Design, formulation and sensory evaluation of a polyphenol-rich food placebo: an example of aronia juice for food intervention studies

Products suitable for use as controls in food interventions designed to demonstrate the role of minor components are largely lacking. In the present study, we aimed to develop a formulation to be used as a placebo in a clinical trial designed to assess the effects of aronia juice polyphenols on platelet function. Three formulations with the same nutrient composition as aronia juice were prepared by mixing various nutrients, artificial colours and flavours with water. The similarity of formulations to aronia juice in terms of taste, colour, smell and texture was assessed by six food panellists. The final placebo was tested for its impact on platelet function, biochemical and anthropometric parameters in a 4-week long study. No significant changes in platelet function, or in several cardiovascular and safety markers were recorded. Formulation suitable for use as a placebo for dietary intervention studies using aronia juice has been developed and demonstrated to be well tolerated in humans.