected foods and consumption data.     

Plasticizers in total diet samples, baby food and infant formulae

The plasticizers di-n-butylphthalate (DBP), butylbenzylphthalate (BBP), di-2-(ethylhexyl)phthalate (DEHP) and di-2-(ethylhexyl)adipate (DEHA) were analysed in 29 total diet samples, in 11 samples of baby food and in 11 samples of infant formulae. In all of the total diet samples the presence of one or more of the plasticizers was demonstrated. Maximum and minimum mean concentrations in the total diet samples were: 0.09-0.19mg DBP/kg, 0.017-0.019mg BBP/kg, 0.11-0.18mg DEHP/kg and 0.13-0.14mg DEHA/kg. One or more of the phthalates was also found in about 50% of the samples of baby food as well as in infant formulae. The calculated mean maximum intakes of the individual compounds from the total diet samples were below 10% of the restrictions proposed by the EU Scientific Committee for Food (SCF), and the spread in individual intakes was considerable. DEHP was the plasticizer determined most frequently and contributed the highest fraction of its tolerable daily intake (TDI). Hence, the maximum calculated intake of DEHP from single samples of the foodstuffs analysed could be up to one-third of the TDI. The calculated mean intake of DEHA was about 1% of the TDI with a maximum value of 13% of the TDI. Violations of the restrictions proposed by the EU Scientific Committee for Food (SCF) in the form of TDI values or specific migration limits were not found in this investigation.     

Radical scavenging activities,endogenous oxidative enzymes and total phenols in edible mushrooms commonly consumed in Europe

Edible mushrooms are a good source of antioxidants. Methanol extracts of mushrooms such as Pleurotus sp., Agaricus bisporus, Morchella esculenta, Boletus edulis (approx. 2 mg mL^?1) showed a high 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) scavenging activity close to 90%. Water extracts showed even higher antioxidant activity. In this case, B. edulis, Lentinus edodes and Amanita cesarea showed the highest 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS) scavenging activity at approx. 0.14 mg mL^?1. Other mushrooms such as Lactarius deliciosus and Cantharellus cibarius showed lower antioxidant activity in both extracts. Oxidative enzymes (peroxidases and polyphenol oxidases) present in the water fractions reduced their antioxidant activity by different extents since the phenols responsible for the antioxidant activity were not only those substrates of the oxidative enzymes. Other phenolic compounds and low‐molecular‐weight compounds were also involved in the antioxidant activity and differed depending on mushroom species. Copyright © 2007 Society of Chemical Industry     

不同贮藏条件下“张杂谷”系列小米总酚含量的变化规律

通过分析在不同的贮藏条件下,随贮存时间的延长,"张杂谷"系列小米总酚含量的变化,探讨贮藏条件和总酚之间的相关性。结果表明,"张杂谷"系列小米总酚含量和贮藏条件有着显著的关系,为有效保留多酚类物质,增加抗氧化活性,"张杂谷"系列小米在进行大规模仓储时,以25℃条件保存效果较好,且要进行良好的通风,控制中心温度、环境湿度与光照条件。     

车前草总酚的微波提取

为优化得到车前草中总酚的最佳微波提取工艺条件,通过单因素和正交试验进行筛选。结果表明:影响车前草总酚提取率的主要因素顺序为,微波处理时间>乙醇浓度>料液比>微波功率;车前草总酚的最佳提取工艺为,60%乙醇、料液比1∶15(g∶mL)、微波处理3 min、微波功率为450 W。在此条件下车前草总酚的提取率最高,为3.61%。该法对车前草总酚提取率高,且缩短提取时间,节约能源。     

Multiple regression models and Computer Vision Systems to predict antioxidant activity and total phenols in pigmented carrots

The relationships between colour parameters obtained by a Computer Vision System (CVS) and both antioxidant activity (AA) and total phenol contents (TP) on coloured carrots were expressed as multivariate models obtained by multiple linear regression. The AA and TP predicted by the proposed models showed a good correlation with the real AA (R² = 0.97, P ? 0.001) and TP (R² = 0.94, P ? 0.001) measurements on the data set including internal and external parts of carrots. The predictions on the data set including only the internal (unevenly pigmented) parts of the carrots exhibited lower determination coefficients (R² = 0.93 for AA and R² = 0.86 for TP, P ? 0.001). The effectiveness of the models was checked also on the colour information provided by a colorimeter whose measures proved to be more sensitive to the uneven pigmentation of the carrots. Finally, the proposed models were able to successfully estimate the AA and the TP contents of pigmented carrots when applied to colours measured by the CVS.     

Aniline in vegetable and fruit samples from the Canadian total diet study

An isotope dilution method based on solvent extraction followed by GC–MS analysis was developed and used to determine aniline in vegetable and fruit samples collected from the Canadian total diet study. Aniline was not detected in any of the 23 vegetable samples from the 2005 total diet study at a method detection limit of 0.01 mg kg^–1. Among the 16 fruit samples, it was detected only in apple samples, with an average concentration of 0.278 mg kg^–1. Aniline was not detected in apple samples collected in the 2002, 2003, 2006 or 2007 total diet studies, but it was detected in the apple samples collected from the 2001 and 2004 studies, at concentrations of 0.085 and 0.468 mg kg^–1, respectively. The average aniline concentration for the 2001, 2004 and 2005 apple samples was 0.277 mg kg^–1. Good repeatability of the method was observed with replicate analysis of apple samples, with relative standard deviations (RSD) ranging 3.8–21% and an average of 11%.     

A survey of trialkyl and triaryl phosphates in United Kingdom total diet samples

Composite total diet samples, representative of 15 different commodity types overall encompassing an average complete adult diet, from each of eight regions in the UK, were analysed for the presence of trialkyl- and triarylphosphates. The analytical method consisted of solvent extraction, size exclusion clean-up and determination of individual phosphates by gas chromatography using phosphorus specific detection (alkali flame or flame photometric detection). Of the food groups offal, other animal products and nuts consistently contained the highest levels of trialkyl/triaryl phosphates, but there was variation in the incidence of individual compounds between different groups. Total phosphate intake was estimated to be between 0.07 and 0.1 mg per person per day.