Adhesion, Cohesion, and Friction Estimated from Combining Cutting and Peeling Test Results for Thin Noodle Sheets

Abstract

The aim of this study was to estimate the adhesive and cohesive fracture energies, and frictional characteristics of 7 types of cooked starch and flour sheets and combine these into a model framework for textural analysis. Cutting tests with wires of diameter 0.30 to 0.89 mm were performed with and without lubrication. Plots of the work done, normalized to the area cut by the wire, showed that this to be linearly related to wire diameter irrespective of lubrication. The oil had little impact on the intercept of these plots, giving cohesive fracture energy (Gc ) ranges for these foods between 6.8 and 32.5 J/m(2) . However, lubrication had a strong influence on the slope of the plots. From a comparison of the slopes for lubricated versus unlubricated tests, the kinetic coefficient of friction μkcould be calculated. Values for μk between 0.007 and 0.521 for different foods were obtained. Peeling tests were performed by lifting sheets vertically away from a fresh mica surface. The adhesive fracture energy Ga , varied from 2.5 to 4.8 J/m(2) . The results can be modeled by plotting the ratio of cohesive to adhesive fracture energy against the coefficient of friction. Thresholds in both axes suggest a physical basis for distinguishing textural perceptions. However, sensory testing with 12 subjects using the 7 food types could not establish whether this framework, however well-established physically, would apply to oral sensations. A much larger test would be required.

Rheology and tribology of starch + κ‐carrageenan mixtures

“…For CS1 (Figure 1biii), the Stribeck curve obtained using Equation (2) did not show good agreement with increasing concentration of CS1, the Stribeck curves being significantly shifted to the right of the data points. These results support the idea that the stickiness of starch granules in the dispersions might resist the relative motion of the tribo‐pairs due to molecular adhesion as reported by previous studies (Liu et al, 2016; Wu, Gunaratne, Collado, Corke, & Lucas, 2015; Zhang et al, 2017), although this needs further investigation.…”

Morphometric Analysis of Transverse Surface of Fractured Maltodextrin Agglomerates

“…[4,5] The fracture occurs when bonds between structural elements break, resulting in the modification of the morphology of the product in several scales. [6] The fracture behavior has been considered as an important feature to optimize food processes and the design of new products, [7] so that breakage has been assessed to understand and analyze food texture. [8] Texture and sensory features, such as crispness and crunchiness, have been related to the forcedeformation curve, peak force, and fracture points [9] and is an important quality attribute in food products since they influence smoothness, coarseness, and graininess.…”

Rheology for Safe Swallowing 1

“…According to this model, solid food should be comminuted into smaller fragments and mixed with saliva to be lubricated and forms a bolus before swallowing. A raw oyster is very slippery with low adhesion or friction, and very difficult to control in the mouth as commented by Wu, Guneratne, Collado, Corke & Lucas 43) . Thus, a slippery food such as a raw oyster and beverages/drinks are usually swallowed immediately except in the wine tasting or in a similar situation/ condition.…”

“…In short, foods are crushed and mixed with saliva thus lubricated and are formed into a bolus, transported to the posterior part of the mouth and then swallowed. In the initial phase of food oral processing, bulk rheology plays a dominant role, while in the later phase, especially in the bolus transport by the tongue, the tribological aspect becomes more important 43,[69][70][71] .…”