This study was conducted to evaluate the effect of supplementing tuna oil to diets of growing-finishing pigs (barrows and gilts) on backfat characteristics when slaughtered at different weights. Four hundred and eighty crossbred (Large White×Landrace×Duroc) pigs averaging 30 kg were allotted to 12 treatment combinations (40 pigs/treatment combination) in a completely randomized design with a 2×2×3 factorial arrangement of treatments. The treatments were: dietary tuna oil supplementation (0 and 2%); sex (barrows and gilts); and slaughter weight (90, 100 and 110 kg). As pigs reached their slaughter weight, they were randomly selected (8 pigs/treatment combination; 96 pigs in total) and slaughtered. Backfat colour, hardness and fatty acid profile were assessed. There were significant (p<0.05) differences in colour (L* and a* values) among treatments. Backfat of the control group was harder than on the tuna oil (p<0.001) and that of barrows was harder than of gilts (p<0.05). In addition, the thiobarbituric acid reactive substances (TBARS) values of fat from the tuna oil group stored for 3 days were higher (p<0.001) than the control group. The TBARS values of gilts tended to be higher than those of barrows and increased with increasing slaughter weight in the tuna oil group. The cholesterol and triglyceride levels were not affected by diet and sex but the triglyceride level increased with increasing slaughter weight (p<0.01). The tuna oil group had higher polyunsaturated fatty acid (PUFA) content, ratio of PUFA: saturated fatty acid (SFA) and total n-3 fatty acids but lower monounsaturated fatty acids content and n-6:n-3 fatty acids than the control group (p<0.01). Gilts had higher PUFA and n-6 fatty acids in backfat than barrows (p<0.05). The backfat from both 90 and 100 kg slaughter-weight groups had a lower ratio of n6:n3 fatty acid than the 110 kg slaughter-weight group (p<0.05). However, this was more pronounced in the tuna oil group. The PUFA: SFA was also increased while the n-6:n-3 ratio tended to reach the recommended levels for healthy eating in human beings of <5. However, due to oxidative susceptibility, barrows should not be slaughtered at more than 100 kg for the meat to be acceptable to consumers/
Tag: fatty acids
Physico-chemical characteristics and fatty acid profile of desert date kernel oil in Uganda
The desert date (Balanites aegyptiaca (L.) Del.) is an indigenous fruit tree, common in the arid and semi-arid lands of Africa. Its fruits, available in the height of the dry season, contain edible pulp which is an important food for both humans and livestock. Balanites kernel is a source of highly regarded edible and medicinal oil. Both the fruits and oil are trade items in the west Nile sub-region of Uganda. Because of its growing importance as a source of food and income for dryland communities, an assessment of the physico-chemical characteristics and fatty acid profile of kernel oil in Uganda was carried out. Balanites fruit samples were collected from Katakwi, Adjumani and Moroto districts; representing the Teso, West Nile and Karamoja tree populations, respectively. Balanites kernels constituted 19.5% of the nuts, and kernel oil yield was 44.5% (v/v or w/w). The oil was light yellow with a refractive index of 1.46 at 20 oC and viscosity of 15.75 – 22.60 cSt at 40 oC. The saponification value of the oil was 186.28 mg KOH g-1; while the acid value was generally low (1.33 -1.95 mg KOH g-1). Iodine value ranged from 98.20 to 103.32 I2 g 100 g-1. Four major fatty acids; linoleic (39.85%), (oleic 25.74%), stearic (19.01%) and palmitic (15.40%) were found in Balanites oil. This gives a high percentage of the nutritionally beneficial unsaturated fatty acids (65.6%). Balanites kernel oil is a good source of essential unsaturated fatty acids. Attempts should be made to increase its utilisation through improved processing and packaging for the benefit of rural and peri-urban communities.