Xoconostle fruit (Opuntia matudae Scheinvar cv. Rosa) by-products as potential functional ingredients

There is a lack of information on the potential use of xoconostle cultivars as sources of antioxidants for food, pharmaceutical and colorant industries. The aim of this study was to provide a phytochemical characterisation and antioxidant activity evaluation of Opuntia matudae Scheinvar cv. Rosa by-products (epicarp and endocarp mucilage's), in order to evaluate their interest as sources of functional ingredients for human or animal foods. These by-products showed a high content in glucose, citric and linoleic acids, tocopherols, and isorhamnetin-O-(di-deoxyhexosyl-hexoside) (mainly in epicarp), and presented relevant antioxidant properties. The obtained results support the use of O. matudae Scheinvar cv. Rosa agro-industrial by-products as functional food ingredients, namely for antioxidant-enriched formulations, instead of being discarded.The authors are grateful to the Foundation for Science and Technology (Portugal) for financial support to CIMO (strategic project Pest-OE/AGR/UI0690/2011) and to L. Barros (researcher contract under “Programa Compromisso com Ciência-2008”). The authors also acknowledge the support of Mexican association CoMenTuna for providing the plant materials

Anthocyanin Copigmentation: Evaluation, Mechanisms and Implications for the Colour of Red Wines

[EN]Copigmentation is the main colour-stabilizing mechanism in plants and in food products of vegetable origin. It is a spontaneous and exothermic process that consists of the stacking of an organic molecule, called copigment, on the planar polarizable moieties of the anthocyanin coloured forms. Although this phenomenon has long been described, there are some aspects that are still not well understood or controversial like the nature of the interaction pigment to copigment, the way to quantify the extent of the process, its effect on other anthocyanin properties like astringency or reactivity. In this article a review of the most significant advances achieved in the last years in the field of intramolecular and intermolecular copigmentation is presented. Also, the most recent findings regarding wine copigments and their effects on the colour of red wines are revised

Alcohol y salud

It is beyond doubt that alcohol consumption, especially when it is excessive or irresponsible, has severe consequences for health. Nonetheless, there are also studies that associate the moderate intake of alcoholic drinks, namely red wine, with a lower risk of some chronic diseases and, in particular, cardiovascular disease. Those studies have received some attention by the media, which have sometimes contributed to spread a message confusing or contradictory, if not biased, in which marketing interests might be involved. This article reviews some of these aspects, both regarding the risks and the putative health benefits of moderate drinking. It is, however, important to highlight that it is far from any intention to contribute arguments that might be used to justify the consumption of alcoholic drinks with the aim of gaining health benefits.Está fuera de toda duda que el consumo de alcohol, especialmente si es excesivo o irresponsable, tiene severas consecuencias para la salud. Sin embargo, existen también estudios que relacionan el consumo moderado y responsable de bebidas alcohólicas, sobre todo de vino tinto, con un menor riesgo de sufrir determinadas enfermedades, especialmente de tipo cardiovascular. Estos estudios han recibido cierta atención por parte de los medios de comunicación, haciendo llegar a los consumidores un mensaje en ocasiones confuso o contradictorio, cuando no sesgado, al mezclarse intereses comerciales. En este artículo se revisan algunos de estos aspectos, tanto en cuanto a los riesgos para la salud como a los posibles beneficios del consumo moderado de alcohol. Es pertinente señalar que está lejos de cualquier intención aportar argumentos que puedan ser utilizados para justificar el consumo de vino u otras bebidas alcohólicas con el objeto de obtener beneficios para la salud

Aproximación al análisis de las relaciones causales en las ciencias de la salud

Trabajo de Fin de Máster en Investigación en Lógica y Filosofía de la Ciencia, curso 2017-2018[ES] Un adecuado análisis de la causalidad adquiere particular relevancia en áreas de conocimiento en las que son necesarios grados de confianza elevados a la hora de adoptar decisiones frente a ciertos problemas/conflictos sociales, económicos o sanitarios. Una revisión de la investigación publicada sobre causalidad en el ámbito de la salud pública en las últimas décadas revela que en la mayoría de los escenarios planteados en las ciencias de la salud, las relaciones causa-efecto no son deterministas, ni absolutamente ciertas y completas, a lo que se suma el hecho de que en el caso de muchas disciplinas biomédicas, como la epidemiología o la farmacovigilancia, no es posible realizar experimentos para aislar el factor causal de interés (manteniendo todas la condiciones iguales y asegurando la restricción ceteris paribus), lo que incrementa la complejidad del análisis causal. Quizá por ello, la mayoría de epidemiólogos prefieren hablar de determinantes, exposiciones y factores de riesgo y categorizan las causas de forma descriptiva sin enfrentar los problemas de la definición de causa, a pesar de que muchos son conscientes de la trascendencia que puede tener sobre las intervenciones sanitarias la adopción de una definición determinada de causalidad, que razonablemente debería ser la de mayor utilidad.[EN] A suitable analysis of causality acquires a particular relevance in areas of knowledge in which high degrees of confidence are required when making decisions regarding certain social, economic or health issues. A review of published research on causality in the field of public health in recent decades reveals that in most of the scenarios posed in the health sciences, cause-effect relationships are not deterministic, nor absolutely certain and complete, to which is added the fact that in many biomedical disciplines, such as epidemiology or pharmacovigilance, it is not possible to carry out experiments to isolate the causal factor of interest (keeping all the conditions unchanged and thus ensuring the ceteris paribus restriction), which increases the complexity of the causal analysis. Perhaps for this reason, most epidemiologists prefer to talk about determinants, exposures and risk factors and they categorize the causes in a descriptive way without facing the problems of definition of cause, although many are aware of the transcendence that can have on the health interventions the adoption of a specific definition of causality, which reasonably should be the most useful

Stability of pelargonidin 3-glucoside in model solutions in the presence and absence of flavanols

The stability of pelargonidin 3-g1ucoside (Pg3g1uc), the main anthocyanin in strawberry, has been studied in model citrate solutions (PH 3.5, 25°C) in the absence and presence flavanols (catechin and procyanidin B3) and/or oxygen. Changes in the solutions were monitorized by HPLC-DAD/MS and UV-visible spectra.Governo Português e Fundo Social Europeu através da medida n.º 5/Acção nº5.3 - PRODEP (III)(referência 5.3/N/199.006/00-Doutoramento)

Proposal of a method for fluorimetric analysis of malvin in red wines

A fluorimetric method for the quantitative determination of malvin (malvidin 3,5-diglucoside) in red wines is described. The method is based on previous fractionation of the wine in a Polyclar AT column and later formation of a fluorophore, by oxidation of the malvin. The proposed method has good precision and accuracy and when applied to hybrid red wines affords results significantly comparable with those obtained by HPLC

Avaliação da bioatividade e caracterização química de uma espécie de uso tópico: Juglans regia L.

As folhas de Juglans regia L. (nogueira), são consideradas uma fonte de compostos benéficos para a saúde, sendo amplamente utilizadas na medicina tradicional. Alguns dos compostos bioativos presentes e, com maior destaque, são os compostos fenólicos (antioxidantes). No presente estudo, analisou-se a composição em ácidos orgânicos, mono e oligossacáridos, e tocoferóis nas folhas de nogueira e respetiva decocção (vulgarmente utilizada para aplicações tópicas). A composição fenólica e a bioatividade foram também avaliadas na decocção e no extracto metanólico. O ácido málico, a sacarose, o α-tocoferol e os ácidos 3-O-cafeoilquínicos e quercetina O-pentósido foram, respetivamente, o ácido orgânico, dissacárido, isoforma de tocoferol e compostos fenólicos, mais abundantes. O extrato metanólico apresentou maior potencial antioxidante e antitumoral do que a decocção; nenhuma das amostras apresentou toxicidade em culturas de células primárias de fígado. Este estudo permitiu uma caracterização mais completa de compostos fenólicos de folhas de nogueira e, tanto quanto sabemos, esta é a primeira vez que a presença de procianidinas, derivados de taxifolina e tocoferóis é descrita em folhas de J. regia

Avaliação da bioatividade e caracterização química de uma espécie de uso tópico: Juglans regia L.

As folhas de Juglans regia L. (nogueira), são consideradas uma fonte de compostos benéficos para a saúde, sendo amplamente utilizadas na medicina tradicional. Alguns dos compostos bioativos presentes e, com maior destaque, são os compostos fenólicos (antioxidantes). No presente estudo, analisou-se a composição em ácidos orgânicos, mono e oligossacáridos, e tocoferóis nas folhas de nogueira e respetiva decocção (vulgarmente utilizada para aplicações tópicas). A composição fenólica e a bioatividade foram também avaliadas na decocção e no extracto metanólico. O ácido málico, a sacarose, o α-tocoferol e os ácidos 3-O-cafeoilquínicos e quercetina O-pentósido foram, respetivamente, o ácido orgânico, dissacárido, isoforma de tocoferol e compostos fenólicos, mais abundantes. O extrato metanólico apresentou maior potencial antioxidante e antitumoral do que a decocção; nenhuma das amostras apresentou toxicidade em culturas de células primárias de fígado. Este estudo permitiu uma caracterização mais completa de compostos fenólicos de folhas de nogueira e, tanto quanto sabemos, esta é a primeira vez que a presença de procianidinas, derivados de taxifolina e tocoferóis é descrita em folhas de J. regia

Phenolic acids determination by HPLC-DAD-ESI/MS in sixteen different portuguese wild mushrooms species

Analysis of phenolic compounds in sixteen Portuguese wild mushrooms species has been carried out by high-performance liquid chromatography coupled to photodiode array detector and mass spectrometer (HPLC–DAD–ESI/MS). No flavonoids were detected in the analysed samples, but diverse phenolic acids namely protocatechuic, p-hydroxybenzoic and p-coumaric acids, and two vanillic acid isomers were found and quantified. A related non-phenolic compound, cinnamic acid, was also detected in some samples, being the only compound found in Cantharellus cibarius (14.97 mg/kg, dry matter), Lycoperdon perlatum (14.36 mg/kg) and Macrolepiota procera (21.53 mg/kg). p-Hydroxybenzoic acid was found in the majority of the samples, being the most abundant compound in Agaricus silvicola (238.7 mg/kg). Ramaria botrytis showed the highest phenolic acids concentration (356.7 mg/kg) due to the significant contribution of protocatechuic acid (342.7 mg/kg)