Differential scanning calorimetry (DSC) is a method widely used to examine the melting or crystal... more Differential scanning calorimetry (DSC) is a method widely used to examine the melting or crystallization profile of cocoa butter and chocolate. The (perceived) ease of use makes the method very appealing not only in academia, but also in the chocolate industry. Our study presents a critical evaluation of the parameters that influence the generated information (i.e., the apparent melting point and specific heat of fusion) on dark chocolates of various cocoa contents and evaluates the suitability of DSC as generic or “universal” analytical method. The tested parameters included sample weight and form, temperature protocol, and heating rate. In general, the melting point of all dark chocolates increased as a function of increasing heating rate. The weight and form of the samples influenced the melting points but not the specific heat of fusion, while the starting temperatures of the thermal analysis did not seem to affect the melting profiles of the chocolates. We observe that a comparison between different studies researching chocolate behavior using DSC is not trivial due to insufficient detail on the procedure followed and conclude that DSC is maybe better suited for inner-study comparisons.
Applying science, scientific reasoning, and scientific methodologies to the study of food and coo... more Applying science, scientific reasoning, and scientific methodologies to the study of food and cooking is an old trait that to a large extent is based on the chemical sciences. The focus has been on chemical compounds as well as chemical reactions and transformations involved in foodstuff, preparation techniques, and culinary precision. Gastrophysics is proposed as a generic term to characterize an emerging scientific discipline primarily based on the physical sciences underpinned by all three pillars of modern physics: theory, experiment, and modeling/simulation. Gastrophysics takes its inspiration from the world of cooking and gastronomy. It is our contention that gastrophysics is a science in its own right, not a discipline designed only to service chefs in interpreting and creating new dishes. Gastrophysics is physics, and its empirical basis of gastrophysics is gastronomy itself. Physics or stamp collecting? The British physicist Ernest Rutherford is quoted to have said ‘All sci...
Abstract The reactivity of solid particles of two forms of TiO2, rutile and anatase, with H2O2 va... more Abstract The reactivity of solid particles of two forms of TiO2, rutile and anatase, with H2O2 vapour was investigated for use as reactive coatings protecting granular formulations of enzymes. Reactivity tests using potassium titanium oxide oxalate as a competition probe showed a high reactivity of anatase at both high and low H2O2 pressure, whereas rutile was moderately reactive only at high H2O2 pressure. Heating H2O2-treated rutile and anatase led to release of oxygen, but not of surface-bound H2O2. For rutile, electron spin resonance measurements showed formation of radical intermediates. Anatase showed a mechanism comprising reversible binding of H2O2 and catalytic cleavage of H2O2 without formation of radicals. Anatase-coated detergent enzyme granules confirmed the protection against H2O2 vapour. Overall, this work shows the potential of anatase as a reactive coating material in laundry granules as an alternative to the current formulation.
Abstract Background Caking is a recurrent problem in various industries, whether it occurs during... more Abstract Background Caking is a recurrent problem in various industries, whether it occurs during the production, storage or transport of powders. Caked powder results in longer processing times and decreased product quality, leading to significant economic loss. Several caking mechanisms have been described in the literature. However, they are often difficult to take into account in an industrial context, given the many parameters which influence the overall caking phenomenon. Scope and approach This review describes the three relevant caking mechanisms for food powders in general. Focussing on predominantly crystalline lactose powder, we discuss how each of these mechanisms can explain caking and be prevented in the industrial context. The second part of this paper presents a critical review of the methods used to characterise caking to date. Key findings and conclusions The presence of amorphous material and other impurities must be assessed in crystalline lactose powders, as they can trigger amorphous and humidity caking. Particle size distribution is another key parameter requiring control as it can encourage caking through enhancement of particle interactions. In general, preventing caking in food powders can only be achieved by a thorough understanding of the production process and storage conditions. Moreover, the characterisation of caking remains a challenge as most methods published in the literature do not fit the needs of the food industry. The real demand is for a reliable method to predict caking which would be rapid and easy enough to be applied to each batch for quality control.
A hybrid coating based on multilayers of proteins and biopolymers was developed to enhance the pr... more A hybrid coating based on multilayers of proteins and biopolymers was developed to enhance the protection performance of alginate microbeads against acidic conditions for delivery of probiotics (Lactobacillus rhamnosus GG). Zeta potential measurements and quartz crystal microbalance with dissipation confirmed layer‐by‐layer deposition of protein‐polymer layers. The stability of protein‐based coatings during simulated gastric fluid (SGF) treatment was monitored by microscopy. Protein‐coated microbeads were partially dismantled, whereas polymer‐coated microbeads were intact after a sequential treatment in simulated gastric and intestinal fluids. This suggests that hybrid formulation offers an advantage over the coatings based on biopolymer multilayers in terms of better release of bacteria. Uncoated alginate microbeads completely dissolved and could not protect bacteria after SGF treatment whereas microbeads with hybrid coating showed increased physical stability and a modest decrease of culturability of 3.8 log units. Therefore, this work provides a concept for future protein‐based hybrid coatings for bacterial delivery systems.
In order to mimic physical characteristics of solid fat, ethylcellulose (EC) was used as an oleog... more In order to mimic physical characteristics of solid fat, ethylcellulose (EC) was used as an oleogelator in ice creams made with high oleic sunflower oil (HOSO). The aim was to improve structure of ice cream made with fully liquid vegetable oil by inhibiting droplet coalescence and to enable a colloidal fat network by making the oil droplets solid-like. Two different methods for incorporating EC into emulsions were developed, both designed to involve high pressure homogenization of ice cream mixes as in traditional ice cream production. Ice creams based on 10% HOSO and 1% EC (cP10 or cP20) were successfully made. Two types of emulsifiers in the ice cream formulations were tested: unsaturated monoglyceride (GMU) or saturated mono-diglyceride. GMU enhanced fat destabilization of ice cream resulting in coalescence of unstructured HOSO droplets. Presence of EC in HOSO based ice cream inhibited coalescence of oil droplets and the structure of the lipid phase resembled the small, evenly distributed fat globules in the reference ice cream made with saturated coconut fat. The resisting effect toward coalescence increased with higher molecular weight of EC, accordingly oil droplets made with EC cP20 were smaller compared to oil droplets containing EC cP10. EC did not increase the amount of air that was incorporated in ice creams based on HOSO, irrespective of the type of emulsifier. In general the overrun in HOSO-based ice creams (with and without EC) was considerably lower compared to ice cream made with coconut fat. PRACTICAL APPLICATION Interest for product development of ice cream based on unsaturated liquid oil is increasing. To compensate for the lacking fat crystals that provide structure and stability in traditional ice cream, the liquid oil is transformed into solid-like material by ethylcellulose (EC). The process of ice cream includes high pressure homogenization, and in order to adapt to this process step, two new methods of incorporation of EC into the oil of ice cream mixes were developed.
International Journal of Gastronomy and Food Science
Abstract Wine is often used as an ingredient in butter sauces such as hollandaise sauce, but norm... more Abstract Wine is often used as an ingredient in butter sauces such as hollandaise sauce, but normally in its reduced form. Hollandaise sauce is an emulsion, and roughly consists of a continuous phase (water based ingredients) and a dispersed phase (fat). In addition, hollandaise sauce contains varying amounts of incorporated air, seen as air bubbles in the sauce. In this study, the influence of wines and wine reductions on sauce flavor was studied. Butter sauces, where the aqueous phase of the sauces varied, were made and analyzed. Four different types of white wine (Chardonnay, Riesling, Sauvignon blanc and a blended wine) and these wines’ corresponding wine reductions were incorporated in butter sauce to produce model products (eight sauces in total). In the reductions, approximately 51% of the volume was removed by evaporation. The wines were selected based on both non-volatile composition and aroma differences. A trained sensory panel (n=10) evaluated sauce flavor and texture. Volatile profiles of sauces were studied by GC-MS, and sauce texture was evaluated by texture analysis, microscopy and dry matter measurements. Results showed that the degree of reduction is more important for sauce flavor than the wine type.
Differential scanning calorimetry (DSC) is a method widely used to examine the melting or crystal... more Differential scanning calorimetry (DSC) is a method widely used to examine the melting or crystallization profile of cocoa butter and chocolate. The (perceived) ease of use makes the method very appealing not only in academia, but also in the chocolate industry. Our study presents a critical evaluation of the parameters that influence the generated information (i.e., the apparent melting point and specific heat of fusion) on dark chocolates of various cocoa contents and evaluates the suitability of DSC as generic or “universal” analytical method. The tested parameters included sample weight and form, temperature protocol, and heating rate. In general, the melting point of all dark chocolates increased as a function of increasing heating rate. The weight and form of the samples influenced the melting points but not the specific heat of fusion, while the starting temperatures of the thermal analysis did not seem to affect the melting profiles of the chocolates. We observe that a comparison between different studies researching chocolate behavior using DSC is not trivial due to insufficient detail on the procedure followed and conclude that DSC is maybe better suited for inner-study comparisons.
Applying science, scientific reasoning, and scientific methodologies to the study of food and coo... more Applying science, scientific reasoning, and scientific methodologies to the study of food and cooking is an old trait that to a large extent is based on the chemical sciences. The focus has been on chemical compounds as well as chemical reactions and transformations involved in foodstuff, preparation techniques, and culinary precision. Gastrophysics is proposed as a generic term to characterize an emerging scientific discipline primarily based on the physical sciences underpinned by all three pillars of modern physics: theory, experiment, and modeling/simulation. Gastrophysics takes its inspiration from the world of cooking and gastronomy. It is our contention that gastrophysics is a science in its own right, not a discipline designed only to service chefs in interpreting and creating new dishes. Gastrophysics is physics, and its empirical basis of gastrophysics is gastronomy itself. Physics or stamp collecting? The British physicist Ernest Rutherford is quoted to have said ‘All sci...
Abstract The reactivity of solid particles of two forms of TiO2, rutile and anatase, with H2O2 va... more Abstract The reactivity of solid particles of two forms of TiO2, rutile and anatase, with H2O2 vapour was investigated for use as reactive coatings protecting granular formulations of enzymes. Reactivity tests using potassium titanium oxide oxalate as a competition probe showed a high reactivity of anatase at both high and low H2O2 pressure, whereas rutile was moderately reactive only at high H2O2 pressure. Heating H2O2-treated rutile and anatase led to release of oxygen, but not of surface-bound H2O2. For rutile, electron spin resonance measurements showed formation of radical intermediates. Anatase showed a mechanism comprising reversible binding of H2O2 and catalytic cleavage of H2O2 without formation of radicals. Anatase-coated detergent enzyme granules confirmed the protection against H2O2 vapour. Overall, this work shows the potential of anatase as a reactive coating material in laundry granules as an alternative to the current formulation.
Abstract Background Caking is a recurrent problem in various industries, whether it occurs during... more Abstract Background Caking is a recurrent problem in various industries, whether it occurs during the production, storage or transport of powders. Caked powder results in longer processing times and decreased product quality, leading to significant economic loss. Several caking mechanisms have been described in the literature. However, they are often difficult to take into account in an industrial context, given the many parameters which influence the overall caking phenomenon. Scope and approach This review describes the three relevant caking mechanisms for food powders in general. Focussing on predominantly crystalline lactose powder, we discuss how each of these mechanisms can explain caking and be prevented in the industrial context. The second part of this paper presents a critical review of the methods used to characterise caking to date. Key findings and conclusions The presence of amorphous material and other impurities must be assessed in crystalline lactose powders, as they can trigger amorphous and humidity caking. Particle size distribution is another key parameter requiring control as it can encourage caking through enhancement of particle interactions. In general, preventing caking in food powders can only be achieved by a thorough understanding of the production process and storage conditions. Moreover, the characterisation of caking remains a challenge as most methods published in the literature do not fit the needs of the food industry. The real demand is for a reliable method to predict caking which would be rapid and easy enough to be applied to each batch for quality control.
A hybrid coating based on multilayers of proteins and biopolymers was developed to enhance the pr... more A hybrid coating based on multilayers of proteins and biopolymers was developed to enhance the protection performance of alginate microbeads against acidic conditions for delivery of probiotics (Lactobacillus rhamnosus GG). Zeta potential measurements and quartz crystal microbalance with dissipation confirmed layer‐by‐layer deposition of protein‐polymer layers. The stability of protein‐based coatings during simulated gastric fluid (SGF) treatment was monitored by microscopy. Protein‐coated microbeads were partially dismantled, whereas polymer‐coated microbeads were intact after a sequential treatment in simulated gastric and intestinal fluids. This suggests that hybrid formulation offers an advantage over the coatings based on biopolymer multilayers in terms of better release of bacteria. Uncoated alginate microbeads completely dissolved and could not protect bacteria after SGF treatment whereas microbeads with hybrid coating showed increased physical stability and a modest decrease of culturability of 3.8 log units. Therefore, this work provides a concept for future protein‐based hybrid coatings for bacterial delivery systems.
In order to mimic physical characteristics of solid fat, ethylcellulose (EC) was used as an oleog... more In order to mimic physical characteristics of solid fat, ethylcellulose (EC) was used as an oleogelator in ice creams made with high oleic sunflower oil (HOSO). The aim was to improve structure of ice cream made with fully liquid vegetable oil by inhibiting droplet coalescence and to enable a colloidal fat network by making the oil droplets solid-like. Two different methods for incorporating EC into emulsions were developed, both designed to involve high pressure homogenization of ice cream mixes as in traditional ice cream production. Ice creams based on 10% HOSO and 1% EC (cP10 or cP20) were successfully made. Two types of emulsifiers in the ice cream formulations were tested: unsaturated monoglyceride (GMU) or saturated mono-diglyceride. GMU enhanced fat destabilization of ice cream resulting in coalescence of unstructured HOSO droplets. Presence of EC in HOSO based ice cream inhibited coalescence of oil droplets and the structure of the lipid phase resembled the small, evenly distributed fat globules in the reference ice cream made with saturated coconut fat. The resisting effect toward coalescence increased with higher molecular weight of EC, accordingly oil droplets made with EC cP20 were smaller compared to oil droplets containing EC cP10. EC did not increase the amount of air that was incorporated in ice creams based on HOSO, irrespective of the type of emulsifier. In general the overrun in HOSO-based ice creams (with and without EC) was considerably lower compared to ice cream made with coconut fat. PRACTICAL APPLICATION Interest for product development of ice cream based on unsaturated liquid oil is increasing. To compensate for the lacking fat crystals that provide structure and stability in traditional ice cream, the liquid oil is transformed into solid-like material by ethylcellulose (EC). The process of ice cream includes high pressure homogenization, and in order to adapt to this process step, two new methods of incorporation of EC into the oil of ice cream mixes were developed.
International Journal of Gastronomy and Food Science
Abstract Wine is often used as an ingredient in butter sauces such as hollandaise sauce, but norm... more Abstract Wine is often used as an ingredient in butter sauces such as hollandaise sauce, but normally in its reduced form. Hollandaise sauce is an emulsion, and roughly consists of a continuous phase (water based ingredients) and a dispersed phase (fat). In addition, hollandaise sauce contains varying amounts of incorporated air, seen as air bubbles in the sauce. In this study, the influence of wines and wine reductions on sauce flavor was studied. Butter sauces, where the aqueous phase of the sauces varied, were made and analyzed. Four different types of white wine (Chardonnay, Riesling, Sauvignon blanc and a blended wine) and these wines’ corresponding wine reductions were incorporated in butter sauce to produce model products (eight sauces in total). In the reductions, approximately 51% of the volume was removed by evaporation. The wines were selected based on both non-volatile composition and aroma differences. A trained sensory panel (n=10) evaluated sauce flavor and texture. Volatile profiles of sauces were studied by GC-MS, and sauce texture was evaluated by texture analysis, microscopy and dry matter measurements. Results showed that the degree of reduction is more important for sauce flavor than the wine type.
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