Multiple choice If we take food rich in lime juice, then action of ptyalin on starch is enhanced action of ptyalin on starch is reduced action of ptyalin on starch is unaffected action of ptyalin on starch stops Reveal answer Fill a bubble to check yourself B Correct answer Explanation If we take food rich in lime juice, then action of ptyalin on starch is reduced as ptyalin becomes inactive at acidic pH.