Abstract: This study was executed to investigate the effect of different methods of magnesium chloride addition on tofu yield and quality. Tofu was produced using four different stirring speeds (60, 120, 180 and 240 r/min) and three different stirring times (10, 20 and 30 s), and compared for differences in quality properties. Furthermore, a comparative evaluation was made of the quality of tofu produced by one-time and portionwise addition of magnesium chloride (in two, three and four portions) under optimum stirring conditions. The results indicated that one-time addition of tofu coagulant with a stirring speed of 120 r/min and a stirring time of 30 s provided the highest tofu yield of 282.0 g/100 g whereas the lowest value of 183.9 g/100 g was obtained with a stirring speed of 240 r/min and a stirring time of 30 s. Tofu prepared by coagulant addition in batches had higher water-retaining capacity and better quality than that prepared by one-time addition. Addition in three portions was found to be optimal for the maximum increase in hardness, cohesiveness and gumminess by 19.9%, 6.9% and 30.0%, respectively.

Key words: anchor agitator, stirring conditions, coagulant addition in batches, magnesium chloride tofu, quality properties