— Frozen yoghurt is a frozen desserts made with yoghurt and quite similar to ice cream but low in calorie, which cointains milk, sweetener, stabilizers, emulsifier, and lactic acid bacteria (LAB) cultures through combination of process freezing and agitation. The optimal pH about 5.5 on LAB growth and the use of different strains of LAB culture or LAB mixed cultures that can maintain the viability of LAB during processing and freezing storage of frozen yoghurt. The use of LAB mixed cultures could improve viscos ity and overrun of frozen yogurt. The viability of the LAB cultures remained above minimal limit of 107CFU/g in frozen yogurt due to the viability of LAB decrease significantly during processing and freezing storage , high viable survival rate during delivery through the gastrointestinal tract higher than 106CFU/g. The issues that often arise relates to frozen yogurt processing are a grainy texture, Faster melting rate and the low viscosity and overrun value. Addition of porang flour in frozen Yogurt as stabilizer and emulsifier that has an extremely high water-holding capacity, which is able to bind water 200 times its molecular weight due to its high solubility, porang glucomannan gel formed in freezing process which can improve the quality of organoleptic having the better consistency and texture of frozen yoghurt. The use of different concentration of porang flour which can have different result in the final gel formed, have complex effects on viscosity, overrun, melting rate, pH, titratable acidity (TA), total LAB and decrease the ability proteolysis of LAB in frozen yoghurt.
Keywords: frozen yoghurt, porang, viability