A stability study of green tea catechins during the biscuit making process

► A RP-HPLC method was developed for the separation and quantification of tea catechins in green tea extract, biscuit dough, and biscuit samples. ► Green tea catechins were relatively stable in the biscuit dough. ► The relative stability of catechins in the biscuit system can be sequenced as (−)-CG > (−)-GCG > (−)-ECG > (−)-EGCG. ► Percentages of (−)-EGCG and (−)-ECG in the dough and biscuit increased as the initial concentration of GTE was increased. ► Retention rates of green tea catechins were improved by reducing the pH of the dough.