2809, 2018

Effect of carbonation level on the perception of sparkling wine

John Castura/ September 28, 2018/ Symposium/ 0 comments

The relationship between instrumental and sensory measurements were investigated in 11 wines varying in their carbonation level. Although sourness intensities of the wines were not significantly different, increased carbonation concentration affected the dynamics of sourness perception. Both the onset and extinction of the sourness perception were delayed with increased carbonation. Amongst potential explanations are that dynamic effects of carbonation draw

Read More

1506, 2018

How task instructions affect performance on the unspecified tetrad test

John Castura/ June 15, 2018/ Peer-reviewed Paper/ 0 comments

This parallel‐groups study (n = 1,857) investigates compliance of untrained assessors with tetrad instructions. Stimuli are four unique color swatches that differ only in their green chromaticities. Results confirm that the swatches used in this study were generally perceived as nonconfusable visual stimuli ordered A, B, C, D, and that AB and CD were more different than BC. These stimuli thus modeled

Read More

1506, 2018

Establishing the consumer relevance of a sensory difference using the same-different method

John Castura/ June 15, 2018/ Invited, Symposium/ 0 comments

Establishing the consumer relevance of a sensory difference is essential to reach a conclusion of ‘similarity’ or ‘difference’ between products. Rousseau and Ennis (2013) propose conducting a designed same-different study using a Thurstonian-derived model to obtain discriminal sensory distances (d’) and the consumer-based threshold tau.

1506, 2018

Historical Developments in the ASTM Guide for Sensory Claim Substantiation

John Castura/ June 15, 2018/ Invited, Symposium/ 0 comments

The manner in which “no preference” responses have been treated in the E1958 Standard Guide for Sensory Claim Substantiation has evolved between 1998 and the current (2016) guide. For example, the 1998 guide proposes that an interviewer present consumers with a forced-choice preference question, and accept a “no preference” response from consumers who indicate that they do not have a

Read More

3004, 2018

The analysis of temporal check-all-that-apply (TCATA) data

John Castura/ April 30, 2018/ Peer-reviewed Paper, Type/ 0 comments

Temporal check-all-that-apply (TCATA) extends classical check-all-that-apply (CATA) by adding a temporal dimension to the evaluation. From a data analysis point of view, TCATA data are similar to Temporal Dominance of Sensations (TDS) data but differ in that more than one attribute can be selected at any time point. Procedures for analyzing TCATA data can hence be generalized from methods for

Read More

2312, 2016

Using contrails and animated sequences to visualize uncertainty in dynamic sensory profiles obtained from temporal check-all-that-apply (TCATA) data

John Castura/ December 23, 2016/ Peer-reviewed Paper/ 0 comments

Approaches for analyzing temporal check-all-that-apply (TCATA) data are further developed and illustrated using data arising from a Syrah wine finish evaluation. Raw and smoothed trajectories are obtained using principal component analysis. Virtual panels are obtained from a partial bootstrap, and the attribute citation proportions are then projected into the solution space to form contrails.