Effects of quinoa and amaranth on zinc,magnesium and calcium content in beer wort

Pseudocereals such as quinoa and amaranth can be used as partial replacements for malt in the production of new beers. Quinoa and amaranth are of interest due to their high levels of nutrients and micronutrients, including minerals which can significantly improve the performance of brewing yeast and the fermentation rate. In this study, we investigated whether the use of quinoa or amaranth as partial replacements for malt affected the concentration of ions such as zinc and magnesium in beer wort. The use of amaranth, and in particular quinoa, increased the content of both zinc and magnesium ions substantially, even when only 10% of the barley malt was replaced. With 10% quinoa, Zn²⁺ and Mg²⁺ content increased by 41% and 49%, respectively, while the ratio of Mg²⁺ to Ca²⁺ rose from 1.4:1 to 1.9:1. Use of unmalted quinoa and amaranth appears a good way of enriching wort with essential metal ions.     

几种常见绿茶茶碱与咖啡碱成分的分析

利用高效液相色谱法(HPLC),对9种绿茶进行了生物碱的定量和定性分析和比较.通过实验得出鉴别绿茶品质的重要参数.结果表明:茶碱含量与产地气候有密切关系,咖啡碱的含量随产地气候变化较小,而咖啡碱含量与茶碱含量比值具有稳定而明显的差异,可以作为绿茶的生化鉴别依据之一.     

江西修水双井绿茶加工技术

为探究不同等级双井绿茶香气物质组成特征,利用顶空固相微萃取-气相色谱-质谱联用技术（Headspace solid-phase micro extraction and gas chromatography mass spectrometry,HS-SPME-GC/MS）对修水县双井银毫、双井绿茶特级、双井绿茶一级和双井绿茶二级四个不同等级的双井绿茶的香气物质进行了检测分析。结果表明,从四个不同等级的双井绿茶中共鉴定出70种香气物质,主要包括醇类、烯烃类、烷烃类、酯类等化合物。不同等级的双井绿茶中香气物质组成及相对含量均有差异,通过主成分分析（Principal component analysis,PCA）和偏最小二乘法-判别分析（Partial least squares-discriminant analysis,PLS-DA）,可以有效区分不同等级的双井绿茶。不同等级双井绿茶香气差异主要由反式-β-金合欢烯、香叶醇、水杨酸甲酯、茉莉酮、苯乙醇等14种关键化合物差异引起。在不同等级双井绿茶中关键香气物质表现出不同的分布规律,随着芽叶开展,α-椰油烯、石竹烯及己酸乙酯含量降低,而顺式-3-己烯醇、香叶醇及水杨酸甲酯含量呈增加趋势,芳樟醇、茉莉酮、反式-橙花叔醇含量从低到高,随后含量又迅速下降。本文研究了不同等级双井绿茶中香气物质的组成特征及关键香气物质的分布规律,为今后双井绿茶生产提供了理论依据。

     

Sodium, potassium, calcium and magnesium content in breakfast cereals: products highly consumed by the spanish population

 In this work is presented a study of the sodium, potassium, calcium and magnesium contents in 15 samples of the breakfast cereals that are most consumed by the Spanish population. We have found that they are of varied compositions, both in relation to the number of cereals which are the basis of their formulations, and to the rest of the ingredients added to enrich these products. This results in a wide variation in the macroelements contents, although all are found in significant quantities. In all samples, sodium was the predominant cation, reaching levels above 800 mg/100 g, and magnesium was the most scarce cation, with values ranging between 7 mg/100 g and 67 mg/100 g. Potassium and calcium also varied greatly, the former particulary in those breakfast cereals which contained wheat, and the latter in those enriched with milk or calcium salts. Received: 25 November 1999 / Revised version: 7 February 2000     

Copper, zinc, calcium and magnesium content of alcoholic beverages and by-products from Spain: nutritional supply.

Levels of copper, zinc, calcium and magnesium were measured in alcoholic beverages (whiskies, gins, rums, liquors, brandies, wines and beers) and by-products (non-alcoholic liquors and vinegars) using flame atomic absorption spectrometry (FAAS). Mineral concentrations were found to be significantly different between the nine alcoholic and non-alcoholic by-products studied (p < 0.001). In distilled alcoholic beverages, concentrations measured in rums and brandies were statistically lower than those determined in gins and alcoholic liquors (p = 0.001). For Cu, measured concentrations were statistically different for each of the five groups of distilled alcoholic beverages studied (p < 0.001). In fermented beverages, Zn, Ca and Mg levels were significantly higher than those concentrations determined in distilled drinks (p < 0.005). Contrarily, Cu concentrations were statistically lower (p < 0.001). Wines designated as sherry had significantly higher Ca and Mg levels (p < 0.005). White wines had significantly higher Ca and Zn levels (p < 0.05) compared with red wines and, contrarily, Cu concentrations were significantly lower (p < 0.005). In wine samples and corresponding by-products (brandy and vinegar), statistical differences were established for all minerals analysed (p < 0.01). Remarkably, for Cu, the concentrations determined in brandies were statistically higher. On the basis of element levels and the official data on consumption of alcoholic beverages and by-products in Spain, their contribution to the daily dietary intake (DDI) was calculated to be 124.6 microg Cu day(-1) and 193.3 microg Zn day(-1), 40.3 mg Ca day(-1) and 19.9 mg Mg day(-1). From all studied elements, Cu was the one for which alcoholic beverages constitute a significant source (more than 10% of recommended daily intake). These findings are of potential use to food composition tables.     

市售茶酒中5种高级醇含量的检测与分析

目的 检测并分析市售茶酒中5种高级醇含量。方法 随机购买9款茶酒,按其酒精度进行不同程度的稀释,采用静态顶空-气相色谱法测定高级醇含量(包括异丁醇、异戊醇、正丙醇、正丁醇、正戊醇等5个指标),以2款普通黄酒进行检测方法的准确性验证,同时将茶酒中高级醇含量与2款普通白酒进行对比。结果 2款普通黄酒的高级醇含量测定结果与文献报道相符,表明本研究方法具有科学性,数据可靠;换算成相同酒精度(100%vol)后,研究所用茶酒中白酒的高级醇含量显著高于啤酒、配制酒和露酒,均在2000 mg/L以上;研究所用同类型酒中茶酒的高级醇含量相对随机购买的普通酒更低。结论 本研究中不同类型的市售茶酒中高级醇含量差异明显,含茶白酒高于其他类型含茶酒,而低于普通酒,这有助于为茶酒等新型功能酒的进一步开发提供数据参考。     

焙炒对米茶中丙烯酰胺和晚期糖基化终产物的影响

研究焙炒温度、时间、加水量和浸润时间对米茶加工过程中丙烯酰胺(Acrylamide,AA)和晚期糖基化终产物(Advanced glycation end products,AGEs)的影响。结果表明,随着焙炒温度升高和时间的增加,AA和AGEs含量增加,但是当温度高于200℃时AA含量会呈现降低趋势;随加水量增加和浸润时间延长,AGEs含量显著性减少(p<0.05),米茶中的AA含量先降低,在加水量超过10%,浸润时间超过10 min之后升高。在190℃,加水量10%(w/w),浸润10 min,焙炒35 min最适加工条件下AA和AGEs含量分别为141μg/kg和360 AU/g,低于同类产品,正常食用对人体安全。      

食盐中钙镁离子测定影响的消除

GB/T 13025.6-1991《制盐工业通用试验方法钙和镁离子的测定》容量法中,当用EDTA标准溶液对钙、镁离子进行滴定时,常会遇到终点无法到达或终点延迟的现象,通过大量的实验,发现这些现象是由于待测溶液中存在的重金属离子,特别是铜离子造成的影响.文章通过对实验方法的改进,达到了消除干扰的效果,提高了测定的准确性.     

3种新式茉莉花茶饮基底茶品质分析

目的:探究新式茉莉花茶饮基底茶的品质特点。方法:以福建、云南、四川3地茶坯窨制而成的3种新式茉莉花茶茶饮基底茶(福建香毫、云南毛尖、四川香茗)为研究对象,利用电子舌、固相微萃取—气相色谱质谱技术,结合理化检测和感官审评,从主要化学成分以及滋味、香气等品质进行分析。结果:3种基底茶的水浸出物含量为49.40%～51.40%,茶多酚含量为18.00%～23.20%,咖啡碱含量为3.20%～4.30%,游离氨基酸含量为3.32%～3.50%。除游离氨基酸外,云南毛尖的主要生化成分含量、酚氨比及16种氨基酸含量均高于其他两种。云南毛尖茶汤的涩味、咸味及丰富度响应值最大,但甜度响应值最低,茶汤浓厚;福建香毫涩味、咸味响应值最小,但水浸出物含量高,茶汤浓醇。香气组分中酯类相对含量最高,其次是醇类和烯烃类化合物;3种基底茶的香气品质由高到低为福建香毫、云南毛尖、四川香茗,均属于中等。结论:3种基底茶内含物质丰富,但香气质量有待提高。     

Organic food and the impact on human health

In the last decade, the production and consumption of organic food have increased steadily worldwide, despite the lower productivity of organic crops. Indeed, the population attributes healthier properties to organic food. Although scientific evidence is still scarce, organic agriculture seems to contribute to maintaining an optimal health status and decreases the risk of developing chronic diseases. This may be due to the higher content of bioactive compounds and lower content of unhealthy substances such as cadmium and synthetic fertilizers and pesticides in organic foods of plant origin compared to conventional agricultural products. Thus, large long-term intervention studies are needed to determine whether an organic diet is healthier than a diet including conventionally grown food products. This review provides an update of the present knowledge of the impact of an organic versus a conventional food diet on health.     

虾青素的抗氧化作用及对人体健康的影响

目的探讨虾青素的抗氧化作用和对人体健康的影响。方法将120名健康志愿者按血清丙二醛含量随机分为试食组和对照组,试食组连续服用受试物90 d,对照组服用安慰剂,测定两组人群血清中丙二醛(MDA)含量及超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性和安全性指标。结果试食组血清MDA含量显著下降,与对照组的差异有统计学意义(P<0.01),试食组血清SOD和GSH-Px活性显著升高,与对照组的差异有统计学意义(P<0.01)。试验前后两组人群的各项安全性指标均在正常范围内。结论虾青素可提高人体的抗氧化能力,且对人体健康无损害作用。     

奶茶中茶多酚含量测定方法的改进

茶多酚含量的高低是评价茶饮料质量好坏的一个主要指标,GB/T21733-2008中采用酒石酸铁比色法测定茶饮料中茶多酚的含量,实际操作时,我们发现其中对奶茶类饮料的样品预处理存在一定缺陷,影响了测定结果的准确度。本文通过改进样品预处理方法,即采用酸性丙酮破乳和沉淀蛋白质,提高了奶茶饮料中茶多酚含量测定的精密度和准确度。方法的平均回收率为99.6%～102.2%,相对标准偏差RSD为0.21%～0.26%(n=6),可广泛应用于奶茶类饮料中茶多酚含量的测定。     

Sorghum (Sorghum bicolor L.): Nutrients,bioactive compounds,and potential impact on human health

Sorghum is the fifth most produced cereal in the world and is a source of nutrients and bioactive compounds for the human diet. We summarize the recent findings concerning the nutrients and bioactive compounds of sorghum and its potential impact on human health, analyzing the limitations and positive points of the studies and proposing directions for future research. Sorghum is basically composed of starch, which is more slowly digested than that of other cereals, has low digestibility proteins and unsaturated lipids, and is a source of some minerals and vitamins. Furthermore, most sorghum varieties are rich in phenolic compounds, especially 3-deoxyanthocyanidins and tannins. The results obtained in vitro and in animals have shown that phenolics compounds and fat soluble compounds (polycosanols) isolated from sorghum benefit the gut microbiota and parameters related to obesity, oxidative stress, inflammation, diabetes, dyslipidemia, cancer, and hypertension. The effects of whole sorghum and its fractions on human health need to be evaluated. In conclusion, sorghum is a source of nutrients and bioactive compounds, especially 3-deoxyanthocyanidins, tannins, and polycosanols, which beneficially modulate, in vitro and in animals, parameters related to noncommunicable diseases. Studies should be conducted to evaluate the effects of different processing on protein and starch digestibility of sorghum as well as on the profile and bioavailability of its bioactive compounds, especially 3-deoxyanthocyanidins and tannins. Furthermore, the benefits resulting from the interaction of bioactive compounds in sorghum and human microbiota should be studied.     

K and Ca content of fresh green tea, black tea, and tea residue determined by X-ray fluorescence analysis

Summary X-Ray fluoresence (XRF) can be successfully used for the qualitative and quantitative elemental analysis of various agricultural products. Its simplicity, high throughput and the possibility of automation make it useful for screening large numbers of samples. The K and Ca content of 138 samples of fresh green tea, black tea and black tea residues were determined by applying the XRF system. Such a method of mineral analysis of food products is not very common. Tea from different teagrowing areas of Turkey, green tea of different shooting periods, black tea processed at different tea plants and tea residues from these black tea were analysed. The K content of green tea, processed black tea and tea residues after brewing were found to have ranges of 19,049–26,254 mg/kg, 21,904–26,883 mg/kg and 9,468–13,778 mg/kg, respectively. In the same samples the Ca content was determined as 3,580–4,799 mg/kg, 3,370–4,823 mg/kg, and 3,743–5,733 mg/kg, respectively. These findings were compared with the results of atomic emission techniques and it was concluded that the XRF system could be effectively used for quantitative analysis of the K and Ca content of tea samples.

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Die Bestimmung des K- und Ca-Gehaltes von frischem Tee, schwarzem Tee und Teerückstand durch die X-Ray-Fluoreszenz-Technik

Zusammenfassung Mit der X-Ray Fluoreszenztechnik können die qualitativen und quantitativen Bestimmungen der Mineralstoffe in verschiedenen Produkten erfolgreich durchgeführt werden. Mit dieser Methode wurde der Ca- und K-Gehalt von 138 Proben untersucht, und zwar frischer Tee, schwarzer Tee und Teerückstand. Diese Methode ist in der Lebensmitteltechnologie, insbesondere bei der Mineralstoffbestimmung nicht üblich. Die Teeproben stammten aus verschiedenen Teeanbaugebieten der Türkei. In dieser Arbeit wurden die Wirkung der Sproßperiode, der Verarbeitungstechnik und des Anbaugebietes auf den Ca- und K-Gehalt der Teeproben untersucht. Der durchschnittliche K-Gehalt betrug: in frischem Tee 19049–26254 mg/kg, in schwarzem Tee 21904–26883 mg/kg, in Teerückstand 9468–13778 mg/kg; der Ca-Gehalt 3580–4799 mg/kg, 3370–4823 mg/kg und 3473–5733 mg/kg.

     

Acrolein scavengers: reactivity, mechanism and impact on health

Acrolein (ACR) is an α,β-unsaturated aldehyde that exists extensively in the environment and (thermally processed) foods. It can also be generated through endogenous metabolism. Its high electrophilicity makes this aldehyde notorious for its facile reaction with biological nucleophiles, leading to the modification of proteins/DNA and depletion of glutathione. Recent studies also have revealed its roles in disturbing various cell signing pathways in biological systems. With growing evidences of ACR's implication in human diseases, strategies to eliminate its hazardous impacts are of great importance. One of the intervention strategies is the application of reactive scavengers to directly trap ACR. Some known ACR scavengers include sulfur (thiol)-containing and nitrogen (amino)-containing compounds as well as the newly emerging natural polyphenols. In this review, the interactions between ACR and its scavengers are highlighted. The discussion about ACR scavengers is mainly focused on their chemical reactivity, trapping mechanisms as well as their roles extended to biological relevance. In addition to their direct trapping effect on ACR, these scavengers might possess multiple functions and offer additional benefits against ACR-induced toxicity. A comprehensive understanding of the mechanism involved may help to establish ACR scavenging as a novel therapeutic intervention against human diseases that are associated with ACR and/or oxidative stress.     

Effect of potassium,magnesium and sulphur applied in different forms of fertilisers on free amino acid content in leaves of tea (Camellia sinensisL)

Free amino acids in tea leaves are important chemical constituents that considerably influence the quality of tea, especially that of green tea. The present study was conducted to investigate the effects of the nutrients potassium, magnesium and sulphur on biomass production and amino acid accumulation in tea leaves in pot and field experiments. The results show that biomass production and the free amino acid contents in tea leaves increased considerably following the application of potassium and magnesium. Combined application of both nutrients produced the highest increment in free amino acids. The increased free amino acid content in tea leaves was accompanied by enhanced nitrate reductase activity. This indicates that potassium and magnesium application improved the nitrogen metabolism, leading to an increased synthesis of amino acids. A comparison between K₂CO₃ vs K₂SO₄ and MgO vs MgSO₄ revealed significantly higher amino acid contents in tea leaves when both potassium and magnesium were applied in the sulphate form, indicating that not only potassium and magnesium but also sulphur plays an important role in the accumulation of amino acids in tea leaves. A pot experiment using KCl and K₂SO₄ was carried out in order to compare the two commercially available potassium fertiliser forms in their effect on biomass production and the content of free amino acids in tea leaves. The results showed no difference on biomass production between the two fertiliser forms. However, whereas KCl tentatively depressed nitrate reductase activity and hence the accumulation of free amino acids, K₂SO₄ significantly increased the contents of these quality promoting constituents of tea leaves. The role of fertiliser composition, detrimental effects of accompanying anions, eg Cl⁻ and differences in nutrient availability (eg oxide≪sulphate form) and possible impact on soil chemistry as main reasons for the observations, being crucial aspects with regard to fertilisation of tea for good quality are discussed. © 1998 SCI.     

ORAC法评价16种茶叶的抗氧化能力

目的评价4类不同发酵类型16种茶叶样品总抗氧化能力。方法采用氧自由基吸收能力(oxygen radical absorbance capacity,ORAC)法。结果闽红茶样品ORAC值最高,为1379.1μmol TE/g,其次为乌龙茶水仙,其ORAC值为1270.7μmol TE/g,第三位绿茶品种的古丈毛尖,其ORAC值为1247.1μmol TE/g。绿茶样品整体均具有较高的ORAC值,但4类茶叶的ORAC值无统计学差异(P0.05)。结论 4类茶叶样品均具有一定的抗氧化活性,但尚不能认为不同种类茶叶的ORAC值不同。