儿茶素类的保健作用及机制

茶是二十一世纪风靡全球的健康饮料。茶叶中含有多种保健功能成分, 尤其是儿茶素类物质。儿茶素 具有诸多医疗保健功能和一些特殊性质, 不仅被应用于经口服的膳食补充剂、保健食品、保健饮料等产品, 还应用于化妆品、日化用品等外用型的健康产品, 具有良好的市场开发潜力。本文综述了内服和外用两种方式下儿茶素类物质的保健作用及其作用机制。     

Nutrients in non-alcholic beverages in Nigeria

Forty-one samples of carbonated soft drinks in Nigeria have been shown, on analysis, to contain high sugar contents (mean value, 14·0%) despite the high cost of this ingredient; the Food and Drug regulations allow 9%–14%. There is a considerable divergence in the mean values of sugar for the four brands examined; 14·9%, 15·3%, 12·4% and 13·7% for the Cola, Fanta, clear drinks and fruit juice, respectively. Similar large deviations in mean values were recorded for other chemical constituents of the drinks. Ascorbic acid, for example, has an overall mean value of 12·2 mg/100 ml whereas individual samples have mean values ranging from 36·3 to 7·25 mg/100 ml. The ascorbic acid values for the fruit juice drinks fall short of expectation in all cases.     

Determination of cyanidin-3-glucoside (red kernel food colour) in beverages by high performance liquid chromatography and a study of its degradation by quadruple time-of-flight mass spectrometry

A method for the determination of cyanidin-3-glucoside (red kernel colour, RKC) in various matrices, including carbonated soft drinks, fruit-based soft drinks, sugar confectionery and milk-based drinks, by high performance liquid chromatography (HPLC) based on UV–Vis detection (at 520?nm) have been developed. Pre-treatment procedures for various matrices have been optimised. For soft drinks, the pH values were adjusted to 2.0, and sugar confectionery and milk-based drinks were extracted with 30 and 50% methanol in 0.1% formic acid (pH?～?2.5) aqueous solutions, respectively. The limits of detection for the established methods ranged from 0.2?mg/kg for soft drinks to 2.0?mg/kg for the sugar confectionery and milk-based drinks with the relative standard deviations lower than 7%, which satisfy the method performance requirements for quality control for the beverages. The stability of the colourant RKC under various thermal and pH conditions was investigated by quadruple time-of-flight mass spectrometry (Q-TOF-MS). The main colourant component of RKC, cyanidin-3-glucoside (Cyd-3-Glu), lost the glucose entity under thermal treatment. A new component was identified when RKC degraded under various pH conditions and a degradation pathway is proposed. The results will assist in understanding the degradation mechanism of the colourant Cyd-3-Glu.     

Determination of cyanidin-3-glucoside (red kernel food colour) in beverages by high performance liquid chromatography and a study of its degradation by quadruple time-of-flight mass spectrometry

A method for the determination of cyanidin-3-glucoside (red kernel colour, RKC) in various matrices, including carbonated soft drinks, fruit-based soft drinks, sugar confectionery and milk-based drinks, by high performance liquid chromatography (HPLC) based on UV-Vis detection (at 520 nm) have been developed. Pre-treatment procedures for various matrices have been optimised. For soft drinks, the pH values were adjusted to 2.0, and sugar confectionery and milk-based drinks were extracted with 30 and 50% methanol in 0.1% formic acid (pH ~ 2.5) aqueous solutions, respectively. The limits of detection for the established methods ranged from 0.2 mg/kg for soft drinks to 2.0 mg/kg for the sugar confectionery and milk-based drinks with the relative standard deviations lower than 7%, which satisfy the method performance requirements for quality control for the beverages. The stability of the colourant RKC under various thermal and pH conditions was investigated by quadruple time-of-flight mass spectrometry (Q-TOF-MS). The main colourant component of RKC, cyanidin-3-glucoside (Cyd-3-Glu), lost the glucose entity under thermal treatment. A new component was identified when RKC degraded under various pH conditions and a degradation pathway is proposed. The results will assist in understanding the degradation mechanism of the colourant Cyd-3-Glu.     

包装茶饮料质量特性的研究

本研究采集了部分茶饮料样品,分别在对样品的包装名称及其内容物进行了调查的基础上,分析了内容物的pH值,滴定酸度、茶水汤色(L、a、b)值,可溶性固形物、咖啡因、茶多酚、游离氨基酸、总黄酮和感官品质,探索茶饮料在检验和质量控制方面的可行性。     

Regulatory Control of Energy Drinks Using 1H NMR Spectroscopy

400 MHz ¹H nuclear magnetic resonance (NMR) spectroscopy was used in the context of food surveillance to control the regulatory limits of selected constituents of energy drinks. The preparation of the samples required only degassing, addition of 0.1 % of TSP in D₂O for locking and referencing and phosphate buffer (pH 4.0) for chemical shifts adjustment. The quantification of caffeine, glucuronolactone, taurine and inositol was simultaneously possible using external calibration curves and applying TSP as internal standard. The applicability of the method was proven by analysis of 73 samples of energy drinks. The average caffeine concentration was 0.30 g/L, which is below the maximum limit of 0.32 g/L.     

Boysenberry and blackcurrant drinks increased the plasma antioxidant capacity in an elderly population but had little effect on other markers of oxidative stress

BACKGROUND: The consumption of fruit and vegetables promotes good health by protecting against various degenerative diseases. Even though the constituents responsible are not known, some evidence indicates that the antioxidant properties of fruit and vegetable phytochemicals are responsible. Previous studies have shown that blackcurrant and Boysenberry reduce oxidative stress using in vitro cell systems. The aim of this study was to determine if blackcurrant or Boysenberry drinks could improve measures of oxidative stress and inflammation in an elderly population with below‐average memory abilities. The intervention parallel study was fully blinded with a placebo control. RESULTS: Of the six measures of oxidative stress assessed, only plasma antioxidant capacity significantly increased for both the Boysenberry and blackcurrant treatments compared with the placebo. Plasma malondialdehyde decreased in both the Boysenberry and blackcurrant treatments although the decrease was not statistically significant. Measures of oxidative stress for protein oxidation and lipid peroxidation improved for the berryfruit treatments during the study but were not statistically different from the placebo. CONCLUSION: Long‐term consumption of both the Boysenberry and blackcurrant drinks raised the plasma total antioxidant capacity of the study participants suggesting that Boysenberry and blackcurrant may help protect against oxidative stress‐related health conditions. Copyright © 2007 Society of Chemical Industry     

Antioxidant capacity of some caramel-containing soft drinks

Antioxidant properties of foods and beverages have been widely studied; however, few data have been reported on the antioxidant capacity of soft drinks. Apart from fruit juice-based drinks, some of the most common soft drinks contain as a colouring agent one of the four caramel colours allowed in foods (E150 d). Caramels contain melanoidin compounds, which have been reported to contribute to the antioxidant powers of some foodstuff. This study aimed to ascertain the contribution to the antioxidant activity of some caramel-containing soft drinks, such as cola drinks, and chinotto, an original Italian soft drink. Some commercial caramel colours were analysed for main parameters, i.e. HMF (5-(hydroxymethyl)-2-furfural), residual glucose and fructose content, total reducing compounds by the Folin–Ciocalteau reagent, and the antioxidant activity by the FRAP and DPPH^∗ methods. Similar analyses were performed on various soft drinks coloured with E150 d. The results showed that even if soft drinks have a lower antioxidant activity than other beverages such as tea, coffee or chocolate, they may contribute to the antioxidant pool assumed with the diet, since the antioxidant activity ranged from 0.2 for cola-like soft drinks to 1.0 mmoles Trolox equivalent/l for chinotto drinks.     

Analysis of the sugar content of fruit juices and drinks using ultrasonic velocity measurements

The use of ultrasound to determine the sugar content of fruit juices and drinks has been assessed. The velocity of ultrasound and the density were measured in solutions of D-glucose, D-fructose, and sucrose at various concentrations (0–40% w/v) and temperatures (10–30°C). The velocity of ultrasound was measured in 50:50wt:wt mixed solutions of sucrose and D-glucose over the same range of concentrations and temperatures. Measurements of the velocity of ultrasound, the density and the refractive index were made on various fruit juices and drinks at 20°C. The sugar content of the juices and drinks was determined by enzymatic assay. Ultrasonic measurements are shown to predict sugar contents in pure sugar solutions to within 0.2% w/v and in mixed sugar solutions to within 0.5% w/v. The ultrasonic measurements were sensitive to sugar species. It is shown that ultrasound compares well with other techniques for sugar content determination in fruit juices and drinks, and has the advantage that the equipment can be used for on-line process control. Applications for this ultrasonic technique are proposed.     

Acrylamide levels in Finnish foodstuffs analysed with liquid chromatography tandem mass spectrometry

Sample clean-up and HPLC with tandem mass spectrometric detection (LC-MS/MS) was validated for the routine analysis of acrylamide in various foodstuffs. The method used proved to be reliable and the detection limit for routine monitoring was sensitive enough for foods and drinks (38 microg/kg for foods and 5 microg/L for drinks). The RSDs for repeatability and day-to-day variation were below 15% in all food matrices. Two hundred and one samples which included more than 30 different types of food and foods manufactured and prepared in various ways were analysed. The main types of food analysed were potato and cereal-based foods, processed foods (pizza, minced beef meat, meat balls, chicken nuggets, potato-ham casserole and fried bacon) and coffee. Acrylamide was detected at levels, ranging from nondetectable to 1480 microg/kg level in solid food, with crisp bread exhibiting the highest levels. In drinks, the highest value (29 microg/L) was found in regular coffee drinks.     

饮料中肠杆菌科细菌污染情况分析

国内不同地区几家企业生产的绿茶、还原乳、蜜橘饮料、奶茶中出现产品变质,胀瓶、产气等感官指标的变化,pH值均有所下降。主要污染菌经过16S rDNA序列比对鉴定为肠杆菌科Enterobacteriaceae细菌。蜜橘饮料和奶茶中分离到的3株典型污染菌,经过进一步的rpoB序列比对,鉴定为阴沟肠杆菌(Enterobacter cloacae)。肠杆菌科细菌不耐热,这些产品的污染属杀菌后的二次污染,该类微生物中有不少种类的菌对人体有害,或与致病菌有着亲密的亲缘关系。从生产线排查情况看,这类微生物的污染经由水(冲洗或冷凝水)或车间内湿润空气带入。     

Trace heavy metals composition of some Nigerian beverages and food drinks

Several beverages and food drinks available in the market in Nigeria were analysed for their contents of the heavy metals, cadmium, cobalt, chromium, copper, iron, nickel, lead and zinc. The beverage types were grouped into tea, cocoa-based, coffee, cereal-based, dairy products, fruit juices, malt drinks, carbonated soft drinks and wines (non-alcoholic). The levels of the various metals were generally low, and within statutory safe limits. The levels compare well with those reported for similar beverages from some other parts of the world. ©     

磁珠法提取植物蛋白饮料DNA

目的 建立一种快速、高效的植物蛋白饮料基因组DNA提取方法并应用于植物蛋白饮料中植物源性成分的检测。方法 以豆浆、豆奶、芝麻糊、花生牛奶、榛子乳5种植物蛋白饮料为研究对象, 建立利用硅羟基磁珠提取植物蛋白饮料DNA的方法, 通过分析所提取DNA的浓度和纯度, 实时荧光PCR扩增效率, 并与十六烷基三甲基溴化铵法(cetyltrimethylammonium ammonium bromide, CTAB)比较, 综合评价磁珠法提取植物蛋白饮料的效果。结果 大部分样品磁珠法提取的DNA浓度比CTAB法高, ODA260/A280均大于1.70。 结论 磁珠法提取的DNA纯度较高, 杂质少, 能满足植物蛋白饮料源性成分的分析要求, 尤其适用于大豆类蛋白饮料的DNA提取, 为快速、高效获取质量好的植物蛋白饮料基因组DNA提供参考。     

NITROGEN COMPOUNDS IN RUM AND WHISKEY

SUMMARY— The nitrogen compounds from a Jamaica rum and a Scotch blended whiskey were isolated and identified by gas chromatography and mass spectrometry. In both spirits were found: pyridine, α-picoline, β-picoline, thiazole, methylpyrazine, 2,5-dimethylpyrazine, 2,6-dimethylpyrazine, 2,3-dimethylpyrazine, 2-methyl-6-ethy/pyrazine, 2-methyl-5-ethylpyrazine, trimethylpyrazine and 2.5.dimethyl-3-ethylpyrazine. 2.Methyl-6-vinylpyrazine was detected only in rum. Nine compounds in whiskey and eleven in rum have not previously been reported as constituents of these drinks or fusel oils.     

羧甲基纤维素钠对酸性乳饮料稳定作用的研究

通过测定添加不同含量的羧甲基纤维素钠(CMC)对酸性乳饮料的沉淀率、粘度、粒径分布、水分子流动性及Zeta电位的影响,研究了CMC对酸性乳饮料的稳定作用。结果表明,CMC对酸性乳饮料的稳定作用表现为使产品的沉淀率降低,粘度升高,在微观性质上表现为使产品的粒径减小,水分流动性减弱,Zeta电位的绝对值升高。     

酸性豆乳饮料稳定性的研究

对不同ＨＬＢ值混合乳化剂和几处稳定剂的稳定效果进行了研究，并确定了最佳的杀菌工艺条件。     

Data evaluation for soft drink quality control using principal component analysis and back-propagation neural networks

This work describes an alternative for chemical data research, with the aim of evaluating finished product quality. Analytical data for additives in soft drinks are interpreted by the use of multivariate data analysis: principal component analysis (PCA), factor analysis, cluster analysis, and artificial neural networks. Taking into account various chemical components like sorbic, benzoic, and ascorbic acids; saccharose; caffeine; Na, K, Ca, Mg, Fe, Zn, Cu, P, and B, soft drinks were characterized and classified. The ratios of Na, K, Ca + Mg, P, and K/Na have been studied. The application of PCA, cluster analysis, and artificial neural networks showed that combination of these chemometric tools offers effective means for modeling and classifying soft drinks in accordance with their contents in additives and heavy metals.     

Corrosion of aluminium in soft drinks

The corrosion of aluminium (A1) in several brands of soft drinks (cola- and citrate-based drinks) has been studied, using an electrochemical method, namely potentiodynamic polarization. The results show that the corrosion of A1 in soft drinks is a very slow, time-dependent and complex process, strongly influenced by the passivation, complexation and adsorption processes. The corrosion of A1 in these drinks occurs principally due to the presence of acids: citric acid in citrate-based drinks and orthophosphoric acid in cola-based drinks. The corrosion rate of A1 rose with an increase in the acidity of soft drinks, i.e. with increase of the content of total acids. The corrosion rates are much higher in the cola-based drinks than those in citrate-based drinks, due to the facts that: (1) orthophosphoric acid is more corrosive to A1 than is citric acid, (2) a quite different passive oxide layer (with different properties) is formed on A1, depending on whether the drink is cola or citrate based. The method of potentiodynamic polarization was shown as being very suitable for the study of corrosion of A1 in soft drinks, especially if it is combined with some non-electrochemical method, e.g. graphite furnace atomic absorption spectrometry (GFAAS).     

Comparison of antioxidant capacity of commonly consumed youth beverages in the United States

Epidemiological evidence supports that polyphenol‐rich foods with high antioxidant potency promote health and may influence various metabolic diseases' development. Often beverage products claim to have antioxidant potency based on the perceived polyphenol content; however, few studies have examined the antioxidant potency of beverages with none reporting on commonly consumed youth beverages. This study's purpose was to measure total antioxidant capacity (TAC), expressed in Trolox equivalents (μmol mL^?1), in a variety of youth beverages, including juices, vitamin enhanced waters, sport drinks, energy drinks and various milk products. Significantly higher TAC (3.8–6.7 μmol mL^?1) was measured in 100% juices, while vitamin enhanced waters varied by brand (0.2–3.1 μmol mL^?1). Soda, energy and sports drinks measured the least activity (0.0–0.3 μmol mL^?1), whereas other milk types (strawberry, organic, regular and soya) measured no activity, except chocolate milk (3.0 μmol mL^?1). These results may improve beverage selection practices for youth, parents and dietitians to increase TAC of the paediatric diet.     

市售茶饮料中主要功效成分分析

目的研究市售茶饮料中主要品质成分含量情况,并分析其差异原因。方法采用酒石酸铁比色法测定茶多酚(teapolyphenols,TP);采用水合茚三酮比色法测定游离氨基酸总量;采用高效液相色谱法(high performance liquid chromatography, HPLC)法检测6种儿茶素以及咖啡碱(caffeine, CAF)含量。结果目前市售茶饮料以调味茶饮料居多,不同种类、不同品牌茶饮料中的茶多酚、儿茶素、CAF以及游离氨基酸含量具有明显差异。结论绿茶饮料各种主要品质成分含量较高,其次为乌龙茶饮料,红茶饮料较低。CAF含量全部样品符合国家标, TP含量仅有一款红茶饮料低于国家标准,其余均符合国家标。