Effect of Protein Thermal Denaturation on the Texture Profile Evolution of Beijing Roast Duck.

Yanxia Liu,Teng Hui,Zhenyu Wang,Teng Pan,Qingwu Shen,Huan Liu,Dequan Zhang

doi:10.3390/foods11050664

Abstract

To investigate the mechanism of the texture formed by protein thermal denaturation, the profile and formation of texture and thermal denaturation of protein were evaluated using texture profile analysis (TPA) and transmission electron microscopy (TEM) combined with differential scanning calorimeter (DSC). Results indicated that the surface temperature of Beijing roast duck increased from 23.9 to 174.4 °C, while the center temperature rose from 20.6 to 99.3 °C during roasting. Shear force decreased significantly during the first 20 min, and the texture profile largely changed at 20 and 40 min. Firstly, Band I was broken and twisted, Band A was overstruck, and Z-line was diffused and finally disappeared, resulting in a blurred myofibril structure. The sarcomere considerably contracted within 30 min. Secondly, the main myofibrillar proteins were denatured at 20 and 40 min, respectively. The formation of hydrophobic interactions and the reduction of ionic bonds were observed. Thirdly, roasting induced protein thermal denaturation, which was correlated with interprotein forces, texture profile, and the shear force. Muscle fibers were damaged and shrunken, accompanied by the formation of hydrophobic interactions and the reduction of ionic bonds. The turning points were at 20 and 40 min, and the main proteins were denatured, leading to the formation of tenderness of Beijing roast duck.

Highlights

Beijing roast duck is a kind of traditional Chinese food, which is very popular among consumers [1]
In order to obtain the relationship between the surface temperature and the center temperature, the prediction equation of Beijing roast duck was established by Origin software
Results of this study showed that protein thermal denaturation was responsible for the texture profile evolution and the delicacy of the Beijing roast duck

Summary

Introduction

Beijing roast duck is a kind of traditional Chinese food, which is very popular among consumers [1]. Tenderness is one of the important indicators of roast duck and is a general summary of the structural characteristics of proteins. High correlations have been found between heat-, glycolysis-, energy metabolism-, muscle fiber structure-, oxidation-, and degradation-related protein and meat tenderness or tenderization [2,3]. When meat is exposed to heat, proteins will denature and coagulate, thereby reducing the space of myofibrils, and forming the texture of the product [3]. Roasting time and temperature affect protein aggregation, muscle fiber contraction, and sarcomere length, and eventually affect meat tenderness. Different shear forces and textures were formed under different roasting temperatures, and meat was less tender after roasting in general

Methods

Results

Discussion

Conclusion