Quantitative study of the α- and γ-tocopherols accumulation in muscle and backfat from Iberian pigs kept free-range as affected by time of free-range feeding or weight gain

Abstract

Quantitative study of the α-and γ-tocopherols accumulation in muscle and backfat from Iberian pigs kept free-range as affected by time of freerange feeding or weight gain AbstractThe experiment was undertaken to quantify the a and g-tocopherols accumulation in muscle and backfat from Iberian pigs given food free-range as affected by the time of free-range feeding or the weight gained during the fattening in free-range. Pigs were given their food in a free-range production system with pasture and acorns (Quercus rotundifolia) for different periods of time: 46 days (free-range 3), 83 days (free-range 2) and 111 days (free-range 1). A control was given food free-range for 0 days. In addition another experiment was developed to determinate the effect of the the weight gained on the tocopherols accumulation at a similar period of time (111 days) given food free-range: one group gained 68·7 kg of weight (free-range A) and the other 43·6 kg (free-range B). The concentration of g-tocopherol significantly ( P , 0·0001) increased after 83 days of feeding in the longissimus dorsi (LD) and biceps femoris (BF) muscles, and after 111 days in the inner and outer backfat layers. The concentration of a-tocopherol was not statistically affected by the days of free-range feeding in any case. Iberian pigs that put on more weight had significantly ( P , 0·0001) higher concentration of a and g-tocopherols in the inner and outer backfat layers, and a-tocopherol in the BF muscle than those given food free-range B. However, no differences were detected in the proportion of a-tocopherol in the LD and g-tocopherol in the LD and BF. The g-tocopherol content of LD and BF muscles depending on the days of feeding were adjusted to linear and quadratic regressions ( R 2 ¼ 0·8705 and 0·8697, respectively), while the outer and inner backfat layers were linear equations ( R 2 ¼ 0·8480 and 0·8119, respectively). However, the g-tocopherol concentration as affected by the weight gained in free-range showed in all tissues a linear and a quadratic trend that were adjusted to exponential responses. The a-tocopherol content was affected by the g-tocopherol concentration in muscle and outer backfat layer. The tocopherol concentration (a and g-tocopherols) in the backfat layers may discriminate better between the pigs of high quality that were given food free-range for a long period of time and those that stayed an intermediate period. However, to discriminate between the pigs on formulated food and those given food free-range, the quantification of the g-tocopherol concentration in muscle could be a better indicator.

Effects of oral micellized natural vitamin E (d-α-tocopherol) v. synthetic vitamin E (dl-α-tocopherol) in feed on α-tocopherol levels, stereoisomer distribution, oxidative stress and the immune response in piglets

“…The α-tocopherol concentration in serum from sows and piglets was quantified as described by Rey et al (2006) by direct extraction. Thus, serum samples were mixed with 0.054 M dibasic sodium phosphate buffer adjusted to pH 7.0 with HCl and absolute ethanol.…”

“…Tocopherols were analysed by reverse phase HPLC (HP 1100, equipped with a diode array detector; Agilent Technologies, Waldbronn, Germany) as described (Rey et al, 2006). Identification and quantification were carried out by means of a standard curve (R 2 = 0.999) built using the pure compound (Sigma, Alcobendas, Madrid, Spain).…”

“…α-Tocopherols in subcutaneous fat was analysed using the procedure described by Rey et al (2006). In this case, samples were saponified in the presence of pyrogalol (3% in ethanol), KCl (1.15%) and KOH (50%) and afterwards mixed with hexane.…”

Effects of dietary vitamin E (DL-α-tocopheryl acetate) and vitamin C combination on piglets oxidative status and immune response at weaning

“…The α-tocopherol concentration in serum was quantified as described by Rey et al (2006) by direct extraction. Thus, serum samples were mixed with 0.054 M dibasic sodium phosphate buffer adjusted to pH 7.0 with HCl and absolute ethanol.…”

High dietary vitamin A interferes with tissue α-tocopherol concentrations in fattening pigs: a study that examines administration and withdrawal times

“…Retinol and a-tocopherol in adipose tissue, were analyzed using a method described by Rey et al (2006). Samples (0.05 g) were saponified in the presence of KOH (50%), KCl (1.15%) and pyrogallol (3% in ethanol) at 708C for 30 min.…”