Qualification and quantisation of processed strawberry juice based on electronic nose and tongue

Abstract

An electronic nose (E-nose) and an electronic tongue (E-tongue) have been used to characterise strawberry juices based on different processes (i.e. Microwave Pasteurisation, Steam Blanching, High Temperature Short Time Pasteurisation, Frozen-Thawed, and Freshly Squeezed). Quality parameters (vitamin C, pH, total soluble solid, total acid and sugar/acid ratio) were detected by traditional measuring methods. For qualitative discrimination, E-tongue system reached higher accuracy than E-nose did, and lower than the simultaneous utilisation. For quantitative prediction, E-tongue system had better performance (R2 ranged from 0.7294 to 0.8622 for the calibration, and R2 ranged from 0.7362 to 0.9527 for the validation) than E-nose did (R2 ranged from 0.5344 to 0.8741 for the calibration, and R2 ranged from 0.4444 to 0.7258 for the validation), and worse than the simultaneous utilisation (R2 ranged from 0.9627 to 0.9834 for the calibration, and R2 ranged from 0.8553 to 0.8959 for the validation). Either E-nose or E-tongue was suited to classify strawberry juice, but was insufficient to predict the values of quality parameters (vitamin C, pH, total soluble solid, total acid, and sugar/acid ratio). This work indicates that the simultaneous utilisation of E-nose and E-tongue can discriminate processed juices and predict juice quality parameters successfully for the food industry.