Five days at 4 °C are a quality signal, not a safety date

A study published on October 22 examines how the physicochemical and oxidative quality of beef changes during 20 days of refrigerated storage at 4 °C. The authors monitored pH, water activity, colour on the outer and inner surfaces, thiobarbituric-acid-reactive substances (TBARS), and protein carbonyls. pH rose from 5.15 at the start to 6.52 on day 20; outer-surface a* declined markedly while b* increased, patterns consistent with pigment degradation and lipid oxidation.