Relationship between meat toughness and properties of connective tissue from cows and young bulls heat treated at low temperatures for prolonged times

Low temperature, long time treatment of porcine M. longissimus thoracis et lumborum in a combi steamer under commercial conditions

“…Cooking loss is mainly associated with a contraction of the surrounding connective tissue, which leads to a physical constraint on the myofibrillar structure. However, the degree of contraction seems to be less in LTLT treated meat (Christensen et al, 2013) compared to higher temperatures because of disintegration processes and subsequent denaturation of connective tissue before any contraction occurs.…”

“…Prolonged heat treatment at a temperature range between 50 and 60 °C has been reported to make beef (Beilken et al, 1986;Bouton et al, 1975;Christensen et al, 2013;Davey & Niederer, 1977;Laakonen et al, 1970a), pork (Christensen et al, 2011a;Christensen et al, 2011b;Christensen et al, 2012;Christensen et al, 2010) and lamb (Roldán et al, 2013) tender.…”

“…This gentle cooking process is believed to ensure particularly tender and juicy meat in comparison to conventional heating methods at higher temperatures (Aaslyng, Bejerholm, Ertbjerg, Bertram, & Andersen, 2003;Beilken, Bouton, & Harris, 1986;Bouton, Harris, & Ratcliff, 1981;Bouton, Harris, & Shorthose, 1975;Christensen, Bertram, Aaslyng, & Christensen, 2011a;Christensen, Ertbjerg, Aaslyng, & Christensen, 2011b;Christensen et al, 2013;Christensen et al, 2012;Christensen, Purslowa, & Larsen, 2000;Laakonen, Wellington, & Sherbon, 1970a;Vaudagna et al, 2002).…”

“…There have been disagreements in the past whether alterations in myofibrillar components (Davey & Niederer, 1977) or collagen weakening Bouton et al, 1975;Laakonen et al, 1970a) are the main contributors to the decreasing toughness of LTLT meat. However, new studies suggest that both connective tissue weakening and, to a lower extent, myofibrillar changes can explain the tenderization effects of LTLT meat over time (Christensen et al, 2011a;Christensen et al, 2011b;Christensen et al, 2013;Sanchez del Pulgar, Gazquez, & Ruiz-Carrascal, 2012). Furthermore, heating at low temperatures reduces the cooking loss compared to higher temperatures, which leads to a more juicy product (Aaslyng et al, 2003;Christensen et al, 2012;Laakonen et al, 1970a;Offer, Restall, & Trinick, 1984;Vaudagna et al, 2002).…”

“…In addition, heating temperature has considerable effects on meat color. Changes in redness are mainly due to variations in the A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 3 myoglobin redox status or denaturation, which is why core temperatures below 60 °C generally lead to a more raw appearance compared to a well-done appearance at higher temperatures (Christensen et al, 2011b;Christensen et al, 2013;Hunt, Sørheim, & Slinde, 1999;King & Whyte, 2006;Mancini & Hunt, 2005;Martens, Stabursvik, & Martens, 1982). As found by Christensen et al (2011b), a* values of LTLT treated pork meat did not differ considerably when time and temperature were increased, so that a well-done appearance could not be reached.…”