New Insights into Stringiness from Extensional Rheology




The final arbiter of consumer acceptance of a food product are sensory studies, which can be roughly categorized into liking studies and quantitative sensory analysis. In the latter sensory qualities of a food product are evaluated by panelists on a defined scale. These are invaluable instruments in setting targets for product development, but also as the final quality arbiters for a new product. Instrumental analysis, be it texture analysis or shear rheology, have served as valuable tools to accelerate food and food ingredient R&D where correlations between instrumental analysis and sensory science can be established. However, there are sensory attributes which are not easily described by shear rheology and other techniques are needed. This is especially true if the kinematic of the deformation at the root of the perception is not matched by shear rheology. This is for example the case with texture length (also called ropiness or stringiness). Despite the relevance of this perception aspect to the quality of the food item, formulation is guided by shear rheology. This bears the risk that formulation recommendations are off target and can lead to costly iterations. We will present a small study which connects careful extensional rheology to a sensory study on a condensed milk model. While the number of samples is small, this study demonstrates the general approach one can take. It points to which attributes are uniquely captured by extensional rheology and therefore where this
technique adds distinct value and where conventional shear rheology suffices.

Author Biographies

Leanie Louw

Research and Development - Sensory Science
IFF (International Flavors and Fragrances)

Florian Nettesheim

Department of Functional Ingredients, Nourish R&D
IFF (International Flavors and Fragrances)


(1) KOKINI, J. L.; KADANE, J. B.; CUSSLER, E. L. Liquid Texture Perceived in the Mouth. J. Texture Stud. 1977, 8 (2), 195-218.

(2) Kokini, J. L.; Cussler, E. L. Predicting the Texture of Liquid and Melting Semi-Solid Foods. J. Food Sci. 1983, 48 (4), 623-630.

(3) Kokini, J. L. Fluid and Semi-Solid Food Texture and Texture Taste Interactions. Food Technol. 1985, 39 (11), 86-95.

(4) Dickie, A. M.; Kokini, J. L. An Improved Model for Food Thickness from Non-Newtonian Fluid-Mechanics in the Mouth. J. Food Sci. 1983, 48 (1), 57-65.

(5) Stokes, J. R.; Boehm, M. W.; Baier, S. K. Oral Processing, Texture and Mouthfeel: From Rheology to Tribology and Beyond. Curr. Opin. Colloid Interface Sci. 2013, 18 (4), 349-359.

(6) Spyropoulos, F.; Heuer, E. A. K.; Mills, T. B.; Bakalis, S. Protein-Stabilised Emulsions and Rheological Aspects of Structure and Mouthfeel. In Practical Food Rheology: An interprative approach; Blackwell Publishing Ltd, 2011.

(7) Sarkar, A.; Soltanahmadi, S.; Chen, J.; Stokes, J. R. Oral Tribology: Providing Insight into Oral Processing of Food Colloids. Food Hydrocoll. 2021, 117 (December 2020), 106635.

(8) Zembyla, M.; Liamas, E.; Andablo-Reyes, E.; Gu, K.; Krop, E. M.; Kew, B.; Sarkar, A. Surface Adsorption and Lubrication Properties of Plant and Dairy Proteins: A Comparative Study. Food Hydrocoll. 2021, 111 (September), 106364.

(9) Meulleneti, J. Relationship between Sensory and Instrumental Texture Profile Attributes. J. Sens. Stud. 1998, 13 (1998), 77.

(10) Foegeding, E. A. Rheology and Sensory Texture of Biopolymer Gels. Curr. Opin. Colloid Interface Sci. 2007, 12 (4-5), 242-250.

(11) Kilcast, D.; Clegg, S. Sensory Perception of Creaminess and Its Relationship with Food Structure. Food Qual. Prefer. 2002, 13, 609-623.

(12) He, Q.; Hort, J.; Wolf, B. Predicting Sensory Perceptions of Thickened Solutions Based on Rheological Analysis. Food Hydrocoll. 2016, 61, 221-232.

(13) Sarkar, A.; Andablo-reyes, E.; Bryant, M.; Dowson, D.; Neville, A. ScienceDirect Lubrication of Soft Oral Surfaces. Curr. Opin. Colloid Interface Sci. 2019, 39 (February), 61-75.

(14) Andablo-Reyes, E.; Bryant, M.; Neville, A.; Hyde, P.; Sarkar, R.; Francis, M.; Sarkar, A. 3D Biomimetic Tongue-Emulating Surfaces for Tribological Applications. ACS Appl. Mater. Interfaces 2020, 12 (44), 49371-49385.

(15) Kew, B.; Holmes, M.; Stieger, M.; Sarkar, A. Oral Tribology, Adsorption and Rheology of Alternative Food Proteins. Food Hydrocoll. 2021, 116 (November 2020), 106636.

(16) Brown, F. N.; Mackie, A. R.; He, Q.; Branch, A.; Sarkar, A. Protein-Saliva Interactions: A Systematic Review. Food Funct. 2021, 12 (8), 3324-3351.

(17) Tournier, C.; Sulmont-Rossé, C.; Guichard, E. Flavour Perception: Aroma, Taste and Texture Interactions; 2007.

(18) Meilgaard, M.; Meilgaard, M. C.; Civille, G. V.; Carr, T. B. Sensory Evaluation Techniques; CRC Press LLC: Boca Raton, 1991.

(19) Dickinson, E. On the Road to Understanding and Control of Creaminess Perception in Food Colloids. Food Hydrocoll. 2018, 77, 372-385.

(20) Evageliou, V. Shear and Extensional Rheology of Selected Polysaccharides. Int. J. Food Sci. Technol. 2020, 55 (5), 1853-1861.

(21) Waqas, M. Q.; Stading, M. Shear and Extensional Rheology of Commercial Thickeners Used for Dysphagia Shear and Extensional Rheology of Commercial Thickeners Used for Dysphagia Management. J. Texture Stud. 2017, No. March, 1-11.

(22) Marconati, M.; Ramaioli, M. The Role of Extensional Rheology in the Oral Phase of Swallowing: An: In Vitro Study. Food Funct. 2020, 11 (5), 4363-4375.

(23) O'Brien, N.; Alvarez, N. J.; Behabtu, N.; Hansen, K.; Ewert, J.; Nettesheim, F. Extensional Rheology of Condensed Milk Treated with Glucosyl Transferases. Food Hydrocoll. 2024, 146 (PB), 109299.

(24) Zhu, J.; Mizunuma, H. Shear and Extensional Rheology of Mucilages Derived from Natural Foods. Nihon Reoroji 2017, 45 (2), 91-99.

(25) Hadde, E. K.; Ann, J.; Cichero, Y.; Zhao, S.; Chen, W.; Chen, J. The Importance of Extensional Rheology in Bolus Control during Swallowing. Sci. Rep. 2019, 2-11.

(26) Waqas, Muhammad Qazi; Wiklund, Johan; Altskär, Annika; Ekberg, Olle; Stading, M.; Waqas, M. Q.; Wiklund, J.; Altskär, A.; Ekberg, O.; Stading, M. Shear and Extensional Rheology of Commercial Thickeners Used for Dysphagia Management. J. Texture Stud. 2017, 48 (6), 507-517.

(27) Torres, M. D.; Hallmark, B.; Wilson, D. I. Effect of Concentration on Shear and Extensional Rheology of Guar Gum Solutions. FOOD Hydrocoll. 2014, 40, 85-95.

(28) Surber, G.; Jaros, D.; Rohm, H. Shear and Extensional Rheology of Acid Milk Gel Suspensions with Varying Ropiness. J. Texture Stud. 2020, 51 (1), 111-119.

(29) Houghton, J. W.; Hans, J.; Pesaro, M.; Ley, J. P.; Carpenter, G. H.; Proctor, G. Sensory Effects of Transient Receptor Potential Channel Agonists on Whole Mouth Saliva Extensional Rheology. J. Texture Stud. 2017, 48 (4), 313-317.

(30) Martín-Alfonso, J. E.; Cuadri, A. A.; Berta, M.; Stading, M. Relation between Concentration and Shear-Extensional Rheology Properties of Xanthan and Guar Gum Solutions. Carbohydr. Polym. 2018, 181 (August 2017), 63-70.

(31) Lin, Y.; Liu, Y.; Liu, S.; Kortesniemi, M.; Liu, J.; Zhu, B.; Laaksonen, O. Sensory and Chemical Characterization of Chinese Bog Bilberry Wines Using Check-All-That-Apply Method and GC-Quadrupole-MS and GC-Orbitrap-MS Analyses. Food Res. Int. 2022, 151, 110809.

(32) Alamu, E.; Teeken, B. B.; Ayetigbo, O.; Adesokan, M.; Kayondo, S. I.; Chijioke, U.; Madu, C.; B.C, O.; Abolore, B.; Njoku, D.; Rabbi, I.; Egesi, C.; Ndjouenkeu, R.; Bouniol, A.; De Sousa, K.; Dominique, D.; Maziya-Dixon, B.; Alamu Emmanuel, O.; Teeken, B. B.; Ayetigbo, O.; Adesokan, M.; Kayondo, I.; Chijioke, U.; Madu, C.; Okoye, B.; Abolore, B.; Njoku, D.; Rabbi, I.; Egesi, C.; Ndjouenkeu, R.; Bouniol, A.; De Sousa, K.; Dufour, D.; Maziya-Dixon, B. Establishing the Linkage between Eba's Instrumental and Sensory Descriptive Profiles and Their Correlation with Consumer Preferences: Implications for Cassava Breeding. J. Sci. Food Agric. 2023.

(33) Schädle, C. N.; Bader-Mittermaier, S.; Sanahuja, S. Characterization of Reduced-Fat Mayonnaise and Comparison of Sensory Perception, Rheological, Tribological, and Textural Analyses. Foods. 2022.

(34) McKinley, G. H. Visco-Elasto-Capillary Thinning and Break-Up of Complex Fluids. Polymer (Guildf). 2005, No. 05, 1274-1277.

(35) Anna, S. L.; McKinley, G. H. Elasto-Capillary Thinning and Breakup of Model Elastic Liquids. J. Rheol. (N. Y. N. Y). 2001, 45 (1), 115.

(36) McKinley, G. H.; Sridhar, T. FILAMENT-STRETCHING RHEOMETRY OF COMPLEX FLUIDS. Annu. Rev. Fluid Mech. 2002, 34 (1), 375-415.

(37) Clasen, C. Capillary Breakup Extensional Rheometry of Semi-Dilute Polymer Solutions. Korea-Australia Rheol. J. 2010, 5 (December), 331-338.

(38) Sharma, V.; Haward, S. J.; Serdy, J.; Keshavarz, B.; Soderlund, A.; Threlfall-holmes, P.; Mckinley, G. H. The Rheology of Aqueous Solutions of Ethyl Hydroxy-Ethyl Cellulose (EHEC) and Its Hydrophobically Modified Analogue (HmEHEC): Extensional Flow Response in Capillary Break-up, Jetting (ROJER) and in a Cross-Slot Extensional Rheometer. Soft Matter 2015, 00 (January), 1-20.

(39) Miller, E.; Clasen, C.; Rothstein, J. P. The Effect of Step-Stretch Parameters on Capillary Breakup Extensional Rheology (CaBER) Measurements. Rheol. Acta 2009, 48 (6), 625-639.

(40) Campo-Deaño, L.; Clasen, C. The Slow Retraction Method (SRM) for the Determination of Ultra-Short Relaxation Times in Capillary Breakup Extensional Rheometry Experiments. J. Nonnewton. Fluid Mech. 2010, 165 (23-24), 1688-1699.

(41) Clasen, C.; Plog, J. P.; Kulicke, W.-M.; Owens, M.; Macosko, C.; Scriven, L. E.; Verani, M.; McKinley, G. H. How Dilute Are Dilute Solutions in Extensional Flows? J. Rheol. (N. Y. N. Y). 2006, 50 (06), 849.

(42) Nyström, M.; Jahromi, H. R. T.; Stading, M.; Webster, M. F. Numerical Simulations of Boger Fluids through Different Contraction Configurations for the Development of a Measuring System for Extensional Viscosity. Rheol. Acta 2012, 51 (8), 713-727.

(43) Hoyle, D. M.; Huang, Q.; Auhl, D.; Hassell, D.; Rasmussen, H. K.; Skov, A. L.; Harlen, O. G.; Hassager, O.; McLeish, T. C. B. Transient Overshoot Extensional Rheology of Long-Chain Branched Polyethylenes: Experimental and Numerical Comparisons between Filament Stretching and Cross-Slot Flow. J. Rheol. (N. Y. N. Y). 2013, 57 (1), 293.

(44) Keshavarz, B.; Sharma, V.; Houze, E. C.; Koerner, M. R.; Moore, J. R.; Cotts, P. M.; Threlfall-Holmes, P.; McKinley, G. H. Studying the Effects of Elongational Properties on Atomization of Weakly Viscoelastic Solutions Using Rayleigh Ohnesorge Jetting Extensional Rheometry (ROJER). J. Nonnewton. Fluid Mech. 2014.

(45) Kjaer, K. H.; Ewert, J. F.; Kralj, S.; Behabtu, N. Method for Reducing Sugar in Food Stuff. WO2023055902A1, 2023.

(46) EyeQuestion. EyeQuestion Software.

(47) Prediktera. Evince hyperspectral imaging.