Lipid composition of Australian pork cuts 2005/2006

A study of the cholesterol content and fatty acid composition of fresh retail Australian pork was undertaken to determine whether new breeding, feeding and processing methods had resulted in any compositional changes in fresh pork in the market place since surveys undertaken in previous decades. Samples of 13 popular pork cuts were purchased from randomly selected supermarkets and butchers’ stores in urban areas across the socioeconomic scale in three States of Australia, and analysed, separable fat and separable lean, in late 2005 and early 2006. Variability was low across States for saturated and monounsaturated fatty acids, but more pronounced for polyunsaturated acids. The separable lean portions of all pork cuts contained levels of n-3 fatty acids and conjugated linoleic acid (C18:1c9t11) in measurable but not nutritionally claimable amounts, whilst total trans fatty acid levels were very low. There appeared to be some differences in fatty acid composition across States that may have resulted from feeding method. Cholesterol contents were similar to levels in the 80s and 90s for separable lean pork tissue, but presently are lower for separable fat tissue than for separable lean.

Effects of dietary lipid sources on flavour volatile compounds of brown trout (Salmo trutta L.) fillet

The high cost and unpredictable availability of fish meal and fish oil (FO) forced feed mill companies to look for alternative ingredients for aquafeeds. In this study, the effects of alternative dietary lipid sources [FO as control, canola oil (CO), oleine oil (OO), poultry fat (PF) and pork lard (PL)] in trout feed on flavour volatile compounds occurring in brown trout (Salmo trutta L.) fillet were evaluated after 70 days of feeding (rearing temperature 14.6°C). Total amounts of volatile compounds identified were higher for fillets of fish fed diets containing only FO as lipid sources. Total amount of alcohols and aldehydes of the fillets were linearly directly related to the percentage content of polyunsaturated fatty acids (PUFA) n-3 of brown trout flesh. The use of alternative dietary lipid sources, modifying the fillet fatty acids composition, affect the total amount of volatile compounds and, changing the relative amount of each volatile compound, affect the flavour of the fish flesh.

Effects of alternative dietary lipid sources on performance, tissues chemical composition, mitochondrial fatty acid oxidation capabilities, and sensory characteristics in brown trout (Salmo trutta L.)

The efficiency of five dietary lipid sources (fish oil as control—C; canola oil—CO; poultry fat—PF; pork lard—PL; and oleine oil—OO) were evaluated in juvenile brown trout (58.4±0.7 g) in an experiment conducted over 70 days at 14.6±0.4 °C. The best growth was observed in fish fed the C diet whereas the PL diet fed fish had the best feed utilization. Significant differences in carcass and muscle proximate composition, but not in liver, were noted among fish fed the different dietary treatments. The fatty acid composition of muscle largely reflected that of the diets, while total cholesterol was not affected. The atherogenicity and the thrombogenicity qualities of the trout flesh were modified by the lipid sources. Sensory analysis did not show any significant differences among the cooked fillets with respect to dietary treatments, while in uncooked products, some significant differences were observed. The carnitine palmitoyltransferase I and II (CPT-I and CPT-II) activities of liver and white muscle were assayed for a better understanding of the potential β-oxidation capability of the different dietary lipid sources. The hepatic, but not white muscle CPT-I and CPT-II activities were affected by dietary treatments. This study showed that alternative lipid sources could be used effectively for oil coating extruded diets for brown trout.

Omega-3 polyunsaturated fatty acid contents of canned meats avaialbe in Australia

Total lipid content of 20 species of canned meats available in Australia ranged from 2% in chicken (Hormel, USA) to 41% in stewed pork (Ma Ling, China). Total n-3 polyunsaturated fatty acids (PUFA) ranged from 30 in canned chicken (Hormel) to 659 mg/100 g in chicken hot dog (Tulip, Denmark). The 18:2n-6 was the predominant PUFA, ranging from 187 in corned beef (Hamper, Australia) to 2832 mg/100 g in chicken luncheon meat (Tulip). Other main PUFA, in order of concentration, were 18:3n-3, ranging from 14 in canned chicken (Hormel) to 590 mg/100 g in chicken hot dog (Tulip); conjugated 18:2n-6 (CLA) from 1 in chicken (Hormel) to 135 mg/100 g in corned mutton (Colonial, Australia); 20:4n- 6 from 11 in camp pie (Tom Piper, Australia) to 73 mg/100 g in spiced ham (Hormel); and 22:5n-3 from 5 in chicken (Hormel) and chicken luncheon (Almaraai, Jordan) to 45 mg/100 g in stewed pork (Ma Ling). Total saturated fatty acids (SFA) ranged from 598 to 14 660 mg/100 g, with 16:0 predominant followed by 18:0. Total monounsaturated fatty acid concentration ranged between 813 to 20 218 mg/100 g with 18:1 the major fatty acid. Trans 18:1 ranged from 10 to 698 mg/100 g. The canned meats contained 20 and 22-carbon long chain n-3 PUFA at levels comparable with or greater than those in fresh lean meat.

Differential effects of natural palm oil, chemically and enzymatically-modified palm oil on weight gain, blood lipid metabolites and fat deposition in a pediatric pig model

Background: Increasing prevalence of obesity and overweight in the Western world, continue to be a major health threat and is responsible for increased health care costs. Dietary intervention studies show a strong positive association between saturated fat intake and the development of obesity and cardiovascular disease. This study investigated the effect of positional distribution of palmitic acid (Sn-1, 2 & 3) of palm oil on cardiovascular health and development of obesity, using weaner pigs as a model for young children.

Methods: Male and female weaner piglets were randomly allocated to 4 dietary treatment groups: 1) pork lard (LRD); 2) natural palm olein (NPO); 3) chemically inter-esterified PO (CPO) and 4) enzymatically inter-esterified PO (EnPO) as the fat source. Diets were formulated with 11% lard or with palm olein in order to provide 31% of digestible energy from fat in the diet and were balanced for cholesterol, protein and energy across treatments.

Results: From 8 weeks onwards, pigs on EnPO diet gained (P < 0.05) more weight than all other groups. Feed conversion efficiency (feed to gain) over the 12 week experimental period did not vary between treatment groups. Plasma LDL-C content and LDL-C/HDL-C ratio in pigs fed natural PO tended to be lower compared to all other diets. The natural PO lowered (P < 0.02) the plasma triglyceride (TG) content relative to the lard or EnPO diets, but was not different from the CPO diet. The natural PO diet was associated with lower (P < 0.05) saturated fat levels in subcutaneous adipose tissue than the CPO and EnPO diets that had lower saturated fat levels than the lard diet. Female pigs had lower lean and higher fat and fat:lean ratio in the body compared with male pigs. No difference in weight gain or blood lipid parameters was observed between sexes.

Conclusions: The observations on plasma TG, muscle and adipose tissue saturated fatty acid contents and back fat (subcutaneous) thickness suggest that natural palm oil may reduce deposition of body fat. In addition, dietary supplementation with natural palm oil containing palmitic acid at different positions in meat producing animals may lead to the production of meat and meat products with lower saturated fats. An increase in fat content and a decrease in lean content in female pigs resulted in an increased body fat:lean ratio but gender had no effect on blood lipid parameters or insulin concentrations.