ISO 8588:2017 感官分析 方法学 “A”-“非A”试验

标准编号：ISO 8588:2017

中文名称：感官分析 方法学 “A”-“非A”试验

英文名称：Sensory analysis — Methodology — "A" - "not A" test

发布日期：2017-07

标准范围

ISO 8588:2017规定了确定两种产品样品之间是否存在明显感官差异的程序。该方法适用于单个感官属性或多个感官属性是否存在差异。“A”？“非A”测试可通过以下方式用于感官分析:a） 作为差异测试，尤其是用于评估在外观（难以获得完全相同的重复样品）或回味（难以进行直接比较）方面存在差异的样品；b） 作为一种识别测试，尤其是用于确定评估员或评估组是否识别出与已知刺激物相关的新刺激物（例如，识别新甜味剂的甜味质量）；c） 作为一种感知测试，确定评估者辨别刺激的能力。“A”？“非A”测试不适用于评估两种产品是否足够相似，可以互换使用（即用于相似性测试），因为“A”？“非A”测试本质上涉及所有评估人员对相同产品的重复评估。这些重复评估违反了相似性测试在统计上有效的基本假设。附录B中给出了其应用示例。注:Bi和Ennis[1]指出，“A”和“非A”样本之间的判别距离d'的估计值是相同的，无论测试中执行的重复评估的性质如何，但d'方差的估计值确实取决于重复评估的执行方式。因此，没有对瑟斯顿式的“a”分析进行一般性讨论？本文件中采用了“非A”方法，也没有测试的威力。感兴趣的读者可参考参考文献[1]对该主题进行详细讨论。

ISO 8588:2017 specifies a procedure for determining whether a perceptible sensory difference exists between samples of two products. The method applies whether a difference exists in a single sensory attribute or in several.

The "A"?"not A" test can be used in sensory analysis in the following ways:

a) as a difference test, particularly for evaluating samples having variations, for example, in appearance (making it difficult to obtain strictly identical repeat samples) or in aftertaste (making direct comparison difficult);

b) as a recognition test, particularly for determining whether an assessor or group of assessors identifies a new stimulus in relation to a known stimulus (for example, recognition of the quality of the sweet taste of a new sweetener);

c) as a perception test, to determine the ability of an assessor to discriminate stimuli.

The "A"?"not A" test is not appropriate for assessing if two products are sufficiently similar to be used interchangeably (i.e. for similarity testing) because the "A"?"not A" test inherently involves replicate evaluations of the same products by all assessors. These replicate evaluations violate the basic assumptions for similarity tests to be statistically valid.

Examples of its application are given in Annex B.

NOTE Bi and Ennis[1] point out that the estimate of the discriminal distance, d', between the "A" and "not A" samples is the same regardless of the nature of the replicated evaluations performed in the test but that the estimate of the variance of d' does depend on how the replicate evaluations were performed. As such, no general discussion of a Thurstonian analysis of the "A"?"not A" method, nor of the power of the test is undertaken in this document. Interested readers are referred to Reference [1] for a detailed discussion of the topic.

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