Dr. Jianshe Chen is a specially appointed professor at Zhejiang Gongshang University in Hangzhou (China), and a honorary professor at the University of Leeds (UK). He leads a newly established research laboratory in food oral processing at Zhejiang Gongshang University. His research aims to reveal physical, physiological, and psychophysical principles which underpin eating and sensory perception and to apply such principles in the design and manufacturing of quality tasty food for consumers’ satisfaction and well-being, in particular for those disadvantaged consumer groups (e.g. elderly, patients, infants, etc). Dr. Chen is the editor-in-chief of the Journal of Texture Studies and also serves as a member of the editorial board for a number of peer reviewed journals (e.g. Food Digestion, Food Structure, Current Opinion in Food Science, etc). He initiated and organised the first international conference of Food Oral Processing and serves to the scientific committee of this conference. He is an elected fellow of Institute of Food Science and Technology (UK). He is also a founding member of the International Dysphagia Diet Standarisation Initiative (IDDSI), working to establish standard terminologies of texture modified diets for dysphagia patients and elderly people. In 2015, Dr. Chen was awarded as the “One Thousand Talented Scholars” by the Chinese government.
ABSTRACT Bolus swallowing can be a difficult task and/or highly hazardous to people with dysphagi... more ABSTRACT Bolus swallowing can be a difficult task and/or highly hazardous to people with dysphagia (swallowing impairment), involving a risk of choking and airway obstruction. Food and pharmaceutical industries are under growing pressure to design and provide quality food for safe consumption by these disadvantaged populations and urgently need knowledge and a proper understanding of the controlling mechanisms of bolus manipulation and swallowing. In this study, physiological capabilities related to oral food handling, including maximum isometric tongue pressure, the volume of oral cavity, optimum bolus size, and tongue pressures applied during bolus swallowing were investigated. A total of 106 healthy subjects of different ages, genders and ethnic groups were involved in the investigation. A wide range of maximum isometric tongue pressure (from as low as 10 kPa to as high as 70 kPa) and maximum oral volume (from as low as 25 mL to as high as 116 mL) were observed. Further analysis showed that gender had no significant influence on tongue pressure and oral volume capacities. For younger adults (22–64 years), age also appears to have little effect. However, for older adults (>65 years), both maximum isometric tongue pressure and the oral volume showed a gradual decrease with the increasing of age. By investigating basic factors of bolus swallowing, this project aimed to reveal critical controlling factors underlining the process and to test the hypothesis that, because tongue pressure provides the initial driving force for bolus flow, one's capability to generate tongue pressure could be related to the ease with which one can swallow. For this purpose, a selection of subjects with known maximum isometric tongue pressure was further invited to swallow food (bolus) of varying consistencies. A positive correlation was observed between maximum tongue pressure and the maximum consistency of bolus that one can swallow for those who had lower tongue pressure generation capacity (<40 kPa). However, for subjects capable of producing very high tongue pressures (>40 kPa), a tongue pressure reserve (around a third of their maximum capability) was observed during bolus swallowing. Practical ApplicationsThis article investigates a few interesting hypothesis on the bio-mechanics of food processing, especially tongue pressure for bolus management and transfer during oro-pharyngeal swallow. Swallowing is the final stage of food oral processing and is crucial for the transportation of orally processed food (the bolus) to the stomach for further digestion and nutrient absorption. As such, safe swallowing is a major concern for many disadvantaged populations, e.g., some elderly populations, infants, oral and/or pharyngeal dysphagia and cerebrovascular accident (stroke) patients, patients in the late-stage of Alzheimer's disease and other hospital patients. Food and pharmaceutical industries are under an increasing pressure to develop and provide foods that are not only healthy and tasty, but are also safe to consume by these disadvantaged populations. The information presented in this article could be a bridge between oral and food sciences, and also could be of interest to R&D researchers in both food manufacturing and pharmaceutical industries in trying to understand individuals' physiological capability of swallowing and the implications for food provision.
ABSTRACT The dehydration process in thin biopolymer-based films, involving the two main macromole... more ABSTRACT The dehydration process in thin biopolymer-based films, involving the two main macromolecules in food systems, namely, proteins and polysaccharides, has been investigated. Experimental measurements of the weight loss of polymer films were carried out in an enclosed Perspex chamber under controlled conditions of temperature, relative humidity, and air flow. We found that all of the experimental moisture ratio data for films of pure biopolymers, as well as their mixtures, can be superimposed on a single scaled dehydration curve. According to theoretical calculations, this curve cannot be described by a moisture diffusion-dominated drying process, irrespective of whether film shrinkage is included or ignored. We also derived an analytical expression for evaporation-controlled drying. When film shrinkage is fully taken into account in the calculations, very good agreement between the experiments and the theoretically derived curve is obtained. However, the theoretical results can be improved even further by considering a model that includes both diffusion and evaporation processes, with diffusion being fast but nonetheless finite, so as to only play a minor secondary role in the dehydration of such films. Theoretical models have also been extended to describe systems in which film shrinkage can also arise from changes in the partial molar volume and not just loss of moisture. Using a variable “effective” partial molar volume for water provides a possible method for modeling the entire drying process over different stages of dehydration in which the solid phase adopts significantly contrasting structures.
Swallowing is the final stage of an eating process. Even though individuals know exactly when and... more Swallowing is the final stage of an eating process. Even though individuals know exactly when and how to swallow, the controlling mechanisms and the determining criteria of bolus swallowing are still not yet clear. One hypothesis is that bolus rheology, i.e. its flow-ability and stretch-ability, determines the triggering of a swallowing and the main aim of this work was to
Extensive research works have been carried out in investigating the microstructure of heat-set wh... more Extensive research works have been carried out in investigating the microstructure of heat-set whey protein gels and their fractal nature, but little has been done on the surface studies of these systems due to the lack of suitable technique for surface characterization of wet and deformable food gels. This work intended to explore the possibility of applying confocal laser scanning
Critical Reviews in Food Science and Nutrition, 2007
Surface texture is generally accepted as a key sensory factor of food materials and has great imp... more Surface texture is generally accepted as a key sensory factor of food materials and has great impact on consumers' perception and expectation of a food product. However, no authentic definition has been given in the literature for the term surface texture. Its real meaning is often rather confusing, varying from case to case and from person to person. A general consensus is that surface texture is a multi-parameter sensory factor composed of those surface-related features which can be perceived by visual, tactile handfeel, and tactile mouthfeel senses. A list of such surface-related features has been produced in this review, and of those, topographical properties are probably the most intensively investigated features in literature and are discussed in detail in this paper. The surface texture of a food can be characterized by either sensory panel tests or by physical instrument tests. The former uses panellists (trained or untrained) for sensory assessment, while the latter applies physical techniques to characterize the surface. While sensory tests are widely used for studies on consumers' perception and preference of foods, instrumental characterization uses one or few parameters to define a surface (either qualitatively or quantitatively). Physical techniques used for surface characterization are categorized into two groups: surface contacting and non-surface contacting. The former include tribometer, surface force apparatus, contact profilometry, atomic force microscopy, friction force microscopy, etc. Non-surface contacting techniques include gloss metre, fiber optic reflectometer, angle-resolved light scattering apparatus, surface glistening points method, electron microscopy, confocal laser scanning microscopy, etc. The principles and application examples of these techniques were discussed in this review.
World Non-Grid-Connected Wind Power and Energy Conference, 2009
The impact of different electrodeposition conditions in pulse plating process on the composition,... more The impact of different electrodeposition conditions in pulse plating process on the composition, apparent morphology and HER (hydrogen evolution reaction) activity of Ni-Mo-W coating was investigated. The molybdenum content in the coating increases with the addition of molybdenum salt until to a constant value (about 39.0 wt %), while the corresponding HER overpotential decreases to the minimum value. The Ni-Mo-W
This work investigates surface properties of a protein particle gel and effects of polysaccharide... more This work investigates surface properties of a protein particle gel and effects of polysaccharide on the surface microstructure of such a protein gel. Whey protein isolate (WPI) was used as the primary gelling agent, and a polysaccharide (xanthan) was investigated for its surface smoothing effects. The surface properties of heat-set WPI gels with and without the presence of xanthan (0, 0.05, and 0.25%) were characterized using a surface friction technique. The surface friction force of a gel against a stainless steel substrate was found to be highly dependent on the sliding speed for all three gel samples, and the addition of xanthan caused a general reduction of surface friction. The gel containing no xanthan has the largest surface friction and behaved in the most load-dependent manner, whereas the gel containing 0.25% xanthan has the lowest surface friction and showed the least load dependency. It was inferred that the WPI gel containing no xanthan has the roughest surface among the three samples and the presence of xanthan leads to a smoother surface with probably a thinner layer of surface water. Surface features derived from surface friction tests were confirmed by surface microstructure observation from confocal laser scanning microscopy (CLSM) and environmental electron scanning microscopy (ESEM). Surface profiles from CLSM images were used to quantify the surface roughness of these gels. The mean square root surface roughness R(q) was calculated to be 3.8 +/- 0.2, 3.0 +/- 0.2, and 1.5 +/- 0.2 microm for gels containing 0, 0.05, and 0.25% xanthan, respectively. The dual excitation images of protein and xanthan from CLSM observation and images from ESEM observation indicate a xanthan-rich layer at the surfaces of the xanthan-containing gel samples. We speculate that the creation of the outer surface of a particle gel is based on a different particle aggregation mechanism from that leading to network formation in the bulk.
Colloids and Surfaces A-physicochemical and Engineering Aspects, 1995
The effect of interactions of positively charged gelatin and anionic surfactant sodium lauryl eth... more The effect of interactions of positively charged gelatin and anionic surfactant sodium lauryl ether sulphate (SLES 2EO) with negatively charged β-lactoglobulin in solutions and emulsions has been studied. Precipitation was observed in solution for a gelatin + SLES 2EO mixture with and without β-lactoglobulin. The precipitation concentrations of gelatin and SLES 2EO were found to be strongly dependent on the
The extraction of proteins from tea leave pulps, using alkaline and enzyme methods, were investig... more The extraction of proteins from tea leave pulps, using alkaline and enzyme methods, were investigated in this work. Altogether four enzymes (neutrase, alcalase, protamex and flavourzyme) were examined for tea protein extraction. It was found that an alkaline method produced a high protein yield (56.4% extraction rate). The use of an enzyme alone appeared to be less effective in extracting
Viscoelastic properties of acid-induced sodium caseinate emulsion gels have been investigated usi... more Viscoelastic properties of acid-induced sodium caseinate emulsion gels have been investigated using a controlled shear stress rheometer. Gelation was introduced by addition of acidulant glucono-δ-lactone (GDL) at three different temperatures (5, 25 and 45°C). It was found that the gelation temperature has a significant effect on the rate of gelation and on the dynamic moduli of the emulsion gels. The
Colloids and Surfaces A-physicochemical and Engineering Aspects, 1995
We present results of competitive adsorption between proteins and surfactant (nonionic Tween 20 o... more We present results of competitive adsorption between proteins and surfactant (nonionic Tween 20 or anionic sodium lauryl ether sulphate SLES 2EO) in various oil-in-water emulsions. The addition of gelatin to a β-lactoglobulin-stabilized emulsion results in secondary layer adsorption of gelatin. The condition of half-coverage of gelatin correlates with the maximum degree of bridging flocculation. The amount of nonionic surfactant (Tween
The effect of ageing of the protein monolayer around the droplets on the rheology of a heat-set w... more The effect of ageing of the protein monolayer around the droplets on the rheology of a heat-set whey protein emulsion gel has been investigated at neutral pH. A fine β-lactoglobulin-stabilized emulsion (30vol.% oil) was either mixed immediately with whey protein isolate or left for up to few days before mixing and subsequent heat treatment (85°C for 35min). It was found
Small-deformation and large-deformation rheological properties of heat-set whey protein emulsion ... more Small-deformation and large-deformation rheological properties of heat-set whey protein emulsion gels containing active and inactive filler particles have been investigated using a controlled stress rheometer. The results suggest that the contributions to the gel network are quite different for pure protein gels and emulsion gels having similar storage moduli. An emulsion gel containing inactive filler has a larger phase angle
ABSTRACT Bolus swallowing can be a difficult task and/or highly hazardous to people with dysphagi... more ABSTRACT Bolus swallowing can be a difficult task and/or highly hazardous to people with dysphagia (swallowing impairment), involving a risk of choking and airway obstruction. Food and pharmaceutical industries are under growing pressure to design and provide quality food for safe consumption by these disadvantaged populations and urgently need knowledge and a proper understanding of the controlling mechanisms of bolus manipulation and swallowing. In this study, physiological capabilities related to oral food handling, including maximum isometric tongue pressure, the volume of oral cavity, optimum bolus size, and tongue pressures applied during bolus swallowing were investigated. A total of 106 healthy subjects of different ages, genders and ethnic groups were involved in the investigation. A wide range of maximum isometric tongue pressure (from as low as 10 kPa to as high as 70 kPa) and maximum oral volume (from as low as 25 mL to as high as 116 mL) were observed. Further analysis showed that gender had no significant influence on tongue pressure and oral volume capacities. For younger adults (22–64 years), age also appears to have little effect. However, for older adults (>65 years), both maximum isometric tongue pressure and the oral volume showed a gradual decrease with the increasing of age. By investigating basic factors of bolus swallowing, this project aimed to reveal critical controlling factors underlining the process and to test the hypothesis that, because tongue pressure provides the initial driving force for bolus flow, one's capability to generate tongue pressure could be related to the ease with which one can swallow. For this purpose, a selection of subjects with known maximum isometric tongue pressure was further invited to swallow food (bolus) of varying consistencies. A positive correlation was observed between maximum tongue pressure and the maximum consistency of bolus that one can swallow for those who had lower tongue pressure generation capacity (<40 kPa). However, for subjects capable of producing very high tongue pressures (>40 kPa), a tongue pressure reserve (around a third of their maximum capability) was observed during bolus swallowing. Practical ApplicationsThis article investigates a few interesting hypothesis on the bio-mechanics of food processing, especially tongue pressure for bolus management and transfer during oro-pharyngeal swallow. Swallowing is the final stage of food oral processing and is crucial for the transportation of orally processed food (the bolus) to the stomach for further digestion and nutrient absorption. As such, safe swallowing is a major concern for many disadvantaged populations, e.g., some elderly populations, infants, oral and/or pharyngeal dysphagia and cerebrovascular accident (stroke) patients, patients in the late-stage of Alzheimer's disease and other hospital patients. Food and pharmaceutical industries are under an increasing pressure to develop and provide foods that are not only healthy and tasty, but are also safe to consume by these disadvantaged populations. The information presented in this article could be a bridge between oral and food sciences, and also could be of interest to R&D researchers in both food manufacturing and pharmaceutical industries in trying to understand individuals' physiological capability of swallowing and the implications for food provision.
ABSTRACT The dehydration process in thin biopolymer-based films, involving the two main macromole... more ABSTRACT The dehydration process in thin biopolymer-based films, involving the two main macromolecules in food systems, namely, proteins and polysaccharides, has been investigated. Experimental measurements of the weight loss of polymer films were carried out in an enclosed Perspex chamber under controlled conditions of temperature, relative humidity, and air flow. We found that all of the experimental moisture ratio data for films of pure biopolymers, as well as their mixtures, can be superimposed on a single scaled dehydration curve. According to theoretical calculations, this curve cannot be described by a moisture diffusion-dominated drying process, irrespective of whether film shrinkage is included or ignored. We also derived an analytical expression for evaporation-controlled drying. When film shrinkage is fully taken into account in the calculations, very good agreement between the experiments and the theoretically derived curve is obtained. However, the theoretical results can be improved even further by considering a model that includes both diffusion and evaporation processes, with diffusion being fast but nonetheless finite, so as to only play a minor secondary role in the dehydration of such films. Theoretical models have also been extended to describe systems in which film shrinkage can also arise from changes in the partial molar volume and not just loss of moisture. Using a variable “effective” partial molar volume for water provides a possible method for modeling the entire drying process over different stages of dehydration in which the solid phase adopts significantly contrasting structures.
Swallowing is the final stage of an eating process. Even though individuals know exactly when and... more Swallowing is the final stage of an eating process. Even though individuals know exactly when and how to swallow, the controlling mechanisms and the determining criteria of bolus swallowing are still not yet clear. One hypothesis is that bolus rheology, i.e. its flow-ability and stretch-ability, determines the triggering of a swallowing and the main aim of this work was to
Extensive research works have been carried out in investigating the microstructure of heat-set wh... more Extensive research works have been carried out in investigating the microstructure of heat-set whey protein gels and their fractal nature, but little has been done on the surface studies of these systems due to the lack of suitable technique for surface characterization of wet and deformable food gels. This work intended to explore the possibility of applying confocal laser scanning
Critical Reviews in Food Science and Nutrition, 2007
Surface texture is generally accepted as a key sensory factor of food materials and has great imp... more Surface texture is generally accepted as a key sensory factor of food materials and has great impact on consumers' perception and expectation of a food product. However, no authentic definition has been given in the literature for the term surface texture. Its real meaning is often rather confusing, varying from case to case and from person to person. A general consensus is that surface texture is a multi-parameter sensory factor composed of those surface-related features which can be perceived by visual, tactile handfeel, and tactile mouthfeel senses. A list of such surface-related features has been produced in this review, and of those, topographical properties are probably the most intensively investigated features in literature and are discussed in detail in this paper. The surface texture of a food can be characterized by either sensory panel tests or by physical instrument tests. The former uses panellists (trained or untrained) for sensory assessment, while the latter applies physical techniques to characterize the surface. While sensory tests are widely used for studies on consumers' perception and preference of foods, instrumental characterization uses one or few parameters to define a surface (either qualitatively or quantitatively). Physical techniques used for surface characterization are categorized into two groups: surface contacting and non-surface contacting. The former include tribometer, surface force apparatus, contact profilometry, atomic force microscopy, friction force microscopy, etc. Non-surface contacting techniques include gloss metre, fiber optic reflectometer, angle-resolved light scattering apparatus, surface glistening points method, electron microscopy, confocal laser scanning microscopy, etc. The principles and application examples of these techniques were discussed in this review.
World Non-Grid-Connected Wind Power and Energy Conference, 2009
The impact of different electrodeposition conditions in pulse plating process on the composition,... more The impact of different electrodeposition conditions in pulse plating process on the composition, apparent morphology and HER (hydrogen evolution reaction) activity of Ni-Mo-W coating was investigated. The molybdenum content in the coating increases with the addition of molybdenum salt until to a constant value (about 39.0 wt %), while the corresponding HER overpotential decreases to the minimum value. The Ni-Mo-W
This work investigates surface properties of a protein particle gel and effects of polysaccharide... more This work investigates surface properties of a protein particle gel and effects of polysaccharide on the surface microstructure of such a protein gel. Whey protein isolate (WPI) was used as the primary gelling agent, and a polysaccharide (xanthan) was investigated for its surface smoothing effects. The surface properties of heat-set WPI gels with and without the presence of xanthan (0, 0.05, and 0.25%) were characterized using a surface friction technique. The surface friction force of a gel against a stainless steel substrate was found to be highly dependent on the sliding speed for all three gel samples, and the addition of xanthan caused a general reduction of surface friction. The gel containing no xanthan has the largest surface friction and behaved in the most load-dependent manner, whereas the gel containing 0.25% xanthan has the lowest surface friction and showed the least load dependency. It was inferred that the WPI gel containing no xanthan has the roughest surface among the three samples and the presence of xanthan leads to a smoother surface with probably a thinner layer of surface water. Surface features derived from surface friction tests were confirmed by surface microstructure observation from confocal laser scanning microscopy (CLSM) and environmental electron scanning microscopy (ESEM). Surface profiles from CLSM images were used to quantify the surface roughness of these gels. The mean square root surface roughness R(q) was calculated to be 3.8 +/- 0.2, 3.0 +/- 0.2, and 1.5 +/- 0.2 microm for gels containing 0, 0.05, and 0.25% xanthan, respectively. The dual excitation images of protein and xanthan from CLSM observation and images from ESEM observation indicate a xanthan-rich layer at the surfaces of the xanthan-containing gel samples. We speculate that the creation of the outer surface of a particle gel is based on a different particle aggregation mechanism from that leading to network formation in the bulk.
Colloids and Surfaces A-physicochemical and Engineering Aspects, 1995
The effect of interactions of positively charged gelatin and anionic surfactant sodium lauryl eth... more The effect of interactions of positively charged gelatin and anionic surfactant sodium lauryl ether sulphate (SLES 2EO) with negatively charged β-lactoglobulin in solutions and emulsions has been studied. Precipitation was observed in solution for a gelatin + SLES 2EO mixture with and without β-lactoglobulin. The precipitation concentrations of gelatin and SLES 2EO were found to be strongly dependent on the
The extraction of proteins from tea leave pulps, using alkaline and enzyme methods, were investig... more The extraction of proteins from tea leave pulps, using alkaline and enzyme methods, were investigated in this work. Altogether four enzymes (neutrase, alcalase, protamex and flavourzyme) were examined for tea protein extraction. It was found that an alkaline method produced a high protein yield (56.4% extraction rate). The use of an enzyme alone appeared to be less effective in extracting
Viscoelastic properties of acid-induced sodium caseinate emulsion gels have been investigated usi... more Viscoelastic properties of acid-induced sodium caseinate emulsion gels have been investigated using a controlled shear stress rheometer. Gelation was introduced by addition of acidulant glucono-δ-lactone (GDL) at three different temperatures (5, 25 and 45°C). It was found that the gelation temperature has a significant effect on the rate of gelation and on the dynamic moduli of the emulsion gels. The
Colloids and Surfaces A-physicochemical and Engineering Aspects, 1995
We present results of competitive adsorption between proteins and surfactant (nonionic Tween 20 o... more We present results of competitive adsorption between proteins and surfactant (nonionic Tween 20 or anionic sodium lauryl ether sulphate SLES 2EO) in various oil-in-water emulsions. The addition of gelatin to a β-lactoglobulin-stabilized emulsion results in secondary layer adsorption of gelatin. The condition of half-coverage of gelatin correlates with the maximum degree of bridging flocculation. The amount of nonionic surfactant (Tween
The effect of ageing of the protein monolayer around the droplets on the rheology of a heat-set w... more The effect of ageing of the protein monolayer around the droplets on the rheology of a heat-set whey protein emulsion gel has been investigated at neutral pH. A fine β-lactoglobulin-stabilized emulsion (30vol.% oil) was either mixed immediately with whey protein isolate or left for up to few days before mixing and subsequent heat treatment (85°C for 35min). It was found
Small-deformation and large-deformation rheological properties of heat-set whey protein emulsion ... more Small-deformation and large-deformation rheological properties of heat-set whey protein emulsion gels containing active and inactive filler particles have been investigated using a controlled stress rheometer. The results suggest that the contributions to the gel network are quite different for pure protein gels and emulsion gels having similar storage moduli. An emulsion gel containing inactive filler has a larger phase angle
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