Frictional behaviour of molten chocolate as a function of fat content

Rodrigues, Sophia; Shewan, Heather M.; Xu, Yuan; Selway, Nichola; Stokes, Jason R.

doi:10.1039/d0fo03378b

Cited by 6 publications

(19 citation statements)

References 29 publications

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“…The size distribution of solid particles in chocolates is an important parameter to determine whether the particles entrain into the tribocontact gap and hence affect the tribological performance. This is likely when the size of cocoa particles is considerably smaller than the size of the gap. , For a true comparison, the volume density for each chocolate was normalized to the peak maximum of the more pronounced peak ( i.e. , the peak emerged at a larger size, Figure A1).…”

Section: Resultsmentioning

confidence: 99%

“…The particle size distribution (PSD) of the chocolate samples was assessed through the Mie theory of light scattering using a Mastersizer 3000 (Malvern analytical, U.K.) over a broad size measurement range between 0.01 and 10,000 μm. An absorption index of 0.100 and refractive indices of 1.590 and 1.469 for the particles and the SF oil were assumed, respectively . The measurements were carried out at 25 °C and the laser obscuration was maintained below 10–12%.…”

Section: Methodsmentioning

confidence: 99%

“…The measurements were carried out at 25 °C and the laser obscuration was maintained below 10–12%. The PSD curves were deconvoluted by Gaussian distribution function using OriginPro to obtain two peaks …”

Section: Methodsmentioning

confidence: 99%

“…, soy lecithin and polyglycerol polyricinoleate) influence the bulk properties, flow characteristics, and lubrication behavior of chocolates in mouth, impacting the gustation ( i.e. , the primary taste perception). ,− Thinking of the stages of oral processing, the licking starts with a direct contact between the tongue and a solid chocolate followed by a gradual phase transition of the chocolate from a crystalline solid to a continuous molten fat phase containing suspended particles of cocoa and sugar. The molten chocolate is eventually mixed with the biological fluid, i.e.…”

Section: Introductionmentioning

confidence: 99%

“…Attempts have been made to understand often unpleasant sensory attributes of dark chocolates ( e.g. , grittiness, pasty, mouth-coating) through tribological studies of molten chocolates and their mixtures with saliva. ,,− These studies have provided invaluable information on the mouth-feel of chocolates, albeit using materials ( e.g. , smooth polydimethylsiloxane surfaces) or conditions that are far from real biophysical characteristics of tongue–palate contact.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Insights into the Multiscale Lubrication Mechanism of Edible Phase Change Materials

Soltanahmadi

Bryant

Sarkar

2023

ACS Appl. Mater. Interfaces

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Investigation of a lubrication behavior of phase change materials (PCM) can be challenging in applications involving relative motion, e.g., sport (ice skating), food (chocolates), energy (thermal storage), apparel (textiles with PCM), etc. In oral tribology, a phase change often occurs in a sequence of dynamic interactions between the ingested PCM and oral surfaces from a licking stage to a saliva-mixed stage at contact scales spanning micro-(cellular), meso-(papillae), and macroscales. Often the lubrication performance and correlations across length scales and different stages remain poorly understood due to the lack of testing setups mimicking real human tissues. Herein, we bring new insights into lubrication mechanisms of PCM using dark chocolate as an exemplar at a single-papilla (meso)-scale and a full-tongue (macro) scale covering the solid, molten, and saliva-mixed states, uniting highly sophisticated biomimetic oral surfaces with in situ tribomicroscopy for the first time. Unprecedented results from this study supported by transcending lubrication theories reveal how the tribological mechanism in licking shifted from solid fat-dominated lubrication (saliva-poor regime) to aqueous lubrication (saliva-dominant regime), the latter resulted in increasing the coefficient of friction by at least threefold. At the mesoscale, the governing mechanisms were bridging of cocoa butter in between confined cocoa particles and fat coalescence of emulsion droplets for the molten and saliva-mixed states, respectively. At the macroscale, a distinctive hydrodynamic viscous film formed at the interface governing the speed-dependent lubrication behavior indicates the striking importance of multiscale analyses. New tribological insights across different stages and scales of phase transition from this study will inspire rational design of the next generation of PCM and solid particle-containing materials.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Insights into the Multiscale Lubrication Mechanism of Edible Phase Change Materials

Soltanahmadi

Bryant

Sarkar

2023

ACS Appl. Mater. Interfaces

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Utilization of hazelnut oil oleogels for the preparation of milk couverture type compound chocolates: Composition, properties, and sensory evaluations

Yılmaz,

Öz

2024

J Americ Oil Chem Soc

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The aim of this study was to use oleogels in compound chocolates. A control sample with cocoa butter (CNT) and two compound chocolates with hazelnut oil‐sunflower wax oleogel (SWO‐CC), and polyglycerol stearate oleogel (PGSO‐CC) were prepared with the same recipe. The main properties and compositions of the samples were quite similar. While CNT sample included only 37.97% of total unsaturated fatty acids, it was 74.19 and 63.08% in the SWO‐CC and PGSO‐CC, respectively. The melting peak temperatures were 32.1, 25.4, and 23.8°C for CNT, SWO‐CC and PGSO‐CC. The samples had 11.75%, 74.25%, and 74.25% shape retention index values at 60°C. Clearly compound chocolates melted at lower temperatures, but retained their shape at higher temperatures. After 15‐day temperature fluctuation storage, no fat bloom was developed. Rheological data showed that the PGSO‐CC sample was stiffer among all, and the compound chocolates melted slowly up to 40°C, but CNT melted sharply at 38°C. Further, the PGSO‐CC sample showed a lubricating behavior. Although CNT sample included 7 volatile aromatics, SWO‐CC and PGSO‐CC samples had 17 and 14 compounds, respectively. Trained panel described the samples with 13 attributes, and most profoundly the compound chocolates had lower shape, surface gloss, coffee, bitter, cooling, hardness scores, and higher coating scores. Consumer test revealed that compound chocolates had lower appearance scores, and equal aroma scores. The flavor score and acceptability were highest for the PGSO‐CC sample. Overall, this study proved that heat stable and sensorially acceptable compound chocolates could be prepared from the oleogels.

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Accurate Evaluation of the Flow Properties of Molten Chocolate: Circumventing Artefacts

Hendrik

Marchesini²,

Walle³

et al. 2022

Food Anal. Methods

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Methods to characterize the flow behavior of molten chocolate have been set by International Confectionery Association (ICA) in 2000, however, there is no consensus on an accurate method and it is often followed by misinterpretation of the results. This issue is also influenced by flow phenomena generally recurring in yield-stress materials, such as transient effects, gap size effects, apparent wall slip and edge fracture. The state of the art in the field of rheology allow for more precise techniques to circumvent such rheometric artefacts. Nevertheless, a combined approach to accurately determine the flow properties of different types of molten chocolate targeting the prevention of all possible flow artefacts is still not found in the literature. In this paper, two technologically distinct molten dark chocolates are employed on different combinations of flow curve protocols, measuring geometries and viscosity functions to accurately determine their flow properties. Based on the evaluation, a wider shear rate range (𝛾̇= 0.01 -100 s -1 ) with sufficient measurement time per shear rate (> 120s) is recommended for an accurate flow curve protocol, combined with a roughened surface geometry with radii ratio < 1.10. Four-parameter mathematical models, such as the Windhab model or a modified Herschel-Bulkley model, have been proven to be more accurate in further acquiring important flow parameters, but special attention should be given to the physical meaning of some parameters. A comparison between experimental flow curve data, model-fitted data and steady-state data gained from a constant shear rate test confirmed the suitability of these recommendations for both chocolates. The proposed alternative method allows for accurate measurements at lower shear rates, which significantly improves the accuracy to obtain important parameters such as yield stress as well as detecting and preventing rheometric artefacts.

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Frictional behaviour of molten chocolate as a function of fat content

Abstract: Soft tribology is used to probe the lubrication behaviour of molten chocolate between soft contacts, analogous to in-mouth interactions between the tongue and palate. Molten chocolate is a concentrated suspension...

Cited by 6 publications

References 29 publications

Insights into the Multiscale Lubrication Mechanism of Edible Phase Change Materials

Insights into the Multiscale Lubrication Mechanism of Edible Phase Change Materials

Utilization of hazelnut oil oleogels for the preparation of milk couverture type compound chocolates: Composition, properties, and sensory evaluations

Accurate Evaluation of the Flow Properties of Molten Chocolate: Circumventing Artefacts

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