Application of the FTIR technique as a non-invasive tool to discriminate Portuguese olive oils with Protected Designation of Origin.

Three Portuguese olive oils with PDO ('Azeite do Alentejo Interior', 'Azeites da Beira Interior' and 'Azeite de Trás-os-Montes') were studied considering their physicochemical quality, antioxidant capacity, oxidative stability, total phenols content, gustatory sensory sensations and Fourier transform infrared (FTIR) spectra. All oils fulfilled the legal thresholds of EVOOs and the PDO's specifications. Olive oils from 'Azeite da Beira Interior' and 'Azeite de Trás-os-Montes' showed greater total phenols contents and antioxidant capacities, while 'Azeites da Beira Interior' presented higher oxidative stabilities. Linear discriminant models were developed using FTIR spectra (transmittance and the 1st and 2nd derivatives), allowing the correct identification of the oils' PDO (100 % sensitivity and specificity, repeated K-fold-CV). This study also revealed that multiple linear regression models, based on FTIR transmittance data, could predict the sweet, bitter, and pungent intensities of the PDO oils (R2 ≥0.979±0.016; RMSE≤0.26±0.05, repeated K-fold-CV). This demonstrates the potential of using FTIR as a non-destructive technique for authenticating oils with PDO.

Forage based diet as an alternative to a high concentrate diet for finishing young bulls - Effects on growth performance, greenhouse gas emissions and meat quality.

Two groups of 8 individually housed young crossbred-bulls, in the finishing period, were used to test the effect of a Total Mixed Ration diet with high forage content (54% DM), low starch content (14% DM), supplemented with sunflower seeds (10% DM) (HFS) on growth performance, carcass and meat quality, fatty acid profile and carbon footprint, with reference to a conventional concentrate-based (90% DM) (Control) diet. The experiment lasted 64 days before slaughter. During the experiment, feed intake was monitored daily and live weight every 14 days. Individual CH4 emissions were assessed at 16-days intervals, using a GreenFeed for Large Animal unit. Feed intake and feed conversion ratio were higher for HFS diet, but average daily weight gain and feeding costs were similar for the two diets. Dressing percentage was reduced with HFS diet. The HFS increased redness, yellowness and Chroma of subcutaneous fat, but did not compromise commercial value of the carcasses. Meat colour, shear force, or sensory parameters were not affected by diet. The HFS diet allowed a healthier FA profile, due to the higher proportions of 18:3n-3, t11-18:1 and c9,t11-18:2 and the lower proportion of t10-18:1. The HFS diet did not reduce the carbon footprint in the finishing period of young bulls, due to increased digestive CH4 emissions. The results of this experiment showed that the HFS diet can be an alternative to the conventional diets used in finishing young-bulls. Although it may result in a slight reduction in animal performance, it has a strong impact on reducing dependence on inputs from outside the farm.

Geographical discrimination of olive oils from Cv. 'Galega Vulgar'.

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.

Does water addition during the industrial milling phase affect the chemical-sensory quality of olive oils? The case of cv. Arbequina oils.

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.

Impact of fresh olive leaves addition during the extraction of Arbequina virgin olive oils on the phenolic and volatile profiles.

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 secoiridoids (-11%), C6-aldehydes (-16%), and ester compounds (-22%). This could be tentatively related to a reduction of the enzymatic activity of secoiridoids biosynthesis and lipoxygenase pathways, promoted by the leaves' addition. Moreover, in the presence of leaves, the oils' total contents of phenolics and volatiles were significantly reduced (-7 and -17%, respectively). Contrary, the incorporation of leaves significantly increased (P-value < 0.05) the contents of C6-alcohols (+37%) and the intensities of the green fruity (+25%) and apple (+30%) sensations.

Improvement of stability and carotenoids fraction of virgin olive oils by addition of microalgae Scenedesmus almeriensis extracts.

Humans are not capable of synthesizing carotenoids de novo and thus, their presence in human tissues is entirely of dietary origin. Consumption of essential carotenoids is reduced due to the lower intake of fruits and vegetables. Microalgae are a good source of carotenoids that can be exploited. In the present work, carotenoids rich extracts from Scenedesmus almeriensis were added to extra-virgin olive oils at different concentrations (0.1 and 0.21 mg/mL) in order to enhance the consumption of these bioactives. Extracts brought changes in olive oils color, turning them orange-reddish. Quality of olive oils was improved, since peroxidation was inhibited. Olive oils fatty acids and tocopherols were not affected. ß-carotene and lutein contents increase considerably, as well as oxidative stability, improving olive oils shelf-life and nutritional value. Inclusion of S. almeriensis extracts is a good strategy to improve and enhance the consumption of carotenoids, since olive oil consumption is increasing.

Bioactivity and phenolic composition from natural fermented table olives.

In the present work, the phenolic composition, and antioxidant and antimicrobial properties of twenty-four samples of naturally fermented table olives from the northeast of Portugal were evaluated. The analysis of phenolic composition was performed by HPLC/DAD, and ten compounds were identified, hydroxytyrosol, verbascoside derivate and hydroxytyrosol glycol being the most abundant. Total phenolic content varied between 2.37 and 64.17 µg mg(-1) of extract. The IC50 values from the antioxidant activity methods tested varied between 0.30 and 1.66 mg mL(-1) for reducing power, and between 0.13 and 0.83 mg mL(-1) for DPPH. The results obtained in the antioxidant activity were extremely significantly correlated with the main phenolic compounds as well as with the total phenolic content. A principal component analysis allowed grouping the samples according to their phenolic composition and antioxidant potential. Table olive extracts were able to inhibit some pathogenic microorganisms, mainly Gram-positive bacteria. Higher antimicrobial inhibition was recorded in the extracts rich in phenolic compounds and higher antioxidant potential.

Incremental validity of proactive personality over the big five for predicting job performance of software engineers in an innovative context / Validez añadida de la personalidad proactiva sobre los «Cinco Grandes» para predecir el desempeño en el puesto de ingenieros de software en un contexto innovador

This study examined the incremental validity of proactive personality for predicting overall job performance over the Big Five in the context of an innovative software engineering job. Proactive personality and the Big Five were measured in a sample of 243 engineers and overall job performance was assessed through supervisor ratings in a sub-sample of 95 of these engineers. Results showed that even though proactive personality represents a valid and important predictor of performance it does not show a relevant increment on the prediction yielded by extraversion, openness, conscientiousness, emotional stability and organizational tenure. Implications for the relevancy and practical value of proactive personality for personnel selection are discussed(AU)

Este estudio examina la validez añadida de la personalidad proactiva sobre los «cinco grandes» para predecir el desempeño en el trabajo en el contexto de un puesto de trabajo de ingeniero de software. La personalidad proactiva y los «cinco grandes» fueron medidos en una muestra de 243 ingenieros y el desempeño global fue evaluado mediante valoraciones del supervisor en una sub-muestra de 95 de estos ingenieros. Los resultados mostraron que aun cuando la personalidad proactiva representa un importante y válido predictor del desempeño no muestra un incremento relevante en la predicción producida por la extraversión, apertura, conciencia, estabilidad emocional y antigüedad en el puesto. Se discuten las implicaciones, la relevancia y el valor práctico de la personalidad proactiva para la selección de personal(AU)

Influence of spike lavender (Lavandula latifolia Med.) essential oil in the quality, stability and composition of soybean oil during microwave heating.

Lipids oxidation is one of the main factors leading to quality losses in foods. Its prevention or delay could be obtained by the addition of antioxidants. In this sense the present work intend to monitor the protective effects of Lavandula latifolia essential oil during soybean oil microwave heating. To achieve the proposed goal quality parameters (free acidity, peroxide value, specific coefficients of extinction and ΔK), fatty acids profile, tocopherols and tocotrienols composition, antioxidant activity and oxidative stability were evaluated in soybean oil with and without spike lavender essential oils (EO) submitted to different microwave heating exposure times (1, 3, 5, 10 and 15 min; 1000 Watt) with a standard domestic microwave equipment. Microwave heating induced severe quality and composition losses, mainly above 3 min of microwave heating, regardless the sample tested. However, spike lavender EO addition counteracts the oxidation comparatively to control oils, by presenting enhanced values in quality parameters. A higher protection in unsaturated fatty acids loss was also observed as well as a higher antioxidant activity and oxidative stability. The microwave heating effects were clearly different in the samples with essential oils addition, allowing discrimination from plain soybean oils by a principal component analysis, being also capable to discriminate the different heating times tested within each sample.