RESUMEN
Rapeseed and sunflower oil were used to replace pork backfat in UK-style sausages by incorporating the oils as pre-formed emulsions. Replacing the pork backfat emulsion with rapeseed emulsion at total fat content of about 12%, reduced total saturated fatty acid (SFA) composition from 38% to 14% (4.5 to 1.8 g/100 g), increased monounsaturated fatty acid (MUFA) composition from 45% to 59% and increased polyunsaturated fatty acid (PUFA) composition from 15% to 25%. Partial replacement of pork backfat with rapeseed at a fat content of about 20% reduced SFA from 38% to 24% (7.2 to 4.8 g/100 g). There were no significant differences in eating quality and overall liking other than slight differences in the attributes 'firmness' and 'particle size'. Improvement in the fatty acid composition was achieved without adversely affecting colour shelf life or lipid oxidation. The study suggests that a substantial reduction in SFA can be achieved by incorporating 'healthy' oils in UK-style sausages without adversely affecting eating quality or shelf life.
Asunto(s)
Ácidos Grasos Monoinsaturados/análisis , Ácidos Grasos Insaturados/análisis , Productos de la Carne/análisis , Aceites de Plantas/química , Adulto , Animales , Color , Culinaria , Emulsiones/química , Ácidos Grasos/análisis , Femenino , Conservación de Alimentos , Calidad de los Alimentos , Humanos , Metabolismo de los Lípidos , Persona de Mediana Edad , Aceite de Girasol , Porcinos , Tiobarbitúricos/análisisRESUMEN
The effects on compositional changes across the growing-finishing period (40-115 kg) of feeding pig diets with different protein and amino acid levels were investigated using CT scanning (at 60, 85 and 115 kg live weight). Pigs of a lean commercial genotype were fed a commercial control regime (C), or a low protein regime with either high (LP1) or low (LP2) essential amino acid levels, all balanced for net energy. In vivo CT measurements agreed well with post-slaughter sample joint dissection results for carcass tissue weights/proportions, and CT-measured muscle density predicted intramuscular fat accurately. Pigs on C and LP1 regimes did not differ significantly in composition during growth. However, pigs on the LP2 regime had significantly more fat (in carcass, internal and intra-muscular depots) and less muscle, from 85 kg onwards. Although fat levels differed depending on diet regime (LP2>others), proportions of fat in different body depots were unaffected.
Asunto(s)
Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales , Composición Corporal , Dieta con Restricción de Proteínas , Genotipo , Tomógrafos Computarizados por Rayos X , Tejido Adiposo/química , Aminoácidos/química , Animales , Peso Corporal , Ácidos Grasos/química , Modelos Lineales , Masculino , PorcinosRESUMEN
Pigs with a lean genotype were fed diets differing in protein and amino acid contents between 40 and 115 kg live weight. A high protein control regime (C) was compared with one supplying 11% less total protein but the same essential amino acid levels (LP1) and one supplying 16% less protein but lower amino acid levels (LP2). Regime LP2 produced fatter pigs in terms of subcutaneous, intermuscular and intramuscular fat (IMF), the latter measured in longissimus and semimembranosus muscles. The percentage of linoleic acid was lowest and that of oleic acid highest in IMF from LP2 pigs (11.57 and 34.59% respectively in longissimus). Pigs in regime LP1 had more longissimus IMF than C but similar semimembranosus IMF although both muscles had lower percentages of linoleic acid in LP1 than C, suggesting a tendency towards greater fat deposition in LP1. The high IMF content in LP2 produced the most tender, juicy steaks.
Asunto(s)
Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales , Dieta con Restricción de Proteínas , Ácidos Grasos/química , Carne/análisis , Músculo Esquelético/química , Tejido Adiposo/química , Aminoácidos/química , Animales , Peso Corporal , Femenino , Genotipo , Humanos , Concentración de Iones de Hidrógeno , Masculino , Nitrógeno/administración & dosificación , Porcinos , GustoRESUMEN
The effects of storage on carcass weight, carcass composition and the water content of tissues have been investigated. Ten Friesian-cross steer carcasses were used, one side being dissected 1 day after slaughter and the other after storage at + 1°C and 84 % relative humidity for 20 days. The rate of weight loss from the sides (range in hot weight, 103·0 to 201·5 kg) was linear between days 1 and 20, with a mean loss of 4·2 kg (0·17 %/day). During the period of storage, there was a reduction in weight of all tissues except intermuscular fat (IMF) and fatter sides (range 14·72-32·23 % dissectible fat) had a proportionately smaller loss. In percentage composition terms, there was a significant reduction in subcutaneous fat (SCF)of 0·36 percentage units, P < 0·01, and in lean, of 0·59 percentage units, P < 0·05; there was a significant gain in IMF of 0·63 percentage units, P < 0·01, but it was considered that changes were not large enough to seriously affect the interpretations of dissection data in most experiments. During storage, all tissues except IMF lost water, particularly SCF, which lost 28 % of the original amount. In the day 1 sides, 35 % of the total loss from hot weight to recovered tissue weight (after dissection) occurred during jointing and dissection and 65 % during storage. In the day 20 sides, the values were 12 %, and 88 %, respectively.