Advisor(s)
Abstract(s)
Stoned green olives are traditional table olives produced in the Northeast of Portugal. They are highly appreciated
due to their sensory characteristics and levels of complex phenols with strong antioxidant activity, having
a significant agro-economic relevance. During debittering, stoned olives are immersed in water, which is
changed each 2 d during 20 d, leading to the reduction of initial bitterness turning them edible olives. So,
monitoring the basic taste, total phenols contents and the bitterness index during washing is very important
being a time-consuming and expensive task. Thus, the possibility of using an electronic tongue, coupled with
chemometrics, for monitoring debittering of stoned green olives (cvs. Cobrançosa and Negrinha de Freixo), was
evaluated for the first time. The electronic tongue allowed discriminating the different debittering time-periods
(sensitivity ≥ 62%, internal-validation), monitoring the decrease of bitter and pungent intensities and the increase
of the sweet intensity (0.793 ≤ R-Pearson ≤ 0.971; RMSE ≤ 1.388), assessing the decrease of the total
phenols (R-Pearson≥0.934; RMSE ≤ 19.1 g GAE/kg) and of the bitterness index (R-Pearson ≥ 0.892;
RMSE ≤0.864 g Oleuropein/kg). Therefore, the device could be a practical tool to monitor debittering of stoned
green olives during washing.
Description
Keywords
Basic tastes Bitterness index Chemometrics Debittering stoned green olives Electronic tongue Total phenols
Pedagogical Context
Citation
Rodrigues, Nuno; Marx, Ítala M.G.; Dias, Luís G.; Veloso, Ana C.A.; Pereira, José A.; Peres, António M. (2019). Monitoring the debittering of traditional stoned green table olives during the aqueous washing process using an electronic tongue. LWT. ISSN 0023-6438. 109, p. 327-335