Calidad nutricional y contenido fitoquímico de aceites prensados en frío de semillas de chía, cardo mariano, nigella, y amapola blanca y negra

Cold pressed oils obtained from chia (Salvia hispanica L.), milk thistle (Silybum marianum L.), nigella (Nigella sativa L.), and white and black varieties of poppy (Papaver somniferum L.) seeds were character­ized. The nutritional quality was determined based on the analysis of fatty acids, tocochromanol and phytos­terol contents, as well as antioxidant activity and general physico-chemical properties. Among the oils analyzed the fatty acid composition most beneficial for health was found in chia seed oil, with 65.62% of α-linolenic acid and the n-6:n-3 fatty acid ratio of 1:3.5. Other oils studied were rich sources of linoleic acid (18.35-74.70%). Chia seed oil was also distinguished by high contents of phytosterols, mainly β-sitosterol (2160.17 mg/kg oil). The highest content of tocochromanols was found in milk thistle oil with dominant α-tocopherol (530.2 mg/kg oil). In contrast, the highest antioxidant activity was recorded for nigella oil (10.23 μM Trolox/g), which indi­cated that, in addition to tocopherols, other antioxidants influenced its antioxidant potential.Se caracterizaron aceites prensados en frío obtenidos de semillas de chía (Salvia hispanica L.), cardo mariano (Silybum marianum L.), nigella (Nigella sativa L.) y de variedades blancas y negras de amapola (Papaver somniferum L.). La calidad nutricional se determinó en base al análisis de ácidos grasos, el contenido de tococromanoles y fitosteroles, así como la actividad antioxidante y las propie­dades fisicoquímicas generales. Entre los aceites analizados, la composición de ácidos grasos más beneficiosa para la salud se encontró en el aceite de semilla de chía, con un 65,62% de ácido α-linolénico y una relación de ácido graso n-6:n-3 de 1:3,5. Los demás aceites estudiados fueron ricos en ácido linoleico (18,35-74,70%). El aceite de semilla de chía también se distinguió por el alto contenido de fitosteroles, principalmente β-sitosterol (2160,17 mg/kg de aceite). El mayor contenido de tococromanoles se encontró en el aceite de cardo mariano con α-tocoferol dominante (530,2 mg/kg de aceite). Por el contrario, se registró la mayor actividad antioxidante para el aceite de nigella (10,23 μM Trolox/g), lo que indica que, además del tocoferol, otros antioxidantes influyeron en su potencial antioxidante

Efecto de pretratamientos con microondas a semillas de colza sobre la cinética de degradación de los compuestos bioactivos lipófilos del aceite durante el almacenamiento

This study examined the storage stability of tocochromanols and carotenoids in the oils prepared from microwave pre-treated (MV) rapeseeds (2-10 min, 800W) during storage at 20 °C for 12 months. In line with lipophilic antioxidant degradation throughout the storage period, changes in the antioxidant capacity of the oil were monitored. Microwaving significantly affected the concentration of lipophilic antioxidants in the oil. After 10 min of MV pre-treatment the highest content of total tocochromanols (76.64 mg/100g) was achieved, whereas a maximum carotenoid concentration (861.28 μg/100g) was obtained following 6 min seed MV pre-treatment. The degradation kinetics for the tocochromanols and carotenoids followed a zero-order kinetic model. From the kinetic analysis, it was shown that the degradation rate constant (k) of both tocochromanols and carotenoids decreased with longer seed exposure to MV radiation. The kinetics of antioxidant capacity degradation during the storage of oils followed a zero-order reaction. The rate of antioxidant capacity degradation in the control oil was higher (k=9.1 x 10-2 mmol TEAC/l/month) compared with oils prepared from MV pre-treated seeds (k=6.8-8.0 x 10-2 mmol TEAC/l/month).En este estudio se determinó la estabilidad de tococromanoles y carotenoides de aceites preparados a partir de semillas de colza pretratadas con microondas (MV) (2-10 min, 800 W) durante el almacenamiento a 20 °C durante 12 meses. De acuerdo con la degradación de los antioxidantes lipófilos durante el periodo de almacenamiento, se monitorizó el cambio en la capacidad antioxidante del aceite. El microondas afectó significativamente a la concentración de antioxidantes lipofilícos en el aceite. Después de 10 minutos de pretratamiento con MV, se obtuvo el contenido más alto de tocromanoles totales (76,64 mg/100 g), mientras que se obtuvo una concentración máxima de carotenoides (861,28 g/100 g) después de un pretratamiento con MV de 6 minutos. La cinética de degradación para los tococromanoles y carotenoides siguió un modelo cinético de orden cero. A partir del análisis cinético, se demostró que la constante de velocidad de degradación (k) tanto de los tococromanoles como de los carotenoides disminuía con una exposición más prolongada de las semillas a la radiación de MV. La cinética de la degradación de la capacidad antioxidante durante el almacenamiento de los aceites siguió una reacción de orden cero. La tasa de degradación de la capacidad antioxidante en el aceite testigo fue mayor (k = 9,1 x 10-2 mmol TEAC / l / mes) en comparación con los aceites preparados a partir de semillas pretratadas con MV (k = 6,8-8,0 x 10-2 mmol TEAC / l /mes)

Composición química y resistencia a la oxidación de aceite de colza alto oleico prensado de semillas intactas y descascarilladas pre-tratadas con microondas

The influence of a microwave (MV) pre-treatment (3, 6, 9 min, 800W) on the physicochemical properties of high-oleic rapeseed oil prepared from intact (HORO) and de-hulled seeds (DHORO) was investigated in this study. A control DHORO contained higher levels of total tocopherols and carotenoids, while higher concentrations of total phenolic compounds and chlorophylls were detected in the HORO. The MV pre-treatment caused a decrease in the unsaturated fatty acids content that was more evident for the DHOROs. The microwaving time significantly affected phytochemical contents and the color of both types of oils. A vast increase in canolol concentration was noticeable following 9 min of microwaving, which increased 506- and 155-fold in the HORO and DHORO, respectively. At the same time, the antioxidant capacity of oil produced from MV pre-treated seeds for 9 min was nearly 4 times higher than that of the control oil for both types of oilsEn este estudio se investigó la influencia del pretratamiento con microondas (MV) en las propiedades fisicoquímicas del aceite de colza alto oleico preparado a partir de semillas húmedas (HORO) y descascarilladas (DHORO) (3, 6, 9 min, 800W). El control DHORO contenía un nivel más alto de tocoferoles totales y carotenoides, mientras que se detectó una mayor concentración de compuestos fenólicos totales y clorofilas en el HORO. El pretratamiento de MV provocó una disminución en el contenido de ácidos grasos insaturados que fue más evidente para los DHOROs. El tiempo de microondas afectó significativamente al contenido fitoquímico y al color de ambos tipos de aceites. Se observó un gran aumento de la concentración de canolol después de 9 min de microondas, que aumentó 506 y 155 veces en el HORO y DHORO, respectivamente. Al mismo tiempo, la capacidad antioxidante del aceite producido a partir de semillas pretratadas de MV durante 9 min fue casi 4 veces mayor que la del aceite de control para ambos tipos de aceites

Influencia del tostado de colza descascarillada sobre la composición fisicoquímica y el estado oxidativo del aceite

The effect of roasting time on the contents of bioactive compounds (tocopherols, phytosterols, phenolic compounds), antioxidant capacity and physicochemical properties of rapeseed oil pressed from de-hulled seeds was investigated. The de-hulled seeds were roasted at a temperature of 165 °C for 20, 40, 60, 80, and 100 min. The results of this study show that a roasting pre-treatment led to a gradual increase in canolol content (from 1.34 to 117.33 mg/100 g), total phytosterols (from 573.51 to 609.86 mg/100 g) and total carotenoids (0.82 to 2.41 mg/100 g), while only slight changes in the contents of tocopherols were noted. With the increase in roasting time a gradual increase in oxidative stability (from 4.27 to 6.85 h), and antioxidant capacity, seen mainly in the hydrophilic fraction of oil (from 0.32 to 2.30 mmol TEAC/l) was found. Although roasting resulted in the formation of primary and secondary oxidation products, the quality parameters of oils were within Codex Alimentarius limits.Se estudió el efecto del tiempo de tostado sobre el contenido de compuestos bioactivos (tocoferoles, fitoesteroles, compuestos fenólicos), capacidad antioxidante y propiedades fisicoquímicas del aceite de prensado de semillas descascarilladas de colza. Las semillas descascarilladas se tostaron a una temperatura de 165 ºC durante 20, 40, 60, 80 y 100 min. Los resultados de este estudio muestran que el pretratamiento con tostado condujo a un aumento gradual del contenido de canolol (de 1,34 a 117,33 mg/100 g), fitosteroles totales (de 573,51 a 609,86 mg/100 g) y carotenoides totales (0,82 a 2,41 mg/ 100 g). Sólo se observaron ligeros cambios en el contenido de tocoferoles. Con el incremento del tiempo de tostado se observó un aumento gradual de la estabilidad oxidativa (de 4,27 a 6,85 h) y se encontró capacidad antioxidante, observada principalmente en la fracción hidrofílica de aceite (de 0,32 a 2,30 mmol TEAC/l). Aunque, el tostado produjo formación de productos de oxidación primaria y secundaria, los parámetros de calidad de los aceites estaban dentro de los límites del Codex Alimentarius

Cromatografía en columna como método para la eliminación de componentes menores del aceite de colza

The purpose of this study was to verify the influence of different chromatographic column beds (silicic acid, activated charcoal, aluminum oxide, silica gel) on the concentration of individual minor components (sterols, tocopherols, carotenoids and chlorophyll) in rapeseed oil. With the use of a combination of these beds, a three-stage optimized method for removing minor components from rapeseed oil was developed. It was demonstrated that the combination of silicic acid and activated charcoal removed about half of the sterols present from the oil. Aluminum oxide turned out to be the most effective bed in removing tocopherols, purifying the oil to their minimum level (2.6 mg/kg). All adsorbents used had similar capacity to purify oil from pigments (carotenoids and chlorophyll). In the three-stage purification process free sterols were almost completely removed (to the level 90.0 mg/kg). Purification of β-carotene and chlorophyll from the oil was also very effective. Tocopherols were completely removed with this method, except for a small amount of α-tocopherol (0.4 mg/kg), which results from its relatively weak interaction with a hydrophilic bed. The developed method may be used in studies on the effect of association colloids on bulk oil autoxidation processes.El propósito de este estudio fue verificar la influencia de diferentes rellenos de columnas cromatográficas (ácido silícico, carbón activo, óxido de aluminio, gel de sílice) sobre la concentración de componentes menores individuales (esteroles, tocoferoles, carotenoides y clorofila) en aceite de colza. Gracias a esto, se desarrolló un método optimizado de tres etapas para eliminar los componentes secundarios del aceite de colza (utilizando una combinación de todos los rellenos descritos anteriormente). Se ha demostrado que con la combinación de ácido silícico y carbón activo se elimina del aceite alrededor de la mitad de los esteroles presentes. El óxido de aluminio resultó ser el relleno más eficaz para eliminar los tocoferoles, purificando el aceite hasta su nivel mínimo (2,6 mg/kg). Todos los adsorbentes utilizados tenían una capacidad similar para purificar el aceite de pigmentos (carotenoides y clorofila). En el proceso de purificación en tres etapas, los esteroles libres se eliminaron casi por completo (hasta el nivel de 90,0 mg/kg). La purificación de aceite de β-caroteno y clorofila también fue muy efectiva. En este método, los tocoferoles se eliminaron completamente, excepto pequeñas cantidades de α-tocoferol (0,4 mg/kg), lo que resulta de su interacción relativamente débil con un relleno hidrófilo. El método desarrollado se puede usar en los estudios sobre el efecto de los coloides de asociación en los procesos de autooxidación de aceites a granel

The Interactions Between Rapeseed Lipoxygenase and Native Polyphenolic Compounds in a Model System

The focus of the present research was to study inhibition of lipoxygenase activity by rapeseed native polyphenols and the interactions between those compounds and the enzyme. The enzyme and polyphenolic compounds (polyphenols, phenolic acids) were extracted from rapeseed (Brassica napus) varieties Aviso and PR45DO3. The total phenolic compounds concentration in tested rapeseed was 1,485–1,691 mg/100 g d.m. (dry matter) and the free phenolic acids content in both rapeseed varieties was about 76 μg/100 g d.m. The isolated proteins showed lipoxygenase activity. Prooxidant properties of phenolic compounds in the presence of lipoxygenase and linoleic acid were observed rather in the case of extracts containing a relatively high concentration of miscellaneous polyphenols. Antioxidant properties were recorded in the case of phenolic acid extracts which contain only 1.4–1.9% of phenolics present in raw phenolic extracts. We propose that the prooxidant effect of phenolic compounds comes from quinone and oxidized polyphenols formation. The observed antioxidant activity of phenolic acid extracts is probably due to their ability to scavenge free radicals formed from linoleic acid. However, reduction of lipoxygenase ferric to ferrous ions, which prevent the activation of the enzyme and inhibited its activity, was also observed

Influence of de-hulled rapeseed roasting on the physicochemical composition and oxidative state of oil

The effect of roasting time on the contents of bioactive compounds (tocopherols, phytosterols, phenolic compounds), antioxidant capacity and physicochemical properties of rapeseed oil pressed from de-hulled seeds was investigated. The de-hulled seeds were roasted at a temperature of 165 °C for 20, 40, 60, 80, and 100 min. The results of this study show that a roasting pre-treatment led to a gradual increase in canolol content (from 1.34 to 117.33 mg/100 g), total phytosterols (from 573.51 to 609.86 mg/100 g) and total carotenoids (0.82 to 2.41 mg/100 g), while only slight changes in the contents of tocopherols were noted. With the increase in roasting time a gradual increase in oxidative stability (from 4.27 to 6.85 h), and antioxidant capacity, seen mainly in the hydrophilic fraction of oil (from 0.32 to 2.30 mmol TEAC/l) was found. Although roasting resulted in the formation of primary and secondary oxidation products, the quality parameters of oils were within Codex Alimentarius limits