涂油大米中矿物油检测的改进方法

利用整粒大米与KOH溶液进行皂化反应,对大米中是否涂有矿物油进行了定性研究。结果表明：整粒大米在皂化完成后加入沸水,无矿物油的样品皂化液澄清透明,皂化瓶内壁无挂壁现象;添加了矿物油的样品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检测分析。     

掺矿物油大米的定性分析方法研究

采用皂化法、薄层色谱法以及红外光谱法对大米上是否涂抹液体石蜡的定性分析方法进行了研究。研究结果表明:采用索氏抽提法用乙醚从整粒大米中提取1g左右油脂,然后将油脂与氢氧化钾在体积分数95%的乙醇溶液中完全皂化,加入沸水后若溶液呈浑浊状态,则表明该种大米涂抹了石蜡;若透明,则表明没有涂石蜡。采用整粒米(50g)按上述方法也可以直接定性分析液体石蜡的存在。薄层色谱法可以有效地分析液体石蜡的存在。但是,红外光谱法则不能有效地鉴别出大米上是否含有液体石蜡。     

大米中矿物油的薄层色谱定性分析

采用薄层色谱法对大米中矿物油的定性分析方法进行了研究。样品以石油醚快速提取并浓缩，点样于GF254硅胶板，经石油醚－乙醚混合溶剂展开后，于波长254nm紫外灯下观察紫色斑点的比移值（Rf),并结合对照品进行定性分析。结果表明，该方法简便快捷、专属性强、灵敏度高（最低检出含量10mg/Kg)，可用于大米中矿物油的快速检测。     

红外光谱法测定涂油大米中的矿物油

本文主要讨论利用傅立叶变换红外光谱仪对涂有矿物油的大米进行定性鉴别的方法和测试步骤,实际分析中具有用量小、快速、准确度的特点。适用于对大米、饼干、瓜子和食用油中是否掺加工业矿物油的鉴定。     

涂油米线中矿物油的红外光谱法测定

利用傅里叶变换红外光谱仪,对涂有矿物油和过期植物油的大米所加工制成的米线进行了油脂的萃取和红外光谱鉴别试验,此检验方法简便实用,结果准确。     

涂油大米的红外光谱鉴定

论述了利用红外光谱对涂有和掺有矿物的大米进行定性鉴别的方法和测试步骤,实际分析中具有用量小、准确度高的特点。适用于对大米、饼干、瓜子和食用油中是否掺加工业矿物油的鉴定。     

食品中矿物油的测定

根据矿物油脂在荧光灯下有荧光反应和不能皂化的特性 ,探讨了食品中矿物油的提取、定性和定量测定的化学方法。该方法快速、简便。     

涂植物油大米涂油量测定方法研究

研究了涂大豆油、玉米胚油或高芥酸菜籽油大米涂油量的测定方法.选择无水乙醚淋洗法作为大米表面所涂植物油的前处理方法,通过正交试验,确定溶剂种类、用量和试样量等.以所淋出油脂中亚麻酸、亚油酸或芥酸含量为依据,根据大米中油脂的淋出率,确定此3种脂肪酸之一与大豆油、玉米胚油或高芥酸菜籽油相对应的脂肪酸的比例系数,由系数计算出大米涂油量.     

大米中矿物油的化学分析

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.     

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。     

Selected Quality and Shelf Life of Eggs Coated with Mineral Oil with Different Viscosities

ABSTRACT:  Selected quality and shelf life of eggs coated with mineral oil having 6 different viscosities (7, 11, 14, 18, 22, and 26 cP) were evaluated during 5 wk of storage at 25 °C. As the storage time increased, weight loss and albumen pH increased whereas Haugh unit and yolk index values decreased. After 5 wk of storage, eggs coated with 11, 14, 18, 22, or 26 cP oil possessed better quality than the control noncoated eggs and eggs coated with 7 cP oil. Oil coating, irrespective of viscosities, did not improve the emulsion capacity. There was an observable trend that coating with 26 cP oil was more effective in preventing weight loss and in maintaining the Haugh unit of eggs compared with coating with other viscosities of mineral oil. Based on the Haugh unit, the grade of noncoated eggs changed from "AA" at 0 wk to "C" after 3 wk whereas that of 26 cP oil-coated eggs from "AA" at 0 wk to "A" at 3 wk and "B" at 5 wk of storage. Coating with 26 cP oil reduced the weight loss of eggs by more than 10 times (0.85% compared with 8.78%) and extended the shelf life of eggs by at least 3 more weeks compared with the noncoated eggs.     

酶催化浸出米糠油的研究

采用正交试验,对果胶酶和纤维素酶催化浸出米糠油条件进行了研究。结果表明:酶催化浸出米糠油最佳工艺为:先用果胶酶和纤维素酶酶解处理,料液比(W/V)比1:5,果胶酶用量1.5%,纤维素酶用量2.0%,pH5.0,酶解温度50℃,水解5h,再用正己烷浸提米糠油。经过纤维素酶和果胶酶酶解处理后米糠油提取率比单独溶剂浸提法提高了31.9%。     

Effects of Rice Batter on Oil Uptake and Sensory Quality of Coated Fried Okra

ABSTRACT: Okra was coated and deep-fat fried with batters of flour sources including rice flour, a mixture of rice flour and small amounts of pregelatinized rice flour (PGRF), and, as a control, traditional wheat flour. The addition of PGRF, up to 8%, enhanced batter viscosity and the coating properties of the rice batter. Oil uptake of the fried batter decreased with the addition of up to 5% PGRF. Rice flour fried batters, with and without PGRF, were found to absorb substantially lower oil, by as much as 51 %, compared with the wheat batter. The fried okra coated with the rice batter containing 5% PGRF, when evaluated for sensory properties on appearance and surface attributes, was found to be superior or equal to those with the wheat batter and rice batter without PGRF. Particularly, its golden brown color is considered more desirable than the lighter yellow color of the other 2 entities. Similarly, most of its 1st-bite and after-chew properties were slightly better and were in the normal range of commercially available products. Specifically, its distinctive crispiness is considered a positive attribute, whereas its slightly higher tooth packing properties, while remaining in the range of commercial products, may be noticeable to some consumers.     

用米糠油制取生物柴油

论述了用米糠油为原较,甲醇作酯化剂,在催化剂的作用下制取生物柴油的方法。     

食用植物油掺入矿物油的鉴别

重点叙述食用植物油掺（混）入矿物油食用后对人体的危害,所引发的食物中毒案例以及对矿物油的鉴别检验方法。     

基于电导率的地沟油快速定性与半定量分析

以食用油和地沟油为试材,建立基于电导率的地沟油定性与半定量检测方法。探讨油脂种类、温度、振荡时间、水油比对测定结果的影响,确定检测条件,并测定各类地沟油和食用油的萃取水相电导率,并建立食用油与处理后地沟油掺杂定量模型并对模型进行验证。结果表明检测条件为在室温条件下水油比4:1(mL/g)、振荡混合30s、静置分层10min,在此条件下,测得毛地沟油水相电导率为30.15～130.80μS/cm,处理后地沟油水相电导率为22.37～44.61μS/cm,食用油水相电导率为3.18～9.18μS/cm;测定食用油水相电导率大于10μS/cm,可以初步断定其掺伪;模型可实现半定量分析。