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

摘要

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 (p0.05); 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 (p0.10); however, differences in sensory scores for all attributes failed to reach significance (p>0.05). 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