Particle perception: Defining sensory thresholds for grittiness of upcycled apple pomace powders

Abstract

Recent years have seen increased interest in environmentally-friendly and sustainable foods, including upcycled ingredients. However, some of these ingredients can contribute to grittiness or graininess, which could in turn impact consumer acceptance. To explore this topic, the current study used apple pomace powder (APP), a nutrient-rich byproduct from apple juice and cider processing to yield new knowledge on particle perception in upcycled foods. Seven APPs with particle sizes of average hydrated diameter Dv(90): 166, 208, 320, 363, 471, 569, 642 μm were incorporated into fruit yogurts. Napping® was successfully used as a preliminary step to threshold testing to inform selection of threshold testing methodology and an appropriate particle size range. The Ascending Forced Choice Method of Limits was applied to a consumer panel (N = 71) for threshold determination. The group threshold, was 259 μm (Dv(90)). The current study demonstrated that by reducing the particle size, it is possible to use APP in a smoother product, such as yogurt, without introducing grittiness. However, a great deal of individual variability was noted with some participants able to detect the smallest particle sizes (166 μm) and some not able to detect even the largest particle sizes (642 μm). Participants were clustered into groups using agglomerative hierarchical cluster analysis and high (44 %), medium (31 %) and low (25 %) particle sensitivity groups were observed. The diversity of particle size detection thresholds in the population presents both an opportunity and challenge for product developers seeking to avoid gritty or grainy textures and should be further studied.