Pivot profile method: What is the influence of the pivot and product space?

Comparison of Pivot Profile (PP), Rate-All-That-Apply (RATA), and Pivot-CATA for the sensory profiling of commercial Chinese tea products

Rapid sensory profiling methods relying on consumers' perceptions are getting prevalent and broadly utilized by labs and companies to supersede conventional sensory profiling methodologies. Till now, various intensity-based sensory methods such as the newly proposed Pivot-Check-All-That-Apply (CATA) are limitedly developed and compared. In this investigation, Pivot Profile (PP), Rate-All-That-Apply (RATA), and Pivot-CATA methods were applied and validated using tea consumers and commercial Chinese tea products as samples. Data from three approaches were collected, analyzed by correspondence analysis (CA), and used to compare the three methods assessing the panel assessment process, sensory maps, confidence ellipses, and practical applications. Pivot-CATA exhibited a high similarity with RATA (RV = 0.873), and a lower similarity with PP (RV = 0.629). Of the three intensity-related methods, confidence ellipses on the RATA sensory map were the smallest and overlapped the least. However, Pivot-CATA consumed less time in collecting data and its questionnaire was more friendly to participants compared with PP and made the difference in intensity of samples more noticeable to the participants than RATA due to the existence of the pivot sample. Its experimental versatility also allows for a wide range of applications, indicating that the Pivot-CATA is an approach with great promise for routine use.

A multivariate approach to evaluating the chemical and sensorial evolution of South African Sauvignon Blanc and Chenin Blanc wines under different bottle storage conditions

Volatile compound composition contributes to the aroma profile of wine and is susceptible to change due to oxidation which may occur during storage and transportation, especially at high temperatures. Changes in sensory attributes may also occur, altering the sensory profile of wine. Classical univariate analysis only looks at the deviations for one factor at a time and may overlook the overall effect of treatments. In this study, changes in South African Sauvignon Blanc and Chenin Blanc wine sensory profile, volatile and antioxidant-related parameters resulting from storage under different temperatures (room temperature, 15 °C and 25 °C) and durations (0, 3 and 9 months) were investigated using a multivariate approach. Bottled, unwooded wines of both cultivars from six wineries were used. As expected, the chemical evolution of the wines was characterised by increases in absorbance at 420 nm (browning), colour density and hue with prolonged storage at high temperatures. To be able to compare the evolution of the sample sets regardless of the initial (T0/control) wine profile and composition, multivariate regression analysis in the form of regression vector (RV) coefficients were used to assess the correlations in the sensory and chemical changes relative to the control in each set. Using Pivot©Profile for the first time in this type of stability assessment and applying a new algorithm for data handling in addition to the classical one, this study showed that prolonged exposure to higher temperatures resulted in the change from fruity to toasted aroma attributes.