Extended stribeck curves for food samples

Abstract

Stribeck curves have long been used for understanding the lubricating behaviour of oils and greases, and in the recent years for applications ranging from ball point inks to synovial fluids. In the current work, an attempt is made to show as to what one can read from Stribeck curves of food samples such as chocolate spread, sauce etc. Additionally, the effect of salivahuman and artificialon the frictional behaviour has also been studied. The tests were carried out on an MCR Tribometer with a ball-on-three-pin configuration. Polydimethylsiloxane and glass were used to simulate soft contact conditions that exist in the human mouth. Results from the tribological tests are plotted in the form of extended Stribeck curves, wherein, the friction coefficient is plotted as a function of rotational speed. Since the tribometer is capable of speeds as low as a few nanometres per second, it is also possible to observe the build-up of static friction and its transition into the kinetic regime of friction. Results indicate that certain aspects of the Stribeck curve can offer an insight into the correlation between the frictional behaviour of food to their sensory feel.

Polymer grafted graphitic carbon nitrides as precursors for reinforced lubricant hydrogels

“…58,59 Notably, the low friction properties are combined with high compressibility in the lubA material. Also the shape of the extended Stribeck curve is in agreement with the literature 60,61 and can be explained with the adsorption-repulsion model. 62 In the present case, the friction of hydrogel on hydrogel was investigated (Fig.…”

“…The local maximum at a sliding velocity of 10 −6 m s −1 in the extended Stribeck curve of sample lubB is another literature known effect, which has been attributed to the onset of macroscopic motion. 61 Overall, for the first time, charged monomers can be employed together with g-CN for visible light induced gelation which allows a variety of functions to be investigated in future.…”

Tribology and its growing use toward the study of food oral processing and sensory perception

“…The most frequently used instruments and many of the references for each are included below: Rolling‐ball on rotating‐disk (“ball‐on‐disk”) mini traction machine (MTM) PCS Instruments with soft PDMS contact(s), with well‐over 50 food oral processing relevant publications (ca. 30 publications are included in further discussion below). Rotating ball on three‐fixed plates/pins using the Rheo‐tribocell attachment for the modular compact rheometer (MCR) rheometers (Anton Paar, Gratz, Austria) (Baier et al, ; Biegler, Delius, Käsdorf, Hofmann, & Lieleg, ; Carvalho‐da‐Silva, Van Damme, Taylor, Hort, & Wolf, ; Kieserling, Schalow, & Drusch, ; Kim, Wolf, & Baier, ; Krzeminski, Wohlhuter, Heyer, Utz, & Hinrichs, ; Pondicherry, Rummel, & Laeuger, ; Sonne, Busch‐Stockfisch, Weiss, & Hinrichs, ; Steinbach, Guthrie, Smith, Lindgren, & Debon, ). Ring on plate tribo‐rheometry using the Discovery Hybrid Rheometer (TA Instruments) on a rough plastic surface of 3 M Transpore Surgical Tape 1527‐2 (3 M Health Care). (Ng, Nguyen, Bhandari, & Prakash, ; Nguyen, Bhandari, & Prakash, ). Optical tribometer configuration (Dresselhuis et al, ; Dresselhuis, de Hoog, Stuart, & van Aken, ; Liu, Stieger, et al, ; Liu, Stieger, van der Linden, & van de Velde, ). Double‐ball‐on‐plate apparatus attached to MCR rheometers (Goh, Versluis, Appelqvist, & Bialek, ; Joyner et al, ; Joyner, Pernell, & Daubert, ; Joyner, Pernell, & Daubert, ). Plate on three balls (based on a modified texture analyzer (TA‐XT2, TA Instruments) (Chen, Liu, & Prakash, ; Morell, Chen, & Fiszman, ; Sanahuja, Upadhyay, Briesen, & Chen, ), including consideration for stick–slip (Sanahuja et al ()). High frequency reciprocating rig (HFRR) PCS Instrument UK (Tsui, Tandy, Myant, Masen, & Cann, ), and reciprocating pin‐on‐disk (TriboLab, Bruker, Germany) (van Stee, de Hoog, & van de Velde, ). Rotating shaft with sliding bar (de Hoog, Prinz, Huntjens, Dresselhuis, & van Aken, ; Prinz, de Wijk, & Huntjens, ). …”

Instrumental characteristics from extensional rheology and tribology of polysaccharide solutions

“…Although the surface roughness of human tongue reported; approx. 90 μm (Wang, Upadhyay, & Chen, 2019) is larger than that of the geometry used, usage of this geometry has been validated previously in terms of the suitability to texture evaluation (Kim et al, 2015; Pondicherry et al, 2018). For measurements, 1 ml of each test solution was placed into the container, followed by application of the normal force at 0.3 N between the upper surface and the test solution.…”

“…It is necessary to recreate the reality of humans' actual eating conditions (Carpenter et al, 2019; Dresselhuis, de Hoog, Cohen Stuart, & van Aken, 2008), and in this context, polydimethylsiloxane (PDMS) was proposed as a material with suitable wettability and deformability that mimics the tongue, whereas frosted glass as a material with suitable surface roughness that mimics the hard palate (Bongaerts, Fourtouni, & Stokes, 2007). Lubricity of various foods has been investigated so far using an instrumental set‐up constituting a glass ball as a plunger and PDMS plates as a substrate (stage) on a rotational rheometer (Anton Paar, Gratz, Austria; Baier et al, 2009; Biegler, Delius, Käsdorf, Hofmann, & Lieleg, 2016; Carvalho‐da‐Silva, Damme, Taylor, Hort, & Wolf, 2013; Kieserling, Schalow, & Drusch, 2018; Kim, Wolf, & Baier, 2015; Krzeminski, Wohlhüter, Heyer, Utz, & Hinrichs, 2012; Pondicherry, Rummel, & Laeuger, 2018; Sonne, Busch‐Stockfisch, Weiss, & Hinrichs, 2014).…”