The effects of temperature on the retention and denaturation of protein in lucerne leaves subjected to mechanical dewatering

Abstract

AbstractThe effects of pretreatment temperature on the retention and denaturation of protein were studied in relation to moisture removal from lucerne forage subjected to mechanical pressing. Leaf samples were held for 5 min at a temperature between 40‐100°C, then pressed. Although the protein concentration of the expressed juice decreased with increasing temperature, the amount of soluble protein lost in the expressed juice was fairly constant, amounting at most to only 4%. The maximum reduction in water content (76 ± 1%) was achieved by pressing after a treatment of 60‐70°C. However, the protein retained in the residue was not denatured completely until the pretreatment temperature exceeded 80°C. At 60°C, with maximum water removal, only one‐third of the protein became denatured; at 50°C, 80% of the maximum water removal was obtained with only 16% denaturation of retained protein.