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Papers by Daniel Kalnin

Proceedings of the Virtual 2021 AOCS Annual Meeting & Expo, 2021

HAL (Le Centre pour la Communication Scientifique Directe), 2005

Proceedings of 2022 AOCS Annual Meeting & Expo

"In this study, we compare beans of Theobroma cacao from different climatic regions of Togo.... more "In this study, we compare beans of Theobroma cacao from different climatic regions of Togo. Togo is a country in West Africa, in the Gulf of Guinea, located between the latitudes 6° and 11° north, it is therefore in the tropical equatorial zone. The country extends over 600km from north to south and 160km from west to east. This explains the diversity of climates within it. Indeed, it is possible to identify two distinct zones: a tropical Guinean climate with 4 seasons in the south and a Saudi climate with two seasons in the north. These differences in climates imply diversity in the composition of cocoa beans. Among the varieties present in Togo, the Forastero variety is in the majority, followed by Trinitatio. The Criollo variety is not very abundant. The composition can also be influenced by the genetic variety of cocoa beans that are used for chocolate production, growing conditions, and post-harvest techniques. The amount of triacylglycerol in cocoa beans can vary depending on its origin, environmental conditions, agricultural practices, and also post-harvest treatments. of the bean. The aim of the study is therefore to analyze and compare the different beans of different varieties of Theobroma cacao according to the climatic regions of Togo. We use Calorimetric analysis (DSC), Visual analysis (Cut Test), Sensory analysis using a test panel for the identification and differentiation of cocoa beans from different origins. Differential Scanning Calorimetry (DSC) allows for a determination of a rough lipid profile. The cut test allows the analysis of the fermentation during the post-harvest processes observing their coloration and compartmentalization, which are two characteristics fundamentally related to the chemical composition. Sensory analysis is used in conjunction with previous analyses, it allows to highlight correlations between observed physicochemical properties and sensory qualities analyzed."

Fatty food foams are in fact foamed emulsions. The state of fat (occurring either liquid or in va... more Fatty food foams are in fact foamed emulsions. The state of fat (occurring either liquid or in various amounts of polymorph forms depending on temperature/time) largely contributes to their structural and textural properties. The characterization of a foam based on lard is presented. The evolution of the fat’s physical state as a function of temperature was followed by X-ray diffraction coupled with differential scanning calorimetry, DSC and NMR relaxometry. The mechanical properties of each sample were followed in dynamic mode. The fat’s physical state has a direct effect on the mechanical properties of the crude and cooked foams. For the emulsion and then for the corresponding foam, the contribution of fat to the rigidity of the system depends on its degree of dispersion. The structure and the properties of the foam are clearly dependent on the stability of the emulsion while heating, This evolution can be evidenced by following the rheological properties in temperature cycle up t...

24 European Crystallographic Meeting, ECM24, Marrakech, 2007 Page s205 Acta Cryst. (2007). A63, s... more 24 European Crystallographic Meeting, ECM24, Marrakech, 2007 Page s205 Acta Cryst. (2007). A63, s205 Chlorpropamide, 4-chloro-N-((propylaminocarbonyl)benzenesulfonamide, is an antidiabetic drug. Although the existence of several polymorphs of this compound was reported, by 2006, the crystal structure was solved only for one of them [1]. In 2006, we have initiated a systematic study of the crystallization of chlorpropamide from different solvents and from the same solvent under different conditions. Up to now, five polymorphs were obtained as single crystals, and for three of them crystal structures were solved [2-4]. The structures can serve as a very beautiful example of the polymorphism in a system with similar intermolecular hydrogen-bonds pattern, but different packing of molecules in different conformations. Different structures result in the pronounced differences in density (up to 5 %), IR-spectra, melting temperatures (several °C) and melting enthalpy (up to 15 %).

$Research paper thumbnail of Coupling of Differential Scanning Calorimetry and X-Ray Diffraction to Study the Crystallization Properties and Polymorphism of Triacyglycerols : Chapter 8$

Coupling of Differential Scanning Calorimetry and X-Ray Diffraction to Study the Crystallization ... more Coupling of Differential Scanning Calorimetry and X-Ray Diffraction to Study the Crystallization Properties and Polymorphism of Triacyglycerols : Chapter 8

Acta Crystallographica Section A Foundations of Crystallography, 2007

Chlorpropamide, 4-chloro-N-((propylaminocarbonyl)benzenesulfonamide, is an antidiabetic drug. Alt... more Chlorpropamide, 4-chloro-N-((propylaminocarbonyl)benzenesulfonamide, is an antidiabetic drug. Although the existence of several polymorphs of this compound was reported, by 2006, the crystal structure was solved only for one of them [1]. In 2006, we have initiated a systematic study of the crystallization of chlorpropamide from different solvents and from the same solvent under different conditions. Up to now, five polymorphs were obtained as single crystals, and for three of them crystal structures were solved [2-4]. The structures can serve as a very beautiful example of the polymorphism in a system with similar intermolecular hydrogen-bonds pattern, but different packing of molecules in different conformations. Different structures result in the pronounced differences in density (up to 5 %), IR-spectra, melting temperatures (several °C) and melting enthalpy (up to 15 %).

Surface and Colloid Science, 2004

ABSTRACT This work shows a close correlation between density, sound velocity and X-ray scattering... more ABSTRACT This work shows a close correlation between density, sound velocity and X-ray scattering measurements at very small angles (SAXS) for solutions of industrial grade sodium caseinate (SC). As SAXS measurements at synchrotron radiation sources are not applicable on a laboratory scale every day we prove a close correlation between the structural data derived from scattering techniques with combined density and sound velocity measurements. As a new method for the determination of SC concentration we propose density measurements which require minimal sample preparation, have a short measuring cycle of just a few minutes, and yield very accurate, reproducible results, which allows sample reuse after the measurements. Linear density changes on the order of Δρ 1 bar 20 °C = 0.0027±0.0003 g cm−3 per weight percent of protein in the range of 0.99≤ρ 1 bar 20 °C ≤1.04 g cm−3 are addressed. Such density dependence enables us to accurately determine the SC concentration in the continuous phase of model emulsions. The droplet mean size D[4,3] of emulsion droplets is measured by laser light diffraction using the Mie theory coupled with polarization intensity differential scattering. To determine the SC concentration in the serum in equilibrium with the surrounding emulsion particles dispersed and continuous phase are separated using centrifugation at 2400g. Coupling of density measurement that provides the SC concentration in the aqueous phase and the mean droplet size measurement allows us to evaluate the surface density on emulsion globules, which is essential for emulsion studies. KeywordsDensity measurements–Small-angle scattering–Sodium caseinate–Emulsifier concentration–Emulsions

$Research paper thumbnail of Monitoring both fat crystallization and self-assembly of sodium caseinate in model emulsions using synchrotron X-ray diffraction$

Trends in Colloid and Interface Science XVII, 2004

X-Ray diffraction analysis at small angles is proposed as a nondestructive method for characteriz... more X-Ray diffraction analysis at small angles is proposed as a nondestructive method for characterization of emulsions. The paper focuses on determinations of both, the concentration of sodium caseinate (SC) used as a stabilizer and the organization of triglyceride crystals, located outside and within emulsion droplets, respectively. Measurements performed at very small angles using ID 02a at a sample-to-detector distance of

Sciences des Aliments, 2005

Nous avons utilise differentes techniques physiques pour la caracterisation structurale d'une... more Nous avons utilise differentes techniques physiques pour la caracterisation structurale d'une emulsion de matiere grasse laitiere (MGL), dont nous avons evalue les parametres de stabilite physique (distribution de taille des globules gras, fraction de proteines adsorbees a la phase grasse). Les signaux obtenus en microcalorimetrie differentielle (MCD) ont montre que AT, difference entre la temperature de debut de cristallisation et celle de fin de fusion de la MGL, ainsi que t max (4 °C), temps necessaire a l'observation du pic de cristallisation a 4 °C, sont superieurs de pres de 10 °C et 12 min, respectivement, pour la MGL emulsionnee que pour la MGL non emulsionnee. L'analyse des structures cristallines par application simultanee de la MCD et de la diffraction de rayons X a montre que la MGL emulsionnee cristallise sous forme a (apres un tres bref debut de cristallisation sous forme suba) puis se maintient sous cette variete instable jusqu'a ce que celle-ci se transforme en variete β' lors du chauffage. Des essais rheologiques en mode dynamique ont mis en evidence une faible contribution de la cristallisation des globules gras a la consistance de l'emulsion pendant la maturation a 4 °C. Celle-ci s'ajoute a celle de la gelatine contenue dans la phase continue, en cours de chauffage ou refroidissement. Enfin, la separation des signaux de relaxation du proton de l'eau et de la matiere grasse observes par resonance magnetique, a indique que la fraction de la matiere grasse cristallisee a 4 °C semble etre davantage modifiee par la presence de tensio-actifs, que par l'etat disperse des globules gras. Ces resultats sont presentes et discutes en fonction de la potentialite des differentes techniques utilisees pour la catacterisation structurale des emulsions.

Sciences Des Aliments - SCI ALIMENT, 2005

La cristallisation et la fusion de la matiere grasse de lait anhydre (MGLA) ont ete etudiees dans... more La cristallisation et la fusion de la matiere grasse de lait anhydre (MGLA) ont ete etudiees dans le cadre du programme CANAL-SEA qui vise, en particulier, a mettre en evidence le role joue par les globules gras, destabilises ou non, dans les proprietes structurales des mousses alimentaires. Le comportement complexe de la MGLA, a ete mis en evidence par l'application de la microcalorimetrie differentielle en mode isotherme ou en mode balayage (MCD), de la rheologie et de la RMN du proton. Les resultats combines a ceux observes par couplage de la diffraction des rayons X aux grands et aux petits angles et de la microcalorimetrie differentielle, ont permis non seulement l'observation des transitions de structures induites par la chaleur, mais aussi l'identification d'une ou deux transitions polymorphiques 2L(/3L)a → 2L(/3L)β' entre deux groupes de triacyl-glycerols en fonction des conditions de temperature (4 ou 22 °C). D'autre part, la MCD et la rheologie ont montre que l'addition a la MGLA d'un melange de mono et diglycerides (E471) en proportions variables (0 et 2,5 %) peut declencher la cristallisation de la MGLA a des temperatures qui augmentent avec la concentration d'emulsifiant (approx. 5,2 °C pour 1 % de E471). Par ailleurs, la relaxation RMN de la fraction cristallisee de la MGLA en presence de tensioactifs, traduirait egalement d'autres modifications structurales des cristaux. L'existence du polymorphisme et ses evolutions complexes doivent etre prises en compte dans tous les procedes utilisant la matiere grasse laitiere.

$Research paper thumbnail of Monitoring fat crystallization in aerated food emulsions by combined DSC and time-resolved synchrotron X-ray diffraction$

Food Research International, 2002

The thermal and structural evolutions associated to the fat crystallization in a whipped emulsion... more The thermal and structural evolutions associated to the fat crystallization in a whipped emulsion made from interesterified palm oil are monitored using a new instrument allowing simultaneous time-resolved synchrotron X-ray diffraction at both wide and small angles as a function of temperature (XRDT). This is performed simultaneously with high sensitivity differential scanning calorimetry (DSC) that is carried out in the same apparatus at scanning rates between 0. 01 and 10 K/min on the same sample (typical: 20 mg) in the À30 to +230 C range. The thermal and structural properties of palm oil-based emulsions are also studied. It is found that the combination of these techniques allows the thermal monitoring of fat polymorphism even within the fat droplets at scanning rates of up to 5 K/min. The formation of a, b 0 and b phases,and their transitions are followed simultaneously by DSC and XRDT allowing the identification of the thermal events recorded. It is shown that this interpretation is only possible when high resolution X-ray scattering at small angles and wide angles is coupled with DSC from the same sample.

Food Research …, 2007

The textural and structural properties of organogels made by structuring liquid oil with mixtures... more The textural and structural properties of organogels made by structuring liquid oil with mixtures of stearic acid (octadecanoic acid) and stearyl alcohol (octadecanol) have been studied. Optical, rheological and X-ray diffraction measurements have been used to ...

Cocoa Butter and Related Compounds, 2012

Characterization of crystallization behavior of fats within emulsion droplets of oil in water emu... more Characterization of crystallization behavior of fats within emulsion droplets of oil in water emulsions -of pharmaceutical and agronomic interest- is the main focus of this research. Due to the multiplicity of components added - proteins, hydrocolloids and other surfactants - which are all susceptible to influence the emulsions' crystallization behavior - investigation of emulsions can be difficult (1,2,3). Triglycerides (TAGs), the main constituents of fats, exhibit a complex monotropic polymorphism that frequently forecloses the study of thermal and structural properties of the fats. In that case one has to choose simple adequate models for the study. We choose a model only containing Sodium Caseinate (SC), hydrogenated vegetable fat and one lipid emulsifier in our model emulsions. In that model only two polymorph forms of α an β' types are subsequently formed upon cooling and are evidenced dependant on the samples time temperature history and protein concentration (3,4,5)...