Histological Characteristics, Tenderness, and Drip Losses of Beef in Relation to Temperature of Freezing

Abstract

As a result of earlier studies by two of the present authors and other workers, the fact seemed well established that the temperature of freezing has an important bearing on tenderness and on the drip loss of meat in thawing. To determine the basic cause of these effects was an obvious need. The purpose of the studies reported here was to throw light on the relation between the histological characteristics of beef frozen at different temperatures, on one hand, and tenderness and drip loss of the product, on the other. REVIEW OF LITERATUREIn a study of ice formation, &loran (1931) found that in meat frozen a t -2Q°C. (--4"F.) large crystals were formed in the center of the sample, whereas on the outside layer, where the time required for freezing was short, the ice crystals were very small. Moran (1932) also reported that approximately 82 per cent of the water in meat was frozen a t -5°C. (23°F.). A t lower temperatures more of the water was frozen, but it was of smaller percentage in relation to the reduction in temperature. Koonz and Ramsbottom (1939), using a modification of the Altmann-Gersh freezing-drying technic, studied frozen sections of chicken muscle and reported that ice crystals formed externally to the muscle fibers when freezing was done at -26.1°C. (-150F.) or above. The ice formations became larger, fewer in number, and the component fibers and bundles of fibers were forced into compact groups when freezing was slow. At -75.6"C. (-104°F.) a sample several millimeters in thickness froze in a few seconds, and water separated from the fiber protoplasm so that the ice crystals were extremely small but numerous. On histological examination the fibers closely resembled those of fresh, unfrozen tissue. A whole bird frozen a t --48.3"C. (-55"F.) showed a different picture, owing to slower freezing. The fibers appeared distorted and were characterized by jagged outer surfaces. The longitudinal sections of 'these fibers showed ice within the sarcolemma, which formed parallel to the long axis of the fiber, and extended its full length. The diameter of these ice columns increased in proportion to temperature increase. DuBois, Tressler, and Fenton (1940, 1942) and Tressler and DuBois (1940) report that boned, rolled beef rib roasts, frozen in still air at -31.7 or -23.3"C. (-25 or -1O0F.), or in an air blast a t -17.8"C. (O'F.), showed some cell disruption, whereas those frozen in still air at -16.7"C. (2°F.) showed considerable breakdown in the tissue. The same conditions were observed in case of chicken flesh. Shrewsbury and co-312

Effects of Freezing Rate, Frozen Storage Temperature and Storage Time on Tenderness Values of Beef Patties

“…The intracellular ice crystal formation arising from fast freezing has been shown to result in fiber splitting and damage which in some cases (Hiner et al, 1945;Hiner and Hankins, 1947;Carroll et al, 1981) has been associated with greater tenderness.…”

Evaluation of combined effects of ageing period and freezing rate on quality attributes of beef loins

“…The impact of freezing rates on meat tenderness has been debated by several researchers. The positive fast freezing impact on meat tenderness has been reported, where quick frozen samples showed less resistance to shearing or higher scores of sensory tenderness compared to slow frozen counterparts (Hiner, Madsen, & Hankins, 1945;Petrović et al, 1993). In contrast, no substantial freezing rate effect on eating quality attributes of beef including tenderness and water-holding capacity has also been reported (Hergenreder et al, 2013;Paul & Child, 1937).…”

“…3). Numerous studies have found a tenderising effect of freezing/thawing (Hankins & Hiner, 1938;Hiner et al, 1945;Leygonie et al, 2012a;Petrović et al, 1993;Shanks, Wulf, & Maddock, 2002;Vieira et al, 2009), which is likely associated with the loss of structural integrity induced by ice crystal formation (Leygonie et al, 2012a). Furthermore, ageing-then-freezing might allow the formation of intracellular crystals between degraded myofibrillar proteins, which could subsequently induce greater muscle fibre fragmentation and/or structural weakening during thawing resulting in an increase in meat tenderness (Mateo-Oyague & Perez-Chabela, 2004).…”

“…The discrepancy between the studies could be attributed to the different freezing rate and/or possibly different freezing methods adopted in each study. The studies, where significant freezing rate impacts on meat tenderness were found, mostly applied to freezing temperature at − 40°C or even lower temperatures (Hiner et al, 1945;Petrović et al, 1993). Petrović et al (1993) reported that the solubility of myofibrillar proteins and meat tenderness increased with faster freezing rates, which could have resulted from the formation of smaller sized intracellular ice crystals within the fibres thus leading to less denaturation compared to the slower freezing rate.…”

Chemical Deterioration of Frozen Bovine Muscle at −4° C

“…The loss of proteins, mostly sarcoplasmic protein, in the drip of previously-frozen bovine muscle has been reported by Howard et al (1960). The protein content of drip, calculated as percentage of total muscle protein, increased from about 5.86 for unfrozen muscle to 17.03 for muscle frozen for S weeks ( Table 2).…”