Influence of Repeated Freeze-Thaw Cycles on Color, pH, and Oxidative Stability of Chicken Thigh Meat

Abstract

This study investigates of repeated freeze-thaw (FT) cycles on the color, pH, and oxidative stability of vacuum-packaged chicken thigh meat. Samples were evaluated at Fresh, Frozen (2 weeks), FT1 (2-times FT, 4 weeks), and FT2 (3-times FT, 6 weeks). FT1 resulted in a higher pH, but the pH was slightly reduced in FT2. Oxidative stability declined with each cycle, as evidenced by significant increases in thiobarbituric acid reactive substances (TBARS), carbonyl content, and peroxide value (POV). Meanwhile, thiol content decreased notably. Color parameters were also affected by FT cycles. Redness (a*) decreased in the frozen group but increased in subsequent cycles. Lightness (L*) fluctuated, with a significant increase after FT2, and yellowness (b*) showed slight increases and subsequent decreases. Chroma (c*) and hue angle (h°) also fluctuated due to repeated freeze-thaw cycles. Furthermore, correlation analysis revealed strong positive associations between TBARS, carbonyls, POV, and pH, while thiol content showed strong negative correlations with these oxidative markers, reinforcing the oxidative degradation trend. This comprehensive analysis illustrates the multifaceted impacts of freeze-thaw processes on the color, pH, and oxidation markers of chicken thigh meat, emphasizing the importance of understanding these effects for proper storage and safety.