Identificación de los polifenoles en zumos de frutas rojas

De un tiempo a esta parte lo relacionado con los zumos de frutas rojas ha cobrado gran importancia, generando así un interés cada vez mayor, desde el momento en el que el consumidor asocia un potencial beneficio para su salud por el consumo de estos zumos. Esto repercute en la necesidad de disponer de métodos analíticos que permitan controlar la calidad y autenticidad de estos zumos, que adquieren en el mercado mayores precios, y se encuentran sometidos a una mayor posibilidad de fraudes. Las adulteraciones o posibles fraudes alimentarios son un problema económico y por ello, la autentificación de los productos alimenticios es un objetivo de gran importancia. En el caso de los zumos de frutas rojas, el tipo de adulteración más frecuente es la mezcla del zumo original con zumos de frutas más baratas principalmente uva tinta. La estrategia de los métodos de autentificación consiste en medir o analizar un número de compuestos químicos, que formen en conjunto el perfil característico de cada fruta o zumo de fruta. Es decir, la huella dactilar de cada fruta. La variabilidad en las proporciones y contenidos de antocianinas en los zumos de frutas rojas analizados permite determinar la denominada “huella dactilar” de antocianos. La determinación de este perfil de antocianos es ampliamente usado para verificar la autenticidad de productos alimentarios preparados con frutas rojas, tales como siropes, mermeladas y zumos de frutas (www.solociencia.com/quimica/08012602.htm). Por todo ello, el principal objetivo que se planteó en este proyecto fin de máster, fue caracterizar el perfil polifenólico de cinco frutas rojas diferentes: mirtilo, arándano, grosella, cereza y uva tinta. Para realizar esta caracterización se aplicará un método de análisis por HPLC de los polifenoles de zumos de frutas rojas como alternativa al método IFU nº 71 empleado para antocianos (CODEX STAN 247-2005). Para ello se estudiará la detección simultánea por PDA y espectrometría de masas. Esta última técnica analítica usada, de forma complementaria a la detección óptica, es capaz de dar información estructural y complementaria muy útil a la hora de confirmar la presencia de polifenoles identificados con PDA y con fluorescencia en algunos casos.De forma desglosada los objetivos planteados fueron los siguientes: Objetivo 1: Estudiar los espectros de PDA y masas de patrones de polifenoles para seleccionar las longitudes de onda de absorción para su detección y las fragmentaciones posibles que tienen lugar en los polifenoles presentes en zumos de frutas rojas. Objetivo 2: Conseguir resolver en un mismo cromatograma el mayor número de polifenoles posibles, evitando solapamientos de picos de compuestos Objetivo 3: Analizar el perfil de antocianos y ácidos fenólicos en zumos de frutas rojas. Objetivo 4: Ampliar el estudio a un mayor número de frutas abriendo el abanico abarcando también a otro tipo de frutas. Objetivo 5: Interpretación de los espectros de masas, en la medida de lo posible, de los distintos polifenoles presentes en las frutas rojas. Objetivo 6: Mejorar el método de trabajo inicial acortando el tiempo de análisis mediante el empleo de un UPLC y complementar la detección por PDA, con detección por tándem de masas y fluorescenciaEscuela Técnica Superior de Ingeniería IndustrialUniversidad Politécnica de Cartagen

Plant water status indicators for detecting water stress in pomegranate trees

Measurements obtained by the continuous monitoring of trunk diameter fluctuations were compared with discrete measurements of midday stem water potential (stem) and midday leaf conductance (gl) in adult pomegranate trees (Punica granatum (L.) cv. Mollar de Elche). Control plants (T0) were irrigated daily above their crop water requirements in order to attain non‐limiting soil water conditions, while T1 plants were subjected to water stress by depriving them of irrigation water for 34 days, after which time irrigation was restored and plant recovery was studied for 7 days. T1 plants showed a substantial degree of water stress, which developed slowly. Maximum daily trunk shrinkage (MDS) was identified to be the most suitable plant‐based indicator for irrigation scheduling in adult pomegranate trees, because its signal:noise ((T1/T0):coefficient of variation) ratio was higher than that for stem ((T1/T0):coefficient of variation) and gl ((T0/T1):coefficient of variation). MDS increased in response to water stress, but when the stem fell below −1.67 MPa, the MDS values decreased.This research was supported by CICYT/FEDER (AGL2010‐19201‐C04‐01AGR) and AECID (A1/035430/11) grants to the authors. AG, JCG and ZNC were funded by a FPU, a FPI and a AECID grant, respectively

Criteria for HydroSOS Quality Index. Application to Extra Virgin Olive Oil and Processed Table Olives

Water, especially in arid and semiarid regions, is increasingly a disputed commodity among different productive sectors; the pressure for a more sustainable use of water in agriculture will grow. The main strategy to cope with water scarcity is the use of improved, innovative, and precise deficit irrigation management practices which are able to minimize the impact on fruit yield and quality. The aim of this paper was to develop a certification index or hydroSOS quality index for extra virgin olive oil and processed table olives. The hydrosSOS fruits and vegetables are those cultivated under regulated deficit irrigation (RDI). Different indicators in three quality areas ((i) fatty acids, (ii) phenolic compounds, and (iii) sensory attributes) were identified as showing characteristic or typical responses under RDI conditions. Marks or scores were assigned to each one of these indicators to calculate the proposed index. It can be concluded that an extra virgin olive oil (EVOO) or processed table olives are hydroSOStainable foods, if they meet 2 conditions: (i) fulfill the conditions established in the hydroSOS “irrigation” index, and (ii) fulfill the requirements of the hydroSOS “quality” index. HydroSOS quality index will be specific to each crop and variety and will depend on functional and sensory factors

Mapeo varietal de fitoprostanos en almendras: identificación y cuantificación

Recientemente, algunos investigadores han estudiado la relación existente entre el estrés oxidativo y el contenido de determinados compuestos presentes en las plantas denominados fitoprostanos. Las almendras tienen un contenido elevado de ácidos grasos poliinsaturados siendo el mayoritario el ácido α‐ linolénico. En 1998, se descubrió que los fitoprostanos se generan a partir del ácido α‐ linolénico en una vía no enzimática, iniciada por una mayor formación de radicales libres. En este trabajo se propone la identificación y la cuantificación de fitoprostanos presentes en almendras averiguando si la variedad influye en el contenido de los mismos. Como resultado se obtuvo que en las cinco variedades de almendra estudiadas, el fitoprostano 9–F1t‐fitoprostano fue el más abundante aunque también se obtuvieron otros fitoprostanos en menor concentración tipo 9‐epi‐9E1t‐fitoprostano, 9‐E1tfitoprostano, 16‐B1‐fitoprostano y 9‐L1‐fitoprostano. Además, la concentración de fitoprostanos se vio afectada por la variedad siendo “Ramillete” la que presentó niveles más elevados

Sustainability of the Legal Endowments of Water in Almond Trees and a New Generation of High Quality Hydrosustainable Almonds

The great consumption of water and its scarcity in many areas of the world leads „irremediably” to accept that Spanish agriculture, like other Mediterranean agricultures, must adapt to the lack of this natural resource. Deficit irrigation (DI) strategies are routine practices used worldwide in order to increase net farm income by growing the crops effectiveness to use water. The importance of using this type of strategies is the fact that farmers have the opportunity not just to reduce the water consumption but also to obtain hydro sustainable products. Those are “theoretically” characterized by a high accumulation of secondary carbon metabolites in plant and a great accumulation of bioactive compounds in fruit, according to other studies already done in pistachio or table olives. As almond is the major nut crop in Mediterranean area different DI strategies are presented within this review together with their effect on the final product quality. Thus, the aim of the current review paper is to find all the necessary information about which DI strategies are the recommended to be applied in the almond crop in order to obtain high-quality fruits environmentally friendly. In addition, methods used to determine de quality and steps necessary to certify and protect this type of products are also presented

Merging Heat Stress Tolerance and Health-Promoting Properties: The Effects of Exogenous Arginine in Cauliflower (Brassica oleracea var. botrytis L.)

In the last decades, cauliflower consumption has increased due to its observed beneficial effects on human health, especially on chronic diseases. Furthermore, the use of arginine has been shown to improve the heat stress tolerance of plants by increasing the polyamine content. Thus, we aimed to investigate the effects of the exogenous application of arginine on the physical and chemical quality parameters of cauliflower florets under heat stress. For this, we applied two concentrations of arginine (1 and 4 mM) to the leaves of cauliflower (Brassica oleracea var. botrytis L.) plants grown in three different temperatures (ambient, elevated, and extreme). Our data show that potassium and phosphate, as well as iron were the most abundant macro- and micronutrients, respectively. The combination of high temperature and exogenous application of arginine increased the antioxidant activity, total content of phenolic compounds, polyamines, and proteins. The data presented herein indicate that the combination of an adequate heat stress and the appropriate foliar arginine treatment may be a useful strategy that could be used to increase the number of valuable plant compounds in our diet

Effects of Selenium on the Chlorophylls, Gas Exchange, Antioxidant Activity and Amino Acid Composition of Lettuce Grown under an Aquaponics System

Aquaponics is a sustainable technique that is respectful to the environment, as it reuses products and minimizes the consumption of new materials. The combination of this technique with the foliar application of selenium (as Na2SeO4) could lead to healthier and more sustainable products, which are increasingly requested by consumers. Lettuce (Lactuca sativa L.) plants were grown in an aquaponics system (fish water) as compared with a control (conventional soilless fertigation), and sprayed with different concentrations of selenium (0, 4, 8, and 16 µmol L−1). The results showed a reduction in the dry weight and N content of lettuce plants irrigated with the fish water mixture treatment. However, the application of Se relieved this stress, increasing the photosynthetic rate and ABTS, and reducing the content of chlorophylls, β-carotene, and several of the measured amino acids. The best results were observed with the highest concentration of Se (16 µmol L−1), as an increase in nitrogen content was observed, as shown by a greater weight of the plant. Furthermore, this treatment produced the greatest increase in ABTS and the least reduction in amino acid content. This novel study highlights the possibility of improving the efficiency of N utilization in lettuce by applying foliar selenium in combination with an aquaponics system

Effects of Different Nitrogen Forms and Exogenous Application of Putrescine on Heat Stress of Cauliflower: Photosynthetic Gas Exchange, Mineral Concentration and Lipid Peroxidation

This study examines the effect of the exogenous application of polyamine putrescine together with the application of different ratios of nitrate/ammonium (NO3−/NH4+), on the physiology of cauliflower subjected to heat stress. The 50:50 NO3−/NH4+ ratio was the best ratio against heat stress. As a result of the joint application of these compounds, a higher photosynthetic rate, a higher accumulation of both photosynthesis-related compounds and pigments, total proteins, and a change in the status of nutrients were obtained. Particularly, the decrease in content of calcium, chloride and sulphate in plants under heat stress is ameliorated by the ammonium effect. Additionally, it is important to highlight that cauliflower waste contains a higher content of mineral nutrients than floret cauliflower. These effects were more marked in young leaves. Furthermore, a synergistic effect for coping with heat stress between the polyamine and the nutritional treatment was observed. For this, both the application of putrescine and the feeding of plants with a 50:50 NO3−/NH4+ ratio before heat stress is proposed for the first time as an agricultural practice for increasing the thermotolerance of cauliflower cv Moonshine. On the other hand, due to the lower lipid peroxidation rate obtained in cauliflower leaves, these plants could be used for health purposes as ointments or other nutraceutical products, making the cultivation of this kind of cruciferous more sustainable

Effects of Selenium on the Chlorophylls, Gas Exchange, Antioxidant Activity and Amino Acid Composition of Lettuce Grown under an Aquaponics System

Aquaponics is a sustainable technique that is respectful to the environment, as it reuses products and minimizes the consumption of new materials. The combination of this technique with the foliar application of selenium (as Na2SeO4) could lead to healthier and more sustainable products, which are increasingly requested by consumers. Lettuce (Lactuca sativa L.) plants were grown in an aquaponics system (fish water) as compared with a control (conventional soilless fertigation), and sprayed with different concentrations of selenium (0, 4, 8, and 16 µmol L−1). The results showed a reduction in the dry weight and N content of lettuce plants irrigated with the fish water mixture treatment. However, the application of Se relieved this stress, increasing the photosynthetic rate and ABTS, and reducing the content of chlorophylls, β-carotene, and several of the measured amino acids. The best results were observed with the highest concentration of Se (16 µmol L−1), as an increase in nitrogen content was observed, as shown by a greater weight of the plant. Furthermore, this treatment produced the greatest increase in ABTS and the least reduction in amino acid content. This novel study highlights the possibility of improving the efficiency of N utilization in lettuce by applying foliar selenium in combination with an aquaponics system

Enhancement of Bioactive Constituents in Fresh Cauliflower By-Products in Challenging Climate Conditions

In order to mitigate the detrimental impact that climate change is having on plants, the study of new practices that allow for the reduction of such effects has become imperative. In addition, the revaluation of the promotion of healthy plant by-products has also markedly increased in importance in recent years. In this work, the modifications in biomass and some antioxidant compounds of cauliflower by-products treated with putrescine under extreme temperatures in two different CO2 scenarios (the control (400 ppm) and a high concentration of CO2 (1000 ppm)) were studied. Additionally, the compositions of inner and outer leaves were also compared. According to results found in this work, cauliflower grown under elevated CO2 and treated with putrescine (2.5 mM) prior to heat stress showed the highest biomass accumulation (20%) compared to the control. Moreover, in the outer leaves from cauliflower grown under elevated CO2 and treated with putrescine prior to high temperature exposure, the highest biosynthesis of sugars (20%) was recorded. Although cauliflower by-products turned out to be rich in polyamines (208.6 nmoles g−1 fresh weight (FW) and 124.3 nmoles g−1 FW for outer and inner leaves, respectively) and phenolic compounds (1070.2 mg gallic acid equivalents ( (GAE) 100 g−1 FW in outer leaves and 772.0 mg GAE 100 g−1 FW in inner leaves), it was the outer leaves that after applying the new strategy showed the greatest increase in polyamines (68%) and phenolic compounds (39%), obtaining here the highest increase in antioxidant activity (3%). Thus, they should no longer be regarded as mere by-products and should be used for pharmaceutical or nutraceutical purposes. The novel strategy presented in this work may allow us to take advantage of both the continued increase in CO2 and heat waves that are becoming more frequent