instrumental measurement of texture and
sensory quality were performed by Principal Component Analysis
(PCA) and were evaluated by calculating Pearson's correlation coefficients.
PCA was applied using the statistical software XLSTAT, version
Pro 7.5 (XLSTAT, 2004), and the Pearson's method using the statistical
software SPSS.
3. Results and discussion
3.1. Meat quality
Meat quality results, which include pH as an indicator of meat
quality, colour measurements, drip loss, cooking loss and lipid oxidation
(TBARS), are presented in Table 2. There was no (P>0.05) effect
of dietary fat supplementation on pHu values and colour parameters
(L*, a*, and b* values). Both 24- and 48-h drip loss percentages were
lower (P≤0.05) in pigs fed control and CaSPO1 diets than pigs fed
AF1. The limited effect of the fat source on all these parameters has
been reported in other studies (Corino et al., 2002; Mitchaothai et
al., 2007; Teye, Sheard, et al., 2006). No significant differences
(P>0.05) were observed among diets for cooking loss percentages,
which agreed with Miller, Shackelford, Hayden, and Reagan (1990)
and Mitchaothai et al. (2007).
Regarding the oxidative behaviour, chops from pigs fed control and
animal fat (AF) diets had greater (P≤0.01) TBARS values than chops
frompigs fed CaSPO1 diet. No significant differences (P>0.05)were observed
for lipid oxidation values between SBO1 and CaSPO1, which
agreed with Teye, Sheard, et al. (2006), or between SBO1 and control
and AF3 diets. Those last results disagreed with some authors, who
found greater TBARS values in pork from pigs fed dietary vegetable
oils than in pork from pigs fed tallow fat (TF) (Corino et al., 2002;
Monahan, Buckley, Morrissey, Lynch, & Gray, 1992) or control diet
(Cardenia et al., 2011). The soyabean oil (SBO) used in the feed industry
is rich in choline, phospholipids, antioxidants and vitamin E,which help
to prevent the oxidative rancidity in the oil (FEDNA, 2010). In the present
study, the antioxidant compounds from the SBO may have prevented
an increased lipid oxidation in the meat from the SBO-fed pigs.
In addition,measures of lipid oxidation were low (b0.2 mg of malonaldehyde/
kg), indicating that there was no rancidity problem in pork
from pigs fed these diets.
3.2. Fatty acid composition
3.2.1. Intramuscular fat (IMF)
IMF content was higher (P≤0.05) in pork from pigs fed AF3 diet
than pork from pigs fed SBO1 diet, whereas pork from pigs fed control,
AF1 and CaSPO1 diets did not show significant differences among them
(Table 3). The vastmajority of previous research has failed to detect differences
between SBO diet and palmoil (PO) diet (Olivares et al., 2009;
Teye, Sheard, et al., 2006) or AF diet (Morel, McIntosh, & Janz, 2006;
Morgan, Noble, Cocchi, & McCartney, 1992) on IMF content. In our
study, AF3 diet had a higher percentage of crude fat compared to
other diets and, therefore, had a higher amount of energy available for
fat deposition, resulting in higher IMF content, which agreed with the
results found by Bee et al. (2002).
Table 2
Means and standard error of the difference (SED) of meat quality parameters.
Control AF1 AF3 SBO1 CaSPO1 SED Sign.
N 8 10 10 9 6
pHu 5.60 5.46 5.48 5.53 5.55 0.09 ns
L* 46.00 46.44 46.89 44.61 45.33 2.02 ns
a* 5.43 6.10 6.78 7.36 6.69 1.18 ns
b* 11.46 12.41 13.23 13.09 12.32 1.07 ns
24-h drip loss (%) 1.4a 2.2b 1.8ab 1.9ab 1.4a 0.4 *
48-h drip loss (%) 2.0a 3.1b 2.6ab 2.7ab 2.1a 0.6 *
Cooking loss (%) 28.5 30.0 27.6 27.8 27.8 2.0 ns
TBARS 0.097bc 0.104c 0.091bc 0.080ab 0.073a 0.011 **
Control: without fat supplemented; AF1: 1% animal fat supplemented; AF3: 3% animal
fat supplemented; SBO1: 1% soyabean oil supplemented; CaSPO1: 1% calcium soaps of
palm oil fatty acids supplemented.
pHu: ultimate pH; TBARS: TBA-reactive substance.
Different letters in the same row indicate significant differences among mean values;
ns=p>0.1; *=p≤0.05; **=p≤0.01