Comparison of boba pearls made from tapioca starch and other unconventional flours and starches: Their glycaemic response (GR)

Introduction: Boba milk tea, also recognised as bubble tea, is a popular beverage in Asia. The primary component in bubble tea is “boba” or “pearl” balls, made of tapioca starch. However, much remains to be seen if tapioca boba pearls have a profound impact on blood glucose. Methods: In a randomised, controlled crossover, single-blinded design study, 12 healthy Chinese male adults (body mass index 21±14 kgm−2) attended four sessions. At each session, bubble tea consisting of boba pearls made from tapioca starch (TS), sago starch (SS), high-amylose starch + sago starch (HA), or kithul flour + sago starch (KF) were served. Boba milk tea was served at breakfast, with volunteers consuming them in a fasted state at each session. The postprandial glycaemic response and insulin response were compared within participants. Results: There were observed differences at time 180min for incremental glucose between HA and SS (p=0.005), and for TS and SS for incremental insulin (p=0.004). Glucose iAUC was lower for TS compared to the other boba pearl treatments, although not significantly (p=0.093). There was no significant difference in iAUC of insulin (p=0.104) between the four boba pearl milk teas. Conclusion: With limited scientific research conducted on bubble milk tea, our study was the first to document the glycaemic responses of tapioca starch boba pearls and boba pearls made using unconventional flours and starches. The findings from this study is an important first step for future work to develop healthier boba pearls for bubble tea.