title: Maillard-reaction-induced modification and aggregation of proteins and hardening of texture in protein bar model systems.
abstract: The hardening of high-protein bars causes problems in their acceptability to consumers. The objective of this study was to determine the progress of the Maillard reaction in model systems of high-protein nutritional bars containing reducing sugars, and to illustrate the influences of the Maillard reaction on the modification and aggregation of proteins and the hardening of bar matrices during storage. The progress of the Maillard reaction, glycation, and aggregation of proteins, and textural changes in bar matrices were investigated during storage at 25, 35, and 45 °C. The initial development of the Maillard reaction caused little changes in hardness; however, further storage resulted in dramatic modification of protein with formation of high-molecular-weight polymers, resulting in the hardening in texture. The replacement of reducing sugars with nonreducing ingredients such as sugar alcohols in the formula minimized the changes in texture.
  
  
  CONCLUSIONS
  The hardening of high-protein bars causes problems in their acceptability to consumers. Maillard reaction is one of the mechanisms contributing to the hardening of bar matrix, particularly for the late stage of storage. The replacement of reducing sugars with nonreducing ingredients such as sugar alcohols in the formula will minimize the changes in texture.
authors: State Key Laboratory of Food Science & Technology, Jiangnan University, Wuxi, Jiangsu Province, China. zhoupeng@jiangnan.edu.cn
authors: Peng
authors: P
authors: Zhou
authors: Mufan
authors: M
authors: Guo
authors: Dasong
authors: D
authors: Liu
authors: Xiaoming
authors: X
authors: Liu
authors: Teodore P
authors: TP
authors: Labuza
mesh_terms: D003258:Consumer Behavior; D004044:Dietary Proteins / Q000032:analysis*; D019422:Dietary Sucrose / Q000032:analysis / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D061353:Food Storage; D006244:Hardness; D015416:Maillard Reaction; D008894:Milk Proteins / Q000032:analysis / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D012995:Solubility; D013402:Sugar Alcohols / Q000032:analysis / Q000737:chemistry; D000067816:Whey Proteins
chemical_list: D004044:Dietary Proteins; D019422:Dietary Sucrose; D008894:Milk Proteins; D011108:Polymers; D013402:Sugar Alcohols; D000067816:Whey Proteins