New domestic processing methods: effect on potato nutritional composition

Background and objectives: Potatoes nutritional and bioactive features are influenced by thermal processing conditions, defining its nutritional composition and health impact. Consumers seek increasingly for faster domestic cooking methods, such as microwave cooking in alternative to current frying or baking. Also, several devices are being commercialized for healthier frying simulation, without a documented characterization of the final processed food nutritional data. Thus, this study aimed to assess and compare the influence of these domestic processing methods on the quality of potatoes processed with olive oil. Methods: Potatoes were processed by frying, baking, microwave and a low-fat frying device, with equivalent shape and olive oil amounts, except frying. Samples were evaluated for crude fat, fatty acid composition, vitamin E, total carotenoids and total phenols. Results: Microwave cooked potatoes presented similar fat contents as standard frying, higher than those achieved by baking or with the low-fat frying device tested, but the fatty acid composition was similar. Vitamin E loss was comparatively higher after frying but no significant differences were found for total carotenoids. Potatoes phenolic compounds were partially loss during cooking, being apparently higher after baking. Conclusions: The distinct nutritional features obtained highlight for the importance of detailing the food compositional tables regarding each processing method, including the “new” domestic methodologies, increasingly used by consumers

Nannochloropsis gaditana grown outdoors in annular photobioreactors: operation strategies

Microalgae are a topic of intense research due to their potential applications in bio-based economy. However, sustainable commercial production is still overpriced due to high cultivation costs, harvesting and dewatering processes. In the present study, trials were conducted with the aim to improve daily operation strategies related to microalgae harvesting processes that did not compromise biomass productivity or the biochemical composition of the cultivated microalgae. Two experimental trials were performed in outdoor tubular annular photobioreactors to evaluate the effects of harvesting and medium dilution time (sunrise vs sunset) on Nannochloropsis gaditana biomass productivity, lipid and fatty acid content. Results showed that harvesting time had no significant effect on cell concentration and biomass productivity. Harvesting and medium dilution time did not affect lipid content. However, lipid content in samples collected at sunset was significantly higher than in samples collected at sunrise for both experimental treatments. The fatty acids profiles were mainly composed by polyunsaturated fatty acids, followed by mono-unsaturated fatty acids and saturated fatty acids. Regardless of medium dilution time, harvesting at sunset indicated that lipidic production (higher polyunsaturated fatty acids and lower saturated fatty acids) was favored without affecting the biomass productivity. The current study showed harvesting in the afternoon is a viable option for large production units that use semi-continuous strategy, without compromising biomass cell and lipid productivity.info:eu-repo/semantics/publishedVersio

Identification of leaf volatiles from olive (Olea europaea) and their possible role in the ovipositional preferences of olive fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae)

The olive fly, Bactrocera oleae (Rossi), is a monophagous pest that displays an oviposition preference among cultivars of olive (Olea europaea L.). To clarify the oviposition preference, the olive leaf volatiles of three olive cultivars (Cobrançosa, Madural and Verdeal Transmontana) were assessed by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) at six different periods of olive fruit maturation and degrees of infestation. A total of 39 volatiles were identified, mainly esters and alcohols, with a minor percentage of aldehydes, ketones and terpenic compounds, including sesquiterpenes. At sampling dates with higher degrees of infestation, cv. Cobrançosa had, simultaneously, significantly lower infestation degrees and higher volatile amounts than the other two cultivars, with a probable deterrent effect for oviposition. The green leaf volatiles (GLVs) (Z)-3-hexen-1-ol and (Z)-3-hexen-1-ol acetate) were the main compounds identified in all cultivars, together with toluene. The abundance of GLVs decreas ed significantly throughout maturation, without significant differences among cultivars, while toluene showed a general increase and positive correlation with olive fly infestation levels. The results obtained could broaden our understanding of the roles of various types and amounts of olive volatiles in the environment, especially in olive fly host selection and cultivar preference.The authors are grateful to the Portuguese Foundation of Science and Technology for financial support through the project EXCL/AGR-PRO/0591/2012 “Olive crop protection in sustainable production under global climatic changes: linking ecological infrastructures to ecosystem functions”. R. Malheiro thanks FCT, POPH-QREN and FSE for PhD grant (SFRH/BD/74675/2010). This manuscript is part of Ricardo Malheiro PhD Thesis.info:eu-repo/semantics/publishedVersio

Classification PDO olive oils on the basis of their sterol composition by multivariate analysis

The sterol compositions (GLC/FID/capillary column) of monovarietal olive oils (51 samples) from the most important cultivars of northeastern Portugal (Cvs. Cobranc¸osa, Madural and Verdeal Transmontana) and 27 commercial samples of olive oils with protected denomination of origin (PDO) from the same region and cultivars were evaluated. Δ-sitosterol, Δ5-avenasterol and campesterol were the most representative sterols. Cholesterol, stigmasterol, clerosterol and Δ7-stigmastenol were also found in all samples. All studied samples respected EC Regulation N. 2568, and in all cases total sterols were remarkably higher than the minimum limit set by legislation, ranging from 2003 to 2682 mg/kg. Results were analysed with the help of several statistical techniques, including reduction of dimensionality by principal component analysis with cross-validation of the number of components, followed by the use of canonical variate predictive biplots for model development and canonical variate interpolative biplots for approximate classification of monovarietal and PDO olive oils. These biplots proved to be a very interesting solution in the present case study, overcoming the problems of interpretation and classification that arise whenever different multivariate analyses are coupled together

Análise de ciclo de vida do azeite transmontano

O sector do azeite é um importante factor económico em Portugal. Sendo Portugal um grande consumidor deste produto, também é um dos principais produtores Europeus (o quarto maior produtor da Europa, atrás da Grécia, Itália e Espanha) e exportadores. A nível nacional, a região de Trás-os-Montes e segundo o Recenseamento Agrícola, é a segunda maior região olivícola, sendo que é a principal a nível de azeitona para a mesa. Numa altura em que a consciencialização ambiental está a ganhar um peso nas escolhas de produtos para o nosso dia-a-dia, é cada vez mais importante haver uma produção “amiga do ambiente”. É neste ponto em que entra a chamada Análise de Ciclo de Vida (ACV). A ACV é um estudo assente num sistema de modelação com todos os componentes necessários para a produção de um determinado bem, fazendo de seguida uma avaliação aos impactes causados no ambiente. Este teve como ponto de partida inquéritos aplicados a três produtores de azeitonas (F1, F2 e F3) e a dois lagares de azeite (P2 e P3), tendo estas actividades características diferenciadas. O F1 é um olival de tamanho mediano (~12ha), com uma prática agrícola considerada normal. Relativamente ao F2, este é considerado um olival de grande tamanho (mais de 100ha), com uma prática agrícola também considerada normal. O F3 também é um olival de grande tamanho (mais de 100ha), mas é praticado uma agricultura biológica. Nos lagares, a grande diferença é o modo utilizado para a extracção do azeite, sendo que o P2 é de duas fases e o P3 é de três fases. Para uma correta análise, foi seguido a metodologia referida nas ISO’s 14040 e 14044 e a parametrização referida na última versão do Environmental Product Declaration (EPD). Os resultados obtidos resultam da avaliação de diferentes interacções entre o olival e o lagar, obtendo-se um total de seis cenários com diferentes resultados, expressos na intensidade de indicadores de avaliação de impacto (mid-points).info:eu-repo/semantics/publishedVersio

Chemometric characterization of three varietal olive oils (Cvs. cobrancosa, madural and verdeal Transmontana) extracted from olives with different maturation indices

This paper evaluates the usefulness of three chemical parameters (compositions on tocopherols, sterols and fatty acids) as a tool to discriminate three varietal olive oils (Cvs. Cobrançosa, Madural and Verdeal Transmontana), which are permitted cultivars for the production of ‘‘Trás-os-Montes olive oil’’, a Portuguese protected designation of origin (PDO) product. The olives were collected during the year crop 2000/2001 from the same orchard, in order to eliminate the geographical and climatic influences. Lots with different maturation indices were prepared to allow the evaluation of the ripening stage on the characteristics of varietal olive oils produced from each cultivar. Statistical methods such as multivariate analysis of variance (MANOVA), principal components analysis (PCA) and cluster analysis were used to evaluate significant differences on the studied parameters. Regarding the results, the three cultivars were clearly discriminated

Constraining the Volume Density of Dusty Star-forming Galaxies through the First 3 mm Number Counts from ALMA

Large scale structure and cosmolog

Ricci-flat deformation of orbifolds and localized tachyonic modes

We study Ricci-flat deformations of orbifolds in type II theory. We obtain a simple formula for mass corrections to the twisted modes due to the deformations, and apply it to originally tachyonic and massless states in several examples. In the case of supersymmetric orbifolds, we find that tachyonic states appear when the deformation breaks all the supersymmetries. We also study nonsupersymmetric orbifolds C^2/Z_{2N(2N+1)}, which is T-dual to N type 0 NS5-branes. For N>=2, we compute mass corrections for states, which have string scale tachyonic masses. We find that the corrected masses coincide to ones obtained by solving the wave equation for the tachyon field in the smeared type 0 NS5-brane background geometry. For N=1, we show that the unstable mode representing the bubble creation is the unique tachyonic mode.Comment: 20 pages, minor collection