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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.

Triacylglycerols of 50 samples of subcutaneous fat of Iberian pigs reared extensively on two different feeding systems: montanera (M) and cebo (C) have been analysed by gas chromatography flame ionization detector. The lipids were extracted by melting from subcutaneous fat into microwave oven. The fat was then filtered and dissolved in hexane. This analysis was performed on a column (30 m x 0.25 mm i.d.) coated with a bonded stationary phase DB-17HT (50% phenyl-50% methylpolysiloxane; 0.15 microm film thickness) with hydrogen (2.1 mL min(-1)) as a carrier gas, programmed temperature was kept at 320 degrees C, and was then raised to 350 degrees C at a rate of 2.0 degrees C min(-1) and flame ionization detector. By using the triacylglycerols as chemical descriptors, pattern recognition techniques were applied to differentiate between montanera and cebo fattening diet of Iberian pig. Triolein, palmitoyl-stearyl-oleoyl glycerol and di-oleoyl-linoleoyl glycerol were found to be the most differentiating variables.

9 pages, 4 tables, 3 figures.-- Research article., [EN] The n-Alkene content in samples of subcutaneous fat corresponding to 755 castrated male Iberian pigs has been determined by an off-line combination of HPLC and GC method. The samples corresponded to three groups based on the type of feeding during the finish fattening period (“Montanera”, fed on acorns and pasture; “Recebo”, fed on acorns, feed and pasture; and “Cebo”, fed on feed and pasture). By using the n-alkenes as chemical descriptors, multivariate statistical techniques were applied to differentiate between the three fattening diet types for Iberian pigs. The most differentiating variables were n-C16:1, n-C18:1, n-C22:1 and n-C24:1. However, a clear classification of the samples was not achieved. The level of classification was improved when the data corresponding to the animals fed with the “Recebo” fattening diet was removed from the analysis. A relationship between n-C14:1, n-C16:1 and n-C18:1 levels and the slaughter period was found to be very low for the animals fed with the “Cebo” fattening diet when the animals had not been closely managed and pasture had not been included in their fattening diet., [ES] El contenido de n-alquenos de la grasa subcutánea de 755 muestras procedentes de cerdos ibéricos machos, se ha determinado mediante combinación off-line de los métodos HPLC y GC. Las muestras correspondían a tres grupos según el tipo de alimentación en el período final de engorde (“Montanera”, alimentados con bellota y pasto; “Recebo”, alimentados con bellota, pasto y pienso; y “Cebo”, alimentados con pienso y pasto). Usando los n-alquenos como descriptores químicos, se aplicaron técnicas de análisis multivariante para diferenciar entre los tres tipos de alimentación de cerdo ibérico. Se encontró que las variables más diferenciadores fueron n-C16:1, n-C18:1, n-C22:1 y n-C24:1. Sin embargo, el total de las muestras no están clasificadas, mejorando el nivel de clasificación cuando se eliminan las muestras correspondientes a animales de “Recebo”. Para el “Cebo”, se encontró una relación entre los niveles de n-C14:1, n-C16:1 y n-C18:1 y el período de sacrificio, siendo los niveles de estos muy bajos cuando los animales, no eran de cría en extensivo y no tenían pasto en su dieta de engorde.

10 pages, 5 tables, 4 figures., [EN] The triacylglycerol (TGs) composition of 1, 560 samples of subcutaneous fat of Iberian purebred and crossbred (iberianxDuroc) pigs reared extensively on three different feeding systems: montanera (M), cebo (C) and recebo (R), were determined. Seventeen TG species were identified by Gas Chromatography and six of them (POO, PSO, POL, OOO, SOO, OOL) accounted for 75 %. Significant differences (p < 0.01) were found for the majority of TG species among the three types of feeding. The effect of the duration of montanera on the TG composition was also explored and a significant positive correlation (p < 0.05) was found with the following TGs: OOO, SOL, OOL and OLL. After 110 days of Montanera, all the samples showed a percentage of OOO and OOL over 9.5 % and 4.5% respectively. Genotype also showed a significant effect (p < 0.01) on the TG composition. Principal Component and Linear Discriminant analyses were applied to the data set. No clear separation among the three groups (M, R and C) according to the TG profile was achieved. Only M and C groups were clearly separated according to their TG composition., [ES] Se ha determinado la composición de trigliceridos (TGs) en 1560 muestras de grasa subcutánea de cerdo ibérico puro y cruzado (ibericoxDuroc) criados en régimen extensivo en tres sistemas de alimentación: montanera (M), cebo (C) y recebo (R). Diecisiete TGs se han identificado mediante Cromatografía de Gases, y seis de ellos (POO, PSO, POL, OOO, SOO, OOL) representan el 75 %. Se encontraron diferencias significativas (p < 0.01) para la mayoría de los TGs entre los tres tipos de alimentación. También se investigó el efecto del tiempo de montanera sobre la composición de TGs, encontrándose una correlación positiva (p < 0.05) con los siguientes TGs: OOO, SOL, OOL y OLL. Tras 110 días de Montanera, todas las muestras presentaron % de OOO y OOL por encima del 9.5 % y 4.5 % respectivamente. El genotipo también mostró un efecto significativo (p < 0.01) sobre la composición de TGs. Se aplicó Análisis de Componentes Principales y Análisis Lineal Discriminantes a los datos obtenidos. No se obtuvo una buena separación entre los tres grupos de alimentación (M, R y C), sólo para los grupos de M y C se obtuvo una clara separación en base a la composición de TGs.