Effects of moisture-induced whey protein aggregation on protein conformation, the state of water molecules, and the microstructure and texture of high-protein-containing matrix.
Moisture-induced protein aggregation through intermolecular interactions such as disulfide bonding can occur in a high-protein-containing food matrix during nonthermal processing and storage. The present study investigated the effect of moisture-induced whey protein aggregation on the structure and texture of such high-protein-containing matrices using a protein/buffer model system. Whey proteins in the protein/buffer model systems formed insoluble aggregates during 3 months' storage at temperatures varying from 4 to 45 degrees C, resulting in changes in microstructure and texture. The level of aggregation that began to cause significant texture change was an inverse function of storage temperature. The protein conformation and the state of water molecules in the model system also changed during storage, as measured by differential scanning calorimetry and Fourier transform infrared spectroscopy. During storage, the model system that had an initially smooth structure formed aggregated particles (100-200 nm) as measured by scanning electron microscopy, which lead to an aggregation network in the high-protein-containing matrix and caused a harder texture.
Zhou
Peng
P
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu Province 214122, People's Republic of China.
Liu
Xiaoming
X
Labuza
Ted P
TP
D002152:Calorimetry, Differential Scanning; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004044:Dietary Proteins / Q000032:analysis*; D005511:Food Handling; D005519:Food Preservation; D008855:Microscopy, Electron, Scanning; D008894:Milk Proteins / Q000737:chemistry* / Q000648:ultrastructure; D011487:Protein Conformation; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014867:Water / Q000737:chemistry*; D000067816:Whey Proteins
D004044:Dietary Proteins; D008894:Milk Proteins; D000067816:Whey Proteins; D014867:Water