Comparing the impacts of conventional and emerging roasting processes on duck myofibrillar protein structure,
Jiawei Zhao1, Xinze Li1, Jiamin Shen2
1Department of Food Science and Engineering, College of Food Science and Technology, Ningbo University, Ningbo 315211, China.
Abstract:
This investigation compared the effects of traditional charcoal roasting (CGT) and emerging heat sources, including microwave (MP), far-infrared (IP) and electric-heating (ERT), on the conformational alterations of duck myofibrillar proteins, the evolution of volatile flavor profiles, and the formation of polycyclic aromatic hydrocarbons (PAHs), with the aim to elucidate their potential mechanistic linking. The results demonstrated that thermal roasting processes markedly promoted protein aggregation across all treatment groups, with CGT-roasted samples exhibiting the most pronounced aggregation behavior. The highest protein carbonyl contents were observed in CGT, followed by ERT and IP-roasted samples, whereas MP group exhibited the lowest level. Conversely, an opposite trend was observed for thiol content. CGT-roasted samples exhibited a significantly reduced α-helix proportion compared with ERT, IP and MP groups. In addition, charcoal-roasting resulted in the lowest intrinsic fluorescence intensity and the highest surface hydrophobicity, indicating significant protein unfolding. Lipid oxidation analysis revealed that the CGT group presented significantly higher peroxide value and thiobarbituric acid reactive substances levels than emerging roasting processes, which were positively associated with PAHs accumulation. The MP group retained the highest reducing sugar content and the lowest Schiff base formation. A total of 104 volatile compounds were identified using HS-SPME-GC-MS, with significant difference observed in the composition and abundance of volatile flavor compounds in differentially roasted meats. The OPLS-DA models identified key differential markers, including hexanal, heptanal, styrene, and 1-octen-3-ol. Correlation analysis further confirmed that traditional CGT showed higher degrees to induce α-helix disruption, accelerate protein-lipid co-oxidation, and intensify Maillard reactions, thus synergistically contributing to higher accumulation of PAHs than emerging roasting processes. These findings provide novel insights into the regulatory mechanisms of emerging heating-roasting technologies on the physicochemical properties and safety attributes of meat products, particularly the relationship between PAHs formation and heating-induced protein depolymerization-oxidation behaviors.
