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The detection and level assessment of microorganisms is a practical quality/contamination indicator of food and water samples. Conventional analytical procedures (e.g., culture methods, immunological techniques, and polymerase chain reactions), while accurate and widely used, are time-consuming, costly, and generate a large amount of waste. Electronic noses (E-noses), combined with chemometrics, provide a direct, green, and non-invasive assessment of the volatile fraction without the need for sample pre-treatments. The unique olfactory fingerprint generated during each microorganism’s growth can be a vehicle for its detection using gas sensors. A lab-made E-nose, comprising metal oxide semiconductor sensors was applied, to analyze solid medium containing Gram-positive (Enterococcus faecalis and Staphylococcus aureus) or Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The electrical-resistance signals generated by the E-nose coupled with linear discriminant analysis allowed the discrimination of the four bacteria (90% of correct classifications for leave-one-out cross-validation). Furthermore, multiple linear regression models were also established allowing quantifying the number of colony-forming units (CFU) (0.9428 ≤ R2 ≤ 0.9946), with maximum root mean square errors lower than 4 CFU. Overall, the E-nose showed to be a powerful qualitative–quantitative device for bacteria preliminary analysis, being envisaged its possible application in solid food matrices., This research was funded by the Foundation for Science and Technology (FCT, Portugal), through national funds FCT/MCTES (PIDDAC), to CIMO (UIDB/00690/2020 and UIDP/00690/2020), to CEB (UIDB/04469/2020) and to the Associate Laboratory SusTEC (LA/P/0007/2020)., info:eu-repo/semantics/publishedVersion

The effect of typical domestic microwave heating (015min, at 800W) on the thermal degradation of unflavored and flavored olive oils' minor bioactive compounds and related antioxidant activity was studied. Olive oils from cv. Arbequina were flavored with lemon verbena essential oil (0\%, 0.2\% and 0.4\%, w/w) leading to a linear increase of total phenols (112160 mg gallic acid kg1 oil, R-Pearson=+0.9870), total carotenoids (2.192.56 mg lutein kg1 oil, R-Pearson=+0.9611), and, to a less extent, of chlorophyll (2.323.19 mg pheophytin kg1 oil, R-Pearson=+0.8238). However, no such linear trend was observed for the oxidative stability (6.57.8 h) or the radical scavenging activity (inhibition rates: 40\%43\%). The contents of total phenols, total carotenoids, and chlorophyll decreased with the rise of the microwave heating time, following their thermal degradation, a second-order kinetic model (0.8784R-Pearson0.9926). The essential oil addition did not influence the estimated second-order rate reaction constants of total phenols (0.000700.00072kg oil min1 mg1 gallic acid)and total carotenoids (0.140.17kg oil min1 mg1 lutein), with a broader variation observed for chlorophyll (0.0140.022kg oil min1 mg1 pheophytin). Globally, total carotenoids degraded faster than total phenols and chlorophyll (half-life of 2.33.4, 8.812.8, and 14.530.8 min, respectively). Moreover, except for chlorophyll, the half-life of total phenols and carotenoids linearly decreased with the essential oil addition (R-Pearson: 0.9999 and 0.9421, respectively), showing that flavoring did not have a protective effect against degradation when subjected to a microwave heating., Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020), to CEB (UIDB/04469/2020) and to BioTecNorte operation (NORTE-01-0145-FEDER-000004) and Project “GreenHealth—Digital strategies in biological assets to improve well-being and promote green health” (Norte-01-0145-FEDER-000042) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte. Nuno Rodrigues thanks the National funding by FCT—Foundation for Science and Technology, P.I., through the institutional scientific employment program–contract., info:eu-repo/semantics/publishedVersion

Cv. Arbequina fruits were inoculated during one day with suspensions of Aureobasidium pullulans, Epicoccum nigrum or both species (104 spores/g olives), isolated from olive leaves, aiming to increase the phenolic content of the olive oils. Oils were extracted from non-inoculated (control) and inoculated olives, being evaluated for their oxidative stability, and phenolic composition. Compared to the control oils, those extracted from inoculated olives showed higher oxidative stability (+1629%), phenolic acids contents (up to+37%), phenolic alcohols (up to+101%), flavonoids (up to+154%) and secoiridoid derivatives (up to + 12%). These positive effects could be attributed to the hydrolytic activity of enzymes secreted by the studied fungi on the fruit cellular membranes and extracted phenolics, increasing the extractability and, consequently, altering the phenolic concentration. Considering the two fungi species, E. nigrum inoculation had a more significant positive impact on the contents of tyrosol, oleuropein, and ligstroside derivatives, showing an inhibition effect regarding the oleacein formation. Contrary, A. pullulans inoculation mainly resulted into an accentuated increase of luteolin and oleacein contents (3 and 12-times higher compared with control oils, respectively). Overall, no enhanced positive synergetic effect could be attributed to the inoculation with a suspension containing both fungi. The significant changes observed on the phenolic contents, due to the fungal inoculation, allowed the successful discrimination of the four types of extracted oils using an electronic tongue. This device acts as an artificial taste device allowing anticipating an impact at the oils basic taste sensations due to the fungi inoculation., The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for fnancial support by national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020), CEB (UIDB/04469/2020), REQUIMTE-LAQV (UIDB/50006/2020) units and SusTEC (LA/P/0007/2020); to Project “GreenHealth—Digital strategies in biological assets to improve well being and promote green health” (Norte-01–0145-FEDER-000042) and to Project AgriFood XXI (NORTE-01–0145-FEDER-000041), funded by the European Regional Development Fund under the scope of Norte2020 ‐ Programa Operacional Regional do Norte. Ítala M.G. Marx acknowledges the Ph.D. grant (SFRH/BD/137283/2018) pro vided by FCT. Nuno Rodrigues thanks to National funding by FCT-Foundation for Science and Technology, P.I., through the institutional scientifc employment program-contract, info:eu-repo/semantics/publishedVersion

Leaves incorporation during the extraction of olive oils can enhance their chemical-sensory quality. Thus, leaves from cvs. Arbequina or Santulhana were added (1%, w/w) during the extraction of Arbequina oils using an Abencor system, being discussed the impacts on the phenolics and volatiles formation enzymatic pathways. Leaves addition contributed to a significant decrease (P-value, The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020), CEB (UIDB/04469/2020), REQUIMTE-LAQV (UIDB/50006/2020) units and SusTEC (LA/P/0007/ 2020); to BioTecNorte operation (NORTE-01-0145-FEDER-000004), to Project “GreenHealth - Digital strategies in biological assets to improve well-being and promote green health” (Norte-01-0145-FEDER-000042) and to Project AgriFood XXI (NORTE-01-0145-FEDER-000041), funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Ítala M.G. Marx acknowledges the Ph.D. grant (SFRH/BD/137283/2018) provided by FCT. 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/publishedVersion

The consumption of carotenoids has several health benefits. It is known that the fortification of olive oils with carotenoids, namely -carotene or lutein, enhanced the oils physicochemical properties, being a possible strategy to increase carotenoids intake. This study showed that a lab-made potentiometric electronic tongue, comprising lipid sensor membranes, could discriminate non-fortified olive oils from those fortified with different levels -carotene or lutein (repeated K-fold cross-validation sensitivities: 87±8%), confirming the impact of the fortification on the oils phenolic contents and sensory sensations. Moreover, the device could, semi-quantitatively, discriminate oils fortified with different amounts (0, 0.05, 0.10, and 0.15 mg/mL) of each carotenoid (repeated K-fold cross-validation sensitivities: 94±9% and 97±7%, for -carotene and lutein, respectively). This could be related to the capability of detecting increasing levels of the carotenoids and to the ability to assess the changes induced by the addition of carotenoids on the total phenols contents and on the intensities of the basic taste sensations. Indeed, satisfactory first- or second-order correlations could be established between the centroids of the first discriminant functions of the linear discriminant models and the carotenoid fortification levels, the total phenols contents, as well as with the sweetness, bitterness, and pungency intensities of the fortified oils (0.865R20.998). The successful qualitative and (semi-)quantitative performance of the electronic tongue may foresee its future application as a practical and cost-effective tool for assessing the impact of the fortification of olive oils with carotenoids at the carotenoids, phenols, and basic taste levels., The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial sup port by national funds FCT/MCTES to CIMO (UIDB/00690/2020) and to CEB (UIDB/04469/2020) units, to the Associate Laboratory SusTEC (LA/P/0007/2020), as well as 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 fund ing by FCT—Foundation for Science and Technology, P.I., through the institutional scientifc employment program-contract. Mª Carmen Murillo-Cruz thanks to the University of Jaén and Cortijo de la Loma S. L. for her pre-doctoral fellowship and also to the University of Jaén Doctoral School for the stay fnancial support provided., info:eu-repo/semantics/publishedVersion

The effect of olive leaves addition (1%, w/w, cvs. Arbequina or Santulhana), during the industrial extraction of Arbequina oils, on their physicochemical, color, phenolic profile, and sensory characteristics, was studied. Leaves incorporation reduced the primary oxidation (peroxide value by 33% and K232 by 17%) and increased the oxidative stability (19%), with the impact being more pronounced for Arbequina leaves. For these latter oils, leaves incorporation increased the total phenolic content (293±9 mg GAE/kg), which became richer in secoiridoid derivatives (143.7±3.0 mg/kg). Also, only Arbequina oils extracted with their own leaves supported the health claim regarding the protection of blood lipids against oxidative stress (hydroxytyrosol and tyrosol derivatives content greater than 5 mg per 20 g of olive oil). On the other hand, the incorporation of leaves from cvs. Arbequina and Santulhana during extraction enhanced the bitterness (5559%) and decreased the pungency (2533%). Santulhana leaves promoted an increase of the green-fruitiness (5.3±0.5), while Arbequina leaves enhanced the oils sweetness (7.0±0.4). Moreover, a potentiometric laboratory-made electronic tongue was applied, as a taste sensor device, being capable of successfully discriminating Arbequina oils extracted without or with addition of leaves, allowing the identification of (un)deliberated leaves incorporation during oils extraction. Lastly, it was found that the quality and composition of Arbequina oils industrially extracted were leaf cultivar dependent, with the low level of phenolics of control oils promoted by the incorporation of Arbequina leaves., The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020), CEB (UIDB/04469/2020) and REQUIMTE-LAQV (UIDB/50006/2020) units and to the Associate Laboratories for Green Chemistry-LAQV (UIDB/50006/2020) and SusTEC (LA/P/0007/2020), as well as to BioTecNorte operation (NORTE‐01‐0145‐FEDER‐000004) and to Project “GreenHealth—Digital strategies in biological assets to improve well-being and promote green health” (Norte-01–0145-FEDER-000042) funded by the European Regional Development Fund under the scope of Norte2020 ‐ Programa Operacional Regional do Norte. Ítala M.G. Marx acknowledges the Ph.D. grant (SFRH/BD/137283/2018) provided by FCT. 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/publishedVersion

Flavouring and fortifying virgin olive oils is an increasing commercial trend, aiming to meet new consumers’ preferences and provide new differentiated products. These practices usually positively impact the oils’ sensory profile and chemical composition, increasing their natural richness on bioactive compounds. However, some negative effects have also been reported. Scope and approach: This review provides a summary of common flavouring/fortification techniques as well as of the usual natural agents used. Co-extraction, contact and essential oils incorporation techniques are addressed. Usually, flavouring/fortification enhances desirable sensory sensations, and shelf-life, and promotes the incorporation of bioactive compounds like antioxidants. Also, the excess of flavouring may promote the appearance of unpleasant sensory sensations and, in some cases, results in pro-oxidant activity. Fortification, in turn, involves the incorporation of extracts rich in bioactive compounds, contributing to the nutritional and healthy enrichment of the olive oil. However, fortification may also increase the oil’s turbidity and/or promote the appearance of unpleasant sensory sensations, resulting in a less appealing oil, hindering the consumers’ purchasing. Key findings and conclusions: Although traditional in the Mediterranean, olive oil flavouring or fortification may have positive/negative effects at chemical and sensory levels. This awareness is of paramount commercial importance and can be used as a decision-maker tool for olive oil producers. Thus, the advantages/disadvantages of the different methodologies are discussed, and some perspectives and possible future directions are proposed and briefly discussed. The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020) unit and SusTEC (LA/P/0007/2020); to Project “GreenHealth - Digital strategies in biological assets to improve well-being and promote green health” (Norte-01-0145-FEDER- 000042) 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/publishedVersion

"Available online 24 June 2022", At olive oil industrial extraction, water addition is a practice overcoming the formation of thick pastes. The effect of water addition (0 to 6.2%, kgadded water/kgolives), during the industrial milling of cv. Arbequina olives, on the oils chemical-sensory quality, was evaluated. Despite the extra virgin olive oil classification, compared with the water incorporation (1.2-6.2%), extraction without water addition resulted into oils that showed less primary oxidation (lower peroxide values and K232), greater total phenolic content (+12-22%) and higher oxidative stability (+22-31%). No water addition increased the oils secoiridoids content (+5-13%), mainly oleacein (+27-79%). Oils extracted without water addition had a more intense ripe fruity sensation ( +11%) but lower fruit intensities (at least 4%). Thus, the quality and stability of the cv. Arbequina oils can be favoured if extracted without adding water during the olives industrial milling., The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020), CEB (UIDB/04469/2020), REQUIMTE-LAQV (UIDB/50006/2020) units and SusTEC (LA/P/0007/2020); to BioTecNorte operation (NORTE‐01‐0145‐FEDER‐000004), to Project “GreenHealth - Digital strategies in biological assets to improve well-being and promote green health” (Norte-01-0145-FEDER-000042) and to Project AgriFood XXI (NORTE-01-0145-FEDER-000041), funded by the European Regional Development Fund under the scope of Norte2020 ‐ Programa Operacional Regional do Norte. Ítala M.G. Marx acknowledges the Ph.D. grant (SFRH/BD/137283/2018) provided by FCT. 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/publishedVersion

This study evaluated the effects of lutein or -carotene incorporation (0.1mg/ml) on the quality, sensory attributes and stability of Arbequina, Picual or Royal monovarietal extra virgin olive oils. The fortification significantly decreased (p value, Foundation for Science and Technology (FCT, Portugal), Grant/Award Numbers: CIMO(UIDP/00690/2020), CIMO(UIDB/00690/2020), CEB(UIDB/04469/2020), SusTEC(LA/P/0007/2020); University of Jaén and Cortijo de la Loma S. L., info:eu-repo/semantics/publishedVersion

Olive oils from seven Portuguese regions were selected to study the effect of the geographical origin on the oils' composition. Quality parameters, fatty acids, tocopherols, hydroxytyrosol and tyrosol derivatives, and oxidative stability were evaluated. All olive oils could be classified as extra virgin, and the geographical origin significantly affected the oils chemical composition. Principal component analysis further confirmed the significant impact of the geographical origin on the composition and, indirectly, on stability of the oils, showing that the evaluated parameters could be used as markers for geographical origin identification. Alternatively, Fourier transform infrared spectroscopy was applied, allowing to establish a linear discriminant model that correctly identified the geographical origin of the olive oils with a mean sensitivity of 99 ± 3 % (internal validation), confirming the impact of the oil origin on its characteristics. This finding allowed foreseeing the future application of the spectroscopy approach as a green, fast and non-invasive authentication tool.

Cv. Arbequina extra virgin olive oils (EVOO) were flavored with cinnamon, garlic, and rosemary and characterized. Although flavoring significantly affected the physicochemical quality parameters, all oils fulfilled the legal thresholds for EVOO classification. Flavoring increased (20 to 40%) the total phenolic contents, whereas oxidative stability was dependent on the flavoring agent (a slight increase for rosemary and a decrease for cinnamon and garlic). Flavoring also had a significant impact on the sensory profiles. Unflavored oils, cinnamon, and garlic flavored oils had a fruity-ripe sensation while rosemary flavored oils were fruity-green oils. Fruit-related sensations, perceived in unflavored oils, disappeared with flavoring. Flavoring decreased the sweetness, enhanced the bitterness, and did not influence the pungency of the oils. According to the EU regulations, flavored oils cannot be commercialized as EVOO. Thus, to guarantee the legal labelling requirement and to meet the expectations of the market-specific consumers for differentiated olive oils, a lab-made electronic nose was applied. The device successfully discriminated unflavored from flavored oils and identified the type of flavoring agent (90 ± 10% of correct classifications for the repeated K-fold cross-validation method). Thus, the electronic nose could be used as a practical non-destructive preliminary classification tool for recognizing olive oils’ flavoring practice., The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020) and to CEB (UIDB/04469/2020) units and to the Associate Laboratory SusTEC (LA/P/0007/2020), as well as to BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte 2020—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/publishedVersion

Tocopherols are compounds with high biological activity, beneficial for human health that can be found in vegetable oils like olive oil, contributing for its resistance to oxidation. In this work, the tocopherol contents of olive oils extracted from centenarian olive trees of six cultivars (cvs. Lentisca, Madural, Rebol~a, Redondal, Verdeal, and Verdeal Transmontana) were evaluated during five consecutive crop seasons (2013–2017). Three tocopherol isoforms (α-, β- and γ-tocopherols) were detected in all analyzed olive oils, and their content varied significantly with the cultivar and year of production. The highest amounts were found in cv. Lentisca (456 122 mg/kg olive oil), while the lowest were observed in cv. Verdeal (179 45 mg/kg olive oil). Crop year was the most influential factor, with the highest contents observed in 2013 and lowest in 2014. Principal component analysis and hierarchical clustering analysis helped differentiate olive oils according to cultivar or production year. These data suggest that tocopherol composition may serve as a chemical marker to distinguish the subject cultivar olive oils from centenarian trees either by olive cultivar or by crop year, being some cultivars identified as potential candidates for guaranteeing the production of olive oils rich in these compounds. This work was financially supported by Project UIDB/00690/2020 (CIMO) and Project UID/QUI/50006/2019 (REQUIMTE-LAQV); all funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI) and by national funds through Fundação para a Ciência e a Tecnologia (FCT), Portugal. This work was also supported by PRODER project OliveOld—Identificação e caraterização de oliveiras centenárias para obtenção de produtos diferenciados” nº 53988. Nuno Rodrigues thanks FCT, POPH-QREN and FSE for the PhD Grant SFRH/BD/104038/2014 info:eu-repo/semantics/publishedVersion

Serra da Estrela is a Portuguese traditional cheese produced with raw ewes milk from Churra Mondegueira and Bordaleira autochthonous breeds and the wild thistle flower (Cynara cardunculus L.), which benefits from the status of Protected Designation of Origin. Cheese chemical composition, namely the fatty acids profile, depends on milk composition and on manufacturing practices. Thus, the identification of possible chemical biomarkers capable of classifying Serra da Estrela cheeses according to the dairy manufacturing plant, geographical origin or production date would be of utmost relevance for producers and consumers. A typical fatty acids profile, including 23 saturated and unsaturated fatty acids, was identified for the studied cheeses, being butyric, caproic, caprilic, capric, lauric, miristic, palmitic, stearic, oleic, linoleic and its trans-isomer and -linolenic acids the most abundant ones (relative mean abundances ranging from 1.4%±0.5% to 23.9%±1.9%). Linear discriminant models were established based on the most discriminative fatty acids (namely, caproic, caprilic, undecanoic, lauric, pentadecanoic, palmitic, palmitoleic, heptadecanoic, oleic, linoleic trans-isomer, heneicosanoic and arachidonic acids) that included less abundant fatty acids, which were selected using the simulated annealing algorithm. The established models enabled assessing cheeses origin (models based on 1012 fatty acids) and/or production date (model based on 20 fatty acids) with predictive sensitivities of 7188%. Therefore, fatty acids profiles coupled with chemometric techniques, could be foreseen as a fingerprint of cheeses genuineness, enhancing the consumers confidence when purchasing this high-value cheese, This work was financially supported by Associate Laboratory LSRE-LCM - UID/EQU/50020/2019, strategic funding UID/BIO/04469/2019-CEB and BioTecNorte operation (NORTE01-0145-FEDER-000004), and strategic project PEst-OE/AGR/ UI0690/2014–CIMO funded by—funded by national funds through FCT/MCTES (PIDDAC). The authors would also like to acknowledge the funding provided by the approved Project, with reference 02/ SAICT/ 2016/23290, entitled Characterization and Valorization of QSE PDO and its ability for health promotion (QCLASSE), financed by FCT., info:eu-repo/semantics/publishedVersion

The present study investigated the effect of malaxation times (Mt) (0, 15, 30, 45 and 60 min), during the industrial extraction of cv. Arbequina oils at 25 °C on total phenolic content of olive pastes. Additionally, the possibility of applying a lab-made potentiometric electronic tongue (E-tongue), comprising 40 lipid/polymer sensor membranes with cross sensitivity, to discriminate the olive pastes according to the Mt, was evaluated. The results pointed out that the olive pastes’ total phenolic contents significantly decreased (p-value < 0.001, one-way ANOVA) with the increase of the Mt (from 2.21 ± 0.02 to 1.99 ± 0.03 g gallic acid equivalents/kg olive paste), there being observed a linear decreasing trend (R-Pearson = −0.910). These findings may be tentatively attributed to the migration of the phenolic compounds from the olive pastes to the extracted oil and water phases, during the malaxation process. Finally, the E-tongue signals, acquired during the analysis of the olive pastes’ methanolic extracts (methanol:water, 80:20 v/v), together with a linear discriminant analysis (LDA), coupled with a simulated annealing (SA) algorithm, allowed us to establish a successful classification model. The E-tongue-LDA-SA model, based on 11 selected non-redundant sensors, allowed us to correctly discriminate all the studied olive pastes according to the Mt (sensitivities of 100% for training and leave-one-out cross-validation). The satisfactory performance of the E-tongue could be tentatively explained by the known capability of lipid/polymeric sensor membranes to interact with phenolic compounds, through electrostatic interactions and/or hydrogen bonds, which total content depended on the Mt. The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020), to CEB (UIDB/04469/2020), to REQUIMTE-LAQV (UIDB/50006/2020) 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. Ítala Marx acknowledges the Ph.D. research grant (SFRH/BD/137283/2018) provided by FCT. Nuno Rodrigues thanks the National funding by FCT-Foundation for Science and Technology, P.I., through the institutional scientific employment program contract. info:eu-repo/semantics/publishedVersion

The high proportions of monounsaturated fatty acids (MUFA) represent one of the most important technological and nutritional features of olive oils. The present study details the fatty acid (FA) composition of autochthonous cultivars (Lentisca, Madural, Redondal, Rebolã, Verdeal, and Verdeal Transmontana) produced from centenarian trees during five crop years (2013–2017). Olive cultivar highly influenced the FA composition, namely, oleic acid (70.3% for Madural to 80.7% for Redondal) and palmitic acid (10.4% for Lentisca to 13.5% for Verdeal). Similarly, crop year significantly influenced the individual FA contents. Principal component analysis of FA data enabled the unsupervised classification by cultivar and, within each cultivar, by crop year. Furthermore, the levels of nine individual FAs, together with the polyunsaturated fatty acid contents, selected using the simulated annealing algorithm, allowed for their correct classification, on the basis of linear discriminant analysis, according to the olive cultivar, with an overall sensitivity of 92%, for leave-one-out cross-validation procedure. Globally, the cultivar effect superimposed that of crop year, showing that some cultivars, such as Redondal and Verdeal Transmontana, have consistently high and homogeneous proportions of MUFA, indicating that they are worth exploring in terms of future selection of cultivars that are able to produce olive oils with increased nutritional value and that are less prone to oxidation. The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020), and to REQUIMTE (NORTE-01-0145-FEDER-LAQV (UIDB/50006/2020). This work was also supported by PRODER project OliveOld—“Identificação e caraterização de oliveiras centenárias para obtenção de produtos diferenciados” no. 53988. Nuno Rodrigues thanks national funding by FCT—Foundation for Science and Technology, P.I., through the institutional scientific employment program-contract. info:eu-repo/semantics/publishedVersion

Phenolic compounds contribute to the bioactive properties of olive oil. However, olive oils can only support a health claim concerning the protection against oxidative stress depending on the polyphenolic concentration, requiring effective measures during extraction to preserve/enhance their concentrations. The effect of the malaxation temperature (22, 28 and 34 °C) on the phenolic profile was studied for industrially extracted cv. Cobrançosa oils. Higher malaxation temperatures decreased the contents of the majority of the chromatographically detected compounds (P, The authors are grateful to the Foundation for Science andTechnology (FCT, Portugal) forfinancial support by national fundsFCT/MCTES to CIMO (UIDB/00690/2020), to CEB (UIDB/04469/2020), to REQUIMTE-LAQV (UIDB/50006/2020) and to BioTecNorteoperation (NORTE‐01‐0145‐FEDER‐000004) funded by the EuropeanRegional Development Fund under the scope of Norte2020‐Programa Operacional Regional do Norte. Ítala Marx acknowledges the Ph.D.research grant (SFRH/BD/137283/2018) provided by FCT. NunoRodrigues thanks the National funding by FCT- Foundation for Scienceand Technology, P.I., through the institutional scientific employment program-contract., info:eu-repo/semantics/publishedVersion

Electronic tongues include any electrochemical nonspecific multisensor device with global selectivity, aiming mimicking the human tongue taste capability. Electronic tongues have been widely and successfully applied as taste sensors in food and pharmaceutical areas showing huge potential as a complementary analytical tool for routine sensory analysis. In comparison with trained human panelists, the electronic tongue shows several advantages namely no detection fatigue, the possibility of analyzing toxic substances and performing objective analysis, while minimizing the risk of human subjectivity. This chapter aims to compile and discuss the main research advances reported in the last decade regarding the electronic tongues’ applications as taste sensors, being focused on the operating principles and types of devices. Thus, the main advantages and limitations of these fast, accurate, bioinspired potentiometric, voltammetric, and/or amperometric green sensor-based tools will be addressed, aiming to make an overview of the recent and future challenges toward industrial and commercial applications. The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020), to CEB (UIDB/04469/2020), to REQUIMTE-LAQV (UID/QUI/50006/2020) 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. I´tala M.G. Marx also acknowledges FCT for the PhD grant (reference number SFRH/BD/137283/2018). info:eu-repo/semantics/publishedVersion

Today, consumers are very concerned regarding food quality, nutritional composition and positive health effects of consumed foods. In this context, the preference and consumption of organic products has been increasing worldwide. In the present work, sweet peppers in two maturation stages (i.e., green and red peppers) from organic and conventional production systems were evaluated in regards to phenolic composition and antioxidant activity. Nine phenolic compounds were identified and quantified by a high-performance liquid chromatography-diode-array detector (HPLC-DAD), namely resveratrol, meta-coumaric acid, ortho-coumaric acid, clorogenic acid, caffeic acid, myricetin, rutin, luteolin-7-O-glucoside and quercitin-3-O-rhamnoside. In contrast to the production system, the maturation stage showed a pronounced significant effect on the phenolic composition of the studied sweet peppers, in general, green peppers possessed higher contents than red ones. Meta-coumaric acid, ortho-coumaric acid and quercitin-3-O-rhamnoside were more abundant in green conventional peppers and chlorogenic acid, caffeic acid and rutin were found in higher levels in red organic peppers. Regarding the antioxidant activity, green conventional peppers showed the highest DPPH, ABTS&bull, + and total reducing capacities, while red conventional peppers had higher TEAC values. Finally, principal component analysis showed that the phenolic composition together with the antioxidant capacities could be used to differentiate the production system and the maturation stage of sweet peppers. This finding confirmed that both factors influenced the peppers&rsquo, phenolic composition and antioxidant capacity, allowing their possible use as maturation&ndash, production biomarkers.

Physicochemical parameters, total phenols contents (TPC), and oxidative stabilities at 120160 °C were evaluated for two monovarietal (Arbequina and Cobrançosa cultivars, cvs.) and one blend extravirgin olive oil, confirming the label quality grade and allowing grouping them according to the different TPC (TPC = 88±7, 112±6 and 144±4mg CAE/kg, for cv. Arbequina, blend and cv. Cobrançosa oils, respectively). The lipid oxidation rate increased with the decrease of the TPC, being Cobrançosa oils (higher TPC) more thermally stable. Kineticthermodynamic parameters were determined using the activated complex/transitionstate theory and the values did not significantly differ for Cobrançosa and blend oils, which had the highest TPC, suggesting a hypothetically threshold saturation of the beneficial effect. Cobrançosa oils had a significant more negative temperature coefficient, higher temperature acceleration factor, greater activation energy and frequency factor, higher positive enthalpy of activation, lower negative entropy of activation, and greater positive Gibbs free energy of activation, probably due to the higher TPC. The results confirmed that lipid oxidation was a nonspontaneous, endothermic, and endergonic process with activated formed complexes structurally more ordered than the reactants. A negative deviation from the Arrhenius behavior was observed for all oils being the superArrhenius behavior more marked for Arbequina oils that had the lowest TPC. Finally, the kineticthermodynamic parameters allowed classifying oils according to the binomial olive cultivar/total phenols level, being the temperature acceleration factor and the Gibbs free energy of activation at 160 °C the most powerful discriminating parameters., The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) 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/publishedVersion

This study shows the potential application of a potentiometric electronic tongue coupled with a lab-made DataLogger device for the classification of dairy products according to the type of milk used in their production, i.e., natural, fermented and UHT milk. The electronic tongue device merged a commercial pH electrode and 15 lipid/polymeric membranes, which were obtained by a drop-by-drop technique. The potentiometric signal profiles gathered from the 16 sensors, during the analysis of the 11 dairy products (with ten replicate samples), together with principal component analysis showed that dairy samples could be naturally grouped according to the three types of milk evaluated. To further investigate and verify this capability, a linear discriminant analysis together with a simulated annealing variable selection algorithm was also applied to the electrochemical data, which were randomly split into two datasets, one used for model training and internal-validation using a repeated K-fold cross-validation procedure (with 64\% of the data); and the other for external validation purposes (containing the remaining 36\% of the data). The multivariate supervised strategy used allowed establishing a classification model, based on the potentiometric information of four sensor lipid membranes, which enabled achieving a successful discrimination rate of 100\\% for both internal- and external-validation processes. The demonstrated versatility of the built electronic tongue for discriminating dairy products according to the type of milk used in their production combined with its simplicity, low-cost and fast time analysis may envisage a possible future application in dairy industry., This study was funded in part by the Ministry of Research, Technology and Higher Education, the Republic of Indonesia, Project 001/SP2H/LT/DRPM/IV/2017. The authors also thank the Directorate General of Islamic Education and Instituto Politécnico de Bragança, Portugal, for their support throughout the completion of this work. This work was financially supported by Project POCI01–0145-FEDER-006984 – Associate Laboratory LSRE-LCM, Project UID/BIO/04469/2013 – CEB and strategic project PEst-OE/ AGR/UI0690/2014 – CIMO all funded by FEDER - Fundo Europeu de Desenvolvimento Regional through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT - Fundação para a Ciência e a Tecnologia, Portugal., info:eu-repo/semantics/publishedVersion

Table olives are prone to the appearance of sensory defects that decrease their quality and in some cases result in olives unsuitable for consumption. The evaluation of the type and intensity of the sensory negative attributes of table olives is recommended by the International Olive Council, although not being legally required for commercialization. However, the accomplishment of this task requires the training and implementation of sensory panels according to strict directives, turning out in a time-consuming and expensive procedure that involves a degree of subjectivity. In this work, an electronic tongue is proposed as a taste sensor device for evaluating the intensity of sensory defects of table olives. The potentiometric signal profiles gathered allowed establishing multiple linear regression models, based on the most informative subsets of signals (from 24 to 29 recorded during the analysis of olive aqueous pastes and brine solutions) selected using a simulated annealing meta-heuristic algorithm. The models enabled the prediction of the median intensities (R2 ≥ 0.942 and RMSE ≤ 0.356, for leave-one-out or repeated K-fold cross-validation procedures) of butyric, musty, putrid, winey-vinegary, and zapateria negative sensations being, in general, the predicted intensities within the range of intensities perceived by the sensory panel. Indeed, based on the predicted mean intensities of the sensory defects, the electrochemical-chemometric approach developed could correctly classify 86.4% of the table olive samples according to their trade category based on a sensory panel evaluation and following the International Olive Council regulations (i.e., extra, 1st choice, 2nd choice, and olives that may not be sold as table olives). So, the satisfactory overall predictions achieved demonstrate that the electronic tongue could be a complementary tool for assessing table olive defects, reducing the effort of trained panelists and minimizing the risk of subjective evaluations., This work was financially supported by Project POCI-01-0145-FEDER-006984—Associate Laboratory LSRE-LCM, by Project UID/QUI/00616/2013 —CQ-VR, and UID/AGR/00690/ 2013—CIMO, all funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI) and by national funds through Fundação para a Ciência e a Tecnologia (FCT), Portugal. Strategic funding of UID/BIO/04469/2013 unit is also acknowledged. Nuno Rodrigues thanks FCT, POPH-QREN, and FSE for the Ph.D. Grant (SFRH/BD/104038/2014)., info:eu-repo/semantics/publishedVersion

The composition of Serra da Estrela PDO cheeses (total fat, total protein, salt and free amino acids) was assessed using NIR spectrophotometry and UPLC-DAD-MS/MS. In total, 24 cheeses were acquired from 6 certified cheesemakers located in 5 different municipalities within the delimited PDO geographical region. Cheeses were produced from raw ewe milk of two autochthonous Portuguese sheep breeds, between November 2017 and March 2018, and were acquired after 45 days of maturation. The data include the mean (and respective standard deviations) levels of moisture (%), total fat (%), total protein (%) and salt (%), obtained by NIR spectrophotometry. As well the mean (and respective standard deviations) of free amino acids contents (mg/100 g of cheese, in wet basis) evaluated using a UPLC-DAD-MS/MS method are also shown. The latter data include information regarding 8 essential free amino acids (histidine, leucine-isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine) and 9 non-essential free amino acids (arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, proline, tyrosine and serine). Leucine and isoleucine, being isomers, were quantified together. Leucine-isoleucine, phenylalanine and serine were the most abundant essential free amino acids and cysteine, proline and asparagine were the most abundant non-essential free amino acids. Free amino acids contents depended on the cheese producer as well as on the production time-period., The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO - UID/AGR/00690/2019, to Associate Laboratory LSRE-LCM - UID/EQU/50020/2019, to the strategic funding CEB - UID/BIO/04469/2019 and BioTecNorte operation (NORTE-01-0145-FEDER-000004). The authors would also like to acknowledge the funding provided by the approved Project, with reference 02/SAICT/2016/23290, entitled "Characterization and Valorization of QSE PDO and its ability for health promotion (QCLASSE)", financed by FCT. S. Falcão thanks National funding by FCT- Foundation for Science and Technology, P.I., through the institutional scientific employment program-contract., info:eu-repo/semantics/publishedVersion

Glucose, fructose and sucrose are sugars with known physiological effects, and their consumption has impact on the human health, also having an important effect on food sensory attributes. The analytical methods routinely used for identification and quantification of sugars in foods, like liquid chromatography and visible spectrophotometry have several disadvantages, like longer analysis times, high consumption of chemicals and the need for pretreatments of samples. To overcome these drawbacks, in this work, a potentiometric electronic tongue built with two identical multi-sensor systems of 20 cross-selectivity polymeric sensors, coupled with multivariate calibration with feature selection (a simulated annealing algorithm) was applied to quantify glucose, fructose and sucrose, and the total content of sugars as well. Standard solutions of ternary mixtures of the three sugars were used for multivariate calibration purposes, according to an orthogonal experimental design (multilevel fractional factorial design) with or without ionic background (KCl solution). The quantitative models&rsquo, predictive performance was evaluated by cross-validation with K-folds (internal validation) using selected data for training (selected with the K-means algorithm) and by external validation using test data. Overall, satisfactory predictive quantifications were achieved for all sugars and total sugar content based on subsets comprising 16 or 17 sensors. The test data allowed us to compare models&rsquo, predictions values and the respective sugar experimental values, showing slopes varying between 0.95 and 1.03, intercept values statistically equal to zero (p-value &ge, 0.05) and determination coefficients equal to or greater than 0.986. No significant differences were found between the predictive performances for the quantification of sugars using synthetic solutions with or without KCl (1 mol L&minus, 1), although the adjustment of the ionic background allowed a better homogenization of the solution&rsquo, s matrix and probably contributed to an enhanced confidence in the analytical work across all of the calibration working range.