食用油脂中矿物油的定性检测方法研究

研究了皂化法、薄层色谱法及棒状薄层色谱-氢火焰离子化检测器(TLC-FID)法检测食用油脂中的矿物油。结果表明:皂化法简便、快捷,最低检测限可达0.5%,但不适用于本身含蜡质的食用油脂(如米糠油、玉米油及葵花油等);薄层色谱法(TLC)同样可对食用油脂中的矿物油进行定性检测,最低检测限可达到0.2%左右,但仍不适用于本身含蜡质的食用油脂;TLC-FID法克服了以上两种方法的缺陷,不仅适用于本身不含蜡质的食用油脂,还可对本身含蜡质的食用油脂进行矿物油的定性检测,不会出现误检,相比之下更具有优越性。     

食用油脂中矿物油污染检测的气相色谱法研究

食用油脂被矿物油污染的质量事故时有发生，在食用油脂中矿物油污染检测的气相色谱法中，采用依据色谱图的特征与标准样对照相结合的定性方法，以所检出矿物油的某一种组分作为标准物质，用校正值法计算样品中矿物油的总含量。     

食品中矿物油的快速测定方法探讨

矿物油系石油烃类产品,如柴油、润滑油、石蜡等,目前市场上一些不法商贩用矿物油加工生产饼干或将矿物油掺入食用油脂和大米中,严重危害公众健康。矿物油中加入的一些添加剂,如阻燃剂磷酸三甲苯酯类化合物,对人体具有相当大的毒性,严重的可引起神经性麻痹,为了加强食品卫生监督查处食品中掺假违法行为,保护消费利益,本对掺入食品中的矿物油检测方法进行了探讨,现报告如下。     

大米中矿化油的化学分析

矿物油是工业用油 ,属非食用油脂。矿物油中含有重金属、苯并芘、长碳链烷烃、芳香烃等有害物质 ,食用了受矿物油污染的食品 ,可能导致急性和慢性中毒、严重腹泻、昏迷等症状 ,并可能危及人的神经系统。近年来 ,一些不法商贩为了谋取暴利、以次充好 ,用矿物油对大米进行上光处理 ,以工业基础油、白色油、石蜡油等矿物油为原料 ,使消费者的健康受到损害。为此 ,国家有关部门联合下文要求各地卫生、质量技术监督部门严厉查处。国家在大米标准和粮食卫生标准中均未对大米中矿物油的检测方法进行规定 ,我们通常采用感官检验、物理检验 (荧光法 )…     

示踪剂技术用于废弃食用油脂快速检测与鉴别

建立荧光分光光度法和高效液相色谱-荧光检测法快速测定废弃食用油脂中示踪剂罗丹明B的方法。将添加了示踪剂罗丹明B的油样用无水乙醇提取后,分别采用荧光分光光度计和高效液相色谱-荧光检测器进行检测。结果表明,采用两种方法检测时,罗丹明B在0.5μg/L~30μg/L浓度范围内均呈良好的线性关系;检出限均为1μg/kg;在10、50、100μg/kg添加水平时,均能有效测定出示踪剂含量,两种方法均适用于食用油中非法添加废弃食用油脂的确证。本研究建立的基于示踪技术的废弃食用油脂快速检测手段和方法,可有效防止废弃食用油脂回流餐桌,确保我国食用油的安全使用,同时也为废弃食用油脂的监管提供新的思路与依据。     

涂油大米中矿物油的定性分析

为检测大米中是否掺有矿物油,利用植物油脂能够与KOH发生皂化反应,而矿物油不能与碱类物质发生反应,对大米中是否涂有矿物油进行了定性研究。结果表明,涂有矿物油的大米的粗脂肪在皂化完全加入沸水后,皂化瓶内壁的水有明显挂壁现象,同时产生混浊。这种方法可以快速、准确的对大米中是否涂有矿物油进行定性检测。     

餐饮业废弃油脂鉴别检测方法研究进展

餐饮业废弃油脂是我国目前食品安全非常关注的问题之一。对目前餐饮业废弃油脂的鉴别和检测方法进行了综述,并提出了试纸法、电导率检测法、红外光谱法、近红外光谱法、核磁共振检测法、电子鼻检测方法可作为今后餐饮业废弃油脂的检测技术研究与开发方向。     

食用植物油中矿物油污染物的分析进展

矿物油是C_(10)~C_(50)烃类化合物的总称,包括直链、支链和环状烷烃以及烷基取代芳烃两大类,化学成分复杂。食用植物油中普遍存在矿物油污染,含量达到1~1 000 mg/kg,矿物油污染来源广泛,涉及原料的采收、运输、加工和油脂的精炼、包装与储存等过程。植物油中干扰矿物油分析的成分较多,如甘油三酯、奇数碳正构烷烃、角鲨烯、甾烯、胡萝卜素等,需要采用适当方法排除。由于矿物油组成复杂,目前常用具有等碳响应的氢火焰离子化检测器分析含量,其中液相色谱-气相色谱联用是测定矿物油的理想技术。考虑到普及性问题,一些实验室开发了固相萃取结合大体积进样气相色谱法。综述了国内外近十年来食用植物油中矿物油的分析方法,以期为我国油脂及其相关产品中矿物油的检测工作提供参考。     

食用油中掺入非食用油的鉴别

较系统地介绍了食用植物油中掺入矿物油、桐油、大麻籽油、蓖麻油、巴豆油、青油、亚麻仁油等7种非食用油、矿物油的检测方法，简便易行，对食用植物油中掺伪成分的检测具有一定的参考作用。     

低场核磁共振技术在食用油脂掺假检测中的应用进展

对低场核磁共振技术在食用油脂掺假检测中的应用进展进行了研究,介绍了低场核磁共振技术的基本原理,归纳了该技术在食用油脂掺假检测中的应用现状,并对其未来在食用油脂掺假检测中的应用进行了展望。     

生物技术在制浆造纸中的应用与研究进展

介绍了生物技术在制浆造纸工业的应用与研究进展，包括生物制浆、生物漂白、生物脱墨及造纸过程中的生物技术等。     

2018年深圳市售蔬菜和鸡蛋中氟虫腈及其代谢物的检测分析

目的 建立超高效液相色谱-串联质谱法同时测定蔬菜和鸡蛋中氟虫腈及其代谢物(氟甲腈、氟虫腈砜和氟虫腈亚砜), 并对深圳市售的蔬菜和鸡蛋中氟虫腈及其代谢物残留状况进行抽样检测。方法 采用QuEChERS前处理方法, 以C18色谱柱为分离柱, 以乙腈和10 mmol甲酸+6 mmol甲酸铵水溶液为流动相进行梯度洗脱, 用超高效液相色谱-串联质谱(ultra performance liquid chromatography-mass spectrometry/mass spectrometry, UPLC-MS/MS), 电喷雾电离(electrospray ionization, ESI), 多反应监测(multiple reaction monitoring, MRM)模式检测, 外标法同时定量测定氟虫腈及其代谢物。结果 方法的线性范围为0.1~2.0 μg/L, 线性相关系数均大于0.9994, 检出限0.0005 mg/kg, 定量限0.001 mg/kg; 蔬菜中3个水平的平均加标回收率88.0%~101.2%, 相对标准偏差(relative standard deviation, RSD)均小于8.5%; 鸡蛋中3个水平的平均加标回收率86.1%~104.8%, 相对标准偏差(RSD)均小于9.2%。结论 该方法具有操作简单、干扰少、快速、准确可靠等特点, 可适用于蔬菜鸡蛋中氟虫腈及其代谢物的检测。     

Differences in content and composition of free lipids and carotenoids in flour of spring and winter wheat cultivated in Poland

The work presents the content and composition of free lipids and carotenoids in spring and winter classes of wheat flour. It discusses genetical and physiological aspects of their synthesis and accumulation in wheat kernels and also indicates how methodological differences explain differences in results presented in the literature. It has been reported that spring wheat flours are richer in free lipids, especially in the non-polar fraction. The content of glycolipids ranged from 134 to 215 mg/100 g flour and was more stable within the winter wheat class. The percentages of the two main fractions, namely DGDG and MGDG, were similar in both wheat classes and reached ca. 77%. Phospholipids constituted the smallest fraction of the flour free lipids in both wheat classes; however, spring wheat flours were richer in these compounds, which is likely associated with a greater content of spherosomes in the endosperm of this wheat class. The free lipids of spring wheat flour contained more oleic and slightly less linoleic and linolenic acids. Spring wheat flour was also richer in carotenoids, although there were varieties in both classes that deviated from this. The main carotenoid was lutein, whose total percentage in the form of different isomers ranged from 71.3% to 83.3% and was slightly lower for spring wheat flour. Lutein, in the form of a trans-isomer, constituted about 62% and 70% of all carotenoids in spring and winter wheat flours, respectively.     

Influence of ouabain of electrolyte and water transport in the rabbit ileum and colon in vitro and in vivo

We studied the influence of the Na⁺-K⁺ pump inhibitor ouabain on water and electrolyte transport in the rabbit distal ileum and proximal colon in vitro and in vivo. Under in vitro conditions, ouabain markedly reduced the absorption of water, sodium, chloride and bicarbonate, and reduced potassium secretion in both the ileum and the colon. In vivo results were similar but less marked than those obtained in vitro, with significant differences only at the level of the distal ileum.     

Determination of nitrite and nitrate in some horticultural and meat products and in samples of soil

This study of quantitative determination of nitrite and nitrate contents is based on spectrophotometric measurement of the red colour formed when sulphanilic acid is diazotised by the nitrite to be determined and coupled to 1-naphthylamine-7-sulphonic acid (Cleve's acid 1-7). Nitrate is first reduced to nitrite in a cadmium reducing column. Good results have been obtained with some horticultural and meat products and samples of soil.     

Advantages and limitations of in vitro and in vivo methods of iron and zinc bioavailability evaluation in the assessment of biofortification program effectiveness

ABSTRACT

Biofortification aims to improve the micronutrient concentration of staple food crops through the best practices of breeding and modern biotechnology. However, increased zinc and iron concentrations in food crops may not always translate into proportional increases in absorbed zinc (Zn) and iron (Fe). Therefore, assessing iron and zinc bioavailability in biofortified crops is imperative to evaluate the efficacy of breeding programs. This review aimed to investigate the advantages and limitations of in vitro and in vivo methods of iron and zinc bioavailability evaluation in the assessment of biofortification program effectiveness. In vitro, animal and isotopic human studies have shown high iron and zinc bioavailability in biofortified staple food crops. Human studies provide direct knowledge regarding the effectiveness of biofortification, however, human studies are time consuming and are more expensive than in vitro and animal studies. Moreover, in vitro studies may be a useful preliminary screening method to identify promising plant cultivars, however, these studies cannot provide data that are directly applicable to humans. None of these methods provides complete information regarding mineral bioavailability, thus, a combination of these methods should be the most appropriate strategy to investigate the effectiveness of zinc and iron biofortification programs.     

鸡卵类黏蛋白过敏原性的在体与离体实验

通过观察卵类黏蛋白引起的豚鼠过敏性休克以及对致敏豚鼠离体肠平滑肌过敏性收缩反应（Schultz- Dale反应）的影响,研究鸡卵类黏蛋白的过敏原性,并初步建立其过敏实验的动物模型。结果显示：1）在实验 观察剂量下,1 mg/mL卵清白蛋白组豚鼠100%出现过敏性休克并死亡,全身性过敏反应呈极强阳性（4 分）; 卵类黏蛋白组豚鼠的反应与卵白蛋白组相似（P＞0.05）,大部分动物出现死亡,全身性过敏反应100%呈阳性 （2.04～3.68 分）;不同剂量的卵类黏蛋白引起的豚鼠全身过敏反应呈现出剂量依赖性,当致敏剂量为4 mg/mL 时,全身性过敏反应评分为3.68。2）卵类黏蛋白对Schultz-Dale反应的影响也与卵清白蛋白相似,使致敏的肠平滑 肌收缩活动明显加强;以2 mg/mL致敏时,豚鼠离体肠收缩力改变率最高,为538.5%。3）不同致敏剂量卵类黏蛋 白组豚鼠血清免疫球蛋白（immunoglobulin,Ig）G水平较对照组明显升高,且呈剂量依赖性。由此建立的卵类黏 蛋白在体与离体过敏实验的动物模型可用以检测卵类黏蛋白过敏原及评价其过敏原的消减效果。     

Distribution and characteristics of Aeromonas in food and drinking water in Denmark

A total of 970 Danish commercial foods and drinking water samples were examined for the presence of motile Aeromonas spp. With a detection limit of 10²/g the frequent prevalence in raw foods was confirmed. Aeromonas occurred in 7% of 779 samples of prepared foods; most frequently in whipped cream from ice cream parlors (28%) and mayonnaise salads (10%) with numbers occasionally exceeding 10⁵/g. The prevalence in drinking water was 28% with a detection limit of 1/100 ml. A. hydrophila was the dominating species in both food and water. Hemolysin production was demonstrated in 37% of the 51 isolates tested with 10% having high titers.     

果蔬制品中链格孢霉毒素检测与控制研究进展

链格孢霉属(Alternaria species)是链格孢霉毒素这种次级代谢产物的已知生产者。链格孢霉毒素具有明显的毒理学潜力,食用被其污染的果蔬和粮食产品会对消费者的健康造成威胁。果蔬营养丰富、含水量高,更易于被链格孢霉毒素感染,因此建立高效、简单、快速的检测技术和实现该毒素的高效控制一直是当今果蔬领域研究的热点。本文总结和分析了链格孢霉毒素常见的检测技术和控制方法,以期为链格孢霉毒素的快速检测和果蔬类食品安全控制与风险评估等提供参考。     

葡萄酒及软木塞中TCA的检测分析方法研究现状及应用前景

软木塞污染已经成为葡萄酒行业最为严重的问题之一,而导致软木塞和葡萄酒污染的最主要物质之一就是TCA。本文主要介绍葡萄酒和软木塞中TCA 的检测方法和萃取浓缩方法,同时也对TCA 检测的应用前景和发展趋势进行了展望。