P. Santoro

The effect of dietary supplementation of vitamins C and E on the α-tocopherol content of muscles, liver and kidney, on the stability of lipids, and on certain meat quality parameters of the longissimus dorsi of rabbits

The trial was carried out to investigate the effects of adding to the diet of rabbits vitamin E (40; 300; 500 ppm) and C (0; 500 ppm), on vitamin E deposition in the muscles and organs, on the oxidative stability of muscular lipids, and on various meat quality characteristics. The α-tocopherol content in muscles and organs was roughly doubled by feeding the highest levels of vitamin E; it was also increased by giving 500 ppm of vitamin C, but only in those muscles of rabbits receiving 40 ppm of vitamin E. The α-tocopherol content in tissues was negatively correlated with TBARS values of the longissimus dorsi (LD) at days 6 and 8 post mortem (p.m.). Five hundred parts per million (ppm) of vitamin C increased lipid stability of the LD at both 6 and 8 days p.m., though its effect was significant only with 40 ppm of vitamin E. Moreover, 500 ppm of vitamin C resulted in the lowest L(*) and highest pH values at all p.m. times, when the dietary vitamin E was equal to 40 ppm, and in the highest L(*) and lowest pH values when the vitamin E was equal to 300 ppm. Conversely, weight losses of the LD were the lowest, at days 6 and 8 p.m., in the group fed the highest levels of both vitamins.

Effect of dietary conjugated linoleic acid (CLA) supplementation on CLA isomers content and fatty acid composition of dry-cured Parma ham

To evaluate the effects of dietary conjugated linoleic acid (CLA) supplementation on cis-9, trans-11 and trans-10, cis-12 isomer content and on the fatty acid composition of subcutaneous adipose tissue and intramuscular lipids of biceps femoris, the lipids of 24 dry cured Parma hams, obtained from Large White pigs fed isoenergetic diets supplemented with either 0 (CON) or 0.25% (T1) CLA from 97 to 172kg live weight, were analysed by Ag(+)-HPLC and capillary GLC. The dietary treatment had no influence on lipid content of BF and subcutaneous adipose tissue but increased (P<0.01) the content of both isomers, more markedly in the latter tissue. CLA supplementation increased (P<0.01) myristic, palmitic, palmitoleic and total saturated fatty acids, and decreased oleic and eicosenoic acids in both tissues. In adipose tissue, an increase (P<0.05) in stearic acid content was observed. Supplementing the finishing diet of heavy pigs with CLA has thus shown to be an effective tool for increasing the CLA content in cured ham and, also, the saturated:unsaturated ratio of the lipids, a positive effect from a technological point of view. From a human nutritional standpoint, the changes occurring in fatty acid composition negatively affect the atherogenic and thrombogenic indexes, but probably these changes are of no particular concern, as they would only partly offset the progressive increase in the degree of unsaturation of heavy pig lipids that has occurred in recent years, as a consequence of reduced adipose depots in carcasses.

Lipid composition of covering and intramuscular fat in pigs at different slaughter age

To study age-related variations in fatty acid composition of covering and intramuscular fat (IMF), 60 half siblings, Pic X Camborough, of the same age, 30 barrows and 30 gilts, chosen from 10 litters were used. Groups of 20 subjects each, 10 castrated males and 10 females, balanced for litter, were sacrificed at 6, 8.5 and 9.5 months of age, corresponding to the common slaughter age of the three Italian pig production types, at live weights averaging approximately 90, 145 and 160 kg, respectively. Samples of backfat and longissimus thoracis (LT) muscle, taken at the last rib, were analysed. On LT samples, moisture, fat content and drip loss were determined. Fatty acid composition was determined in lipids from subcutaneous adipose tissue and in lipid fractions from LT. Further, backfat lipids were submitted to iodine value (I.V.) determination. The data were evaluated by means of analysis of variance with age at slaughter and sex as the independent variables. As age increased (6, 8.5 and 9.5 months), higher contents of saturated fatty acids (SFA) (36.36, 39.08 and 39.19%, respectively; P<0.01) and monounsaturated fatty acids (MUFA) (41.78, 43.44 and 44.37%, respectively; P<0.01) were observed in backfat, whereas polyunsaturated fatty acids (PUFA) content, PUFA/SFA ratio and I.V. lowered (P<0.01). As total IMF is concerned, by increasing age, MUFA content increased (43.30; 46.76 and 47.28%, respectively; P<0.01), PUFA content decreased (18.63, 15.14 and 14.82%, respectively; P<0.01) and PUFA/SFA decreased as well (P<0.05); neutral lipids followed the same pattern, while an opposite trend was observed in polar lipids. IMF content (1.65%) was modified neither by sex nor age. The study shows that fatty acid composition of subcutaneous and intramuscular fats differs among the 3 slaughtering ages typical of the Italian pig industry. The variations observed, which could be ascribed to the increase of carcass fatness at increasing slaughter age, can affect both the nutritional and technological quality of pork.

Effects of dietary level of pantothenic acid and sex on carcass, meat quality traits and fatty acid composition of thigh subcutaneous adipose tissue in Italian heavy pigs

Two trials were carried out to evaluate the effects of i) supranutritional doses of pantothenic acid (PA) and ii) sex on carcass, meat quality and fatty acid (FA) composition of subcutaneous adipose tissue in Italian heavy pig. In trial 1, 59 Duroc x (LxLW) pigs were fed the same diet containing either 10 [in the control (C) group] or 110 ppm [in the treatment (T) group] PA, from 107 to 168 kg live weight. At slaughtering, forty carcasses were sampled randomly. The T carcasses had lower backfat thickness (P<0.05), lower incidence of adipose cuts (P<0.05), higher lean cuts percentage (63.09 vs 60.64%; P<0.01) and lean meat yield (P<0.07). In trial 2, 42 pigs [Dumeco Cofok x (LxLW)], evenly divided into three groups, were fed the same feed containing respectively 10 (C), 60 (T1) and 110 ppm (T2) PA, from 95 to 165 kg live weight. The treatment lowered total adipose cuts yield (P<0.05) and increased lean/adipose cuts ratio (P<0.07). In the outer layer of thighs subcutaneous adipose tissue, the treatment raised polyunsaturated FA content (P<0.01), unsaturation coefficient (P<0.01) and polyunsaturated/saturated (P/S) FA ratio (P<0.05). In the inner layer, the treatment led to a lower saturated FA (P<0.05) and higher polyunsaturated FA content (P<0.01). In both trials, females generally provided leaner carcasses. In neither trials, vitamin level affected meat quality. Thus, feeding high levels of PA to heavy pigs can yield more valuable carcasses without affecting meat quality. However, effects on FA composition suggest caution in adopting this practice in the Italian heavy pig production.

Influence of conjugated linoleic acid (CLA) on intramuscular fatty acid composition in rabbit

Riassunto Effetto dei coniugati dell’acido linoleico (CLA) sulla composizione acidica del grasso intramuscolare del coniglio. Sono stati utilizzati 42 conigli, del peso vivo (p.v.) medio di circa 1,8 kg, suddivisi in 3 gruppi ed alimentati fino alla macellazione (circa 3,1 kg p.v.) con mangimi che differivano per i livelli d’integrazione di CLA (0; 0,25 o 0,50%). Sul grasso intramuscolare del Longissimus dorsi sono stati determinati il contenuto degli isomeri CLA cis-9,trans-11 e trans-10, cis-12 ed il profilo acidico. Il trattamento alimentare ha determinato un incremento (P<0,01) del tenore di entrambi gli isomeri CLA nel grasso intramuscolare e ne ha modificato il profilo acidico causando un aumento (P<0,01) degli acidi grassi saturi, una riduzione (P<0,01) degli acidi grassi monoinsaturi e variazioni modeste nel tenore in polinsaturi. L’aggiunta di CLA alla dieta del coniglio risulta un mezzo efficace per aumentarne il contenuto nelle carni, anche se aumenta il rapporto saturi/insaturi e gli indici di aterogenicità e di trombogenicità.

Effect of Dietary Pantothenic Acid Supplementation on Meat and Carcass Traits in the Heavy Pig

Recent studies conducted on pigs slaughtered at around 120 kg (Stahly and Lutz, 2001; Autrey et al., 2002) indicate that increasing dietary panthotenic acid to doses higher than currently recommended levels (NRC, 1998) may favourably modify carcass composition, leading to an increase in the percentage of lean tissue, a larger cross sectional area of the l.dorsi muscle and a consequent reduction in adipose tissue, without negatively impacting meat quality parameters. The aim of this study was to investigate the effect of supplementing diets with high doses of pontothenic acid, in excess of currently recommended levels, on the production of heavy pigs intended for the pork processing industry.

The Quality in Parma Hams as Related to Halothane Reactivity

In the present study data are reported concerning hams from halothane negative and halothane positive crossbred pigs, slaughtered at about 130 kg live weight. Seasoning losses were higher in hams from halothane positive pigs, but the difference was not statistically significant. Also separation into boneless cuts and laboratory analysis did not show significant differences. Meat processing techniques probably prevented the detection of meat quality differences between the seasoned products from halothane negative and positive pigs. Moreover, even though halothane positive pigs produce poorer quality fresh meat, it is not easy to ascertain to what extent the tendency towards PSE may cause problems during processing and seasoning.

Effect of pantothenic acid level in the diet of the finishing heavy pig on carcass and meat quality traits

Abstract This study investigated the effect of vitamin B5 dietary level on carcass and meat quality characteristics in the heavy pig. To this aim, 42 pigs, 21 gilts and 21 barrows, of similar weight and age, evenly divided into 3 groups of 14 subjects each, were fed, from approx. 95 kg live weight (lw) till slaughtering (around 165 kg lw), the same basal diet containing either 10 (control, C), or 60 (T1), or 110 ppm (T2) pantothenic acid. At increasing dietary levels of vitamin B5, only numerical improvements of lean meat and lean cuts percentages were observed, whereas total adipose cuts, backfat and jowl percentages decreased (P<0.05). Ham characteristics and meat quality traits, such as colour, pH, intramuscular fat and protein contents, were not affected by the dietary treatment.