Flavour characteristics of Ilex paraguariensis infusion, a typical Argentine product, assessed by sensory evaluation and electronic nose

Sensory evaluation and electronic nose (E-nose) technology were applied to study two formulations of a new product intended to have organoleptic characteristics similar to those of Ilex paraguariensis (Saint Hilaire) infusions. Infusions prepared from I paraguariensis, called yerba mate in South America, possess distinct sensory properties that were described by trained panellists using a lexicon of 17 terms. The two commercial products were formulated by combining various flavour components and processed as instant powders for infusion. Results from the sensory panel showed that it would be necessary to change the product formulation in order to achieve desirable yerba mate characteristics. Odour, mouthfeel and sweetness intensities would have to be improved. The E-nose had an array of 32 sensors which were able to discriminate between infusions prepared from yerba mate and from the instant powders. Using stepwise discriminant analysis, the group of sensors that contributed to this classification was identified. The response of these sensors correlated (P < 0.05) with yerba mate odour, mouthfeel and sweetness attributes. Comparison of the results obtained by the two methodologies enabled the E-nose procedure to be improved and showed that this methodology is suitable for food product development and is a good complement to sensory evaluation.