Monitoring grape ripeness using a voltammetric electronic tongue

Abstract

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 2 grapes. The PCA models, obtained using the physico-chemical or electrochemical data, showed variation of ripeness with time. Moreover the study was completed by using partial least squares (PLS) regression in an attempt to establish a correlation between the data collected from the electronic tongue and Total Acidity, pH and ºBrix values. A good predictive model was obtained for the prediction of Total Acidity and ºBrix. These results suggest the possibility of employing electronic tongues to monitor grape ripeness and of, therefore, evaluating the right time for harvesting.

Characterization of Conventional, Biodynamic, and Organic Purple Grape Juices by Chemical Markers, Antioxidant Capacity, and Instrumental Taste Profile

“…Some of the analytical techniques widely used to evaluate the quality of fruit juices include gas chromatography, routine analysis of nutritional composition, instrumental color, and high‐performance liquid chromatography (HPLC) of phenolic compounds, carotenoids, and some vitamins, among others (Obón and others ; Braga and others ). However, other techniques can also be employed to evaluate commercial fruit juices, such as sensory analysis using consumers and/or a trained taste panel or even by using an instrumental taste sensing system, the electronic tongue (Campos and others ; Wang and Qiu ; Granato and others , ). As well stressed by Savage (), building and maintaining a trained sensory panel is usually expensive for food companies and the analysis of taste by consumers generates subjective data.…”

Use of Nanomaterials in Food Science

“…It also consists of an array of nanosensors, which are sensitive to gases released by spoiling food, and in that case, the sensor changes its color, giving a visible signal about freshness or adulteration of food (Momin et al 2013). Electronic tongue (e-tongue) has been fabricated for determination of concentration of nitrite, nitrate, and chloride in minced meat (Campos et al 2010), ripening of grapes (Campos et al 2013), quality of tea (Kumar et al 2016), polyphenols in wine (Andrei et al 2016;Cetó et al 2012;Magro et al 2016), etc.…”

Capacidad de Discriminación de Dos Redes de Sensores como Unidades Sensibles de una Mini-Lengua Electrónica sobre Muestras de Leche

“…La selectividad cruzada consiste en que cada sensor debe responder de manera distinta frente a una muestra, asegurando así que cada uno aporta información útil para discriminarla y que la red de sensores registra señales distintas frente a cada una de las muestras, permitiendo que las señales recogen información de las diferencias fisicoquímicas entre las muestras. (González-Calabuig et al, 2016;Campos et al, 2013;Vagin y Winquist 2015;Arrieta et al, 2016;Díaz 2017). Esta particularidad es lo que permite que los dispositivos de lengua electrónica tengan la capacidad para clasificar y discriminar muestras complejas.…”

“…Los primeros prototipos de lengua electrónica voltamétricas se basaron en la utilización de sensores metálicos de oro, iridio, platino, plata, cobre, níquel, cobalto, entre otros. (Campos et al, 2013;Lu et al, 2016). Sin embargo, el uso de algunos metales como elementos principales de captación de señales presentaban ciertas dificultades como la formación de capas de óxido cuando son manipulados a ciertos grados de pH y potencial redox.…”