Effects of Different Heating Modes on Gel Properties of Beijing Duck Myosin
ZHOU Yinna, WEI Xiangru, ZHANG Dequan, WANG Zhenyu
1.School of Food and Wine, Ningxia University, Yinchuan 750021, China; 2.Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
Abstract:The effects of heating rate (1.0, 1.5, 2.0 and 2.5 ℃/min) and end point temperature (80, 90 and 100 ℃) on the gel characteristics of Beijing duck myosin were studied by circular dichroism (CD) and low-field nuclear magnetic resonance (LF-NMR). The results showed that the α-helix structure of duck myosin was transformed into β-sheet with increasing temperature during the heating process; the proportion of α-helix gradually decreased, while the proportion of β-sheet gradually increased, which promoted the gelation of myosin. Under the traditional hanging oven heating mode, the hardness, strength and free water content of Beijing duck myosin gel were significantly lower at end point temperature of 80 ℃ than at 90 and 100 ℃ (P < 0.05). In the linear heating mode, the gel water-holding capacity (WHC) and strength of myosin decreased with increasing heating rate. Compared with the traditional hanging oven heating mode, the gel WHC increased at heating rates of 1.0 and 1.5 ℃/min, but decreased significantly at 2.5 ℃/min.