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Electronic nose: a tool to verify the PDO declaration of Portuguese olive oils
Rodrigues, Nuno; Ferreiro, Nuno; Ruano, Daniela; Dias, Francisco; Veloso, Ana C. A.; Pereira, José A.; Peres, António M.The volatile and olfactory profiles of three Portuguese olive oils with protected designations of origin (PDO) were studied: Azeite do Alentejo Interior, Azeites da Beira Interior, and Azeite de Trás-os-Montes. Seven classes of volatiles were identified, with aldehydes, followed by hydrocarbons and alcohols, the most prevalent (5.63, 2.92, and 2.79 mg/kg olive oil, respectively). The Azeites da Beira Interior o...
Impact of the covering vegetable oil on the sensory profile of canned tuna of K...
Ferreiro, Nuno; Rodrigues, Nuno; Veloso, Ana C. A.; Fernandes, Conceição; Paiva, Helga; Pereira, José A.; Peres, António M.The impact of the covering vegetable oil (sunflower oil, refined olive oil and extra virgin olive oil, EVOO) on the physicochemical and sensory profiles of canned tuna (Katsuwonus pelamis species) was evaluated, using analytical techniques and a sensory panel. The results showed that canned tuna covered with EVOO possesses a higher content of total phenols and an enhanced antioxidant capacity. This covering med...
Impact of incorporating olive leaves during the industrial extraction of cv. Ar...
Marx, Ítala M. G.; Casal, Susana; Rodrigues, Nuno; Cruz, Rebeca; Veloso, Ana C. A.; Pereira, José A.; Peres, António M.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 leav...
Multivariate geostatistical analysis of stable isotopes in Portuguese varietal ...
Jiménez-Morillo, Nicasio T.; Palma, Vera; Garcia, Raquel; Pereira, José A.; Barrocas dias, Cristina; Cabrita, Maria J.Stable isotope contents of carbon, hydrogen and oxygen are known to reflect the geo-climatic conditions under which olives grown. This study aims to unravel the correlation between some of the main geographic variables and the isotopic composition of different Portuguese varietal extra virgin olive oil (EVOO) samples. Thus, the isotopic composition (δ13C, δ18O and δ2H) of 38 EVOO samples from 11 olive varieties...
An electronic nose as a non-destructive analytical tool to identify the geograp...
Rodrigues, Nuno; Ferreiro, Nuno; Veloso, Ana C. A.; Pereira, José A.; Peres, António M.The geographical traceability of extra virgin olive oils (EVOO) is of paramount importance for oil chain actors and consumers. Oils produced in two adjacent Portuguese regions, Côa (36 oils) and Douro (31 oils), were evaluated and fulfilled the European legal thresholds for EVOO categorization. Compared to the Douro region, oils from Côa had higher total phenol contents (505 versus 279 mg GAE/kg) and greater ox...
Inoculation of cv. Arbequina olives with fungi isolated from leaves and its eff...
Marx, Ítala M. G.; Baptista, Paula; Casal, Susana; Rodrigues, Nuno; Cruz, Rebeca; Veloso, Ana C. A.; Pereira, José A.; Peres, António M.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...
Does water addition during the industrial milling phase affect the chemical-sen...
Marx, Ítala M. G.; Casal, Susana; Rodrigues, Nuno; Cruz, Rebeca; Veloso, Ana C. A.; Pereira, José A.; Peres, António M.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 additio...
Impact of fresh olive leaves addition during the extraction of Arbequina virgin...
Marx, Ítala M. G.; Casal, Susana; Rodrigues, Nuno; Cruz, Rebeca; Peres, Fátima; Veloso, Ana C. A.; Pereira, José A.; Peres, António M.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 < 0.05) of the contents of s...
Application of a lab-made electronic nose for extra virgin olive oils commercia...
Teixeira, Guilherme G.; Dias, Luís G.; Rodrigues, Nuno; Marx, Ítala M. G.; Veloso, Ana C. A.; Pereira, José A.; Peres, António M.An electronic nose, comprising nine metal oxide sensors, has been built aiming to classify olive oils according to the fruity intensity commercial grade (ripely fruity or light, medium and intense greenly fruity), following European regulated complementary terminology. The lab-made sensor device was capable to differentiate standard aqueous solutions (acetic acid, cis-3-hexenyl, cis-3-hexen-1-ol, hexanal, 1-hex...
Effect of malaxation temperature on the physicochemical and sensory quality of ...
Marx, Ítala M. G.; Rodrigues, Nuno; Veloso, Ana C. A.; Casal, Susana; Pereira, José A.; Peres, António M.Olive oil is consumed worldwide due to its appreciated sensory attributes and health benefits, which are related with its fatty acid profile and richness in phenolic compounds that support a health claim concerning olive oil protective effects on blood lipids. However, to ensure that oils possess a rich phenolic content, the extraction conditions can be optimised. Therefore, the effects of malaxation temperatur...