Research

Welcome to the Sarkar Lab at the University of Leeds, UK. Sarkar Lab led by Prof. Anwesha Sarkar is an interdisciplinary team of Postdoctoral fellows, PhD students, Master Students and Visiting Researchers involved in the multi-scale understanding of the mechanisms governing lubrication performance of multiphasic colloidal structure (e.g. food and other biomaterials). Research in Sarkar Lab lies at the crossroads of experimental colloid science, sustainability and human health, with a specific focus on solving grand challenges across life span and creating fundamental knowledge to pay way for applications in food, healthcare, and allied soft material industries. To understand the interactions of the colloidal structure with saliva and oral mucosa at multiple length scales (nano-to-human scale), the experimental approaches used in Sarkar Lab span from development of new bespoke devices to use of mechanical measurements (tribology, rheology, nanotribology using friction force microscopy (FFM)), adsorption techniques (quartz crystal microbalance with dissipation (QCM-D)), 3D printing and lithography, imaging (confocal laser scanning microscopy, electron microscopy), scattering (light, X-ray), electrophoresis, in vitro oral models with extension to cell cultures and in vivo human trials (sensory, satiety). For instance, we study oral interaction of soft matter (e.g. Pickering emulsions with complex interfaces, complex protein films, emulsion microgels, core-shell structures, heteroprotein complexes/ coacervates, complex gels, microgels, nanogels, particles etc.) fabricated using sustainable materials  and measure their tribological performance in a synthetic tongue like surface.

Edible Delivery Systems - we create new delivery systems (Pickering emulsion, emulsion microgel, microgel-in-hydrogel etc) with natural biopolymers (proteins, polysaccharides) to protect and deliver hydrophilic and lipophilic bioactive components. We use facile physical and chemical processing routes to create these systems and characterize their structural and mechano-chemical properties at various length scales. Fundamental insights from our work may be the basis of creating new exciting food and non-food soft matter applications (cosmetics, pharmaceutical) where "biocompatibility" is a key requirement.

Oral Processing & Tribology - we focus on understanding the mechanisms of oral breakdown in relation to food physics, microstructural collapse/swell and saliva-mediated lubrication, e.g. changing tribology of food particles on exposure to saliva, interaction with lubricious mucin and oral surfaces, oral transportation, bolus formation and the critical criteria of bolus swallowing. We use in vitro to human studies to have mechanistic understanding of oral processing (from rheology-to-tribology-to-sensory). With in-depth quantitative understanding of oral processing, we hope to provide the foundation for designing tailored food for special population (e.g. frail older adults, people with special oral processing needs) as well as create satiety-enhancing foods by triggering oro-sensory pathways.

Microstructure and Gastrointestinal Digestion - our aim is to establish fundamental mechanisms behind the kinetics of breakdown of emulsions (monolayers, composite layers and/or particles at interface), emulsion gels and microgels during in vitro gastrointestinal digestion. We study colloidal interactions in presence of physiological metabolites, enzymes, ions and biosurfactants under fluid flow. Our work may be used for tailoring the material and microstructural properties of food and other delivery systems to modulate lipid digestion for promoting satiety as well as develop novel concepts for controlled release of lipophilic active nutrients.

Our research is highly interdisciplinary. Hence, we are connected with various experts with complementary strengths as well as research facilities within our School of Food Science and Nutrition as well as outside our School in University of Leeds:

• Molecular and Nanoscale Physics (MNP) Group within the School of Physics & Astronomy
• Institute of Functional Surfaces within the School of Mechanical Engineering
• Human Appetite Research Unit (HARU) within the School of Psychology