Protein hydrolysates play an important function in many special dietary foods, e.g. for infants, those with genetic disorders, athletes and geriatrics. Because of hydrolysis these materials are more hygroscopic than the initial intact protein. In this reset the moisture sorption isotherms and the glass transition profile as a function of moisture content for fish protein hydrolysates (FPH), whey protein hydrolysates (WPH) and casein hydrolysates (CH) were determined. The properties of each hydrolysates were related to molecular weight with a lower glass transition curve at lower molecular weight, the Tg was proportional to degree of hydrolysis. These hydrolysates may be as important as sugars in lowering Tg. Fish moisture sorption was related to hydrolysis. CH was less susceptible to caking than FPH and WPH.
Bibliographical noteFunding Information:
The authors wish to acknowledge the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-Brazil for support. This research was also supported in part by the Minnesota-South Dakota Dairy Foods Research Center and by the University of Minnesota Foundation. This is a scientific paper #97118000 of the Minnesota Agricultural Research Experiment Station.