... Funded by CONACyT (Mexico) and Dippin' Dots Inc., KY, USA ... before and after e... more ... Funded by CONACyT (Mexico) and Dippin' Dots Inc., KY, USA ... before and after equilibration) to confirm the water content values obtained during the water sorption study. ... In this case, XRD confirmed that only for the Na-caseinate mixture, crystallization had not occurred (Figure 3 ...
The article discusses initiatives to develop ice cream with lower fat content through research in... more The article discusses initiatives to develop ice cream with lower fat content through research into the structural properties of unsaturated fats by food scientists including Douglas Goff of the University of Guelph in Ontario.
The physicochemical properties of acidified milk gels after the addition of cocoa flavanols were ... more The physicochemical properties of acidified milk gels after the addition of cocoa flavanols were studied. As the flavanol level increased (from 0 to 2.5 mg/g), syneresis and gel elasticity (tan δ) were found to significantly increase and decrease, respectively. Flavanol addition reduced the stress at fracture, with no changes in fracture strain, suggesting that the bond type (i.e., covalent vs noncovalent) was the underlying factor explaining the ease of fracture. Gels made from recombined milks containing the casein fraction of heated milk and the serum of heated flavanol/milk mixtures showed the lowest values of G' and fracture stress. It was concluded that whey proteins/flavanol interactions were responsible for the poor mechanical properties of flavanol-added acidified milk gels. High-performance liquid chromatography analysis of milk sera showed that 60% of the total available monomeric flavanols was found in the serum phase from which 75% was non-associated to whey proteins. Concomitantly, >70% of flavanols with degree of polymerization >3 were found to be associated with the casein fraction.
International Journal of Food Science & Technology, 2008
The effects of trehalose and sucrose on the rate of ice crystal growth in ice cream during accele... more The effects of trehalose and sucrose on the rate of ice crystal growth in ice cream during accelerated shelf-life were compared. Experimental and theoretical freezing curves were shown to be in good agreement. Glass transition temperatures (T g) of maximally freeze concentrated trehalose and sucrose solutions (40% w ⁄ w) were found to be)39.5°C and)47°C respectively. For ice cream mixes, the T g value increased from)46.4°C for the 100% sucrose-based mix to)42.0°C for the 100% trehalose sweetened ice cream. However, no differences in viscosity, nucleation rate or inhibition of ice crystal growth were observed with increasing trehalose concentration in ice cream.
Soft-serve ice cream mixes containing 4% milk protein and 0.14% locust bean gum (LBG) showed exte... more Soft-serve ice cream mixes containing 4% milk protein and 0.14% locust bean gum (LBG) showed extensive visual phaseseparation after 21 days at 5 1C, unless k-carrageenan was added to the formulation. Addition of k-carrageenan (0-0.02%) did not inhibit microscopic phase separation between protein and polysaccharide. A higher degree of ''emulsification'' of the proteinenriched phase into the continuous serum phase was observed as the k-carrageenan concentration increased, which correlated with inhibition of macroscopic serum separation in the mix. After macroscopic separation, the serum phase of mixes with different kcarrageenan concentrations showed similar microstructural and rheological characteristics, implying no concentration of LBG and no presence of k-carrageenan in the serum phase. The rheological behaviour of the protein-enriched phases indicated k-carrageenan/ casein interactions. There was no evidence of ''weak-gel'' formation through the addition of k-carrageenan as a means for macroscopic stability in the system.
Milk constituents [caseins, whey proteins (WP), lactose, and anhydrous milk fat] are used widely ... more Milk constituents [caseins, whey proteins (WP), lactose, and anhydrous milk fat] are used widely in the manufacture of dehydrated dairy and dairy-like emulsions. When sodium caseinate-(NaCas) and WP-stabi
The main physicochemical properties of spray-dried ice cream mixes (i.e. surface composition, wet... more The main physicochemical properties of spray-dried ice cream mixes (i.e. surface composition, wettability, flowability and microstructure) were analyzed. Emulsions contained 19-44% milk fat on a dry basis and included mixes with no added emulsifier and/or sucrose. The time necessary for complete wetting of the powders correlated with the amount of surface free-fat measured by means of solvent extraction. Non-micellar casein (sodium caseinate) showed to be a better co-encapsulant than micellar casein (skim milk) as demonstrated by surface fat coverage measured by electron spectroscopy for chemical analysis (ESCA). Emulsifiers influenced the fat surface composition of the powders by reducing the amount of surface protein due to their lower interfacial tension. Surface fat caused an initial overestimation of the particle size of the powders due to fat-related caking. Powders showed no flow before and after surface fat extraction which was attributed to fat-related caking and very small...
In a word, cookery, whilst continuing to be art, will become scientific and will have to submit i... more In a word, cookery, whilst continuing to be art, will become scientific and will have to submit its formulas which very often are still too empirical, to a method which leaves nothing to chance.'' Escoffier (1907)
Shell-on eggs cooked by immersion in water at low and constant temperatures (∼60-70°C) yield yolk... more Shell-on eggs cooked by immersion in water at low and constant temperatures (∼60-70°C) yield yolks with very particular textures. Structure development in such unique cooking conditions is far from understood. The present study shows that egg yolk, despite its compositional complexity, follows typical gelation kinetics found in many globular proteins and that it can develop structure at temperatures as low as 56°C. It follows that yolk texture is dictated by time/ temperature combinations. Under isothermal, low temperature cooking conditions, the thickening and gelation kinetics of egg yolk follow Arrhenius-type kinetic relationships. The energy of activation of these processes was ∼470 kJ mol −1 , which agrees well with the values reported for the denaturation and gelation of the thermally labile chicken serum albumin and immunoglobulin Y. Results are related to common foodstuffs in order to allow chefs and home cooks to achieve a priori conceived textures in egg yolks.
As simple as some baking recipes may seem, it is imperative for the cook to realize that baking i... more As simple as some baking recipes may seem, it is imperative for the cook to realize that baking is a complex phenomenon where scientific insight may provide a significant benefit. At the same time, scientists have to embrace the notion that cooking and baking are deemed of serious and systematic investigation-as they continue to be clouded with plenty of culinary mysticism. With this contribution, we aim to offer an example as to support these statements. Egg white proteins are the main structural components of meringues and as such, their chemistry and the way they behave during whipping in the presence of sugar(s), acid(s) and cations, notwithstanding the effect of the age of egg-whites and their whipping temperature, will affect the quality of the foams produced and ultimately of the dish they form a part of. We critically review the available and relevant body of knowledge around the biophysics and chemistry of culinary egg whitebased foams. In doing so, we also propose a series of experiments that will help elucidate the mechanism(s) by which copper and cream of tartar stabilize egg white foams.
Blood triglyceride, free fatty acid and insulin levels are lower after acute intake of an oilwat... more Blood triglyceride, free fatty acid and insulin levels are lower after acute intake of an oilwatermonoglyceride gel versus an oilwater mixture, demonstrating that food matrix nanostructure and microstructure can be engineered to modulate the physiological ...
As simple as some baking recipes may seem, it is imperative for the cook to realize that baking i... more As simple as some baking recipes may seem, it is imperative for the cook to realize that baking is a complex phenomenon where scientific insight may provide a significant benefit. At the same time, scientists have to embrace the notion that cooking and baking are deemed of serious and systematic investigation-as they continue to be clouded with plenty of culinary mysticism. With this contribution, we aim to offer an example as to support these statements. Egg white proteins are the main structural components of meringues and as such, their chemistry and the way they behave during whipping in the presence of sugar(s), acid(s) and cations, notwithstanding the effect of the age of egg-whites and their whipping temperature, will affect the quality of the foams produced and ultimately of the dish they form a part of. We critically review the available and relevant body of knowledge around the biophysics and chemistry of culinary egg whitebased foams. In doing so, we also propose a series of experiments that will help elucidate the mechanism(s) by which copper and cream of tartar stabilize egg white foams.
International Journal of Food Science & Technology, 2008
The development of a low glycemic index ice cream with as close as possible physicochemical prope... more The development of a low glycemic index ice cream with as close as possible physicochemical properties and sensory quality compared with a sucrose-sweetened ice cream was investigated. Three relatively new novel commercial sweeteners-tagatose, erythritol and trehalose-were studied, along with maltitol and polydextrose. Once the freezing curves were matched, other physicochemical properties also were found to match. Sweetness and sweet taste could then be adjusted for sensory optimisation with a combination of these sugars and supplementation with sucralose to boost the sweetness as necessary.
Properties of spray-dried anhydrous milk fat emulsions stabilized by micellar casein (milk protei... more Properties of spray-dried anhydrous milk fat emulsions stabilized by micellar casein (milk protein isolate-MPI) or non-micellar casein (sodium caseinate-Na-caseinate) with trehalose or lactose as encapsulants were studied. A lower concentration of Na-caseinate (0.33%) compared with MPI (1.26%) was sufficient to stabilize a 10% fat emulsion. Reconstituted emulsions showed larger droplet size than fresh emulsions, especially for MPI systems (fromo1 mm to around 14 mm), which was attributed to lower shear resistance during atomization. Creaming behavior reflected changes in particle size. Powder surface free fat was affected by protein type and concentration. Trehalose systems (regardless of protein type) released significantly lower amounts of encapsulated fat upon crystallization compared with those containing lactose. Individual and hence, more mobile and flexible casein molecules, as opposed to aggregated and less mobile casein micelles, appear to result in superior co-encapsulation properties of Na-caseinate compared with MPI.
Gastronomica: The Journal of Food and Culture, 2011
There is currently a heated debate about the role of food processing, and the science and technol... more There is currently a heated debate about the role of food processing, and the science and technology that supports it, with many food activists strongly opposing any kind of processed foods. We acknowledge that there are problems associated with the modern diet in many developed countries, such as diet-related diseases (e.g., obesity, hypertension, heart disease, and cancer), pollution, animal care, and sustainability. However, we argue that the application of science and technology to foods must play a role in addressing these problems and that food processing does bring many benefits to society, such as increasing the diversity, quality, and accessibility of foods, while reducing their costs. If societies overall goal is to improve the quality, sustainability, and healthfulness of the food supply, then it is important to acknowledge both the positive and negative roles that food processing can play, and then to use science and technology wisely as one of the tools available to add...
... Funded by CONACyT (Mexico) and Dippin' Dots Inc., KY, USA ... before and after e... more ... Funded by CONACyT (Mexico) and Dippin' Dots Inc., KY, USA ... before and after equilibration) to confirm the water content values obtained during the water sorption study. ... In this case, XRD confirmed that only for the Na-caseinate mixture, crystallization had not occurred (Figure 3 ...
The article discusses initiatives to develop ice cream with lower fat content through research in... more The article discusses initiatives to develop ice cream with lower fat content through research into the structural properties of unsaturated fats by food scientists including Douglas Goff of the University of Guelph in Ontario.
The physicochemical properties of acidified milk gels after the addition of cocoa flavanols were ... more The physicochemical properties of acidified milk gels after the addition of cocoa flavanols were studied. As the flavanol level increased (from 0 to 2.5 mg/g), syneresis and gel elasticity (tan δ) were found to significantly increase and decrease, respectively. Flavanol addition reduced the stress at fracture, with no changes in fracture strain, suggesting that the bond type (i.e., covalent vs noncovalent) was the underlying factor explaining the ease of fracture. Gels made from recombined milks containing the casein fraction of heated milk and the serum of heated flavanol/milk mixtures showed the lowest values of G' and fracture stress. It was concluded that whey proteins/flavanol interactions were responsible for the poor mechanical properties of flavanol-added acidified milk gels. High-performance liquid chromatography analysis of milk sera showed that 60% of the total available monomeric flavanols was found in the serum phase from which 75% was non-associated to whey proteins. Concomitantly, >70% of flavanols with degree of polymerization >3 were found to be associated with the casein fraction.
International Journal of Food Science & Technology, 2008
The effects of trehalose and sucrose on the rate of ice crystal growth in ice cream during accele... more The effects of trehalose and sucrose on the rate of ice crystal growth in ice cream during accelerated shelf-life were compared. Experimental and theoretical freezing curves were shown to be in good agreement. Glass transition temperatures (T g) of maximally freeze concentrated trehalose and sucrose solutions (40% w ⁄ w) were found to be)39.5°C and)47°C respectively. For ice cream mixes, the T g value increased from)46.4°C for the 100% sucrose-based mix to)42.0°C for the 100% trehalose sweetened ice cream. However, no differences in viscosity, nucleation rate or inhibition of ice crystal growth were observed with increasing trehalose concentration in ice cream.
Soft-serve ice cream mixes containing 4% milk protein and 0.14% locust bean gum (LBG) showed exte... more Soft-serve ice cream mixes containing 4% milk protein and 0.14% locust bean gum (LBG) showed extensive visual phaseseparation after 21 days at 5 1C, unless k-carrageenan was added to the formulation. Addition of k-carrageenan (0-0.02%) did not inhibit microscopic phase separation between protein and polysaccharide. A higher degree of ''emulsification'' of the proteinenriched phase into the continuous serum phase was observed as the k-carrageenan concentration increased, which correlated with inhibition of macroscopic serum separation in the mix. After macroscopic separation, the serum phase of mixes with different kcarrageenan concentrations showed similar microstructural and rheological characteristics, implying no concentration of LBG and no presence of k-carrageenan in the serum phase. The rheological behaviour of the protein-enriched phases indicated k-carrageenan/ casein interactions. There was no evidence of ''weak-gel'' formation through the addition of k-carrageenan as a means for macroscopic stability in the system.
Milk constituents [caseins, whey proteins (WP), lactose, and anhydrous milk fat] are used widely ... more Milk constituents [caseins, whey proteins (WP), lactose, and anhydrous milk fat] are used widely in the manufacture of dehydrated dairy and dairy-like emulsions. When sodium caseinate-(NaCas) and WP-stabi
The main physicochemical properties of spray-dried ice cream mixes (i.e. surface composition, wet... more The main physicochemical properties of spray-dried ice cream mixes (i.e. surface composition, wettability, flowability and microstructure) were analyzed. Emulsions contained 19-44% milk fat on a dry basis and included mixes with no added emulsifier and/or sucrose. The time necessary for complete wetting of the powders correlated with the amount of surface free-fat measured by means of solvent extraction. Non-micellar casein (sodium caseinate) showed to be a better co-encapsulant than micellar casein (skim milk) as demonstrated by surface fat coverage measured by electron spectroscopy for chemical analysis (ESCA). Emulsifiers influenced the fat surface composition of the powders by reducing the amount of surface protein due to their lower interfacial tension. Surface fat caused an initial overestimation of the particle size of the powders due to fat-related caking. Powders showed no flow before and after surface fat extraction which was attributed to fat-related caking and very small...
In a word, cookery, whilst continuing to be art, will become scientific and will have to submit i... more In a word, cookery, whilst continuing to be art, will become scientific and will have to submit its formulas which very often are still too empirical, to a method which leaves nothing to chance.'' Escoffier (1907)
Shell-on eggs cooked by immersion in water at low and constant temperatures (∼60-70°C) yield yolk... more Shell-on eggs cooked by immersion in water at low and constant temperatures (∼60-70°C) yield yolks with very particular textures. Structure development in such unique cooking conditions is far from understood. The present study shows that egg yolk, despite its compositional complexity, follows typical gelation kinetics found in many globular proteins and that it can develop structure at temperatures as low as 56°C. It follows that yolk texture is dictated by time/ temperature combinations. Under isothermal, low temperature cooking conditions, the thickening and gelation kinetics of egg yolk follow Arrhenius-type kinetic relationships. The energy of activation of these processes was ∼470 kJ mol −1 , which agrees well with the values reported for the denaturation and gelation of the thermally labile chicken serum albumin and immunoglobulin Y. Results are related to common foodstuffs in order to allow chefs and home cooks to achieve a priori conceived textures in egg yolks.
As simple as some baking recipes may seem, it is imperative for the cook to realize that baking i... more As simple as some baking recipes may seem, it is imperative for the cook to realize that baking is a complex phenomenon where scientific insight may provide a significant benefit. At the same time, scientists have to embrace the notion that cooking and baking are deemed of serious and systematic investigation-as they continue to be clouded with plenty of culinary mysticism. With this contribution, we aim to offer an example as to support these statements. Egg white proteins are the main structural components of meringues and as such, their chemistry and the way they behave during whipping in the presence of sugar(s), acid(s) and cations, notwithstanding the effect of the age of egg-whites and their whipping temperature, will affect the quality of the foams produced and ultimately of the dish they form a part of. We critically review the available and relevant body of knowledge around the biophysics and chemistry of culinary egg whitebased foams. In doing so, we also propose a series of experiments that will help elucidate the mechanism(s) by which copper and cream of tartar stabilize egg white foams.
Blood triglyceride, free fatty acid and insulin levels are lower after acute intake of an oilwat... more Blood triglyceride, free fatty acid and insulin levels are lower after acute intake of an oilwatermonoglyceride gel versus an oilwater mixture, demonstrating that food matrix nanostructure and microstructure can be engineered to modulate the physiological ...
As simple as some baking recipes may seem, it is imperative for the cook to realize that baking i... more As simple as some baking recipes may seem, it is imperative for the cook to realize that baking is a complex phenomenon where scientific insight may provide a significant benefit. At the same time, scientists have to embrace the notion that cooking and baking are deemed of serious and systematic investigation-as they continue to be clouded with plenty of culinary mysticism. With this contribution, we aim to offer an example as to support these statements. Egg white proteins are the main structural components of meringues and as such, their chemistry and the way they behave during whipping in the presence of sugar(s), acid(s) and cations, notwithstanding the effect of the age of egg-whites and their whipping temperature, will affect the quality of the foams produced and ultimately of the dish they form a part of. We critically review the available and relevant body of knowledge around the biophysics and chemistry of culinary egg whitebased foams. In doing so, we also propose a series of experiments that will help elucidate the mechanism(s) by which copper and cream of tartar stabilize egg white foams.
International Journal of Food Science & Technology, 2008
The development of a low glycemic index ice cream with as close as possible physicochemical prope... more The development of a low glycemic index ice cream with as close as possible physicochemical properties and sensory quality compared with a sucrose-sweetened ice cream was investigated. Three relatively new novel commercial sweeteners-tagatose, erythritol and trehalose-were studied, along with maltitol and polydextrose. Once the freezing curves were matched, other physicochemical properties also were found to match. Sweetness and sweet taste could then be adjusted for sensory optimisation with a combination of these sugars and supplementation with sucralose to boost the sweetness as necessary.
Properties of spray-dried anhydrous milk fat emulsions stabilized by micellar casein (milk protei... more Properties of spray-dried anhydrous milk fat emulsions stabilized by micellar casein (milk protein isolate-MPI) or non-micellar casein (sodium caseinate-Na-caseinate) with trehalose or lactose as encapsulants were studied. A lower concentration of Na-caseinate (0.33%) compared with MPI (1.26%) was sufficient to stabilize a 10% fat emulsion. Reconstituted emulsions showed larger droplet size than fresh emulsions, especially for MPI systems (fromo1 mm to around 14 mm), which was attributed to lower shear resistance during atomization. Creaming behavior reflected changes in particle size. Powder surface free fat was affected by protein type and concentration. Trehalose systems (regardless of protein type) released significantly lower amounts of encapsulated fat upon crystallization compared with those containing lactose. Individual and hence, more mobile and flexible casein molecules, as opposed to aggregated and less mobile casein micelles, appear to result in superior co-encapsulation properties of Na-caseinate compared with MPI.
Gastronomica: The Journal of Food and Culture, 2011
There is currently a heated debate about the role of food processing, and the science and technol... more There is currently a heated debate about the role of food processing, and the science and technology that supports it, with many food activists strongly opposing any kind of processed foods. We acknowledge that there are problems associated with the modern diet in many developed countries, such as diet-related diseases (e.g., obesity, hypertension, heart disease, and cancer), pollution, animal care, and sustainability. However, we argue that the application of science and technology to foods must play a role in addressing these problems and that food processing does bring many benefits to society, such as increasing the diversity, quality, and accessibility of foods, while reducing their costs. If societies overall goal is to improve the quality, sustainability, and healthfulness of the food supply, then it is important to acknowledge both the positive and negative roles that food processing can play, and then to use science and technology wisely as one of the tools available to add...
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