Optimizing conditions for thermal processes of soy milk.
Mathematical and kinetic models were set up for heat-induced quality changes in soy milk, including inactivation of trypsin inhibitor activity (TIA) and degradation of thiamin, riboflavin, color, and flavor over a wide range of time-temperature combinations with particular interest in the ultrahigh-temperature (UHT) range. On the basis of these models, multiresponse optimization of the thermal processes for soy milk was carried out to obtain the following effects simultaneously: (1) maximum destruction of bacterial spores, (2) maximum inactivation of TIA, and (3) minimum degradation of sensory and nutritional qualities. By a suitable selection of high temperatures and extended heating times, for example, 143 degrees C/60 s, it is possible to use a single-step UHT process to produce a commercially sterile soy milk with satisfactory TIA inactivation, highly acceptable color and flavor, and thiamin retention between 90 and 93%.
Kwok
Kin-Chor
KC
Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong, People's Republic of China. bckckwok@ polyu.edu.hk
Liang
Han-Hua
HH
Niranjan
Keshavan
K
D001628:Beverages / Q000032:analysis / Q000382:microbiology; D005511:Food Handling; D006358:Hot Temperature; D007700:Kinetics; D008433:Mathematics; D011786:Quality Control; D013025:Glycine max; D013171:Spores, Bacterial; D013831:Thiamine / Q000032:analysis; D014361:Trypsin Inhibitors
D014361:Trypsin Inhibitors; D013831:Thiamine