Composição química e atividade antioxidante de maracujá-roxo (Passiflora edulis Sims edulis)em diferentes graus de maturação

O maracujá-roxo é um fruto tropical que tem ganho destaque devido ao seu valor nutricional, organolético e às emergentes descobertas acerca das suas propriedades farmacêuticas e antioxidantes. Durante o processo de maturação decorrem várias reações de ordem física e química, e no intuito de enriquecer o conhecimento acerca de como a composição química e as propriedades do maracujá-roxo evoluem ao longo da maturação, este trabalho consistiu na caracterização física do fruto inteiro e na caracterização química geral das sementes, casca e polpa em frutos separados em cinco graus de maturação diferentes (G1 a G5). Foi também avaliada a atividade antioxidante (atividade antiradicalar e poder redutor), e o teor em compostos fenólicos (fenóis totais, derivados do ácido hidroxicinâmico e flavonóis) das diferentes matrizes que compõem o fruto ao longo da maturação. A partir dos resultados obtidos verificou-se na casca que o teor em cinza bruta aumenta essencialmente entre G1 e G2 enquanto se verificou uma diminuição da proteína. Em relação à semente, o teor em cinza bruta aumenta gradualmente, e o teor em proteína aumenta de G1 para G2, estabilizando posteriormente nos 8% (base seca). O teor em gordura aumenta gradualmente ao longo da maturação, verificando-se um maior acumulo entre G1 e G2 (9,9 e 19,1% respetivamente). No que respeita à polpa, há uma diminuição nos teores de cinza e proteína e aumento dos sólidos solúveis totais.Verificou-se um aumento ligeiro do pH ao longo da maturação (entre 2,8 a 3,1) e uma diminuição da acidez (entre 12,1 e 6,7 g de ácido cítrico 100 mL-1). Constatou-se que os açúcares predominantes na polpa foram a sacarose, frutose e glucose. Quanto aos ácidos orgánicos, o ácido cítrico foi o maioritário em todos os graus de maturação e teores mais baixos foram quantificados para os ácidos málico e ascórbico. Entre as diferentes partes do fruto estudadas, as cascas foram a matriz mais antioxidante, aumentando o seu potencial bioativo durante a maturação. As sementes apresentaram valores mais elevados de fenóis totais, derivados do ácido hidroxicinâmico e flavonóis. Foi verificado que a atividade antioxidante esteve correlacionada com os valores de fenóis totais presentes nas diferentes partes do fruto ao longo da maturação. De acordo com o conhecimento dos autores, este é o primeiro estudo que toma em consideração as alterações sofridas pelas diferentes partes do maracujá-roxo produzido em Portugal, ao longo da maturação.

Fenóis voláteis em vinhos tintos

As leveduras Dekkera/Brettanomyces são responsáveis pela formação de fenóis voláteis em vinhos tintos, tornando-se numa grande preocupação para a produção enológica a nível mundial, devido à dificuldade em controlá-las. Os fenóis voláteis são responsáveis por aromas desagradáveis nos vinhos tintos, diminuindo a sua qualidade e resultando em grandes perdas económicas. Este trabalho teve como principal objectivo estudar um método de preparação de amostra e um método cromatográfico para analisar e quantificar os principais fenóis voláteis (4-etilfenol, 4-etilguaiacol, 4-etilcatecol, 4-vinilfenol e o 4-vinilguaiacol), em meio sintético e em vinhos tintos comerciais. A preparação de amostras foi efectuada através do método de extracção líquido-líquido e a separação dos compostos foi efectuada por cromatografia gasosa com detector de ionização de chama (GC-FID). Os resultados obtidos permitem concluir que é possível detectar e quantificar os fenóis voláteis com este método, incluindo o 4-etilcatecol. O 4-etilfenol foi o composto mais abundante nos vinhos tintos comerciais estudados. ABSTRACT: The yeasts Dekkera I Brettanomyces are responsible for the formation of volatile phenols in red wine, becoming a major concern for the enological production worldwide because of the difficulty in controlling them. The volatile phenols are responsible for unpleasant aromas in red wines, reducing its quality and resulting in great economic lasses. The main objective of this work was to study a sample preparation and a chromatographic method to analyze main volatile phenols (4-ethylphenol, 4-ethylguaiacol, 4-ethylcatechol, 4-vinylphenol and 4-vinylguaiacol) in synthetic wine and red wines. Sample preparation was done by liquid-liquid extraction and compounds separation was achieved by gas chromatography with flame ionization detector (GC­ FID) Results showed that it is possible to detect and quantified volatile phenols with the methodology proposed, including 4-ethylcatechol. 4-ethylphenol was the main compound found in commercial red wines.

Influence of enzymes and technology on the composition of Cobrançosa and Galega vulgar virgin olive oils

Doutoramento em Engenharia Alimentar - Instituto Superior de Agronomia - UL

Bioactive compounds of citrus as health promoters

Citrus are a group of fruit species, quite heterogeneous in many aspects, including chemical composition of the fruit. Since ancient times, some citrus fruits were used to prevent and cure human diseases. In the recent decades, it has been demonstrated that fruits can actually help prevent and cure some diseases and above all, they are essential in a balanced diet. Citrus fruits, as one of the groups of fruit species, with greater importance in the world, have been studied for their effects on human health. Some species of citrus were referred as potential antioxidant based therapy for heart disease, cancer and inflammation. Fruit peels and seeds have also high antioxidant activity. The health benefits of citrus fruit have mainly been attributed to the high level of bioactive compounds, such as phenols (e.g., flavanone glycosides, hydroxycinnamic acids), carotenoids and vitamin C. These compounds are present in the fruit pulp and hence in the juice. But some bioactive compounds can be found in parts of the fruit which usually are not used for human food. The content of bioactive compounds depends on the species and cultivar, but also depends on the production system followed in the orchard. Citrus fruits, their derivatives and their by-products (peel, pulp and oil) are reach in different bioactive compounds and its maturity, postharvest and agroindustry processes influence their composition and concentration. The aim of this chapter was to review the main bioactive compounds of the different components of citrus and their relationship to health.

Use of alternative wood chips from new botanical species. Their impact on phenolic composition and sensory properties of a white wine from Encruzado grape variety

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

Desenvolvimento de membranas porosas de alumina para fins de tratamento de efluente industrial têxtil

Textile production has been considered as an activity of high environmental impact due to the generation of large volumes of waste water with high load of organic compounds and strongly colored effluents, toxic and difficult biodegradability. This thesis deals with obtaining porous alumina ceramic membranes for filtration of textile effluent in the removal of contaminants, mainly color and turbidity. Two types of alumina with different particle sizes as a basis for the preparation of formulation for mass production of ceramic samples and membranes. The technological properties of the samples were evaluated after using sintering conditions: 1,350ºC-2H, 1,450ºC-30M, 1,450ºC-2H, 1,475ºC-30M and 1,475ºC-2H. The sintered samples were characterized by XRD, XRF, AG, TG, DSC, DL, AA, MEA, RL, MRF-3P, SEM and Intrusion Porosimetry by Mercury. After the characterization, a standard membrane was selected with their respective sintering condition for the filterability tests. The effluent was provided by a local Textile Industry and characterized at the entry and exit of the treatment plant. A statistical analysis was used to study the effluent using the following parameters: pH, temperature, EC, SS, SD, oil and grease, turbidity, COD, DO, total phosphorus, chlorides, phenols, metals and fecal coliform. The filtered effluent was evaluated by using the same parameters. These results demonstrate that the feasibility of the use of porous alumina ceramic membranes for removing contaminants from textile effluent with improved average pore size of 0.4 micrometre (distribution range varying from 0,025 to 2.0 micrometre), with total porosity of 29.66%, and average percentages of color removal efficiency of 89.02%, 92.49% of SS, turbidity of 94.55%, metals 2.70% (manganese) to 71.52% (iron) according to each metal and COD removal of 72.80%

Rejeito de xisto como adsorvente para remoção de fenol em águas produzidas na indústria de petróleo

Produced water is the main effluent linked to the activity of extraction of oil and their caring management is necessary due to the large volume involved, to ensure to minimize the negative impacts of discharges of these waters in the environment. This study aimed to analyze the use of retorted shale, which is a reject from the pyrolysis of pirobituminous shale, as adsorbent for the removal of phenols in produced water. The material was characterized by different techniques (grain sized analysis, thermal analysis, BET, FRX, FT-IR, XRD and SEM), showing the heterogeneity in their composition, showing its potential for the removal of varied compounds, as well as the phenols and their derivatives. For the analysis of the efficiency of the oil shale for the adsorption process, assays of adsorption balance were carried through, and also kinetic studies and dynamics adsorption, in the ETE of the UTPF of Petrobras, in Guamaré-RN. The balance assays shown a bigger conformity with the model of Langmuir and the kinetic model more adjusted to describe the adsorption of phenols in retorted shale was of pseudo-second order. The retorted shale presented a low capacity of adsorption of phenols (1,3mg/g), when related to others conventional adsorbents, however it is enough to the removal of these composites in concentrations presented in the produced water of the UTPF of Guamaré. The assays of dynamics adsorption in field had shown that the concentration of phenol in the effluent was null until reaching its rupture (58 hours). The results showed the possibility of use of the reject for removal of phenols in the final operations of the treatment process, removing as well, satisfactorily, the color and turbidity of the produced water, with more than 90% of removal

Diagnóstico ecotoxicológico dos efluentes lançados no complexo estuarino do Jundiaí/Potengi, Natal/RN

Untreated effluents that reach surface water affect the aquatic life and humans. This study aimed to evaluate the wastewater s toxicity (municipal, industrial and shrimp pond effluents) released in the Estuarine Complex of Jundiaí- Potengi, Natal/RN, through chronic quantitative e qualitative toxicity tests using the test organism Mysidopsis Juniae, CRUSTACEA, MYSIDACEA (Silva, 1979). For this, a new methodology for viewing chronic effects on organisms of M. juniae was used (only renewal), based on another existing methodology to another testorganism very similar to M. Juniae, the M. Bahia (daily renewal).Toxicity tests 7 days duration were used for detecting effects on the survival and fecundity in M. juniae. Lethal Concentration 50% (LC50%) was determined by the Trimmed Spearman-Karber; Inhibition Concentration 50% (IC50%) in fecundity was determined by Linear Interpolation. ANOVA (One Way) tests (p = 0.05) were used to determinate the No Observed Effect Concentration (NOEC) and Low Observed Effect Concentration (LOEC). Effluents flows were measured and the toxic load of the effluents was estimated. Multivariate analysis - Principal Component Analysis (PCA) and Correspondence Analysis (CA) - identified the physic-chemical parameters better explain the patterns of toxicity found in survival and fecundity of M. juniae. We verified the feasibility of applying the only renewal system in chronic tests with M. Juniae. Most efluentes proved toxic on the survival and fecundity of M. Juniae, except for some shrimp pond effluents. The most toxic effluent was ETE Lagoa Aerada (LC50, 6.24%; IC50, 4.82%), ETE Quintas (LC50, 5.85%), Giselda Trigueiro Hospital (LC50, 2.05%), CLAN (LC50, 2.14%) and COTEMINAS (LC50, IC50 and 38.51%, 6.94%). The greatest toxic load was originated from ETE inefficient high flow effluents, textile effluents and CLAN. The organic load was related to the toxic effects of wastewater and hospital effluents in survival of M. Juniae, as well as heavy metals, total residual chlorine and phenols. In industrial effluents was found relationship between toxicity and organic load, phenols, oils and greases and benzene. The effects on fertility were related, in turn, with chlorine and heavy metals. Toxicity tests using other organisms of different trophic levels, as well as analysis of sediment toxicity are recommended to confirm the patterns found with M. Juniae. However, the results indicate the necessity for implementation and improvement of sewage treatment systems affluent to the Potengi s estuary

Epigenetic regulation of neurodevelopmental genes in response to in utero exposure to phthalate plastic chemicals: how can we delineate causal effects?

Accumulating evidence, from animal models and human observational studies, implicates the in utero (and early postnatal) environment in the 'programming' of risk for a variety of adverse outcomes and health trajectories. The modern environment is replete with man-made compounds such as plastic product chemicals (PPC), including phenols and phthalates. Evidence from several human cohorts implicates exposure to these chemicals in adverse offspring neurodevelopment, though a direct causal relationship has not been firmly established. In this review we consider a potential causal pathway that encompasses epigenetic human variation, and how we might test this mechanistic hypothesis in human studies. In the first part of this report we outline how PPCs induce epigenetic change, focusing on the brain derived neurotrophic factor (BDNF) gene, a key regulator of neurodevelopment. Further, we discuss the role of the epigenetics of BDNF and other genes in neurodevelopment and the emerging human evidence of an association between phthalate exposure and adverse offspring neurodevelopment. We discuss aspects of epidemiological and molecular study design and analysis that could be employed to strengthen the level of human evidence to infer causality. We undertake this using an exemplar recent research example: maternal prenatal smoking, linked to methylation change at the aryl hydrocarbon receptor repressor (AHRR) gene at birth, now shown to mediate some of the effects of maternal smoking on birth weight. Characterizing the relationship between the modern environment and the human molecular pathways underpinning its impact on early development is paramount to understanding the public health significance of modern day chemical exposures.

Effects of nitrogen level on purslane antioxidant activity.

The high antioxidant activity of purslane, Portulaca oleracea L., gives it a high nutritional and functional value. The commercial production of purslane has increased in Portugal, making it necessary to know the effects of inputs, mainly nitrogen, on the antioxidant activity. The main goal of this study was to evaluate the influence of nitrogen application on purslane antioxidant activity. The experiment was carried out with for treatments: 30, 60 and 90 kg/ha of nitrogen. Plants of golden-leaf purslane were grown in Styrofoam-boxes filled with substrate and fertigated two times per week, over four weeks with ammonium nitrate solution (16.9% NO3-N and 16.7 NH4+-N). The increase in the nitrogen level decreased the water-soluble proteins content. However the ascorbate, phenols content as well as antioxidant activity measured by FRAP method was not affected by nitrogen level. Plants shoot antioxidant activity, measured by DPPH method decreased significantly in the treatment with 90 kg N/ha (26.20 g/g gallic acid). On the other hand, plant shoot antioxidant activity mediated by peroxidases was higher in treatment 30 kg N/ha (0.459 µmol min-1/mg prot.). Application of 60 kg N/ha allowed a vigorous plant growth without disturb its antioxidants and conservation properties.

Evaluation of the evolution of the anthocyanins profile in red wine grape varieties in Alentejo

The flavonoids (including anthocyanins) are wine compounds with important anti-oxidant activity, protecting the cells against oxidative processes, preventing cardiovascular and neurodegenerative diseases, cancer, among others (Antoniolli et al. 2015; Castañeda-Ovando et al. 2009; Hosu et al. 2014; Huang et al. 2009; Kong et al. 2003). Anthocyanins in grapes at harvest are determinant to red wine quality and their development in the grape must be characterised in order to determine the most suitable date for the harvest. Thus the aim of this research is the evaluation of anthocyanins composition in two red wine grape varieties from véraison continuing through ripening. Anthocyanins were quantified by high resolution liquid chromatography (HPLC-DAD). Additionally, the total phenols content were quantified by UV-Vis Spectrometry. The anthocyanins’ profile evolution may be dependent on the variety and ripening phase. During ripening grape samples have shown an increase of coumaryl derivatives. This information may lead us to understand the anthocyanins biosynthesis pathway in different grape varieties. The development of anthocyanins from the véraison seems to follow a pattern that coincides with the increasing accumulation of soluble sugars.

Characterization of the volatile profile of Brazilian Merlot wines through comprehensive two dimensional gas chromatography time-of-flight mass spectrometric detection.

Wine aroma is an important characteristic and may be related to certain specific parameters, such as raw material and production process. The complexity of Merlot wine aroma was considered suitable for comprehensive two-dimensional gas chromatography (GCGC), as this technique offers superior performance when compared to one-dimensional gas chromatography (1D-GC). The profile of volatile compounds of Merlot wine was, for the first time, qualitatively analyzed by HS-SPME-GCxGC with a time-of-flight mass spectrometric detector (TOFMS), resulting in 179 compounds tentatively identified by comparison of experimental GCxGC retention indices and mass spectra with literature 1D-GC data and 155 compounds tentatively identified only by mass spectra comparison. A set of GCGC experimental retention indices was also, for the first time, presented for a specific inverse set of columns. Esters were present in higher number (94), followed by alcohols (80), ketones (29), acids (29), aldehydes (23), terpenes (23), lactones (16), furans (14), sulfur compounds (9), phenols (7), pyrroles (5), C13-norisoprenoids (3), and pyrans (2). GCxGC/TOFMS parameters were improved and optimal conditions were: a polar (polyethylene glycol)/medium polar (50% phenyl 50% dimethyl arylene siloxane) column set, oven temperature offset of 10ºC, 7 s as modulation period and 1.4 s of hot pulse duration. Co-elutions came up to 138 compounds in 1D and some of them were resolved in 2D. Among the coeluted compounds, thirty-three volatiles co-eluted in both 1D and 2D and their tentative identification was possible only due to spectral deconvolution. Some compounds that might have important contribution to aroma notes were included in these superimposed peaks. Structurally organized distribution of compounds in the 2D space was observed for esters, aldehydes and ketones, alcohols, thiols, lactones, acids and also inside subgroups, as occurred with esters and alcohols. The Fischer Ratio was useful for establishing the analytes responsible for the main differences between Merlot and non-Merlot wines. Differentiation among Merlot wines and wines of other grape varieties were mainly perceived through the following components: ethyl dodecanoate, 1-hexanol, ethyl nonanoate, ethyl hexanoate, ethyl decanoate, dehydro-2-methyl-3(2H)thiophenone, 3-methyl butanoic acid, ethyl tetradecanoate, methyl octanoate, 1,4 butanediol, and 6-methyloctan-1-ol.