School of Nutrition and Food Sciences, Louisiana State Univ. Agricultural Center, Baton Rouge, LA, 70803, U.S.A.
J Food Sci. 2018 Jul;83(7):1933-1940. doi: 10.1111/1750-3841.14194. Epub 2018 Jun 15.
Duplicating ranking tests can improve the power of preference and sensory intensity tests, and reduce the number of panelists required. With multiple-samples rankings, duplications could be served using different protocols: in two serving sessions (two sample sets, that is, 2SS) to allow a break period or jointly in one serving session (one sample set, that is, 1SS). Evaluating the duplicates in a single session improves statistical data analysis but increases concerns of sensory fatigue, adaptation, memory, and possible irritation. The extent to which each serving protocol for duplicated ranking affects detection of differences has not been reported. This study used panelists (n = 75) who performed both ranking test protocols on two sets of orange juice samples (k = 3). One set was designed to obtain higher similarity than the other set to investigate the effects of degree of difference. Sweetness and yellow color intensity rankings were performed separately for each set to compare the protocols between attributes. The magnitude of the differences was evaluated using Mack-Skillings (M-S) statistics, and the total and individual rank sum differences at varied n (10 to 75) values. With similar set samples, the 2SS serving protocol improved differentiation for yellow color intensity. Although in sweetness, using the 1SS serving protocol showed higher M-S statistics and higher sum of total rank sum differences. Paired comparisons followed the same pattern. With very different samples, both protocols had comparable performance. This study showed that serving duplicates in the 1SS can improve duplicated ranking's power, depending on the task difficulty and attribute, and should be considered before splitting replications into two sessions.
This study evaluated two alternative and not previously studied protocols for conducting a duplicated ranking test. One protocol required that each panelist received duplicates in the same single serving session (1SS), against the alternative of serving duplicates separately in two sessions to allow a break period (2SS). Two attributes: yellow color intensity and sweetness intensity of orange juice samples were studied. This study showed that serving duplicates in the same single session can improve duplicated ranking's power, depending on the task difficulty and attribute, and should be considered before splitting replications into two sessions.
复制排序测试可以提高偏好和感官强度测试的功效，并减少所需的品尝小组成员数量。使用多样品排序，可以使用不同的方案来提供重复样品：在两次品尝过程中（两个样品组，即 2SS）允许有休息时间，或在一次品尝过程中（一个样品组，即 1SS）联合进行。在单次品尝过程中评价重复样品可以改进统计数据分析，但会增加感官疲劳、适应、记忆和可能的刺激方面的担忧。每种重复排序的品尝方案对差异检测的影响程度尚未有报道。本研究使用品尝小组成员（n = 75）对两组橙汁样品（k = 3）进行了两种排序测试方案。一组样品设计为获得比另一组样品更高的相似度，以研究差异程度的影响。分别对每组样品的甜度和黄色强度进行了排序，以比较属性之间的方案。使用 Mack-Skillings（M-S）统计量评估差异的大小，并在不同 n（10 到 75）值下评估总排名和个体排名总和差异。对于相似的样品组，2SS 服务方案提高了黄色强度的区分度。尽管在甜度方面，使用 1SS 服务方案显示出更高的 M-S 统计量和更高的总排名总和差异。配对比较遵循相同的模式。对于非常不同的样品，两种方案的性能相当。本研究表明，根据任务难度和属性，在 1SS 中提供重复样品可以提高重复排序的功效，在将重复分成两次品尝之前应考虑这一点。
本研究评估了两种替代的、以前未研究过的方案，用于进行重复排序测试。一种方案要求每个品尝小组成员在同一单次品尝过程中收到重复样品（1SS），另一种方案是将重复样品分开在两次品尝过程中提供，允许有休息时间（2SS）。研究了两个属性：橙汁样品的黄色强度和甜度强度。本研究表明，根据任务难度和属性，在同一单次品尝过程中提供重复样品可以提高重复排序的功效，在将重复分成两次品尝之前应考虑这一点。
