Sensory classification of table olives using an electronic tongue: Analysis of aqueous pastes and brines.

Table olives are highly appreciated and consumed worldwide. Different aspects are used for trade category classification being the sensory assessment of negative defects present in the olives and brines one of the most important. The trade category quality classification must follow the International Olive Council directives, requiring the organoleptic assessment of defects by a trained sensory panel. However, the training process is a hard, complex and sometimes subjective task, being the low number of samples that can be evaluated per day a major drawback considering the real needs of the olive industry. In this context, the development of electronic tongues as taste sensors for defects' sensory evaluation is of utmost relevance. So, an electronic tongue was used for table olives classification according to the presence and intensity of negative defects. Linear discrimination models were established based on sub-sets of sensor signals selected by a simulated annealing algorithm. The predictive potential of the novel approach was first demonstrated for standard solutions of chemical compounds that mimic butyric, putrid and zapateria defects (≥93% for cross-validation procedures). Then its applicability was verified; using reference table olives/brine solutions samples identified with a single intense negative attribute, namely butyric, musty, putrid, zapateria or winey-vinegary defects (≥93% cross-validation procedures). Finally, the E-tongue coupled with the same chemometric approach was applied to classify table olive samples according to the trade commercial categories (extra, 1st choice, 2nd choice and unsuitable for consumption) and an additional quality category (extra free of defects), established based on sensory analysis data. Despite the heterogeneity of the samples studied and number of different sensory defects perceived, the predictive linear discriminant model established showed sensitivities greater than 86%. So, the overall performance achieved showed that the electrochemical device could be used as a taste sensor for table olives organoleptic trade successful classification, allowing a preliminary quality assessment, which could facilitate, in the future, the complex task of sensory panelists.

Avaliação da qualidade microbiológica, físico-química e sensorial de bebidas lácteas fermentadas, sabor morango, comercializadas na cidade de Medianeira, PR / Evaluation of microbiological, physicochemical and sensory properties of fermented milk drinks, strawberry flavor, commercialized in the city of Medianeira, PR

Foram coletadas seis marcas de bebidas lácteas fermentadas, sabor morango, em triplicata, perfazendo um total de dezoito amostras, comercializadas nos principais supermercados da cidade de Medianeira – PR, para posterior realização de análises microbiológicas e físico-químicas, a fim de avaliar se estavam de acordo com os parâmetros da legislação vigente e realização de análise sensorial utilizando Escala Hedônica de 07 pontos, para verificar a aceitabilidade do produto por parte dos consumidores. Em relação aos resultados obtidos, todas as amostras encontraram-se dentro dos parâmetros estabelecidos para contagem de bactérias ácido láticas, porém uma estava fora dos limites exigidos para a determinação de coliformes a 35 e 45ºC, em todas as repetições. As análises físico-químicas mostraram que, dentro do que é exigido pela legislação, neste caso apenas proteína, todas as amostras obedeciam aos padrões vigentes e as demais, em sua maioria, coincidiram com as bibliografias consultadas. Ao serem submetidas à análise sensorial de escala Hedônica as amostras avaliadas obtiveram notas entre as correspondentes a indiferente e a gostei regularmente, sugerindo que todas precisam ser melhoradas quanto ao aspecto sensorial.