Open Access
Shelf life of ground beef enriched with omega-3 and/or conjugated linoleic acid and use of grape seed extract to inhibit lipid oxidation
(Wiley, 2016) Gómez Bastida, Inmaculada; Beriain Apesteguía, María José; Mendizábal Aizpuru, José Antonio; Realini, Carolina; Purroy Unanua, Antonio; Ciencias del Medio Natural; Natura Ingurunearen Zientziak; Producción Agraria; Nekazaritza Ekoizpena
The shelf life and oxidative stability of refrigerated raw ground beef enriched with omega-3 and/or conjugated linoleic acid (CLA) were studied. Grape seed extract (GSE) was used to inhibit lipid oxidation in the ground beef. Eight treatments of ground beef were established according to the enrichment of beef (control, enriched with omega-3, with CLA, or with omega-3 plus CLA) and the use of GSE (0 and 250 mg GSE/kg product). Fresh beef was ground and mixed with GSE and salt. Treatments of beef were stored at 2± 1°C in aerobic packaging for 0, 1, 3, and 6 days under retail display conditions. Oxidation stability (thiobarbituric acid-reactive substances [TBARS]), pH, instrumental color, metmyoglobin formation, and sensory attributes (color and odor) were measured. Omega-3-enriched beef increased the oxidation level at day 6 as determined by TBARS (P<0.05), but the instrumental color was not affected. The enrichment of CLA improved the coordinates of color (P<0.05) until day 3 and decreased the oxidation at day 6 (P<0.05). There were no differences in color and odor values among the types of beef during display, except at day 3, when CLA treatments had the highest scores. Addition of GSE decreased the oxidation level (P<0.001) and did not affect the instrumental color or the sensory parameters.
Open Access
Conversión de las explotaciones de vacuno de leche a la producción de leche A2 ante una posible demanda del mercado: posibilidades e implicaciones
(Asociación Interprofesional para el Desarrollo Agrario, 2019) Alfonso Ruiz, Leopoldo; Urrutia Vera, Olaia; Mendizábal Aizpuru, José Antonio; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD
El mercado de la leche de vaca, tras la desaparición de las cuotas lácteas, está provocando una importante restructuración en el sector. Una de las alternativas que están desarrollando, fundamentalmente las pequeñas explotaciones familiares, es la diferenciación de sus productos. En ese contexto, ha aparecido un tipo diferenciado de leche conocida como leche A2. Esta se caracteriza por estar libre de la variante A1 de la proteína β-caseína que, debido a una mayor producción de β-casomorfina-7 tras la digestión, puede dar lugar a intolerancias y afecciones gastrointestinales. En este trabajo se analizan las posibilidades e implicaciones de una selección a favor de la β-caseína A2 en el caso concreto de las explotaciones familiares de Guipúzcoa. Los resultados obtenidos a partir de 1868 hembras genotipadas muestran que la frecuencia del alelo que codifica la proteína A2 es 0,55, y no se han encontrado asociaciones desfavorables entre el alelo A2 y el valor genético para caracteres productivos, funcionales y morfológicos, ni con otros genes ni haplotipos. Bajo esta situación de partida, y empleando exclusivamente toros A2A2, la utilización o no de semen sexado, junto con las diferentes ratios de reposición que se apliquen, determinarán el periodo y el coste económico de la conversión de los rebaños a la producción de leche A2. En un escenario de costes razonables esta se estima entre los 8 y los 15 años, pudiendo llegar a suponer a una explotación de 150 vacas unos costes de unos 6.000 y 1.000 €/año, respectivamente.
Open Access
Qué dice (y qué no) el informe de la ONU sobre la carne
(Asociación the Conversation España, 2019-09-08) Mendizábal Aizpuru, José Antonio; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
El informe que el IPCC (Panel Intergubernamental de Expertos sobre el Cambio Climático, perteneciente a la ONU) publicó recientemente es exhaustivo y clarificador. El hecho de que hayan participado en su elaboración 107 expertos de 52 países da idea de su importancia y magnitud. Titulado El cambio climático y la tierra, el informe está estructurado en siete capítulos. En total 1384 páginas de texto, más abundante material suplementario. Conscientes de la dificultad que supone para los no expertos en el tema la lectura y el estudio de un texto de tal extensión, el IPCC ha elaborado un comunicado de prensa de siete páginas en varios idiomas, donde recoge las principales ideas y conclusiones del informe. Su lectura, por la transcendencia del tema y la concisión y claridad con que está escrito, resulta muy recomendable para todo ciudadano del mundo.
Open Access
Predicción de la cantidad de grasa intramuscular de la carne de cebones mediante ecografía y análisis de imagen
(Asociación Interprofesional para el Desarrollo Agrario, 2007) Delfa, R.; Mendizábal Aizpuru, José Antonio; Fernández Moreno, Amaia; Ripoll, Guillermo; Blanco, M.; Casasús, I.; Joy Torrens, Margalida; Purroy Unanua, Antonio; Producción Agraria; Nekazaritza Ekoizpena
La cantidad de grasa intramuscular o de infiltración, reflejada en el grado de veteado o marmoreado de la carne, es uno de los factores determinantes de la jugosidad y de la palatabilidad de la misma (Savell et al., 1986). Para poder predecir el grado de veteado en el animal in vivo, con objeto de establecer el momento óptimo de sacrificio en función del grado de infiltración grasa que se quiera obtener en la carne, se está desarrollando estos últimos años la combinación de las técnicas de ecografía y análisis de imagen (Sakowski et al., 2002). En el presente trabajo se aplican dichas técnicas para la predicción in vivo del grado de infiltración grasa de cebones de raza Parda de Montaña criados de acuerdo con el sistema de producción ecológica.
Open Access
Adiposity and adipogenic gene expression in four different muscles in beef cattle
(Public Library of Science, 2017) Martínez del Pino, Lara; Arana Navarro, Ana; Alfonso Ruiz, Leopoldo; Mendizábal Aizpuru, José Antonio; Soret Lafraya, Beatriz; Producción Agraria; Nekazaritza Ekoizpena
Anatomical site and divergent functionalities of muscles can be related to differences in IMF content, metabolism and adipogenic gene expression. Then, potential differences in different muscles in beef cattle were studied. As a second objective, the main sources of experimental variability associated to RT-qPCR results were analyzed following a nested design in order to implement appropriate experimental designs minimizing gene expression variability. To perform the study Longissimus thoracis (LT), Semitendinosus (SM), Masseter (MS), Sternomandibularis (ST) and subcutaneous adipose tissue (SAT) samples of Pirenaica young bulls (n = 4) were collected for IMF, collagen and protein quantification, analysis of adipocyte size distribution and gene expression (PPARG, CEBPA, FAPB4 and WNT10B). A greater IMF content was observed in MS and SM muscles, which had a bimodal adipocyte size distribution while it was unimodal in the muscles LT and ST. This suggest that the different IMF accretion in the muscles studied might be related to different rates of hyperplasia and hypertrophy and that IMF might develop later in LT and ST muscles. The former differences were not mirrored by the expression of the genes analyzed, which might be related to the different contribution of mature and non-mature adipocytes to the total gene expression. When comparing IMF and SAT gene expression, late and early developing tissues respectively, expression of PPARG, CEBPA and FABP4 was higher in the SAT, in agreement with bigger cell size and numbers. The variability study indicates that the analytical factors that add higher variability to the gene expression are the sampling and RT and therefore, it would be appropriate to include those replicates in the design of future experiments. Based on the results, the use of MS and SM muscles could allow less expensive experimental designs and bigger sample size that could permit the detection of lower relevant differences in gene expression.
Open Access
Comparative description of growth, fat deposition, carcass and meat quality characteristics of Basque and Large White pigs
(EDP Sciences, 2005) Alfonso Ruiz, Leopoldo; Mourot, Jacques; Insausti Barrenetxea, Kizkitza; Mendizábal Aizpuru, José Antonio; Arana Navarro, Ana; Producción Agraria; Nekazaritza Ekoizpena; Gobierno de Navarra / Nafarroako Gobernua
Characteristics of growth, fat deposition, carcass and meat quality of pigs from the Basque Black Pied breed were described and compared with those of Large White pigs. Four pens, two per breed, of eleven pigs born during the same two week period, were simultaneously fattened and slaughtered, under the same conditions. The experiment was carried out over a fixed duration (124 days) and slaughter was carried out at a fixed average age (202 days). Basque pigs showed lower growth and feed efficiency and higher backfat depth (2.6 vs. 1.7 cm, P < 0.001) than Large White pigs. The difference was especially noticeable in the middle subcutaneous fat layer (0.5 cm, P < 0.001). The meat of Basque pigs was darker, redder, more marbled, and with higher pH values than in Large White pigs. Differences in fatty acid composition were observed between breeds but they were not statistically significant (P > 0.05) because of high variability observed between animals. The Basque breed exhibited an early and higher adipose development and a higher activity of enzymes responsible for lipid synthesis than the Large White. The diameter of intramuscular adipose cells was larger in Basque (40.2 vs. 33.0 μm, P < 0.001) than in Large White pigs. The results show the particular characteristics of the Basque breed as compared to pig lines highly selected for lean growth efficiency.
Open Access
Predicting beef carcass fatness using an image analysis system
(MDPI, 2021) Mendizábal Aizpuru, José Antonio; Ripoll, Guillermo; Urrutia Vera, Olaia; Insausti Barrenetxea, Kizkitza; Soret Lafraya, Beatriz; Arana Navarro, Ana; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD
The amount and distribution of subcutaneous fat is an important factor affecting beef carcass quality. The degree of fatness is determined by visual assessments scored on a scale of five fatness levels (the SEUROP system). New technologies such as the image analysis method have been developed and applied in an effort to enhance the accuracy and objectivity of this classification system. In this study, 50 young bulls were slaughtered (570 ± 52.5 kg) and after slaughter the carcasses were weighed (360 ± 33.1 kg) and a SEUROP system fatness score assigned. A digital picture of the outer surface of the left side of the carcass was taken and the area of fat cover (fat area) was measured using an image analysis system. Commercial cutting of the carcasses was performed 24 h post-mortem. The fat trimmed away on cutting (cutting fat) was weighed. A regression analysis was carried out for the carcass cutting fat (y-axis) on the carcass fat area (x-axis) to establish the accuracy of the image analysis system. A greater accuracy was obtained by the image analysis (R2 = 0.72; p < 0.001) than from the visual fatness scores (R2 = 0.66; p > 0.001). These results show the image analysis to be more accurate than the visual assessment system for predicting beef carcass fatness.
Open Access
Preservation of milk in liquid nitrogen during sample collection does not affect the RNA quality for RNA-seq analysis
(BMC, 2025-05-24) Jiménez Montenegro, Lucía; Alfonso Ruiz, Leopoldo; Soret Lafraya, Beatriz; Mendizábal Aizpuru, José Antonio; Urrutia Vera, Olaia; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua
Background. Standard procedures for milk sample collection for transcriptome analysis use ice as preservation method, which can afect the RNA stability and requires immediate sample processing. These problems would be eased if the milk samples could be snap-frozen in liquid nitrogen. This study describes the applicability of a new method for milk sample collection and subsequent RNA extraction from milk fat globules, determining whether the quality, integrity and quantity of the RNA extracts met the minimum requirements for downstream RNA-seq. Results. The quality of the extracts measured by A260/280 ratio and the Integrity and Quality (IQ) values obtained fulflled the reference values of 1.9 - 2.1 (P10.05) and failed to meet the RIN≥7 benchmark for RNA-seq (P>0.05). Milk fat globules contain low molecular-weight RNA fragments and minimal 18S and 28S rRNA, suggesting low RIN values were inherent to sample type. Likewise, the RNA concentration from milk fat globules were generally low (120.43±22.27 ng/µL, 102.87±15.64 ng/µL and 109.43±22.69 ng/µL, measured by Nanodrop, Qubit HS and QuanTI Ribogreen, respectively). Nevertheless, RNA-seq yielded 52.7 million paired-end reads per sample. The raw reads passed all quality control parameters having the same sequence-read lengths (151 bp), 100% base-coverage, 49% GC base content, and base quality scores of 36, enabling successful transcriptome profling. Moreover, milk proteins were identifed as the most abundant transcripts in MFG in the analysis of the most expressed genes, indicating that the sequenced reads would accurately refect the transcriptome of this milk fraction. Conclusions. Milk preservation in liquid nitrogen is a suitable sample collection method that overcomes the limitations of immediate sample processing required if ice is used. Thus, this procedure, together with the subsequent RNA isolation from milk fat globules and its sequencing by RNA-seq, would provide a practical and a non-invasive method for measuring the mammary epithelial cell transcriptome, improving the feasibility of conducting studies related to mammary gland and lactation physiology.
Open Access
Caracterización de las 'Costillas de Palo' de cordero de raza Navarra. I. Composición tisular
(Universidad Cardenal Herrera-CEU. Fundación Universitaria San Pablo-CEU, 2002) Mendizábal Aizpuru, José Antonio; Alzón, M.; Arana Navarro, Ana; Eguinoa Ancho, Paola; Delfa, R.; Beriain Apesteguía, María José; Purroy Unanua, Antonio; Producción Agraria; Nekazaritza Ekoizpena
Se ha estudiado la composición tisular de 46 costillas de palo (10ª y 11ª) procedentes de 23 corderos de raza Navarra sacrificados con 24,2±1,55Kg. de peso vivo y 98±6,3d de edad. El peso medio de la costilla fue de 78,4±10,82g, de los que el porcentaje de músculo supuso el 48,5±4,16%, el de grasa 29,3±4,78% y el de hueso 15,0±3,19%, respectivamente. El músculo Longissimus dorsi, que presentó un área media de 9,6±1,34cm2, supuso el 52,4±6,30% del músculo total de la costilla. El componente óseo se distribuyó en un 41,8% en la costilla y el 58,2% en la vertebra. La grasa subcutánea supuso el 50,1% de la grasa total diseccionada, correspondiendo el 49,9% restante a la intermuscular. Por último, se midió la grasa intramuscular o de veteado que presentaba el músculo Longissimus dorsi, ocupando dicha grasa un 2,5±0,98% de la superficie de dicho músculo. El número medio de vetas de grasa en cada costilla fue de 5,6±1,92 y el tamaño medio de éstas de 4,5±1,74mm2.
Open Access
Relación entre la nota de conformación y diferentes medidas morfológicas realizadas mediante análisis de imagen en canales bovinas de diferentes conformaciones
(Asociación Interprofesional para el Desarrollo Agrario, 2005) Mendizábal Aizpuru, José Antonio; Legarra, Andrés; Purroy Unanua, Antonio; Producción Agraria; Nekazaritza Ekoizpena
En el presente trabajo se estudia, en canales bovinas representativas del mercado español y que corresponden a las 6 notas de conformación establecidas en el sistema SEUROP, la relación entre la nota de conformación y diversas medidas morfológicas obtenidas mediante análisis de imagen.