Tocopherol content, weight loss and instrumental color analysis of Iberian dry-cured ham as affected by rearing and feeding systems

Abstract

The effects of rearing (outdoor <i>vs</i> indoor) and feeding systems (acorn and grass vs mixed diets) on ham quality from Duroc x Iberian pigs were studied. Seven groups of 5 females each were used. One group was reared under freerange conditions and fed with acorns and grass (outdoor pigs). Six group were fed mixed diets in confinement (indoor pigs) under a factorial design 3 x 2 with three types of dietary fat: monounsaturated, polyunsaturated and medium (monounsaturated and polyunsaturated) and two levels of α-tocopheryl-acetate. The α-and γ-tocopherol contents were higher (P < 0.05) in hams from outdoor pigs than in hams from indoor pigs. The hams from indoor pigs were lighter than hams from outdoor pigs and redness values were larger in hams from outdoor pigs than in hams from indoor pigs. At 4 days of storage ham samples from outdoor pigs showed a tendency (P < 0.10) to lower weight loss than those from pigs fed a basal level of vitamin E. These results indicate that rearing outdoor and feeding Iberian pigs by acorn and grass increase the α-and γ-tocopherols and improve color and weight losses in dry-cured hams.<br><br>Se ha estudiado el efecto del régimen de producción (en libertad <i>vs</i> estabulados) y el sistema de alimentación (bellota y pasto vs piensos formulados) en la calidad del jamón de cerdos Ibéricos cruzados con Duroc. Siete grupos de 5 hembras cada uno fueron usadas. Un grupo fue criado en condiciones de libertad y alimentado con bellotas y pasto (Cerdos en libertad). Seis grupos fueron alimentados con dietas formuladas en confinamiento (Cerdos estabulados) usando un diseño factorial de 3 x 2 con tres tipos de grasa en la dieta: monoinsaturada, poliinsaturada y media (monoinsaturada y polinsaturada) y dos niveles de acetato de α-tocoferol. Los contenidos de α- y γ-tocoferol fueron más altos (p < 0.05) en jamones de cerdos criados en libertad que en jamones de cerdos estabulados. Los jamones de cerdos estabulados pesaron menos que los jamones de cerdos en libertad y los valores de color rojo fueron mayores en jamones de cerdos en libertad que en cerdos estabulados. Después de 4 días de almacenamiento, la muestra de jamón de cerdos en libertad mostraron una menor tendencia (p < 0.10) a perder peso que aquellos de cerdos alimentados con un nivel basal de vitamina E. Estos resultados indican que cerdos Ibérico criados en libertad y alimentados con bellota y pasto incrementan su contenido en tocoferoles y mejoran el color y las pérdidas de peso de los jamones curados

Accumulation and evolution of tocopherols in dry-cured hams from Iberian pigs as affected by their feeding and rearing system

“…However, these differences in ctocopherol concentration between FREE or ACORN groups were not detected in M. Semimembranosus. This is the first study that examines c-tocopherol concentration in both muscles in cured hams, as previous research developed in hams quantified concentration in the main muscle (B. femoris) (Isabel et al, 2009). These authors also found a higher concentration of c-tocopherols in hams from pigs fed outdoors when compared with others fed mixed diets but the possibility of differentiating hams from pigs fed acorn Table 1 Chemical and fatty acid composition (g/100 g total fatty acids) of the feed.…”

“…A little degradation of a-tocopherol was also reported previously (Isabel et al, 1999) in the Biceps femoris muscle of dry-cured hams after processing despite the presence of NaCl and the relatively high temperature during drying. However, with regard to c-tocopherol, there are no values in the literature for cured fat compared with raw fat as c-tocopherol was measured in the B. femoris muscle in previous studies (Isabel et al, 2009). The stereoisomer composition of M. Biceps femoris from Iberian pig cured hams according to their rearing system was also quantified (Table 3).…”

“…Changes in a* and b* were detected with higher intensity between 1-7 days, when the highest degradation of tocopherols takes place. Isabel et al (2009) quantified the relationship between a-and c-tocopherol concentration and colour Table 4 Evolution of the tocopherol composition (a and c-tocopherols) ( redness and reported that both explained approximately 48% of colour variation. Many other factors such as muscle composition that are modified not only by the feeding but also by the rearing system would be involved in the highest colour stability of the FREE group.…”

“…Isabel, López-Bote, Rey, and Sanz-Arias (1999) reported the persistence of a-tocopherol throughout processing and lower loss of colour in those slices from pigs supplemented with a-tocopherol. The c-tocopherol homologue has also been found in the final product after processing, despite the oxidative changes that take place (Isabel, Cordero, López-Bote, & Daza, 2009). On the other hand, it has been described that the natural form of a-tocopherol (RRR-a-tocopherol) is absorbed more easily and has a higher biological activity, and therefore antioxidant capacity, than the synthetic a-tocopherol (Hosomi et al, 1997), which is a mixture of the eight different stereoisomers.…”

“…Quality control is of special interest in ham as it is one of the most valuable products of the Iberian pig; however, there is not much information of the quantification of these natural compounds in the final cured product. Isabel, Cordero, López-Bote, and Daza (2009) described the presence of ctocopherol in dry-cured hams from Iberian pigs fed in extensive conditions at higher concentrations than in those fed mixed diets. However, to our knowledge no study has evaluated either tocopherol concentration at different anatomical locations in the cured ham or the degradation of tocopherols during storage, the feeding regimen or the rearing system, which would be factors that might affect tocopherol levels and therefore correct classification of the products.…”