FOOD SCIENCE ›› 2020, Vol. 41 ›› Issue (22): 22-27.doi: 10.7506/spkx1002-6630-20190908-105

• Food Chemistry • Previous Articles     Next Articles

Effect of Poly-γ-Glutamic Acid on Quality of Frozen Dough and Steamed Bread

XIE Xinhua, WU Xiuyuan, WU Junhong, SHEN Yue, WANG Na, ZHANG Bei, XU Lina   

  1. (1. College of Food Science and Technology, Henan Agricultural University, Zhengzhou 450002, China;2. Zhengzhou Food and Drug Control Institute, Zhengzhou 450006, China)
  • Online:2020-11-25 Published:2020-11-26

Abstract: A dynamic rheometer, a fermentation rheometer, differential scanning calorimetry, and scanning electron microscopy were used to study the effect of poly-γ-glutamic acid (γ-PGA) addition on the rheological properties, fermentation characteristics, thermodynamic characteristics and microstructure of frozen dough, and the effect on the hardness, moisture distribution and porosity of steamed bread made from frozen dough was evaluated using a texture analyzer, nuclear magnetic resonance and an electronic eye. The results showed that dough supplemented with 0.7% (relative to dry flour mass) γ-PGA exhibited the maximum storage modulus and loss modulus, highest fermentation height and gas-holding capacity, and lowest melting enthalpy. Dough pores became larger more and uniformly distributed and showed improved continuity with increasing addition of γ-PGA. The migration of the water state from weakly bound to free significantly declined in steamed bread with 0.7% γ-PGA with the prolongation of storage time. After 5 days of storage, the hardness was 21.7% lower than that of the control group, and the porosity was 17.92%, lower than that (28.46%) of the control group. The above results indicate that γ-PGA can effectively weaken damage to dough network structure caused by frozen storage, and improve the frozen storage stability of dough and the quality of steamed bread.

Key words: poly-γ-glutamic acid; frozen dough; steamed bread; quality

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