Composición nutricional y actividad antioxidante de diferentes variedades de nueces (Juglans regia L.) de Nerpio (España) en comparación con variedades comerciales

In the Nerpio region (Albacete, Spain), endogenous walnut cultivars have been grown since ancient times. None of them has been chemically characterized to valorize them in comparison to commercial varieties. In this work, 47 native (N) and 7 foreign (F) walnut cultivars grown in Nerpio, and 13 commercial (C) samples were studied during three seasons. The average yield, moisture, and protein and oil contents were slightly lower in the N samples than in C. The composition of fatty acid suggested that the N walnuts could be more stable against oxidation due to their higher amount of MUFA and lower amount of PUFA. The biological protein value for the samples was similar but the antioxidant capacity marked important differences among them: N cultivars reached the highest scores, with intermediate F values. Local walnut varieties from Nerpio should be valorized on the basis of their potentially enhanced health benefits, although further studies must be developed on their phytochemicals.En Nerpio (Albacete, España) se cultivan tradicionalmente variedades locales de nueces que nunca han sido estudiadas con vistas a su puesta en valor frente a variedades comerciales. En este trabajo se han estudiado 47 variedades locales (N) y 7 extranjeras (F) cultivadas en Nerpio, además de 13 comerciales (C). Los valores medios encontrados para rendimiento, humedad, y contenidos graso y proteico fueron ligeramente inferiores en N. Debido a su composición de ácidos grasos, el aceite de nueces N podría ser más estable frente a la oxidación. El valor biológico de sus proteínas es muy similar, siendo la actividad antioxidante la que marca una gran diferencia en favor de los cultivares endémicos: las muestras N dieron los valores más altos, y las F intermedios. Por ello, las variedades locales de Nerpio podrían tener mayores beneficios para la salud que las variedades comerciales, aunque son necesarios estudios sobre su composición en fitoquímicos

Application of artificial neural networks to determine the authentication of fattening diets of Iberian pigs according to their triacylglycerol profiles

The triacylglycerols in the subcutaneous fat from Iberian pigs reared on four different feeding types, Montanera, Recebo, extensive Cebo and intensive Cebo, have been determined by gas chromatography with a flame ionization detector. Analyses were performed in a column coated with a bonded stationary phase (50% phenyl-50% methylpolysiloxane) with hydrogen as the carrier gas. Lipids were extracted by melting the subcutaneous fat in a microwave oven and then filtering and dissolving it in hexane. A total amount of 2783 samples from several campaigns were considered. Using the triacylglycerols as chemical descriptors, a study on the discriminating power to differentiate samples according to the pig feeding type and system was performed. With this aim, pattern recognition techniques, such as linear discriminant analysis (LDA) and multilayer perceptron artificial neural networks (MLPANN), have been used. ANN performed better than LDA, with a mean prediction ability of approximately 97% in the differentiation of fattening diets such as <i>Montanera</i>, extensive <i>Cebo</i> and intensive <i>Cebo</i>. In the case of including the recebo fattening diet, the model presents a mean performance of 82%. The differentiation of fattening systems has also been achieved by means of ANN, with a mean performance of 96%.<br><br>Se ha determinado mediante cromatografía de gases con detector de ionización de llama los triglicéridos de la grasa subcutánea de cerdos ibéricos, cebados con cuatro tipos de alimentación: montanera, recebo, cebo extensivo y cebo intensivo. Los análisis se realizaron en una columna con una fase estacionaria ligada químicamente (50% fenil-50% metilpolisiloxano) usando hidrógeno como gas portador. La grasa subcutánea se extrajo por fusión en horno de microondas, posteriormente se filtró y se disolvió en hexano. Un total de 2.783 muestras de varias campañas fueron analizadas. Usando los triglicéridos como descriptores químicos se ha llevado a cabo un estudio sobre la capacidad de discriminación de éstos para diferenciar el tipo y régimen de alimentación de los cerdos. A tal fin, se han empleado técnicas de reconocimiento de patrones, tales como análisis discriminante lineal (LDA) y redes neuronales artificiales de perceptores multicapa (ANN-MLP). Las ANN presentan mejores resultados que el LDA, con una capacidad de predicción media de aproximadamente 97% en la diferenciación del tipo de alimentación entre <i>Montanera, Cebo</i> extensivo y <i>Cebo</i> intensivo. Al incluir el recebo, el modelo presenta un rendimiento promedio de 82%. La diferenciación del régimen de cebado también se ha llevado a cabo por medio de la ANN, con un rendimiento promedio del 96%

Subcutaneous fat triacylglycerols profile from iberian pigs as a tool to differentiate between intensive and extensive fattening systems

Triacylglycerols of subcutaneous fat of Iberian pigs reared on two different feeding systems, extensive and intensive, have been determined by gas chromatography with a flame ionization detector. Analyses were performed on a column coated with a bonded stationary phase (50% phenyl-50% methylpolysiloxane) with hydrogen as the carrier gas. Lipids were extracted by melting the subcutaneous fat in a microwave oven and then filtering and dissolving in hexane. A total amount of 1995 samples from several campaigns were considered. Palmitoyl-stearyl-oleoyl glycerol and palmitoyl-dioleoyl glycerol were the most abundant triacylglycerols found in the samples. A study on the discriminating power of the triacylglycerols to differentiate samples according to the pig feeding system was performed. By using the triacylglycerols as chemical descriptors, principal component analysis, linear discriminant analysis, and soft independent modeling of class analogy were applied. Dioleoyl-linoleoyl glycerol and oleoyl-dilinoleoyl glycerol were the most discriminating variables. Variable-variable plots of these two glycerols allow separation of the samples according to their content. © 2012 American Chemical Society.This study was supported by project PET 2007_0015.Peer Reviewe