Temporal ranking for characterization and improved discrimination of protein beverages

John Castura/ May 24, 2022/ Peer-reviewed Paper, Uncategorized/ 0 comments

We propose a new temporal sensory method called temporal ranking (TR) in which assessors indicate and rank the three most noticeable sensations at every time point. The TR method was compared to temporal-check-all-that-apply (TCATA) in two trained-panel studies, one study involving six ready-to-mix (RTM) protein beverages and one study involving seven ready-to-drink (RTD) protein beverages. In each study, the same

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Clustering consumers based on product discrimination in check-all-that-apply (CATA) data

John Castura/ March 4, 2022/ Peer-reviewed Paper/ 0 comments

Consumers can be clustered based on their product-related check-all-that-apply (CATA) responses. We identify two paradoxes that can occur if these clusters are derived from conventional similarity coefficients. The first paradox is that clustering similar consumers can nullify within-cluster sensory differentiation of products. The second paradox is that consumers who check many attributes yet disagree can be clustered together, whereas consumers

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Discriminability and uncertainty in principal component analysis (PCA) of temporal check-all-that-apply (TCATA) data

John Castura/ February 1, 2022/ Peer-reviewed Paper/ 0 comments

Temporal check-all-that-apply (TCATA) data can be summarized and explored using principal component analysis (PCA). Here we analyze TCATA data on Syrah wines obtained from a trained sensory panel. We evaluate new and existing methods to explore the uncertainty in the PCA scores. To do so, we use the bootstrap procedure to obtain many virtual panels from the real panel’s data.

Consumer hedonic studies with incomplete block designs

John Castura/ August 25, 2021/ Workshop/ 0 comments

Castura, J.C. (2021). Consumer hedonic studies with incomplete block designs. In: Workshop: A journey of consumer segmentation. History and a discussion of current “preference” segmentation approaches based on incomplete and complete test designs (Zach, J., Rothman, L., Carr, B.T., Thomas, H., Castura, J.C.). 14th Pangborn Sensory Science Symposium, 9-12 August. Online. (Workshop Oral). DOWNLOAD

Temporal Rate-All-That-Apply (TRATA): A novel temporal method for sensory evaluation

John Castura/ August 8, 2021/ Poster/ 0 comments

This study introduces temporal rate-all-that-apply (TRATA) as a new temporal sensory method. It was inspired by rate-all-that-apply (RATA) and temporal check-all-that-apply (TCATA), but is most similar to multiple-attribute time intensity (MATI) in that the TRATA method allows for simultaneous rating of attribute intensities over time. Only attributes that are perceived are scaled. In this case study, the TRATA method was

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Temporal ranking for the characterization and better discrimination of protein beverages with different sweeteners

John Castura/ December 9, 2020/ Poster/ 0 comments

This study proposes the application of ranking to temporal product evaluation to differentiate attribute dominances over time. The ability of the proposed method to discriminate sensory differences was compared to temporal check-all-that-apply (TCATA), a discriminating temporal method for capturing the temporal profile of food and beverage products.

Analyzing data using the chance-corrected beta-binomial model: Parameter estimates and their confidence regions

John Castura/ August 6, 2019/ Poster/ 0 comments

Data arising from replicated sensory discrimination test methods with a correct response are often modelled using the chance-corrected beta-binomial distribution. The model can provide maximum likelihood estimates of the mean proportion of correct responses in the population (and discriminal distances under Thurstonian assumptions) and of the assessor heterogeneity (overdispersion). Both of these parameters are estimated with uncertainty. Previously uncertainty associated

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Analysis of sensory check-all-that-apply (CATA) data which includes the evaluation of a single ideal product

John Castura/ August 6, 2019/ Poster/ 0 comments

When evaluating samples in sensory tests, consumers are sometimes asked not only about real samples but also about imagined ideal products. Check-all-that-apply (CATA) questions are one way to understand consumers’ perceptions of products and their ideal product. We propose the following statistical analyses of consumer CATA data: (i) confidence intervals for head-to-head comparisons based on CATA data; (ii) panel (dis)agreement

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A retail simulation study for investigating product choice and choice satisfaction: A case study involving kombucha

John Castura/ August 6, 2019/ Poster/ 0 comments

Kombucha is a fermented tea that is rapidly growing in popularity in the United States. As part of a larger consumer study conducted in Portland, Oregon, kombucha consumers (n=1303, 68% female, aged 18-86, USA)participated in an online retail simulation test. They evaluated 9 commercial products (bottle images) and made choice selections in a retail simulation.