Electronic Tongue as an Objective Evaluation Method for Taste Profile of Pomegranate Juice in Comparison with Sensory Panel and Chemical Analysis

The taste profile of the juice from four cultivars of pomegranate (PMG) (‘Shani’, ‘Acco’, ‘Emeq’, and ‘116’) was evaluated using an electronic tongue in comparison with commonly used methods such as chemical analysis and a sensory panel. Estimated intensity of taste (EIT) for sourness, astringency and bitterness (including the aftertaste) were calculated according to the linear range outputs of citric acid, tannic acid and iso-alpha acid solutions. The aftertaste EITast and EITbit values showed good correlations with the sensory panel scores, R2 = 0.92 and R2 = 0.78, respectively. Six PMG juices were discriminated based on the taste profile results from the e-tongue sensors and the sensory panel. Sourness and sweetness attributes were the main factors for the variance axis (F1 = 53.2 %) with the juice of ‘116’ being the most sour. Bitterness and astringency were plotted on the second axis, positioning the cvs. ‘Shani’ and ‘Organic Acco’ with positive correlations. The sensors for astringency and bitterness were significantly correlated with the polyphenol and hydrolysable tannin contents. The e-tongue could be used to monitor PMG juice quality in shelf life, mainly for changes in astringency.