<p>Aging has been the main industrial practice for improving beef palatability, but it requires up to 21&#xa0;days of cooler storage to reach the desired tenderness. As an alternative to accelerate the aging process, both the prior freezing/thawing process and the storage at high temperatures have been suggested. This study aimed to develop kinetic models to evaluate the effects of freezing/thawing process and different aging temperatures (1, 7, 14 and 20&#xa0;°C) on vacuum-packed Nellore beef steaks. Changes on fragmentation index (FI), shear force (SF), cooking loss (CL) and total bacteria count (TBC) of raw beef during aging followed a first-order kinetic model. The reaction rate constant (<i>k</i>) increases with increasing aging temperature, and the activation energy (<i>Ea</i>) was lower in frozen/thawed samples than nonfrozen ones for FI (13 vs 24&#xa0;kJ/mol) and SF (25 vs 47&#xa0;kJ/mol). The increase in aging temperature had a lower effect on the FI and SF of frozen/thawed samples than on the nonfrozen ones. Frozen/thawed samples required a shorter aging time than nonfrozen samples to reach the same SF. CL was affected only by aging temperature. The specific growth rate (<i>µ</i>) of TBC increases with increasing aging temperature, but the <i>Ea</i> (51&#xa0;kJ/mol) was not affected by the freezing/thawing process. The developed kinetic models provide a deeper understanding of the mechanism of the quality changes of frozen/thawed beef during aging and suggest that the increased tenderization in the frozen/thawed samples is primarily due to cellular damage rather than the increase in proteolysis rate.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Kinetic Modeling of Myofibrillar Degradation, Shear Force, and Microbial Growth During Beef Accelerated Aging by the Freeze/Thaw Process

  • Johnathan de Lima Ramos,
  • Marielle Maria de Oliveira Paula,
  • Marcelo Stefanini Tanaka,
  • Robledo de Almeida Torres Filho,
  • Alcinéia de Lemos Souza Ramos,
  • Eduardo Mendes Ramos

摘要

Aging has been the main industrial practice for improving beef palatability, but it requires up to 21 days of cooler storage to reach the desired tenderness. As an alternative to accelerate the aging process, both the prior freezing/thawing process and the storage at high temperatures have been suggested. This study aimed to develop kinetic models to evaluate the effects of freezing/thawing process and different aging temperatures (1, 7, 14 and 20 °C) on vacuum-packed Nellore beef steaks. Changes on fragmentation index (FI), shear force (SF), cooking loss (CL) and total bacteria count (TBC) of raw beef during aging followed a first-order kinetic model. The reaction rate constant (k) increases with increasing aging temperature, and the activation energy (Ea) was lower in frozen/thawed samples than nonfrozen ones for FI (13 vs 24 kJ/mol) and SF (25 vs 47 kJ/mol). The increase in aging temperature had a lower effect on the FI and SF of frozen/thawed samples than on the nonfrozen ones. Frozen/thawed samples required a shorter aging time than nonfrozen samples to reach the same SF. CL was affected only by aging temperature. The specific growth rate (µ) of TBC increases with increasing aging temperature, but the Ea (51 kJ/mol) was not affected by the freezing/thawing process. The developed kinetic models provide a deeper understanding of the mechanism of the quality changes of frozen/thawed beef during aging and suggest that the increased tenderization in the frozen/thawed samples is primarily due to cellular damage rather than the increase in proteolysis rate.