Effect of increased carcass weight on fresh pork quality and sensory traits

Abstract

Due to the current trend of increased carcass weights, there is concern that chilling capabilities may become compromised, affecting pork quality and sensory traits. Therefore, the objective was to characterize fresh pork quality and sensory traits of carcasses ranging from 78 to 145 kg (average ~119 kg). Hot carcass weight (HCW), back fat depth, and loin depth was measured on 666 carcasses. Loin pH, instrumental and visual color and iodine value of the clear plate fat (all 3 layers) was measured on approximately 90% of the population. Quality measurements of the ham, 14 d aged loin and chop, and loin chop (cooked to 71°C and 63°C) shear force (SSF) and trained sensory panels (tenderness, juiciness, pork flavor, and other flavor descriptors (beef, brown/roasted, bloody/serumy, fat-like, metallic, liver-like, umami, overall sweet, sweet, sour, salty, bitter, rancid, heated oil, chemical, musty/earthy/hummus, spoiled-putrid, and buttery) were evaluated on approximately 30% of the population. Myosin heavy chain fiber type determination was completed on 49 carcasses. Slopes of regression lines and coefficients of determination between HCW and quality traits were calculated using the REG procedure in SAS and considered significantly different from 0 at P ≤ 0.05. As HCW increased, loin depth (ß1 = 0.2496, P < 0.0001), back fat depth (ß1 = 0.1374, P < 0.0001), loin weight (ß1 = 0.0345, P < 0.0001), and ham weight (ß1 = 0.1044, P < 0.0001) increased. Estimated lean (ß1 = -0.0751, P < 0.0001) and iodine value (ß1 = -0.0922, P < 0.0001) decreased as HCW increased, where HCW accounted for 24% (R2 = 0.24) of the variation in estimated lean and 7% (R2 = 0.07) of the variation in iodine value. However, HCW did not explain variation in ham quality traits (P > 0.15) and did not explain more than 1% (R2 ≤ 0.01) of the variation in 1 d loin color or pH. As HCW increased, chops became more tender as evidenced by a decrease in SSF (71°C ß = -0.0674, P < 0.0001; 63°C ß = -0.0217, P = 0.0167) and an increase in panel scores (71°C ß = 0.0270, P < 0.0001; 63°C ß = 0.0202, P < 0.0001). Water-holding capacity increased with increased carcass weights (decreased loin purge loss ß = -0.0110, P = 0.0005; 71°C cook loss ß = -0.0512, P < 0.0001; 63°C cook loss ß = -0.0287, P < 0.0001). However, HCW explained less than 7% of the variation for any flavor profile trait. Additionally, hot carcass weight did not alter (P > 0.22) muscle fiber type percentage or area. Due to the lack of variation explained by HCW, these results suggest that increasing HCW to an average of 119 kg did not compromise fresh pork quality or sensory traits. Furthermore, these results suggest that increasing HCW resulted in a slight improvement in tenderness and water-holding capacity of chops.