红外光谱结合偏最小二乘法快速检测油茶籽油脂肪酸组成的模型建立与评价北大核心CSCD

为建立快速检测油茶籽油中脂肪酸组成的方法,利用傅里叶红外光谱仪扫描86个油茶籽油样品,红外光谱数据分别通过Savitzky-Golay平滑(SG)、多元散射校正(MSC)、标准正态变换(SNV)、一阶导数(FD)和二阶导数(SD)等5种方法进行降噪处理,然后以气相色谱测定的脂肪酸组成作为标准值,采用全波长偏最小二乘法(PLS)、区间偏最小二乘法(iPLS)和联合区间偏最小二乘法(siPLS)分别构建油茶籽油中主要脂肪酸(油酸、棕榈酸、亚油酸)的定量回归模型。结果表明:油酸、棕榈酸、亚油酸的红外光谱数据预处理分别以SG、SNV、SD较好;siPLS通过有效波段的选择可去掉更多的噪声,比PLS和iPLS建立的模型精确度高,油酸、棕榈酸、亚油酸的校正集和预测集的相关系数(R)分别为0.9479和0.8539、0.9008和0.9101、0.9793和0.9505。红外光谱结合siPLS更适用于油茶籽油脂肪酸组成的快速测定。     

12株油茶种仁含油率及脂肪酸组成分析

测定名邛台地(四川省境内的名山、邛崃、蒲江一带)的12株野生油茶的产量和种仁含油率,采用气相色谱法(GC)对油茶籽油脂肪酸组成进行分析,并对主要脂肪酸组成间进行相关性分析。结果表明:不同油茶的产量和种仁含油率存在差异,单株产量为12.95~54.00 kg,种仁含油率为37.04%~45.56%;油茶籽油脂肪酸组成以油酸、亚油酸、亚麻酸、棕榈酸和硬脂酸为主;各脂肪酸含量之间存在密切的相关性,油酸与亚油酸、亚麻酸、棕榈酸呈极显著负相关,关系最密切的是油酸和亚油酸,其相关系数达到-0.829;根据产量、种仁含油率和脂肪酸组成筛选出的川雅31、川雅21、川雅28、川雅20可作为进一步培育优良品种的材料。     

NIR光谱法测定烟草中棕榈酸、亚麻酸及亚油酸

为了快速检测烟草样品中的棕榈酸、亚麻酸及亚油酸含量,采用偏最小二乘法(PLS)将242个烤烟样品的近红外光谱(NIR)及其棕榈酸、亚麻酸、亚油酸含量GC测定值进行拟合,建立了校正模型,考察了光谱预处理方法和光谱谱区范围对模型的影响,并进行了内部交叉验证和模型精度检验及30个测试样品的外部验证。结果表明:①多元散射校正法和7502~5442.3,4427.9~4246.7 cm-1,一阶导数法和7502~5442.3,4601.5~4246.7 cm-1,矢量归一化法和8724.7~5438.5,4427.9~4246.7 cm-1谱区范围分别适合棕榈酸、亚麻酸、亚油酸模型;②3个模型的平均相对精度分别为98.41%,97.84%,98.84%;③3个模型的预测标准偏差均小于5%,且NIR预测值与GC测定值不存在显著性差异。NIR光谱法适合批量烟叶样品中棕榈酸、亚麻酸及亚油酸含量的快速分析。     

不同品种燕麦的油脂组成及与其它营养物质相关性研究

对我国12种燕麦的主要营养成分,尤其是油脂及其脂肪酸的组成进行了系统研究,并探讨它们之间的相关性。研究结果表明,我国12种燕麦的油脂含量存在较大的差异,并且油脂含量与颗粒重、淀粉呈负相关,而与蛋白质、维生素E呈正相关。燕麦油脂中的脂肪酸主要是由棕榈酸、油酸、亚油酸、硬脂酸和亚麻酸组成。燕麦油脂的含量与脂肪酸组成有一定的相关性,与硬脂酸和油酸呈正相关,而与棕榈酸、亚油酸和亚麻酸呈负相关。燕麦中性油脂(NL)中含有较多的油酸,而糖脂(GL)和磷脂(PL)中含有更多的棕榈酸和亚油酸。     

江西地区油茶籽的含油率和脂肪酸组成的调查与分析

本文对江西地区2011年产的38个油茶籽的含油率和脂肪酸组成进行了分析。结果表明:油茶籽含油率在20.48%~49.84%之间,平均为37.07%。油茶籽油脂肪酸主要是由棕榈酸、硬脂酸、油酸、亚油酸、花生一烯酸等脂肪酸组成,棕榈酸含量平均值8.19%;硬脂酸含量平均值2.48%;油酸含量平均值81.02%;亚油酸含量平均值7.74%;花生一烯酸含量平均值0.46%,主要不饱和脂肪酸油酸和亚油酸含量平均达到了88.76%,说明江西地区的油茶籽油符合高品质食用油的标准。     

紫苏属籽粒含油率及其脂肪酸分析

对来自日本、美国四川和广东、等国家和地区共18份紫苏属籽粒含油率、脂肪酸组成及含量进行测定,并对其籽粒直径、千粒重与含油率和脂肪酸含量间进行相关分析.结果表明,紫苏属籽粒出油率为16.33%～35.28%,其籽油脂肪酸主要包括亚麻酸(70.94%～78.86%)、亚油酸(9.70%～14.57%)、油酸(0.68%～2.20%)、棕榈酸(6.69%～11.03%)和硬脂酸(2.23%～3.76%).其中,以来自日本的P06-37的综合性状表现最好.试验结果还表明,紫苏属籽粒含油率与千粒重间呈现显著正相关.亚麻酸含量与籽粒直径和千粒重间呈显著负相关,油酸含量与千粒重间呈显著正相关,而亚麻酸与亚油酸含量间呈极显著负相关.此外,白苏籽千粒重、含油量和亚油酸含量均相对较高,而其他各脂肪酸含量在紫苏属各原(变)种间无显著差异.     

基于近红外光谱法的哈萨克斯坦亚麻籽油品质指标定量预测模型的建立

为了建立一种快速、准确、高效的针对哈萨克斯坦亚麻籽油酸价、过氧化值及脂肪酸成分的检测方法，用科学的手段表征其质量安全和品质特征，该研究在实验中选取代表性样品116份，分别利用碘量法、热乙醇法、气相色谱串联质谱仪对亚麻籽油样品中过氧化值、酸价、棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸含量予以检测，同时利用近红外成分分析仪建立其特征图谱，根据偏最小二乘法依次对经过不同预处理后的特征光谱加以拟合，经回归数据分析，形成亚麻籽油酸价、过氧化值、棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸的近红外定量预测模型。对模型进行验证和预测精度的评价后，确定：各指标相关系数（R）为0.960 1~0.985 7，绝对偏差为0.039 14~1.246 7，均方根误差（RMSEP）为0.059 21~1.430 2，表明模型具有良好的预测效果，可以有效预测哈萨克斯坦亚麻籽油的品质指标。该模型的建立为哈萨克斯坦亚麻籽油酸价、过氧化值及多种脂肪酸成分同时测定提供了快速检测途径，大大缩短了通关流程时限。     

腊肉加工过程中游离脂肪酸的变化研究

分别对腊肉加工过程中肥肉和瘦肉的游离脂肪酸(FFA)的变化进行了测定,结果表明:肥肉中主要的FFA为油酸(C18∶1)、硬脂酸(C18∶0)、棕榈酸(C16∶0)和亚麻酸(C18∶3),且总FFA不断积累,81h达到最大值;脂肪酸在肥肉中的释放速率为亚油酸>亚麻酸>硬脂酸>油酸>棕榈酸。瘦肉中主要的FFA为硬脂酸、棕榈酸、亚油酸(C18∶2)和油酸,总FFA也不断积累,43h达到最大值;脂肪酸在瘦肉中的释放速率为硬脂酸>亚油酸>棕榈酸>油酸。腊肉加工过程中,脂质发生的降解和氧化对形成腊肉特有的风味发挥了重要作用。     

光皮树果实不同部位油脂组成分析

对光皮树果实中果肉、种核、种仁3个部位的油脂含量及其脂肪酸组成进行了分析,结果表明,果肉中油脂占全果总合油比例为66.95%,种核中油脂占16.96%,种仁中油脂占16.09%.3部位油脂均含有亚油酸、油酸、棕榈酸、硬脂酸和花生酸,只是相对含量不同,其中果肉中油脂主要脂肪酸组成为棕榈酸(24.41%)、亚油酸(32.46%)、油酸(30.07%)、硬脂酸(1.64%)、花生酸(3.09%);种核中油脂的主要脂肪酸组成为棕榈酸(12.48%)、亚油酸(54.79%)、油酸(26.93%)、硬脂酸(2.18%)、花生酸(1.63%);种仁中油脂主要脂肪酸组成为棕榈酸(6.61%)、亚油酸(58.80%)、油酸(22.32%)、硬脂酸(2.03%)、花生酸(0.65%).     

气相色谱-质谱法定性定量测定糜子中的脂肪酸

采用气相色谱-质谱法对糜子中脂肪酸进行定性、定量分析。结果共鉴定出14 种脂肪酸,相对含量为96.9%,其中不饱和脂肪酸8 种（64.533%）,主要有亚油酸（12.371%）、油酸（44.157%）、亚麻酸（1.173%）等。可见糜子中脂肪酸主要以不饱和脂肪酸为主,是优质脂肪酸。通过回归方程计算得出：糜子中棕榈酸、油酸、硬脂酸、亚油酸、亚麻酸的含量分别为100.261、165.309、23.402、52.181、17.516 mg/100 g。通过与其他杂粮进行比较,结果表明糜子和小米、高粱、小麦、燕麦、水稻一样均含有硬脂酸、油酸、亚油酸、亚麻酸和棕榈酸等,不饱和脂肪酸含量高,富含亚油酸和亚麻酸;本研究可为糜子品质的进一步开发和研究提供理论依据。     

浅述酸、酯、醇等成分对白酒的影响

简要叙述了白酒中酸类、酯类和醇类在白酒呈香显味中的作用,并分析了主要呈香物质对白酒风味的影响,从而对白酒的勾兑起指导作用。     

烟丝中糖组分含量对平衡含水率的影响

在不同相对湿度下,对所选13种烟丝样品进行平衡含水率测定和糖组分的定量分析,采用灰色关联分析探讨了烟丝的糖组分含量与持湿能力之间的关系。结果表明:不同空气相对湿度(30%~80%)下,除30%外,烟丝糖组分含量与持湿能力均呈正相关;烟丝不同糖组分对持湿能力影响程度不同,其中果糖对持湿能力影响最显著,其次为糖总量、葡萄糖、蔗糖、麦芽糖。     

Aluminium content of beers

 The aluminium (Al) concentration in different brands of beers packaged in Al cans and glass bottles was measured at the end of the shelf-life of the beer, by the Zeeman graphite furnace atomic absorption spectrophotometry (ZGFAAS) method. The results show that in all cases a brand of beer packaged in an Al can has a higher Al content than the same brand bottled in glass. The measurements of the Al concentration in some Al-canned beers throughout 12 months of storage show that a relatively small increase of the Al concentration in beers occurs throughout storage. All these results indicate that some Al is taken up by the beer in Al cans, presumably through the slight and slow dissolution of Al from the can wall, due to some defects in the protective lacquer layer. The evaluated daily intake of Al (0.256 mg) possible through the consumption of beer was practically negligible in relation to both the total daily dietary Al intake and the tolerable daily Al intake. Thus, beers are an insignificant source of dietary Al intake and it appears that the Al intake from beers (due to the low content of Al in beers and its low bioavailability) should not be a cause for concern with regard to Al toxicity for the human body. Received: 22 April 1996     

Aluminium content of beers

 The aluminium (Al) concentration in different brands of beers packaged in Al cans and glass bottles was measured at the end of the shelf-life of the beer, by the Zeeman graphite furnace atomic absorption spectrophotometry (ZGFAAS) method. The results show that in all cases a brand of beer packaged in an Al can has a higher Al content than the same brand bottled in glass. The measurements of the Al concentration in some Al-canned beers throughout 12 months of storage show that a relatively small increase of the Al concentration in beers occurs throughout storage. All these results indicate that some Al is taken up by the beer in Al cans, presumably through the slight and slow dissolution of Al from the can wall, due to some defects in the protective lacquer layer. The evaluated daily intake of Al (0.256 mg) possible through the consumption of beer was practically negligible in relation to both the total daily dietary Al intake and the tolerable daily Al intake. Thus, beers are an insignificant source of dietary Al intake and it appears that the Al intake from beers (due to the low content of Al in beers and its low bioavailability) should not be a cause for concern with regard to Al toxicity for the human body. Received: 22 April 1996     

小麦呕吐毒素含量与赤霉病粒含量的相关性研究

该文通过大量数据的积累与分析,建立了小麦呕吐毒素含量与赤霉病粒含量的相关性曲线y=297.6x+135.96,并通过数十组实验数据加以验证曲线的正确性。所建立的相关性曲线在辅助仓库进仓小麦呕吐毒素定性筛查上具有较好的应用价值。     

Selenium content of mushrooms

Summary The selenium contents of 83 species of wild mushrooms were determined by oxygen combustion of the sample, followed by conversion of selenite to bromopiazselenol and final estimation by electron capture gas-liquid chromatography. Selenium concentrations were found to range from 0.012–20.0 mg/kg dry weight. Selenium content was species-dependent. High concentrations were found inAgaricaceae and in certainBoletaceae of the genusTubiporus, whereas inRussulaceae, Amanitaceae andCantharellaceae selenium-rich species were absent or rare. Ascomycetes and all mushrooms growing on wood had a very low selenium content.The highest selenium concentrations (up to 20 ppm) were found inBoletus (Tubiporus)edulis, a most popular edible mushroom. Analyses of various parts of carpophores ofB. edulis, Suillus luteus andAmanita muscaria indicate that in all three species the stalk contains less selenium than the fleshy part of the cap. InBoletus andSuillus the highest selenium content was found in the tubes

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Selengehalt der Pilze

Zusammenfassung Der Selengehalt 83 Arten wildgewachsener, höherer Pilze wurde gaschromatographisch mit dem Elektroneneinfangdetektor bestimmt nach Verbrennung der getrockneten Muster in Sauerstoff und Überfuhrung des anorganischen Selens in Brompiazselenol. — Der Selengehalt lag zwischen 0,012 und 20 mg/kg Trockengewicht und war Speciesabhängig. Hohe Konzentrationen wurden in Egerlingen (Agaricus) und gewissen Röhrenpilzen (Tubiporus) gefunden, während bei denAmanitaceae, Russulaceae undCantharellaceae selenreiche Arten eher die Ausnahme darstellten. Ascomyceten und alle auf Holz wachsenden Pilze enthalten fast kein Selen. Der höchste Selengehalt (bis 20 mg/kg Trockengewicht) wurde im eßbaren Steinpilz nachgewiesen. — Analysen von Teilen der Fruchtkörper zeigten, daß der Stiel weniger Selen enthielt als das Hutfleisch. Bei den Röhrlingen war das Selen in der Röhrenschicht angereichert.

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With the technical assistance of J. M. Diserens and M. Pletikosa     

Selenium content of mushrooms

The selenium contents of 83 species of wild mushrooms were determined by oxygen combustion of the sample, followed by conversion of selenite to bromopiazselenol and final estimation by electron capture gas-liquid chromatography. Selenium concentration were found to range from 0.012-20.0 mg/kg dry weight. Selenium content was species-dependent. High concentrations were found in Agaricaceae and in certain Boletaceae of the genus Tubiporus, whereas in Russulaceae, Amanitaceae and Cantharellaceae selenium-rich species were absent or rare. Ascomycetes and all mushrooms growing on wood had a very low selenium content. The highest selenium concentrations (up to 20 ppm) were found in Boletus (Tubiporus) edulis, a most popular edible mushroom. Analyses of various parts of carpophores of B. edulis, Suillus luteus and Amanita muscaria indicate that in all three species the stalk contains less selenium than the fleshy part of the cap. In Boletus and Suillus the highest selenium content was found in the tubes.     

Thiocyanate content of kale

In fresh whole plant tissue thiocyanate was not in a “free” state and to obtain satisfactory thiocyanate values it was necessary to disrupt the tissue thoroughly by homogenisation to permit hydrolysis of the thiocyanate-containing substance. Rape kale contained about 15 mg thiocyanate/100 g of fresh material, less than half the amounts found in thousand head, marrow stem, Maris Kestrel or Canson: there were no consistent differences among the thiocyanate contents of these four types of kale. The thiocyanate content, although fairly constant during most of the growing season, increased about twofold in late September and October then returned to former values. This increase did not occur in rape kale. Small young kale leaves contained more than five times the amount of thiocyanate found in large, fully formed leaves, and about twice the amount present in leaves of intermediate size.     

三聚氰胺含量测定

<正> 在小麦面筋蛋白、奶粉及其他含蛋白的粉类产品的生产中,三聚氰胺污染物的测定是重要的安全考虑。排除蛋白质含量影响的三聚氰胺含量的测定是非常关键的步骤。三聚氰胺与蛋白质分子均含有大量的氮元素,此相同之处导致了三聚氰胺含量测定的困难。在不测定蛋白质含量变化的情况下,而测定三聚氰胺浓度是