the effect of homogenization pressure and stages on the amounts of lactic and acetic acids of probiotic yoghurt

nowadays the use of probiotic products especially yogurt, due to having wonderful and health properties, has become popular in the world. in this study, the effect of homogenization pressure (100, 150 and 200 bars) and stage (single and two) on the amount of lactic and acetic acids was investigated. yoghurts were manufactured from low-fat milk treated using high pressure homogenization at 100,150 and 200 bar and at 60°c. the amount of lactic and acetic acids was determined after the days 1, 7, 14 and 21 of storage at 4ºc. the experiments were set up using a completely randomized design. with the increase of pressure and stage of homogenization, the amount of both acids was increased (p<0.01). the greatest amount of lactic and acetic acids during the storage period was observed in the sample homogenized at a pressure of 200 bars and two stages.