Different chilled (~0.1 °C for up to 5 weeks) then frozen storage (up to 12 months) combinations and two frozen storage holding temperatures (−12 °C and −18 °C) effects on beef M. longissimus lumborum (LL) protein structure degradation and a marker of protein oxidation were tested. Particle size (PS) analysis and protein solubility results found storage combination effects on protein degradation to be significant (P < 0.05), although the influence of frozen holding temperatures was negligible. LL carbonyl, and nitrate and nitrite content responses were variable and yet broadly reflected an increased incidence of protein oxidation across increasing chilled storage and ensuing frozen storage periods – this aspect meriting future exploration. Total myoglobin content and the estimated myoglobin redox fractions (metmyoglobin, deoxymyoglobin, and oxymyoglobin) were also subject to storage treatment. These findings demonstrate the capacity for beef storage selection (chilled-then-frozen) to manage compositional protein changes and its implications on sensory quality traits across comparative ‘long term’ durations.

不同的冷藏（约0.1°C，长达5周）然后冷冻存储（长达12个月）组合，以及两种冷冻存储保持温度（−12°C和−18°C）对长腰牛肉（LL）的影响测试了蛋白质结构的降解和蛋白质氧化的标志物。粒度（PS）分析和蛋白质溶解度结果发现，存储组合对蛋白质降解的影响显着（P <0.05），尽管冷冻保持温度的影响可以忽略不计。LL羰基，硝酸盐和亚硝酸盐含量的响应是可变的，但广泛反映了在冷藏增加和随后的冷藏期间蛋白质氧化的发生率增加–这方面值得进一步探索。总肌红蛋白含量和估计的肌红蛋白氧化还原分数（肌红蛋白，脱氧肌红蛋白和氧化肌红蛋白）也要进行储存处理。这些发现表明，在比较的“长期”持续时间内，牛肉贮藏选择（冷藏然后冷冻）能够处理蛋白质组成变化，并且对感觉质量特征产生影响。