hello! i'm planning to do a biology ia on effect of pH on enzyme activity. the enzyme is bromelain, which i'll obtain from literally juicing a pineapple. i'm going to test out the enzyme activity by rate of hydrolysis of a gelatin cube. i was planning on altering the solution's pH by adding different amounts of vinegar to the pineapple juice, but my teacher advised that that'll react with the glucose causing fermentation which it will make it hard to measure this bromelain.
how else am i supposed to change the pH of pure pineapple juice?