Thermostability and browning development of fungal α-amylase freeze-dried in carbohydrate and PVP matrices

摘要: Abstract Thermal stability and browning development of systems containing fungal α-amylase in lactose, raffinose, sucrose, trehalose polyvinylpyrrolidone (PVP) matrices after heat treatment at 70 °C a constant relative humidity (RH) environment connection with phase transitions were studied. Matrices showed considerable variability their ability to stabilize development. Amorphous was the most efficient matrix for preventing non-enzymatic thermal inactivation α-amylase. Remaining activity decreased as RH% heating time increased, extent effect being different each matrix. Trehalose appeared deactivation ‘0’, 11 20% RH. At 42% RH all lowest degree enzyme stabilization. The matrices' glassy condition not enough ensure stability; lactose allowed retention 80% 96 h treatment; remaining raffinose PVP 50% or less. enzymatic protection given by related molecular weight (which affects packing) associated water content. did follow same pattern loss activity. Browning minimal accelerated above glass transition, even conditions which crystallization should occur (42% RH).