Sweet peppers discrimination according to agronomic production mode and maturation stage using a chemical-sensory approach and an electronic tongue

Abstract

Supplementary data to this article can be found online at https://doi.org/10.1016/j.microc.2020.105034.The demand for organic foods has increased worldwide, in particular due to the association with healthier, more nutritious and tasty products, being a clear trend on sweet peppers consumption. Thus, this study aimed to evaluate the effects of agronomic production mode (conventional and organic) and maturation stage (associated to green, turning and red colours) on the chemical-sensory attributes of peppers grown in open field. It was found that organic peppers had a better visual/tactile aspect (greater firmness and more intense colours) but lower chemical quality (lower titratable acidity and total soluble solids). On the other hand, red peppers (higher maturation stage) had lower visual-tactile quality but higher chemical quality. From sensory analysis, conventional peppers had better overall aspect, colour intensity-homogeneity and brightness. Then again, the maturation stage of peppers mostly influenced the sensory visual attributes, being turning colour peppers the less appreciated, although organic red peppers were less succulent and had a lower global quality. Even so, the chemical-sensory parameters could be used to discriminate peppers taking into account the agronomic production mode and the maturation stage/colour (79±12% of correct classifications for the repeated K-fold cross-validation procedure). However, a trained sensory panel is required, which can be a major drawback considering their scarcity. This limitation was successfully overcome by using a potentiometric electronic tongue, which allowed discriminating the peppers with a higher predictive sensitivity (85±9%), showing that this device could be used as an accurate taste sensor for the qualitative analysis of sweet peppers.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Program PT2020 for financial support to CIMO (UIDB/00690/2020) and to CEB (UIDB/04469/2020) units and to BioTecNorte operation (NORTE‐01‐0145‐FEDER‐000004) funded by the European Regional Development Fund under the scope of Norte2020 ‐ Programa Operacional Regional do Norte. Nuno Rodrigues thanks to National funding by FCT- Foundation for Science and Technology, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio

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