超声波提取-火焰原子吸收光谱法测定金银花中的Fe、Cu和Pb

建立了湿法和超声波提取处理样品,火焰原子吸收光谱法测定金银花湿法消解液及超声波提取液中Fe,Cu和Pb元素含量的方法.金银花中3种元素的含量Fe＞Cu＞Pb,硝酸作为提取剂,提取元素的溶出率的大小:Cu＞Pb＞Fe,回收率为85％-107％,RSD为0.6-1.0％.结果表明,超声波提取能较好地提取金银花中微量元素,元...     

火焰原子吸收光谱法测定冬枣中的铁和锌

采用干法消解、湿法消解和非完全消解法3种方法多种体系处理冬枣样品,应用火焰原子吸收光谱法测定冬枣中铁和锌的含量.在选定的条件下,铁、锌的样品加标回收率在100.0％-101.3％之间,精密度（样品相对标准偏差RSD）均小于1.1％（n=11）.实验结果表明,湿法消解和非完全消解法的测定结果相差不大.其中非完全消解法简便、快捷,测定结果准确,更适用于冬枣中铁和锌的测定.     

3种消解方法在ICP-MS测定沉积物中4种重金属元素的应用

比较了王水回流、密闭容器消解及微波消解3种不同方法对海洋沉积物的消解效果,结果表明消解效果有较大差异:王水回流不能将样品消解完全,而密闭容器消解和微波消解基本能将样品消解完全,且微波消解效果更好,但对Cd元素测定王水回流消解效果较好;并建立了电感耦合等离子体-质谱测定沉积物中Cr、Cd、Hg、Pb等4种重金属元素的分析方法,各元素的线性关系良好(r=0.9999-1.0000),检出限为2.4-9.7ng·g-1,利用该方法分析了标准物质MESS-3,测定值与参考值吻合较好,相对标准偏差(RSD)为2.67％-5.58％,该方法的精密度和准确性良好.     

ICP-AES测定湖泊沉积物中微量元素的样品微波消解研究

为正确测定鄱阳湖沉积物中微量元素而研究样品消解方法,采用密闭式微波消解系统处理样品,以ICP-AES法测定多种微量元素.分别从不同的消解液、用酸量、消解工序以及样品消解量等方面进行研究和优化,最终确定了一个最适合消解鄱阳湖沉积物的前处理消解体系为:消解样用量为0.5 g,180℃电热板上预处理约15 min,消解体系选择酸比例为4:4:2的HNO3-HF-H2O2体系和HNO3-HF-HClO4体系均可,消解工序为5 atm/3 min-10 atm/2 min-15 atm/5 min-20 atm/10 min的逐步加热工序.这种消解方法简单快速、效率高、劳动强度低,为以后鄱阳湖沉积物的测定做了样品准备工作.     

氢化物发生-原子荧光光谱法同时测定生物体中的Hg和As

建立氢化物发生-原子荧光光谱法同时测定生物体中Hg和As的方法,在最佳的实验条件下,经过平板加热和微波消解样品多次实验比较,常压消解法和微波消解法对标准样品分析的结果均符合要求;其中常压消解法Hg、As的相对标准偏差分别为6.2％和4.0％;微波消解法Hg、As的相对标准偏差分别为4.6％和3.4％.两种方法都能满足海洋生物体中Hg和As含量的测定要求,具有分析速度快、操作简便、检验效率高等特点.     

ICP-AES测定海产品中的微量元素

对照了湿法消解和微波消解直接消解湿基海产品的方法.采用微波消解样品,电感耦合等离子体-原子发射光谱法（ICP-AES）测定了12种海产品中Zn、Fe、Ca、Mg、Cu和Mn 6种元素的含量,在最佳工作条件下各元素的加标回收率在97.62％-106.0％之间,相对标准偏差（RSD）为0.59％-2.04％,实验结果为研究营养学提供科学依据.     

微波消解-电感耦合等离子体-质谱法连续测定啤酒花中的11种微量元素

使用带预消解步骤的微波消解方法处理样品,电感耦合等离子体-质谱法结合碰撞池技术(CCT,Collision Cell Technology)连续测定了啤酒花样品中的11种微量元素.方法各元素相关系数均大于0.9995,相对标准偏差RSD＜5％,回收率为82.0％-112.0％.     

两种消解法测定烟用接装纸中铬、铅和镉的比较

采用两种不同的样品消解法消解烟用接装纸样品,并采用电感耦合等离子体-发射光谱仪测定了其中的3种有害元素铬、铅和镉的含量,通过几组样品的测定结果对比,证明两种样品前处理方法均可用于实际样品测定.     

梧桐叶中微量元素的测定

采用微波消解样品,火焰原子吸收光谱法测定汉中地区梧桐叶中Ca、Fe、Cu、Mn、Zn、Cd、Mg、Mo、Sn、Co等10种微量元素的含量.在最佳仪器工作条件下,各元素的加标回收率在98％-105.6％之间,方法的相对标准偏差RSD≤3.6％.该法消解效果理想、检出限低、线性范围较宽、准确率高、精密度好,适用于实际样品的分析.     

ICP-AES法测定蒿甲醚中 Cu、Pb、Zn、As、Sb和Cd

本文有用硝酸－高氯酸消解蒿甲醚样品，ICP－AES法同时测定其中痕量的Cu、Pb、Zn、As、Sb和Cd等。研究了样品处理方法及高氯酸残余量对测定的干扰，选择了仪器最佳工作条件，考查了方法准确度和精密度，6种元素加标回收率在91％－110％范围内，RSD（n=7)为4．2％－6．5％。     

紫草的提取工艺

对紫草提取工艺中各参数进行了优化,为紫草工业化提取提供一定的参考;以左旋紫草素含量的测定为工艺指标,通过正交设计试验,对乙醇浓度,乙醇体积,浸泡时间,及渗漉时间各因素进行了考察;紫草最佳提取工艺为：5倍量80%乙醇浸泡16h,再加10倍量80%的乙醇渗漉4h;适宜工艺为：5倍量80%乙醇浸泡12h,再加10倍量80%的乙醇渗漉4h;本工艺设计合理,工艺稳定,左旋紫草素提取率高,质量可控,适宜于工业化生产。     

甜叶菊中甜菊糖苷提取工艺的优化选择

以提取时间、提取温度、溶剂用量和浸泡时间为考察因素,采用正交试验优化甜叶菊中甜菊糖苷提取工艺。确定最佳工艺条件为:提取时间4h,温度40℃,溶剂用量25倍,不用浸泡。经过重复性实验验证,该工艺稳定可行,提取率较高。     

石墨炉原子吸收光谱法测定海藻制品中的砷

应用石墨炉原子吸收光谱技术建立了在海藻制品中测定总砷和三价无机砷的方法,为开展海藻制品中无机砷的监测和食品安全风险评估提供准确的检测方法。采用湿法消解和微波消解为测定总砷的前处理方式,9m ol/L盐酸浸泡后乙酸丁酯萃取和纯水反萃取作为海藻制品中三价无机砷的提取方式,分别利用塞曼扣背景和氘灯扣背景的石墨炉原子吸收光谱法测定总砷和三价无机砷。塞曼扣背景测定砷的线性范围为3.0—60μg/L,定量限(LOQ)为2.9μg/L,精密度为3.6%,回收率为90%—102%;氘灯扣背景测定砷的线性范围为4.0—80μg/L,定量限(LOQ)为3.6μg/L,精密度为4.1%,回收率为88%—109%。本法对三价无机砷的提取方法简便实用、提取效率高。原子吸收光谱法的两种背景校正方式测定总砷及三价无机砷的结果准确可靠。为基层实验室开展食品中总砷以及三价无机砷的测定提供实用、可靠的分析方法。     

广藿香挥发油提取工艺的优化选择

采用正交试验探讨了不同提取温度、提取剂用量、提取时间以及提取次数对广藿香中挥发油提取率的影响,最终确定了广藿香挥发油的最佳提取工艺,即采用5倍量的石油醚在40℃下浸提4次,提取时间为24h.     

Antidiabetic activity of Armillaria mellea polysaccharides: Joint ultrasonic and enzyme assisted extraction

Armillaria mellea polysaccharides (AMPs) were obtained by ultrasonic assisted extraction (U), enzyme assisted extraction (E) and ultrasonic-enzyme assisted extraction (UE), respectively. The yield of UE-AMPs (6.32 ± 0.14%) was 1.64 times higher than that of U-AMPs (3.86 ± 0.11%) and 1.21 times higher than that of E-AMPs (5.21 ± 0.09%); meanwhile, the highest total sugar content and the lowest protein content were found in UE-AMPs. AMPs obtained from the three extraction methods had the same monosaccharide composition but in different proportions, allowing UE-AMPs to have the most potent antioxidant activity. The antidiabetic activity of UE-AMPs was investigated in streptozotocin (STZ)-induced diabetic mice. UE-AMPs, when given by gavage, greatly prevented weight loss, increased water intake, and considerably decreased blood glucose levels in diabetic mice, which were dose-dependent (P < 0.05). In addition, UE-AMPs also had a positive effect on the reduction of lipid levels in the blood, oxidative damage and liver function impairment. The pathological observation by hematoxylin-eosin staining (HE) revealed that UE-AMPs protected the organs of mice from diabetic complications (liver disease and nephropathy). Hence, our findings demonstrate that UE-AMPs are a suitable choice for improving diabetes and its complications and have great application prospects in the fields of natural medicine and functional food.     

响应面法优化提取-原子吸收光谱法测定茶叶中的铅

研究超声辅助提取（UAE）快速测定茶叶铅。采用Plackett-Burman设计和响应面法得优化提取条件：200mg样品中加入HNO3∶H2O2（1∶1,V/V）5mL浸泡6min、78℃超声8.4min。对GBW 10016茶叶,该法测定值与标准值符合,加标回收率为96.0%—102.2%,检出限0.041μg.L-1,重复测定的RSD为6.3%。该法测定45个茶鲜叶和10种商品茶,铅含量（干基）在0.39—1.22mg.kg-1之间,与湿法消解（WAD）结果无显著差异。     

Ultrasound-assisted extraction of highly nutritious date sugar from date palm (Phoenix dactylifera) fruit powder: Parametric optimization and kinetic modeling

Alternative sweeteners to white sugar with a lower calorie content and glycemic index obtained through date palm fruits is of great interest to the food industry. In this study, ultrasound-assisted extraction of nutritive sugar from date fruit powder was investigated through Box-Behnken design. A maximum total sugar content (TSC) of 812 mg glucose eq./g of DFP was obtained with a sugar extraction yield (SEY) of 81.40 ± 0.27 % under the following optimal extraction conditions: extraction temperature of 60 °C, extraction time of 30 min, and L/S ratio of 7.6 mL/g. Various modern techniques were used to characterize the obtained extracts and associated residues. The results showed that the extract contained fructose, glucose, and sucrose and had good thermal stability. Furthermore, SEM and TSC analysis revealed that ultrasonic treatment of the biomass improved mass transfer diffusion due to acoustic or ultrasonic cavitation, resulting in a higher sugar yield.     

Improving soaking efficiency of soybeans through sweeping frequency ultrasound assisted by parameters optimization

Soybean soaking is important to the processing of bean products, however, restricted by the long soaking time. Herein, the soybean soaking was assisted by 60 kHz sweeping frequency ultrasound (SFU). Shortening mechanism of soaking time and physicochemical properties of soybeans were analyzed. Results showed that soaking temperature of 37 °C, ultrasonic power of 60% (144 W), and soaking time of 214 min were optimum SFU-assisted parameters. The soaking time was reduced by 45.13%, and soluble protein content increased by 14.27% after SFU. Based on analysis of acoustic signals, the maximum voltage amplitude of SFU increased with the increment of oscillation periods of cavitation bubbles, which enlarged the intercellular space and size of soybean, and cell membrane permeability was enhanced by 4.37%. Unpleasant beany flavor compounds were reduced by 16.37%–47.6%. Therefore, SFU could significantly improve the soaking efficiency of soybeans and provide a theoretical basis for the processing enterprises of soybean products.     

不同种皮颜色花生糖含量近红外模型的构建

花生籽仁中的糖含量是影响食味品质的重要指标,建立快速测定糖含量的方法可有效提高食用型花生的检测效率。样品外观颜色是影响近红外分析的重要因素之一,按样品外观颜色分类定标（校正）更有利于提高模型的预测性能。研究选择不同糖含量的花生种质332个,采用色差仪将花生种质按种皮颜色分成黑紫色、红色和粉色三大类。采用3,5-二硝基水杨酸法、蒽酮乙酸乙酯法、蔗糖酶法分别测定籽粒中的总糖、可溶性糖及蔗糖含量。总糖含量分别在6.42%～39.53%（黑紫色籽粒）、9.66%～39.71%（红色籽粒）和8.52%～38.84%（粉色籽粒）之间;可溶性糖含量分别在2.4%～14.32%（黑紫色籽粒）、2.94%～13.75%（红色籽粒）和2.19%～14.53%（粉色籽粒）之间;蔗糖含量分别在0.92%～7.53%（黑紫色籽粒）、1.05%～7.23%（红色籽粒）和0.95%～7.99%（粉色籽粒）之间,变异系数均在33%以上。采用瑞典波通DA7250型近红外分析仪（950～1 650 nm）采集籽粒的近红外光谱值,选用基于全波段的偏最小二乘回归法（PLSR）,通过对比单一和复合预处理方法,对比模型的相关系数和误差确定最佳预测模型。分别建立了黑紫色、红色、粉色花生籽仁的总糖含量、可溶性糖含量和蔗糖含量的近红外光谱定标模型,共计9个模型,预测相关系数（R_c）在0.883～0.925之间,预测均方根误差（RMSEC）在0.370～1.988之间。对总糖含量所建立的模型中,粉色种皮花生的预测相关系数R_c可达0.925,RMSEC为1.705;对可溶性糖含量所建模型中,黑紫色种皮花生的预测相关系数R_c可达0.921,RMSEC为0.667;对蔗糖含量所建的模型中,粉色种皮花生的预测相关系数R_c可达0.914,RMSEC为0.435。并分别用15份种质进行外部验证,9个模型的预测相关系数R_p在0.892～0.967之间,预测均方根误差RMSEP在0.327～2.177之间。本研究建立的近红外光谱模型可同步、快速地检测花生籽粒中的多种糖含量,为高糖含量的鲜食花生育种提供了技术支持。     

The quality of high pressure-induced and heat-induced yuzu marmalade

Yuzu is a typical Japanese citrus with a desirable smell. The objectives of this study are to establish a process for pressure-induced marmalade (without both heating or the addition of pectin) and compare it with heat-induced marmalade. Sliced peel (flavedo) was soaked in 2% citric acid solution (pH 2.0). Albedo, endocarp and juice sacs were homogenized with 0.3% citric acid solution (pH 2.5). After soaking for 24 h, these were mixed and 50% or 60% sucrose of the total weight was added, then pressurized at 500 MPa or boiled (process A). Process B: all processing was done at pH 2.7. Peel of high pressure-induced marmalade maintained a natural color. Flavedo in heat-induced marmalade was softer than that of pressure-induced marmalade. There was no difference in viscosity between heat-induced and high pressure-induced marmalade. High pressure-induced marmalade with 50% sugar was preferred by a sensory test because fresh flavor and color were maintained.