以橄榄油为模拟食品测定微波加热容器的总迁移量

本文以橄榄油为脂肪食品模拟物,对市售微波适用塑料容器中有害物质的总迁移量进行了测定。对照我国现行标准中正己烷模拟物的测定结果,发现以橄榄油为模拟物的方法测得样品合格率为20%,而以正己烷为模拟食品测得样品合格率为100%。说明我国现行的相关标准对评价微波加热容器的安全性还存在不足之处。     

塑料食品包装材料中总迁移量及特定迁移量的中欧检测方法比较

总迁移量和特定迁移量是评判接触食品塑料材料卫生安全性能的重要指标。本文主要综述了我国与欧盟在食品包装塑料材料的总迁移量和特定迁移量测量方法以及标准上的区别,并阐述了各自的优缺点。     

农用地膜总迁移量的研究

以农用PE材质地膜为研究对象,参照GB 31604. 8-2016,分别以4%乙酸(70℃,2h)、10%乙醇(70℃,2h)、4%乙酸(40℃,10d)、10%乙醇(40℃,10d)作为模拟条件对其总迁移量进行研究。结果表明,同一浸泡温度时间条件下总迁移量4%乙酸 10%乙醇,同一模拟液条件下总迁移量40℃10d 70℃2h。即农用PE地膜长期与酸性食品接触更容易迁移出非挥发性物质。     

一次性塑料餐饮具总迁移量的检测及行业现状

针对一次性塑料餐饮具样品卫生指标中的总迁移量项进行研究,共检测150个样品,涵盖该类产品从生产到消费使用终端的多个领域,涉及PP、PE、PS、PET多种使用材质,采用乙醇、乙酸、正己烷作为食品模拟物测定食品接触材料及制品的组分迁移情况,并对其中的不合格项进行深入分析.根据不合格项产生原因,提出针对性解决方案,以期从整体...     

食品包装材料中邻苯二甲酸酯类增塑剂迁移量的测定

建立了一种食品包装材料中邻苯二甲酸酯类(PAEs)增塑剂迁移量的检测方法。以正己烷为萃取溶剂对食品包装材料模拟液中17种PAEs进行提取,然后采用气相色谱-质谱联用法(GC-MS)进行检测。结果表明:17种PAEs的分离较好,方法检出限为0.14~0.30 mg/kg,线性范围0.5~8.0 mg/L,相关系数大于0.996,相对标准偏差(RSD)为2.2%~4.8%,回收率为95.0%~116.0%。该方法操作简便、准确、分离效果好,可同时检测食品包装材料中17种PAEs类增塑剂的迁移量。     

食品接触材料中正丁醇迁移量的测定

建立了食品接触材料中正丁醇迁移量的顶空-气相色谱质谱联用测定方法。采用水、4%(体积分数)乙酸水溶液、10%(体积分数)乙醇水溶液、50%(体积分数)乙醇水溶液、95%(体积分数)乙醇水溶液和橄榄油作为食品模拟物,不同类型食品接触材料在不同迁移条件下的进行迁移试验。浸泡液在顶空70℃下平衡40 min后进样,采用INNOWAX毛细管柱进行分离。在优化的条件下,橄榄油模拟液中正丁醇在0.01~0.5mg/kg范围内线性良好,曲线相关系数(r)为0.999 5,检出限为0.01 mg/kg,其他5种模拟液中正丁醇在0.01~0.5mg/L线性良好,r均大于0.999 5,检出限为0.01 mg/L。在3个添加水平下,平均回收率在90%~110%之间。方法简单、快速、灵敏,可满足食品接触材料中正丁醇迁移量的检测需求。     

中空纤维膨松特性测试时试样量的确定方法探讨

选用七孔中空纤维进行了不同试样量对膨松特性测试结果精度的影响试验 ,并对试验时确定取样量大小的方法进行了理论分析、探讨 ,得出了不同规格中空纤维膨松特性测试时确定合理取样量的方法。     

食品接触用一次性丁腈手套总迁移量的测定

从电商平台上选购7批次食品接触用一次性丁腈手套作为样品,按照GB 4806.11-2016和GB 31604.8-2016所述方法,分别以4％ 乙酸、20％ 乙醇、50％ 乙醇为模拟物,测定丁腈手套在不同迁移时间和迁移方式下的总迁移量.结果表明,在40℃、2h的条件下仅有2批次合格,合格率为28.6％,总迁移量随时间延...     

食品接触塑料袋中塑化剂迁移情况探究

为了探究塑料袋在盛放不同性质和不同温度的食品时,塑化剂向食品中的迁移情况,以GB/T 21911—2008《食品中邻苯二甲酸酯的测定》为主要参考依据,建立了14种邻苯二甲酸酯类塑化剂的气相色谱-质谱联用(GC-MS)分析方法。采用液液萃取和弗罗里硅土固相萃取柱净化的方法对样品进行前处理,然后用GC-MS测定,采用外标法定量。结果表明:在一定质量浓度范围内,标准溶液质量浓度和峰面积之间具有良好的线性关系(R~20.997 9),加标回收率在81.00%~108.17%之间;信噪比取3时,最低检出限小于0.015 mg/L,相对标准偏差在2.5%以内;塑化剂的迁移量随着温度的提高呈上升趋势,且其在油中的迁移量明显高于在水中。该方法灵敏度高,准确可靠,能够用于检测食品模拟液中塑化剂的迁移量。     

与食品接触材料填充法测量总迁移量不确定度

依照欧盟(英国标准)检测方法 BS EN1186:9-2002与食品接触材料——塑料部分——第九部分:填充法测量水性食品模拟液中总迁移量的方法,对分析样品进行预处理,建立总迁移量测量其所引入的不确定度数学模型。通过分析样品处理过程、测定过程中各种不确定度的来源,并量化计算各不确定分量,合成总不确定度。不确定度测试结果为:相对标准不确定度为0.41 mg/dm2,扩展不确定度为0.82mg/dm2(k=2)。     

水中总磷测定时水样预处理方法改进

对水中总磷消解方法进行对比研究,通过实验对各种消解方法在时间、安全性、简捷程度及回收率、准确率、精密度几方面进行比较,得出微波消解具有消解时间短、操作简便、安全性高等优点。     

Enhancement of Bioactive Phenols and Quality Values of Olive Oil by Recycling Olive Mill Waste Water

Mature ‘Chondrolia Chalkidikis’ olives were processed in an industrial olive oil mill equipped with a three‐phase decanter. Water was added to the decanter at a 1:2 water‐to‐paste ratio. Olive mill waste water (ΟΜWW) was used to replace the added water at a rate of 50 or 100%. Following the final separation, the obtained oil was used for chemical analysis and sensory evaluation. All oils had similar acidity, peroxide and Κ values. OMWW‐treated olive oils presented higher total phenolic content and higher antioxidant activity based on DPPH and oven tests, but lower chlorophyll and carotenoids content. However, there was no significant difference between the 50 and 100% replacement. The phenolic profile of the treated olive oils analyzed by quantitative ¹Η NMR revealed more than twofold oleocanthal and oleacein as well as oleuropein and ligstroside aglycone contents than in the control. Sensory evaluation of treated oils also showed an enhancement of fruity, bitter and pungent attributes compared to the control.     

Evolution of Oxidative Values during Kinetic Studies on Olive Oil Oxidation in the Rancimat Test

A comparative study was carried out in order to evaluate the kinetics of the formation of a number of primary and secondary oxidation products during oxidation of olive oil in the Rancimat test at 100–130 °C. There were good correlations between the Rancimat index (OSI) and stability indices (IP) measured in the Rancimat test with no significant differences in kinetic parameters calculated from them. Mean values of the temperature coefficient, Q₁₀ number, activation energy (E_a), frequency factor (A), and free energy of activation (ΔG⁺⁺) for olive oil oxidation were calculated to be ?3.44 × 10^?2°C^?1, 2.21, 98.91 kJ/mol, 12.17 × 10¹² h^?1, and 128.25 kJ/mol, respectively. Each unit change in E_a was accompanied by an average 1.43 × 10¹² change in A, indicating a higher contribution for factor A than for E_a to the olive oil stability. The E_a and A correlated well with the values of enthalpy and entropy, respectively. The values of OSI or IP could be described well by the ΔG⁺⁺ values. Kinetic data indicated that olive oil stability is more affected by the indigenous antioxidants than by the fatty acid composition.     

Effect of the Addition of Membrane Processed Olive Mill Waste Water (OMWW) to Extra Virgin Olive Oil

Modern membrane technologies are useful for enhancing the concentration of phenolic antioxidants in olive mill waste water (OMWW) to produce concentrates with valuable applications in functional foods. Three types of OMWW concentrates, each with different levels of solute concentration and purity, were obtained from a single OMWW batch and dissolved in two extra virgin olive oils to achieve saturated solutions. Three addition levels were considered. Accelerated aging testing of the oils was performed at 60 °C and the samples were analyzed after two, four, and 6 weeks of aging. D-optimal design was used to select the 26 experiments that allowed the evaluation of the influence of the different variables on oil stability. The addition of OMWW concentrates resulted in a significant increase in the Radical Scavenging Activity (RSA) of the olive oils. Under these mild experimental conditions, the moderate formation of fatty acid hydroperoxides was probably masked by interfering compounds.     

Water Addition During Oil Extraction Affects on Virgin Olive Oil Ethanol Content,Quality and Composition

Ethanol is the alcoholic precursor of fatty acid ethyl esters (FAEEs) in virgin olive oil (VOO). Because of its miscibility, water addition during oil extraction may affect oil ethanol content and then, the FAEEs synthesis during oil storage. In this work, the effect of water addition on VOO ethanol content and composition is studied. Water addition at two extraction systems (two and three phases) is compared and for vertical centrifuge, water addition at different temperatures is assayed. Ethanol content, quality parameters, and healthy components are determined in the oils. Results indicate three phase system gives oils with a 25% lower ethanol content than two phases. Ethanol reduction because of water addition is more important for three phases system (≈14%). For vertical centrifugation, ethanol is lowered as water dose and temperature increase. In general, water addition for any of the extraction steps analyzed reduces the oil ethanol concentration but other aspects such as fruity intensity and phenol content are also lowered. Practical applications: Virgin olive oil final ethanol content, and then its FAEEs concentration, does not only depend on the health and conservation status of olives, but also on the extraction system used and the amount of water added to the extraction process. The knowledge of the impact on ethanol content of water addition during oil extraction can be useful for olive oil legislators in order to keep the approved limits of FAEEs or to modify them. For oil producers, results can help to reduce the oil ethanol content and then FAEEs synthesis during virgin olive oil storage.     

油水分离试验及含油量测量方法的研究

首先进行油水混合试样的制备,采用纯机械搅拌方式的破乳,让油水充分混合,然后让油水混合液通过油水分离器进行分离,并对其进行取样,最后利用紫外分光光度计对样品中的含油量进行测量。通过对搅拌机选型、油水分离流程的设计以及含油量的测量方法进行详细的介绍,为以后实验室的油水分离试验提供了一定的参考。     

除水用过滤材料油水分离试验方法研究

对目前国内外除水用过滤材料油水分离试验方法及现状进行了简单介绍,对试验方法的不足进行了分析,并根据经验对今后此试验新方法研究方向阐述了自己的观点。并对过滤材料油水分离试验的行为和其工作原理进行了分析计算,推导出了过滤材料油水分离试验中过滤材料单位面积的平均不溶水含量的计算公式。     

基于预处理的水样检测结果分析

水样预处理过程中的不同处理方法或者说操作步骤对氨氮分析结果的影响有重要的影响,实验分析水样预处理方法对氨氮分析结果产生的影响,希望本实验的结果和分析能为实验操作人员提供一些有用的数据和经验,给广大实验操作者提供比较明确的数据和结论,以使操作人员能清晰判断要预处理与否并对水样进行合理的预处理操作。     

Influence of Water Deficit in Bioactive Compounds of Olive Paste and Oil Content

The main objective of this study was to evaluate the effect of different deficit irrigation treatments (control, regulated deficit irrigation [RDI]‐1, RDI‐2, and RDI‐3) on the phenolic profile of the olive paste and oil content. Irrigation treatments with more stress water led to a considerable increase in the phenolic compounds of olive paste, especially in oleuropein (60.24%), hydroxytyrosol (82%), tyrosol (195%), and verbascoside (223%) compared to control. A significant increase in the content of total flavonoids and phenolic acids was also observed for these samples. In virgin olive oils (VOO) elaborated from the most stressed olive trees (RDI‐2 and RDI‐3), a noticeable increase in phenolic substances with antioxidant properties (oleuropein, hydroxytyrosol, tyrosol, secoiridoid derivatives, and o‐vanillin) was observed. Consequently, water stress conditions improved antioxidant activity of VOO.