Vichi S, Pizzale L, Toffano E, Bortolomeazzi R, Conte L
Udine University, Food Science Department, Italy.
J AOAC Int. 2001 Sep-Oct;84(5):1534-41.
Free sterols were evaluated as factors for discriminating between genuine virgin olive oil and hazelnut-mixed virgin olive oil. Numeric analyses of the results amplified the differences between groups. The application of this method to virgin olive oil samples and their mixtures with 10% hazelnut oil distinguished between genuine and nongenuine virgin olive oil with statistical certainty. Triacylglycerol analysis was tested for the same purpose by using parameter deltaECN42, but although it possessed a discriminating capacity, it alone could not distinguish the aforementioned groups with sufficient certainty. Free delta7-sterols data were combined with deltaECN42 data into a single discriminating function to improve differentiation and bring more ruggedness, and for detection of low amounts (10%) of hazelnut oil in virgin olive oil. In fact, the values obtained by addition of delta7-sterol data and deltaECN42 data showed a higher discriminating capacity than single parameters. In a single operation the method produced all the oil fractions necessary for analysis of free sterols and triacylglycerols with ECN42. Solid-phase extraction was applied in substitution of traditional chromatography on a silica column.
游离甾醇被评估为区分纯正初榨橄榄油和榛果混合初榨橄榄油的因素。结果的数值分析放大了各组之间的差异。将该方法应用于初榨橄榄油样品及其与10%榛果油的混合物，能够在统计学上确定地区分纯正和不纯正的初榨橄榄油。为了同样的目的，使用参数deltaECN42对三酰甘油进行了分析，但尽管它具有区分能力，但仅凭它本身无法足够确定地区分上述各组。将游离δ7-甾醇数据与deltaECN42数据合并为一个单一的判别函数，以提高区分度并带来更高的稳定性，用于检测初榨橄榄油中少量（10%）的榛果油。事实上，通过添加δ7-甾醇数据和deltaECN42数据获得的值显示出比单一参数更高的区分能力。该方法在一次操作中就能产生分析游离甾醇和具有ECN42的三酰甘油所需的所有油馏分。采用固相萃取替代传统的硅胶柱色谱法。
