scholarly journals The effect of dietary inclusion of conjugated linoleic acid in finishing hog feed on sensory characteristics and storage quality indicators of pork loin

2011 ◽  
Author(s):  
◽  
Kaitlin Maditz ◽  
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Quality Indicators ◽  
Storage Stability ◽  
Meat Product ◽  
Storage Period ◽  
Thiobarbituric Acid ◽  
Muscle Ph ◽  
Dietary Conjugated Linoleic Acid ◽  
Pig Feed

Marbling in meat occurs when fat is distributed throughout the skeletal muscle and is visually apparent by light streaks of fat that look like a marble pattern. It is associated with increased quality, tenderness, and likeability. Incorporating dietary conjugated linoleic acid (CLA) into finishing hog feed increases intramuscular fat and decrease backfat in harvested pigs; therefore, the purpose of this study was to determine if inclusion of CLA in pig feed would increase intramuscular marbling and consumer likeability without compromising storage stability. Twenty pigs were housed in ten pens (2 pigs per pen) and fed either 1% Soybean oil or 1% CLA diet for a period of six weeks. After slaughter, pork loins were cut and divided into cranial and caudal ends, vacuum packed and stored at -8°C until evaluations were conducted. Quality indicators of pork were measured on both raw and cooked samples over a 7-d storage period. Measurements included color (L*, a*, b*), muscle pH, texture, and lipid oxidation by thiobarbituric acid reactive test (TBARS). Sensory panelists evaluated tenderness, juiciness, flavor, aroma, off-flavor, and likeability of each sample on an 8-point hedonic scale. Raw and cooked color scores, texture, TBARS, and raw and cooked muscle pH changed over time (p<0.05); however, these changes were independent of diet. Differences in quality indicators between diets were seen numerically but did not reach significance (p>0.05). Sensory evaluation by 20 panelists showed a trend that CLA loins presented with better flavor and juiciness (p0.05). Results of this study indicate that the inclusion of CLA in pig feed provides a meat product similar to soybean pig feed. The similar storage stability and sensory results of this study indicate limited, if any, benefits of feeding a CLA-diet over a traditional one.;Keywords. Linoleic acid; marbling; pork.

Conjugated Linoleic Acid Causes a Marked Increase in Liver α-Tocopherol and Liver α-Tocopherol Transfer Protein in C57BL/6 J Mice

2010 ◽  
Vol 80 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Pei-Min Chao ◽  
Wan-Hsuan Chen ◽  
Chun-Huei Liao ◽  
Huey-Mei Shaw
Keyword(s):  
Antioxidant Enzymes ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Thiobarbituric Acid ◽  
Control Group ◽  
Thiobarbituric Acid Reactive Substances ◽  
Control Groups ◽  
Protein Levels ◽  
Transfer Protein ◽  
And Control

Conjugated linoleic acid (CLA) is a collective term for the positional and geometric isomers of a conjugated diene of linoleic acid (C18:2, n-6). The aims of the present study were to evaluate whether levels of hepatic α-tocopherol, α-tocopherol transfer protein (α-TTP), and antioxidant enzymes in mice were affected by a CLA-supplemented diet. C57BL/6 J mice were divided into the CLA and control groups, which were fed, respectively, a 5 % fat diet with or without 1 g/100 g of CLA (1:1 mixture of cis-9, trans-11 and trans-10, cis-12) for four weeks. α-Tocopherol levels in plasma and liver were significantly higher in the CLA group than in the control group. Liver α-TTP levels were also significantly increased in the CLA group, the α-TTP/β-actin ratio being 2.5-fold higher than that in control mice (p<0.01). Thiobarbituric acid-reactive substances were significantly decreased in the CLA group (p<0.01). There were no significant differences between the two groups in levels of three antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase). The accumulation of liver α-tocopherol seen with the CLA diet can be attributed to the antioxidant potential of CLA and the ability of α-TTP induction. The lack of changes in antioxidant enzyme protein levels and the reduced lipid peroxidation in the liver of CLA mice are due to α-tocopherol accumulation.

scholarly journals Dietary conjugated linoleic acid (CLA) induces apoptosis of colonic mucosa in 1,2-dimethylhydrazine-treated rats: a possible mechanism of the anticarcinogenic effect by CLA

2001 ◽  
Vol 86 (5) ◽  
pp. 549-555 ◽  
Author(s):  
Hyun S. Park ◽  
Ji H. Ryu ◽  
Yeong L. Ha ◽  
Jung H. Y. Park
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Control Diet ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Prostaglandin E ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Tumour Incidence ◽  
Sprague Dawley Rats ◽  
Dietary Conjugated Linoleic Acid

One of the objectives of the present study was to investigate whether 1 % conjugated linoleic acid (CLA) in the diet reduced tumour incidence in the colon of 1,2-dimethylhydrazine (DMH)-treated rats. Colon cancer was induced by injecting 6-week-old, male, Sprague–Dawley rats with 15 mg/kg DMH twice per week for 6 weeks. They were fed either 1 % CLA or a control diet ad libitum for 30 weeks. Dietary CLA significantly decreased colon tumour incidence (P<0·05). Our second objective was to investigate whether apoptosis in the colon mucosa of DMH-treated rats was affected by the amount of dietary CLA and whether the changes in apoptosis were related to those in fatty acid-responsive biomarkers. For this purpose, rats were killed after being fed a diet containing 0 %, 0·5 %, 1 % or 1·5 % CLA for 14 weeks. CLA was undetected in the mucosa of rats fed the 0 % CLA diet and increased to 5·9 mg/g phospholipid in rats fed the 0·5 % diet. The apoptotic index estimated by the terminal deoxynucleotidyl transferase-mediated dUTP nick and labelling technique was increased by 251 % and the 1,2-diacylglycerol content was decreased by 57 % in rats fed 0·5 % CLA. No further changes in these variables were observed when CLA in the diet was raised to 1·0 % or 1·5 %. However, dietary CLA decreased mucosal levels of prostaglandin E2, thromboxane B2 and arachidonic acid in a dose-dependent manner. The present data indicate that dietary CLA can inhibit DMH-induced colon carcinogenesis by mechanisms probably involving increased apoptosis.

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