Consumer acceptability and purchase intent of probiotic yoghurt with added glucose oxidase using sensometrics, artificial neural networks and logistic regression

Abstract

This research aimed to identify the drivers of acceptance and purchase intent of a probiotic (Bifidobacte-rium longum BL05) nonflavoured yoghurt supplemented with glucose oxidase, and to model theconsumers’ acceptability using sensometrics and artificial neural networks (ANN). Consumers (n =100)evaluated the degree of liking of yoghurt assays in respect of appearance, aroma, taste, texture and over-all linking. Sensometric techniques – multiple linear regression (MLR), partial least squares regression(PLS), principal component regression (PCR) – and ANN were used to model the overall liking. Sensorydrivers of global acceptance and purchase intent were also determined using logistic regression (LR).Hierarchical cluster analysis (HCA) identified three consumer segments that presented differences in allsensory attributes evaluated (P < 0.05). The ANN model showed the best performance to predict overallliking, followed by the MLR, PLS and PCR, indicating that taste and texture were the most significantattributes impacting the yoghurts overall liking. In accordance with the logistic models, overall accep-tance and purchase intent could be predicted with 81.94 and 85.49% accuracy, respectively. The logisticregression indicated that taste was the attribute that contributed significantly (P < 0.0001) to higherscores for purchase intent and was considered the driver of acceptance.Keywords Probiotic yoghurt, Glucose oxidase, Sensorial acceptance, Oxygen.INTRODUCTIONThe existence of a fermentation step leads to easyadaptation for the viability of probiotic micro-organisms in dairy products, contributing to thefact that this class of product has become its mostimportant representative (Heller 2001). The great-est concentration of probiotic micro-organisms canbe found in dairy products, especially fermentedproducts, such as yoghurts and drinks based on fer-mented milk and kefir. Of these,yoghurts represent36.6% (Granato et al. 2010a) in the Latin Ameri-can market: probiotic yoghurts increased 32%between 2005 and 2007 (Crowley 2008). Indeed,yoghurt presents the preference of the consumer,acting as the main vehicle for supplementationwith probiotic bacteria (Granato et al. 2010b),being reported in several studies (Korbekandi et al.2009; Wang et al. 2010; Ejtahed et al. 2011;Ramchandran and Shah 2011).The main purpose of technological solutions inprobiotic yoghurts and fermented milks is to main-tain the viability of the strain throughout productstorage in sufficient numbers aimed to have bene-fits to the consumer (Champagne and Gardner2005). These technologies include, among others,freeze drying (Kearney et al. 2009), inclusion offruit matrices (Almeida et al. 2009; Espi´rito Santoet al. 2011), microencapsulation (Ding and Shah2009; Sandoval-Castilla et al. 2010), dry matter