Repeated Freeze–Thaw Cycles and Thawing Methods: Effects on Quality Attributes of Egyptian Native Chicken Breast Fillets

Abstract

Chicken meat is a significant source of protein worldwide, and freezing is typically used to extend its shelf life through the supply chain. This research evaluated the impact of repeated freeze–thaw (F–T) cycles and various thawing approaches on the physicochemical, microbiological, volatile, free amino acid (FAA), and sensory quality of Egyptian native chicken (ENC) breast fillets. Fresh control samples (FC) were compared with meat subjected to three F–T cycles and thawed using microwave thawing (MR), chiller thawing (CT), room-temperature thawing (RT), or water thawing (WT). Results showed progressive deterioration across all quality dimensions with increasing F–T cycles. Drip loss, thawing loss, cooking loss, carbonyl content, TBARS, and microbial load showed clear upward trends (p < 0.05), particularly under RT and WT conditions. Conversely, shear force, water-holding capacity, pH, sulfhydryl content, and sensory scores decreased consistently as the number of F–T cycles increased. FAA profiling revealed marked depletion of umami-, sweet-, aromatic-, and bitter-related amino acids, while volatilomics indicated lower levels of lipid-derived aldehydes and ketones associated with oxidative degradation. Sensory assessment further confirmed a gradual loss of appearance, tenderness, aroma, taste, and overall acceptability with repeated F–T cycles. In conclusion, the findings of this study are highly relevant to frozen chicken supply chains, where repeated freeze–thaw events frequently occur during storage, transportation, and retail handling. By systematically integrating physicochemical, oxidative, microbiological, free amino acid, volatile compound, and sensory analyses, this work provides a comprehensive and novel evaluation of freeze–thaw–induced quality deterioration in ENC, a genotype that remains underrepresented in the literature despite its widespread local consumption. The results demonstrate that the thawing method plays a decisive role in modulating quality loss, with MR and CT offering measurable advantages over RT and WT. From an applied perspective, these findings offer practical guidance for processors, retailers, and consumers by identifying thawing strategies that better preserve quality and safety. Scientifically, the study advances understanding of how repeated freeze–thaw cycles interact with muscle structure, oxidative stability, and flavor-related compounds, thereby contributing to improved management practices and future intervention strategies aimed at reducing freeze–thaw–related deterioration in poultry meat.