Investigating relationships in sensory and instrumental data using component-based methods

John Castura/ October 3, 2024/ Oral Presentation/ 0 comments

This talk focuses on new ways for investigating sensory-instrumental data relationships using component-based methods. The proposed approaches are related to manuscripts that are in preparation at the time of this abstract submission. The proposed methods could be used in a wide range of studies, but the talk will emphasize studies involving one reference treatment and many test treatments, which is

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Investigating test-control paired differences in flavour-molecular correlations

John Castura/ September 25, 2024/ Oral Presentation/ 0 comments

We investigate supervised principal component regression (SPCR) its sensory and instrumental results from a data set of eight pinot noir wines. Data include measured concentrations of volatile organic compounds from headspace—solid phase micro-extraction—gas chromatography—mass spectrometry (HS-SPME-GC-MS) and sensory descriptive analysis results on two selected sensory attributes evaluated orthonasally. We show the solution from SPCR as conducted conventionally is equivalent to

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Investigating sensory-instrumental relationships in a subset of test-control paired comparisons by partial least squares regression

John Castura/ September 5, 2024/ Oral Presentation/ 0 comments

Relationships between sensory and instrumental variables are often investigated using partial least squares regression (PLSR). We describe the conventional PLSR solution. Next, we describe two new approaches for conducting PLSR based on paired comparisons of objects. First, we describe the PLSR of all paired comparisons. Conducting PLSR of all paired comparisons is equivalent to the conventional solution in the sense

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Investigating control-centred results after uncentred principal component analysis

John Castura/ June 14, 2024/ Oral Presentation/ 0 comments

Test-control paired comparisons can be investigated after principal component analysis (PCA). We show that a centred PCA of test-control paired comparisons is equivalent to an uncentred PCA of control-centred results. We demonstrate how to conduct these analyses. We illustrate key properties of centred and uncentred PCA. We justify why coordinates of control-centred results can be visualized in principal components obtained

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Investigating paired differences for data sets with special structures after principal component analysis

John Castura/ September 18, 2023/ Oral Presentation/ 0 comments

Principal component analysis (PCA) is a popular technique for summarizing and exploring multivariate data sets. We propose how to conduct PCA of results from sensory studies that have a special structure, where only a subset of the product paired comparisons are of interest. We illustrate the proposed approach with two data sets, both from trained sensory panels. In the first

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Evaluation of complementary numerical and visual approaches for investigating pairwise comparisons after principal component analysis

John Castura/ November 16, 2022/ Oral Presentation/ 0 comments

We propose and evaluate numerical and visual methods for investigating paired comparisons after principal component analysis (PCA). PCA results can be visualized to facilitate an understanding of the relationships between the products and the sensory attributes. But identifying and visualizing significant product differences in multiple PCs simultaneously is not straightforward. A benefit of the proposed methods is that they provide

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Clustering consumers based on their hedonic responses

John Castura/ November 9, 2022/ Oral Presentation/ 0 comments

Consumers are diverse in their product perceptions. But within the consumer population there are often consumer segments whose product perceptions are relatively homogeneous. To discover these consumer segments, consumers’ product-related responses are submitted to a cluster analysis. The particular cluster analysis is chosen by the researcher. But the choice of clustering algorithm can have profound consequences on the clustering solution

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Analyzing data from sensory discrimination tests: Parameter estimates and confidence regions

John Castura/ June 30, 2019/ Oral Presentation/ 0 comments

The sensory profile of a food product is an important contributor to its identity, and is linked to brand value. Sensory testing provide an objective way to ensure that the product’s target sensory profile is achieved, e.g., after making production changes. Historical data, including business outcomes, can provide context to assist decision making. Unreplicated sensory discrimination tests without response bias

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Is less always more?

John Castura/ June 5, 2019/ Oral Presentation, Symposium/ 0 comments

Here is a question to be answered in mythbusters style: “Do the number of available choices create a choice overload effect in consumers?” As a starting point, consider a well-known study in which consumers receive a coupon in a grocery store after tasting two jams. Consumers who were limited to choosing from only 6 jams followed through with purchase more

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