Studies into factors responsible for the acceptability of pork on the Singaporean market : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, New Zealand
The thesis reports the results of a series of studies looking into the acceptability of pork on the Singapore market. Anecdotal comments have indicated that pork from some countries had a less acceptable flavour than that produced locally, so a survey was conducted to clarify the situation. This indicated that imported pork, including that from New Zealand, had an undesirable mutton-like flavour. Using pork from female pigs fed either a plant only diet (NZP) or one that included some animal products (NZA) it was shown that Singapore consumers favoured the former due to a lower mutton note. The use of garlic essential oil (GEO) to improve the acceptability of NZ pork either by adding it directly to pork or feeding it to pigs was demonstrated. With increasing GEO, garlic flavour strength increased and mutton flavour strength decreased even when diets of the pigs included animal products.
Concentrations of indolic compounds (indole and skatole) in backfat increased with increasing dietary garlic concentration (P<0.001), and were higher in backfat from the NZA group (P<0.05), but were unaffected by different dietary lipid sources (fish oil, tallow, and a mix of linseed oil and soya oil).
A highly acceptable low-fat (<10%) and low-salt (<450 mg/100 g) pork ball with an n-6/n-3 ratio of <4 was developed as a premium product, and effects on its acceptability were assessed using pork from pigs on different diets. A supplement containing selenium, vitamin E, vitamin C and CLA fed to pigs led to pork and pork balls with increased levels of these items. Inclusion of fish oil in the diet (4.4%) increased the levels of the long chain n-3 fatty acids (LCN3FA) in the pork and pork balls, but also increased measures of oxidation (TBARs), especially after a period of storage, and decreased the acceptability of the product due to increased off-flavours (rancid and aftertaste). This occurred when fish oil was removed from the diet either 28 days or 49 days (early and late feeding stage) before slaughter. Further research into ways of improving the flavour aspects of these products is required.
The following articles have been extracted from the thesis due to copyright restrictions:
Leong, J., Purchas, R. W., Morel, P. C. H., & Wilkinson, B. H. P. (2010). The effects of excluding animal products from the diet on sensory properties of pork from pigs grown in New Zealand as assessed by Singaporean panellists, Asian - Australasian Journal of Animal Sciences, 23(1), 122-130.
Leong, J., Morel, P. C. H., Purchas, R. W., & Wilkinson, B. H. P. (2010). The production of pork with garlic flavour notes using garlic essential oil. Meat Science. 84, 699-705
Leong, J., Morel, P. C. H., Purchas, R. W., & Wilkinson, B. H. P. (2011). Effects of dietary components including garlic on concentrations of skatole and indole in subcutaneous fat of female pigs. Meat Science. 88, 45-50.