Authors: Naoko YunoOhta
Publish Date: 2009/10/13
Volume: 287, Issue: 12, Pages: 1487-
Abstract
We investigated the effects of cysteine on βlactoglobulin interactions using ultrasound spectroscopy rheological measurements and differential scanning calorimetry Changes in ultrasonic velocity and attenuation were monitored using ultrasound spectroscopy and we discuss the effects of cysteine on gel formation together with the results obtained using other methods A decrease in ultrasonic velocity occurred around 54 °C suggesting that the compressibility of the system increases at approximately this temperature An increase in ultrasonic attenuation was observed at approximately 54 °C which is much lower than the commonly observed denaturation temperature of 75–80 °C The temperature coincided with the onset of phase transition by differential scanning calorimetry and the initial rise in temperature of dynamic modulus for rheological measurements under heat treatment We conclude that cysteine promotes the polymerization processes of denatured proteins during the initial stage of gelation The ultrasonic spectroscopic analysis is a useful tool to monitor protein molecule interactions prior to gelation
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