“…Generally, there were two types of relative motions between ball and disc: rotating and reciprocating. Rotating motion was more often used in tribology tests to assess food texture (Baier et al, 2009; Chojnicka‐Paszun et al, 2012; de Wijk & Prinz, 2005, 2007; de Wijk, Prinz, & Janssen, 2006; Goh, Versluis, Appelqvist, & Bialek, 2010; Kokini et al, 1977; Liu et al, 2018; Liu et al, 2019; Malone et al, 2003; Meyer, Vermulst, Tromp, & De Hoog, 2011; Myant, Spikes, & Stokes, 2010; Rossetti et al, 2009), then rotating motion was also applied in this article. As far as test load was concerned, force in the mouth was about 0.01 to 10 N (Miller & Watkin, 1996) and 10 N was used in the tests.…”