超声波辅助碱法提取辣椒渣中蛋白质的工艺优化

以辣椒渣为原料,对单一碱法和超声辅助碱法提取蛋白质进行研究。单因素结果表明,超声辅助碱法优于单一碱法,提高了提取率,缩短了提取时间。经正交试验获得最佳提取工艺条件:料液比1∶25(m∶V),碱液浓度0.3 mol/L,超声温度60℃,超声时间120 min,辣椒蛋白质的提取率达到86.41%,蛋白质粗提物中蛋白质质量分数为60.09%,并测得辣椒蛋白质的最佳等电点为p H 3.6。     

Survey of 13 trace elements of toxic and nutritional significance in rice from Brazil and exposure assessment

Twenty-seven rice samples from Brazil, four parboiled brown, seventeen white and six parboiled white were analysed by ICP-MS for trace element determination. Concentrations of arsenic varied from 58.8 to 216.9?ng?g^?1, for cadmium from 6.0 to 20.2?ng?g^?1, for antimony from 0.12 to 1.28?ng?g^?1, and for uranium from 0.025 to 1.28?ng?g^?1. The estimated daily intake through rice consumption was 9.5?µg for As, 2.4?µg for Cd, 0.029?µg for Sb, 0.013?µg for U, 3.1?µg for Co, 0.2?µg for Cu, 85.6?mg for Mg, 1.9?mg for Mn, 333?mg for P, 3.0?µg for Se, 1.6?mg for Zn, 0.9?mg for Rb, and 0.3?µg for V. Found values represent a considerable percentage of the dietary reference intakes and provisional tolerable daily intake for essential and toxic elements, respectively.     

ICP-MS法测定白酒中Mn和毒理性元素的研究

建立电感耦合等离子体质谱（ICP-MS）法测定白酒中Mn和9个毒理性元素含量的分析方法。白酒采用硝酸酸化并加入低浓度盐酸后测定了其中的Be、Cr、Mn、Ni、As、Cd、Sn、Sb、Hg、Pb等元素,盐酸的加入有效地改善了样品溶液中元素的长时间稳定性,尤其是元素Hg和Sn。应用八极杆碰撞/反应池（ORS）技术有效地消除了盐酸的使用所带入的氯离子干扰以及其他质谱干扰,采用基体匹配并通过加入内标溶液有效地补偿样品传输的影响以及溶剂蒸发速率的差异,消除了基体所产生的影响。在选定的工作条件下,方法的线性关系良好,各元素的检出限为0.13¹2.15 ng/L之间,相对标准偏差（RSD）在0.75%³.48%之间,样品的加标回收率为93.80%¹10.00%。该方法具有操作简单、快速、结果准确等特点,可用于白酒的质量控制和安全评价。      

Assessment of daily intake of toxic elements due to consumption of vegetables, fruits, meat, and seafood by inhabitants of Xiamen, China

This study was designed to estimate the dietary intake of cadmium (Cd), lead (Pb), mercury (Hg) (total and methyl), and arsenic (As) by inhabitants of Xiamen, China. The concentrations of these toxic elements (TEs) were determined in vegetables, fruits, meat, and seafood samples randomly acquired in 5 districts of Xiamen between 2005 and 2009. Health risks were evaluated for inhabitants of Xiamen due to dietary consumption. The target hazard quotient (THQ) values for individual elements were far below 1, indicating minimal noncarcinogenic risks from TEs for inhabitants of Xiamen under the current food consumption rate. However, consumption of the entire foodstuffs could lead to potential health risks since the 95th percentile HI was higher than 1. The relative contributions of Cd, Pb, Hg T, and As to the HI were 16.0%, 15.9%, 5.9%, and 62.2% for the mean exposure level, and 13.3%, 13.4%, 5.6%, and 67.9% for the 95th percentile estimate. The THQ value of methyl mercury through consumption of cephalopod was less than 1. Tomato, cephalopod, eggplant, cabbage, orange, and pork were the main sources of total dietary intakes of TEs. The estimation of carcinogenic risk shows that the carcinogenic rate of arsenic exceeded the accepted risk level of 10(-4) . Therefore, the carcinogenic risk of arsenic for inhabitants of Xiamen is of concern. Practical Application: Tomato, cephalopod, eggplant, cabbage, orange, and pork were the main sources of dietary intakes of TEs in Xiamen, China. The carcinogenic risk of arsenic for inhabitants in this area who consume large amounts of fruits and vegetables daily may be of concern. Consumers are encouraged to eat fruits and vegetables with different origins and eat less cephalopod to reduce the possibilities of continuously eating commodities from the contaminated areas.     

Multi‐element characterisation of carob,fig and almond liqueurs by MP‐AES

Carob pod, fig and almond liqueurs are produced in various Mediterranean regions. This work reports the mineral content of these traditional beverages and evaluates the influence of the raw material. Twenty‐five fruit liqueurs from 16 producers were analysed. A simple open‐vessel sample mineralization by wet digestion using nitric acid–hydrogen peroxide (1:1) was used before spectrometric analysis. Nine essential elements (Cu, Ca, Mg, Na, K, Fe, Zn, Mn and P) and two non‐essentials (Cd and Pb) were quantified by microwave plasma–atomic emission spectrometry (MP‐AES). Carob liqueur presented the broader profile of minerals and was the only fruit liqueur containing iron (72.7% of samples), phosphorous, manganese and low levels of lead (in two of the 11 samples). Conversely, almond liqueurs contained the lowest mineral content with only five elements detected. Fruit liqueurs showed variability in mineral content even within the same liqueur, presumably as a consequence of the different manufacturing processes. Despite this variability, application of principal component analysis to essential mineral concentrations (K, Na, Ca, Mg, Mn, Fe and Zn) resulted in satisfactory classification (PC1 and PC2 accounting for 78.5% of the total variance) of the Portuguese liqueurs evaluated. Copyright © 2018 The Institute of Brewing & Distilling     

Effects of sodium and sulphur fertilisers on the concentrations of nitrate and potentially toxic elements (PTEs) in water leached from permanent pasture

The concentrations of nitrate and potentially toxic elements (PTEs) are reported in water leached from a perennial ryegrass pasture to which isonitrogenous quantities of sodium nitrate, ammonium nitrate or ammonium sulphate fertilisers had been applied in an experiment lasting 2 years. The experimental design allowed a comparison of the immediate effects of sodium nitrate in the grazing season in which the fertiliser was applied with the residual effects of applying it in the previous year. Leachate composition was monitored from December of the first year to August of the second year. Sodium fertiliser reduced the concentrations of cadmium in soil and leachate, but it increased lead concentration in soil and reduced it in leachate. Sulphur fertiliser had no effect on any PTE. Nitrate concentration in leachate increased towards the end of the winter to almost reach the EU legal limit in water and then declined during the spring and summer. Sodium fertiliser applied in either but not both years reduced nitrate concentration. Sulphur fertiliser had varied effects on nitrate concentration in leachate depending on the timing of sodium fertiliser application. When applied at the same time as sodium fertiliser, sulphur fertiliser decreased nitrate concentration, but when applied to areas that had received sodium fertiliser in the previous year, it increased nitrate concentration. It is suggested that sodium fertiliser residues may have long‐term effects on leachate nitrate concentration that determine the impact of sulphur fertilisers. It is concluded that sodium fertilisers may reduce the concentrations of at least two PTEs, cadmium and lead, in ground water and that the effects of sulphur fertilisers are dependent on the sodium status of the soil. © 2002 Society of Chemical Industry     

Nitrogen fertiliser source effects on the growth and mineral nutrition of pepper (Capsicum annuum L.) and wheat (Triticum aestivum L.)

BACKGROUND: The presence of stable mixed nitrogen forms (such as nitrate/ammonium/urea or nitrate/urea) in the soil solution is due to the use of nitrification and/or urease inhibitors in urea‐based fertilisers. However, there is no specific information in the literature comparing the efficiency of these urea mixed nitrogen forms as a nitrogen source for plants with that of nitrate and ammonium/nitrate. The aim of this study was to compare the effects on plant growth and mineral nutrition of different nitrogen forms, including mixed nitrogen forms containing urea. RESULTS: The results indicated that for both wheat (Triticum aestivum L.) and pepper (Capsicum annuum L.) the growth of plants fed mixed nitrogen forms containing urea was generally similar to that of plants receiving nitrate and nitrate/ammonium. Only in the case of pepper did ammonium/urea nutrition cause a significant decrease in plant growth. The presence of nitrate corrected the negative effects of mixed nitrogen forms containing ammonium and/or urea on the growth of pepper plants. CONCLUSION: Mixed nitrogen forms containing urea did not cause any negative effect on plant growth or mineral nutrition. In fact, plants fed mixed nitrogen forms containing urea had higher shoot concentrations of potassium, phosphorus, iron and boron than plants receiving nitrate. Copyright © 2007 Society of Chemical Industry     

宜宾多粮浓香型白酒糟生物炭的成分和结构特征分析

以四川宜宾多粮浓香型白酒糟为原料制备生物炭,利用元素组成分析、X-射线衍射和红外光谱对白酒糟生物炭的成分和结构特征进行研究,探讨热解温度对白酒糟生物炭的产率、外观、元素组成、物相和表面基团的影响。结果表明,白酒糟生物炭主要以非晶态碳形式存在,并含有少量石英相。白酒糟加热裂解制备生物炭是一个芳香性增强和极性减弱的过程,生物炭的产率随热解温度的升高而降低,热解温度以400～450 ℃为宜。     

Protection against the toxic effects of the favism factor (divicine) in rats by vitamins E,A and C and iron chelating agents

Five experiments were carried out with weanling Sprague-Dawley rats to determine if prior administration of either free-radical scavenging compounds (vitamins A, C and E) or chelating agents (EDTA and desferox- amine) affected the toxicity of divicine (DV). In all experiments, intraperitoneal (IP) injections of 250 mg g^?1 body weight of DV alone resulted in 100% mortalities within 24 h with most of the deaths occurring before 4 h. Death was accompanied by a rapid decrease in the concentration of glutathione (GSH) in the red blood cells (RBC) and the 576 nm/628 nm absorbance ratio of haemoglobin. The first experiment demonstrated that IP injections of different amounts of vitamin E, 1 h prior to DV injection, prevented the decrease in the haemoglobin absorbancy ratio and GSH concentration and greatly reduced mortalities. In rats that received 1000 IU of vitamin E kg^?1 body weight prior to DV injection, mortality was only 20%. The second experiment demonstrated that the optimal time for IP administration of vitamin E was 1 to 4 h prior to DV injection although some protection was obtained after 96 h. In contrast, the optimal time for intramuscular injections was 24 h prior to DV administration. A dosage of 250 or 500 IU of vitamin E kg^?1 body weight provided complete protection (zero mortalities) against the toxic effects of DV. In the third experiment, the addition of varying amounts of vitamin E to the diet resulted in a dose dependent mortality curve with no deaths occurring in rats fed diets containing the highest concentrations of vitamin E. The fourth experiment also demonstrated that vitamin A, vitamin C, EDTA and desferoxamine each protected rats to varying degrees against the toxic effets of DV. In the final experiment it appeared that the combined injections of a free-radical scavenging compound (vitamin E) and a metal chelator (desferoxamine) provide more protection than vitamin E alone. These results demonstrate for the first time in vivo that certain vitamins, especially vitamin E, and metal chelators can provide varying and in some cases 100% protection against the toxic effects DV.     

山东大泽山葡萄产地土壤及植株中营养元素丰缺状况评价

依据大泽山葡萄产地生态地球化学调查资料对葡萄园土壤、植株营养丰缺状况进行了评价.结果表明:K供给最丰足,有机质相对缺乏,微量营养组分在各园相差较大,但基本处于中等或低的水平;3种葡萄叶片和叶柄诊断显示,营养供给水平总体上处于适量范围;由葡萄叶柄养分平衡指标推断,土壤有机质缺乏、土壤养分吸收利用率低是影响大泽山地区葡萄园产量主要原因.     

食用菌对镉、铅、汞、砷生物富集状况研究进展

食用菌是味鲜、低热量、高蛋白、具有多种生物活性因子的健康食品,野生食用菌更是食物中的珍品。环境镉、铅、汞、砷污染日益严重,通过食物链并经口摄食是人体对环境中有害污染物最主要的暴露途径,所以食品中污染的镉、铅、汞、砷被认为是典型有毒元素。与维管植物相比,大型真菌对生长环境中的金属和类金属等矿质元素具有更强的吸收和富集性能,包括镉、铅、汞、砷。对食用菌中镉、铅、汞、砷的含量水平,在菌体中各部位的分布及其生物富集作用的研究进展进行了概述,特别关注了野生食用蘑菇中镉、铅、汞、砷的研究现状。研究表明通过选择优良品种、改善生产环境、改革栽培技术等,市售人工栽培食用菌在镉、铅、汞、砷的污染问题上有所控制,按照相关标准抽检合格率较高,基本能够保证质量安全。但是野生食用菌种类繁多,生长环境复杂,生长过程可控性差,因此需要进一步加强调研和食用安全风险评价,开发野生食用菌产品质量控制技术,保障消费者的健康。     

The effects of organic and conventional nutrient amendments on strawberry cultivation: Fruit yield and quality

BACKGROUND: The nutrition of food is increasingly important to consumers. The popularity of organic food rests partly on the assumption that these products are healthier despite a lack of conclusive evidence. The effects of organic and inorganic fertilizer amendments on parameters of strawberry fruit quality, in terms of sugar, macro‐ and micro‐nutrients concentrations, and total antioxidant capacity were compared. RESULTS: Treatments did not affect sugar content or total antioxidant capacity. Inorganic fertilizer treatments increased S and Mn content of berries compared to organic treatments. The K and P content of berries differed among years. CONCLUSIONS: Organic amendments did not increase the fruit quality of strawberries compared to inorganic amendments. Copyright © 2008 Society of Chemical Industry     

Synergistic effects of weak-acid preservatives and pH on the growth of Zygosaccharomyces bailii

In completely randomised factorial experiments, individual and synergistic effects of pH, benzoic acid and sorbic acid on the growth rate of the yeast Zygosaccharomyces bailii were determined, and expressed in polynomial equations. Synergism between benzoic and sorbic acid was pH dependent. A distinct effect of the anionic form of benzoic acid on doubling time was demonstrated by experiments in which concentrations of benzoic acid and benzoate were varied. The resultant polynomial equation showed that both species act synergistically.     

大孔吸附树脂分离纯化樟树果红色素及对小鼠的毒理性研究

通过比较8种大孔吸附树脂的吸附和解吸附性能,筛选出D-101为樟树果红色素的最佳优选树脂,随后对其吸附的上样温度、洗脱剂浓度、洗脱剂pH和洗脱温度等工艺参数以及对小鼠的毒理性进行了研究。结果表明:35℃温度下上样吸附,洗脱剂(乙醇)浓度70%、洗脱剂pH1、洗脱温度30℃的条件下洗脱效果较好,色阶提高31.40%。在实验浓度范围内灌胃小鼠,对小鼠生长没有影响。