Digital technologies to assess yoghurt quality traits and consumers acceptability

Abstract

BACKGROUND: Sensory biometrics provide advantages for consumer tasting by quantifying physiological changes and the emotional response from participants, removing variability associated with self-reported responses. The present study aimed to measure consumers' emotional and physiological responses towards different commercial yoghurts, including dairy and plant-based yoghurts. The physiochemical properties of these products were also measured and linked with consumer responses.RESULTS: Six samples (Control, Coconut, Soy, Berry, Cookies and Drinkable) were evaluated for overall liking by n = 62 consumers using a nine-point hedonic scale. Videos from participants were recorded using the Bio-Sensory application during tasting to assess emotions and heart rate. Physicochemical parameters Brix, pH, density, color (L, a and b), firmness and nearinfrared (NIR) spectroscopy were also measured. Principal component analysis and a correlation matrix were used to assess relationships between the measured parameters. Heart rate was positively related to firmness, yaw head movement and overall liking, which were further associated with the Cookies sample. Two machine learning regression models were developed using (i) NIR absorbance values as inputs to predict the physicochemical parameters (Model 1) and (ii) the outputs from Model 1 as inputs to predict consumers overall liking (Model 2). Both models presented very high accuracy (Model 1: R = 0.98; Model 2: R = 0.99). CONCLUSION:The presented methods were shown to be highly accurate and reliable with respect to their potential use by the industry to assess yoghurt quality traits and acceptability.

Acquisition Strategies for Fermentation Processes with a Low-Cost Miniaturized Nir-Spectrometer from Scratch: Issues and Challenges

“…The main variation observed in the spectra is the shift of the baseline due to the different scattering properties of the media of fermentation along with the time of sampling. Spectra interpretation could be proposed based on the literature on dairy products [8,16,31]. The region around 2200 nm and between 1550 and 1780 nm may be ascribed to a combination of tones and to the first overtone of C -H bonds, that could be inferred are related to ethanol concentration.…”