Effect of prolonged heat treatment from 48°C to 63°C on toughness, cooking loss and color of pork

The effect of low temperature long time (LTLT) heat treatment at 48 °C, 53 °C, 58 °C, and 63 °C for Tc (time to reach a core temperature equal to the water bath), Tc + 5 h holding time, and Tc + 17 h holding time was studied in Longissimus dorsi and Semitendinosus muscles from slaughter pigs and sows. Meat toughness (Warner–Bratzler Shear Force), cooking loss and color (Minolta L*a*b*-values) was measured and in the cooking loss the amount of heat-soluble collagen and activity of cathepsin B + L was determined. Decreasing shear force and increasing cooking loss during LTLT treatment was observed between 53 °C and 58 °C. Furthermore, increasing temperature from 53 °C to 58 °C and increasing time from Tc to Tc + 17 h increased the solubility of collagen. Residual activity of cathepsin B + L in LTLT treated pork was mainly affected by temperature, showing the highest activity at 58 °C and 63 °C.