Effect of Miracle Berry on Taste Modification Properties Among Adults Living in Australia: A Multi‐Phase Study Protocol

Abstract

Miracle Berry (MB) contains miraculin, a glycoprotein that alters sour tastes into sweet. MB may enhance the taste perceptions of hypo-palatable foods (e.g., sour/bitter fruits and vegetables) and hyper-palatable foods (e.g., sugar-sweetened beverages (SSBs)), potentially influencing their liking and intake. Therefore, this study aims to assess the effects of different doses of MB on the taste perception, overall liking and intake of hypo-palatable foods and hyper-palatable SSBs. Additionally, it will explore the feasibility of MB in enhancing food preferences, energy intake, and dietary quality in a natural environment. The study consists of four phases. Phase 1 will employ a three-arm pre-post design to assess the effect of different doses of MB on the taste perception of individual food-based solutions and single food items (measured using the generalized labeled magnitude scale, gLMS) in 54 healthy-weight adults. Phases 2 and 3 will utilize a four-arm, placebo-controlled, pre-post trial to determine the effective dose of MB that could change the taste perception (using gLMS), overall liking (using the labeled affective magnitude scale) and intake of hypo-palatable mixed foods and hyper-palatable SSBs in 40 healthy-weight and 40 overweight/obese adults, respectively. Phase 4 will be a 12-week, two-arm, placebo-controlled feasibility trial assessing the effect of MB on food preferences (food liking questionnaire), energy intake (3-day food record and 24-h dietary recall), dietary quality (Australian Recommended Food Score) and other feasibility indicators in 30 overweight/obese adults. Outcomes of phase 4 will be assessed at baseline, Week 1, Week 6, and Week 12. The effects of MB will be evaluated using mixed-effects models, and a post hoc power analysis will be conducted.