欧盟评估维生素D2蘑菇粉作为新型食品的安全性

2020年1月21日应欧盟委员会的要求,欧盟食品安全局(EFSA)营养、新型食品和食品过敏原小组(NDA)就维生素D2蘑菇粉(vitamin D2 mushroom powdr)作为一种新型食品的安全性发布意见。     

微波萃取-反相高效液相色谱法测定钙片中维生素D3的含量

目的建立微波萃取-反相高效液相色谱法(RP-HPLC)测定钙片中维生素D3含量的分析方法。方法以甲醇为萃取溶剂,微波萃取保健食品中的维生素D3。甲醇为流动相,检测波长264 nm,流速1 ml/min,经C18反相高效液相色谱柱(4.6 mm×150 mm,5μm)分离分析,测定钙片中维生素D3的含量。结果采用本方法的线性范围为0~4μg/L(r=0.999 8),检出限为0.02μg/L,回收率为98.8%~100.0%,RSD为0.4%(n=9)。结论本文建立的方法具有操作简单、快速,准确度高,稳定性好等优点,适用于实验室测定钙片中维生素D3的含量。     

欧盟评估维生素D2蘑菇粉作为新型食品的安全性

2020年1月21日,应欧盟委员会的要求,欧盟食品安全局(EFSA)营养、新型食品和食品过敏原小组(NDA)就维生素D2蘑菇粉(vitamin D2 mushroom powder)作为一种新型食品的安全性发布意见。申请人拟将这种新型食品用于各种食品和饮料中,包括特殊医疗用途的食品和食品补充剂。目标人群是普通人群,但食品补充剂的目标人群是7个月以上的人群。经过评估,在拟议的使用条件下,这种新型食品是安全的。     

MoS2/g-C3N4复合纳米催化剂光催化深度处理造纸废水研究

本研究采用N-甲基吡咯烷酮复合MoS₂与g-C₃N₄,制得MoS₂/g-C₃N₄复合纳米催化剂。采用X射线衍射仪（XRD）、X射线光电子能谱仪（XPS）、光致发光光谱仪（PL）和扫描电子显微镜（SEM）对复合纳米催化剂进行表征,并利用MoS₂/g-C₃N₄复合纳米催化剂光催化深度处理造纸废水。结果表明,少量MoS₂与g-C₃N₄复合可提高复合光催化剂的光催化活性,反应时间180 min、pH值5、1.5% MoS₂/g-C₃N₄复合纳米催化剂投加量为2 g/L时,对造纸废水的COD_Cr去除率和色度去除率最高,分别达到63.4%和83.2%。MoS₂/g-C₃N₄的光催化活性有所增强是由于MoS₂与g-C₃N₄的能带结构匹配,降低了光生电子-空穴的复合几率,从而提高了催化剂的光催化活性。     

桑枝SCMP浆H2O2漂白工艺的优化

通过单因素实验探讨漂剂用量、碱比、漂白温度等7个因素对桑枝SCMP浆H_2O_2漂白的影响;采用MODDE分析软件中Plackett-Burman实验设计方案对7个因素进行显著性筛选评价,获得温度、时间和H_2O_2用量为影响显著的因素;运用MODDE软件对桑枝SCMP浆H_2O_2漂白的3个主要影响因素及各自的4个水平进行RSM实验设计及分析。结合单因素实验和MODDE软件获得最佳漂白工艺:温度90℃,时间104 min,浆浓15%,碱比0.7,H_2O_2用量8%,Na_2SiO_3用量0.3%,MgSO_4用量0.10%。     

绿色环保型H2O2稳定剂的应用研究

将H_2O_2稳定剂 (PHS) 和其他螯合剂用于对钙离子的螯合,结果显示,PHS在碱性条件下螯合钙离子的能力达到580 mg/g,且有进一步的增强。将PHS和传统螯合剂EDTA在最佳H_2O_2用量条件下分别用于CTMP浆一段漂白和二段漂白中,考察其对漂终浆料白度和残液中H_2O_2残余量的影响。结果表明,在CTMP浆一段漂白时,PHS和EDTA将浆料的白度由空白浆的57. 0%分别提高至58. 6%和57. 9%,残余H_2O_2含量由23. 2%分别提高至29. 7%和28. 6%;而在CTMP浆二段漂白时,PHS和EDTA能将浆料白度由空白浆的71. 9%分别提高至78. 0%和74. 0%,残余H_2O_2含量由2. 1%分别提高至38. 5%和7. 3%;使用PHS作为H_2O_2稳定剂在达到相同浆料白度时,H_2O_2的用量减少11. 0%,漂白成本降低约16元/t浆。     

TPA/TiO2-SiO2的制备及在地沟油预酯化工艺中的应用

以钛酸丁酯和硅酸乙酯为原料制备TiO₂-SiO₂,以磷钨酸(TPA)为活性组分,通过浸渍法制备TPA/TiO₂-SiO₂,用于高酸值地沟油中的预酯化研究。TPA/TiO₂-SiO₂表征结果表明,TPA/TiO₂-SiO₂具有较好的热稳定性、内部存在孔结构、具有较大的比表面积。以地沟油的酸值变化率为指标,通过单因素试验和正交试验,确定最佳工艺条件：TPA负载量为40%,载体焙烧温度为600 ℃,催化剂用量为5 wt%,反应时间为5 h,醇油质量比为0.8:1。在此条件下,FFAs的转化率可以达到98%。     

超临界CO2萃取美商陆籽油的研究

采用单因素试验,研究了超临界CO2流体萃取美商陆籽油的萃取时间、投料量、萃取压力及萃取温度对美商陆籽油萃取率的影响。试验表明,最佳萃取时间为4 h;最佳投料量为200 g;最佳萃取压力为25MPa;最佳萃取温度为45℃。索氏提取籽油测得萃取率为12.93%。气相色谱分析共测出脂肪酸成分7种,饱和脂肪酸相对质量分数为13.85%。不饱和脂肪酸相对质量分数为85.79%,其中油酸的质量分数为46.34%,亚油酸的为36.56%。高效液相色谱分析测得维生素A的含量为0.369 mg/100 g,维生素E的总含量为22.0 mg/100 g。     

Ni/γ-AlO2O3油脂加氢催化剂的制备研究

以γ-AlO₂O₃为载体,硝酸镧为助剂,采用沉淀法制备了负载型Ni/γ-γ-AlO₂O₃油脂加氢催化剂。考察了中和反应温度、中和反应时间、搅拌速度和老化时间对催化剂活性的影响,得到催化剂最佳制备条件为：中和反应温度85℃,中和反应时间60 min,搅拌速度300 r/min,老化时间1.5 h。分别采用X射线衍射、物理吸附和激光粒度测定对自制催化剂和两种进口催化剂进行了表征,结果表明自制催化剂的比表面积和粒度分布与进口催化剂接近,孔容、孔径较进口催化剂大得多。采用棕榈油加氢反应对比了3种催化剂的加氢性能,结果显示自制催化剂活性优于进口催化剂。     

高得率竹浆漂白中乙醇对H2O2分解规律的影响

本研究采用气量法研究了乙醇介质抑制H₂O₂无效分解的机理和提高高得率竹浆漂白的效果。主要探讨了乙醇质量分数、反应温度等参数对分解反应速率常数（k）和反应活化能（Ea）的影响规律,并对比了乙醇介质对漂白高得率竹浆的白度、返黄值和机械强度的影响。结果表明,乙醇介质通过降低k值和Ea值可以有效抑制H₂O₂的无效分解;乙醇质量分数升高,抑制H₂O₂分解能力增强,质量分数50%的乙醇抑制效果较好;与水介质相比,高得率竹浆在50%乙醇-水介质中进行H₂O₂漂白,漂后浆白度提高了117.4%,返黄值下降了72.2%,纸张抗张指数提升了60.9%。     

The influence of latitude on the concentration of vitamin D3 and 25-hydroxy-vitamin D3 in Australian red meat

There is little information on the vitamin D content of Australian red meat or on the possible influence of latitude on this content. To determine the content of vitamin D₃ and 25-hydroxy-vitamin D₃ (25OHD₃), lamb and beef were analysed from 34° S with LC–IT-MS. To investigate the possible influence of latitude on vitamin D in meat, the lean meat and fat from five cuts of beef were analysed from 17° S and 41° S. Lamb contained 0.10 μg vitamin D₃/100 g and 0.20 μg 25OHD₃/100 g lean meat, while beef contained 0.12 μg vitamin D₃ and 0.27 μg 25OHD₃/100 g (lean meat). Latitude had no effect on the vitamin D₃ (P = 0.21) or 25OHD₃ (P = 0.29) content of lean beef, but fat from cattle in the 17° S latitude group contained significantly higher (P < 0.01) concentrations of vitamin D₃ than fat from the 41° S group of cattle.     

Vitamin D2 stability in milk during processing,packaging and storage

Stability of vitamin D2 in milk was determined in vitamin D2 fortified milk. Reverse phase high pressure liquid chromatography was used to determine the vitamin D₂ loss during processing, packaging and under light. The percentage losses during pasteurization, boiling and sterilization were demonstrated to be statistically insignificant. Milk was stored for seven days in both glass and plastic bottles under refrigerated temperature, non significant loss of vitamin D₂ was observed, whereas, when stored in polyethylene pouches significant loss was observed as vitamin D₂ decreased from 596.66 to 548.04 IU. This clearly indicated that vitamin D₂ was sorbed up by polyethylene material during storage resulting in its loss. Milk samples were stored for 32 h under three different light intensities (14,852,970 and 4455 lux). Non significant loss of vitamin D₂ was observed in glass packaging, whereas significant loss was observed in polyethylene pouches. In milk fortified with both calcium and vitamin D₂, non significant effect of calcium was observed on the loss of vitamin D₂.     

Ultraviolet irradiation: The generator of Vitamin D2 in edible mushrooms

Fresh Shiitake mushrooms (Lentinula edodes), Oyster mushrooms (Pleurotus ostreatus), Button mushrooms (Agaricus bisporus), and Abalone mushrooms (Pleurotus cystidus) were irradiated with Ultraviolet-A (UV-A; wavelength 315–400 nm), Ultraviolet-B (UV-B; wavelength 290–315 nm), and Ultraviolet-C (UV-C; wavelength 190–290 nm). Irradiation of each side of the mushrooms for 1 h, was found to be the optimum period of irradiation in this conversion. The conversions of ergosterol to vitamin D₂ under UV-A, UV-B, and UV-C were shown to be significantly different (p < 0.01). The highest vitamin D₂ content (184 ± 5.71 μg/g DM) was observed in Oyster mushrooms irradiated with UV-B at 35 °C and around 80% moisture. On the other hand, under the same conditions of irradiation, the lowest vitamin D₂ content (22.9 ± 2.68 μg/g DM) was observed in Button mushrooms.     

Sterol and vitamin D2 concentrations in cultivated and wild grown mushrooms: Effects of UV irradiation

Raw and processed mushroom samples including wild grown (chanterelles and king bolete) and cultivated samples (white and brown button, portabella, shiitake, oyster) were bought from the food market and analysed for sterols and vitamin D₂ contents. The different commercial mushrooms selected are abundant in almost every Swedish and European supermarket or outdoor market. Ergosterol was the most abundant sterol found in mushrooms present in somewhat higher concentrations in cultivated mushrooms (4.0-5.0 mg/g dry matter (d.m.)) than those found in wild mushrooms (1.7-3.5 mg/g d.m.). In addition, three closely related minor sterols, including ergosta-7,22-dienol, ergosta-5,7-dienol, and ergosta-7-enol were identified. Chanterelles and king bolete were found to be good sources of vitamin D₂ (0.7-2.2 μg/g d.m.) compared with cultivated mushrooms that had a low content (< 0.1 μg/g d.m.). Canned samples of Agaricus bisporus/white were slightly lower in ergosterol and vitamin D₂ compared to fresh samples. Irradiation with UV light in the A region (366 nm) only slightly affected ergosterol and vitamin D₂ content. In contrast, irradiation with UV light conducted in the C region (254 nm, 0-2 h, 20 cm distance) for fresh white button mushrooms and freeze-dried chanterelles resulted in nonsignificant decrease in ergosterol content, whereas vitamin D₂ increased up to 9-fold (Cantharellus tubaeformis) and 14-fold (A. bisporus/white), respectively.     

高峰淀粉酶活性对饮料中维生素B2测定结果的影响

目的 调查分析高峰淀粉酶来源和酶解参数对饮料中维生素B₂（核黄素-5''-磷酸钠来源）测定结果的影响。方法 按GB 5009.85—2016对受试样品中维生素B₂（核黄素-5''-磷酸钠来源）的含量进行检测,考察高峰淀粉酶及其工作条件对检测结果的影响。结果 不同来源的高峰淀粉酶对维生素B₂（核黄素-5''-磷酸钠来源）的实测结果有明显的影响,实测值与理论值最大相差10倍以上;前处理过程中建议选择酶解时间12 h,酶解pH值6.0~6.5。结论 国标方法检测饮料中维生素B₂（核黄素-5''-磷酸钠来源）时,预先检测高峰淀粉酶的酶解活性是十分必要的。     

国外食品安全监管体系的特点及对我国的启示

食品安全问题是一个复杂的社会问题,在社会经济发展中占据着十分重要的位置。监管是保障食品安全的关键手段之一,发达国家经过多年的发展和经验积累相对来说形成了一个较为成熟的食品安全监管体制。这些国家食品安全监管体系各有特点。为了更好地借鉴发达国家食品安全监管体系建构经验,本文对美国、欧盟、日本、加拿大等主要发达国家的食品安全监管体系进行了概述,以期为我国食品安全监管体系建设提供借鉴。      

中国食品安全监管中行政法的规制研究

当前各种安全问题食品在市场上频繁出现的事实,说明中国现有食品安全监管体制存在很多方面的问题。从行政法的维度对这些问题进行认真的分析,可以发现中国食品安全监管体制存在条块分割、缺乏统一的食品安全监管质量标准、追责力度不足等问题。有必要在现有的基础上对其进行相应的创新,通过建立统一协调垂直管理的高效行政管理体制、推行统一的强制性食品安全可追溯制度、建立食品安全监管的多元追责机制等路径,能使食品安全监管效得到实质性的提高。     

A novel nanosensor based on Pt:Co nanoalloy ionic liquid carbon paste electrode for voltammetric determination of vitamin B9 in food samples

In this work we describe a novel nanoalloy (Pt:Co) room temperature ionic liquid (RTIL) modified carbon paste electrode as a high sensitive sensor for voltammetric determination of vitamin B₉ in food samples. The sensor exhibits an enhanced effectiveness for the electro-oxidation of vitamin B₉ in aqueous solution. The oxidation peak potential for this matter at a surface of the ionic liquid (n-hexyl-3-methylimidazolium hexafluoro phosphate) Pt:Co carbon paste electrode (Pt:Co/IL/CPE) appeared at 685 mV that was about 110 mV lower than the oxidation peak potential at the surface of the traditional carbon paste electrode (CPE) under similar condition. The mechanism of the electro-oxidation process on the surface of the modified electrode was analyzed. Square wave voltammetry (SWV) was applied as a very sensitive electrochemical method for the determination of sub-micro-molar amounts of vitamin B₉. The linear response range and detection limit were found to be 1.0 × 10⁻⁷ to 5.0 × 10⁻⁴ M and 4.0 × 10⁻⁸ M, respectively. The prepared modified electrode shows several advantages such as simple preparation method, high stability, high sensitivity, and excellent catalytic activity, long-term stability and remarkable voltammetric reproducibility for eletrooxidation of vitamin B₉. The proposed sensor was successfully applied for the determination of vitamin B₉ in food samples.     

中国食品安全的刑法规制

中国食品安全监管存在四大问题,即食品安全法律体系太单薄、现行刑法对食品安全犯罪的规制存在明显缺陷、监管人员对食品安全犯罪的危害性认识不足、缺乏具有实际可操作性的监管失职人员问责制度,这些问题的存在导致近几年来食品安全问题频发。要解决这些问题,需要建立以刑法规制为主导的法律规制体系、统一各种危害食品安全犯罪的罪名、完善社会监督预防体系。     

The determination of vitamin D3 in bovine milk by liquid chromatography mass spectrometry

A renewed international interest in vitamin D status has revealed significant deficiencies in several populations, including Australia. Vitamin D exists in two forms, cholcalciferol (D₃) and ergocalciferol (D₂). The main source of vitamin D₃ is from exposure of 7-dehydrocholesterol present in the skin to UV irradiation. However, there is an absolute requirement for vitamin D through proper dietary intake if humans live in the absence of sunlight or exclusively indoors. Bovine milk is considered to be a good dietary source of vitamin D₃, even though the levels are quite low. This paper describes robust methods using liquid chromatography–linear ion trap mass spectrometry (LC–MSⁿ) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) to measure the levels of vitamin D₃ in fresh bovine milk (0.05 μg/100 ml), commercial (natural and fortified) milk samples (0.01–2 μg/100 ml) and a dairy based infant formula (8 μg/100 g), without the need for extensive clean-up procedures. The limits of quantification (LOQ) are 0.01 μg/100 ml and 0.02 μg/100 ml for LC–MSⁿ and LC–MS/MS, respectively. Recoveries of vitamin D₃ added to the samples prior to saponification were satisfactory (range 60–90%). 25-Hydroxyvitamin D₃ was not present in any of the samples analysed (LOQ = 0.01 μg/100 ml, recovery range 30–40%).