Relationships Between Fat Crystal Characteristics and Emulsion Stability in Water in Oil Systems
Notice bibliographique
Résumé
Investigations were made into the stabilization of water in oil emulsions using crystalline particles of paraffin wax and fully hydrogenated canola and cottonseed oils. A model system was studied to develop a methodology of study and provide a benchmark for a subsequent study of a real-world system. The model system involved the use of light mineral oil, purified water, paraffin wax and glycerol monooleate emulsifier. The wax was crystallized prior to and following emulsification. Prepared emulsion samples were monitored for sedimentation and flocculation behaviour. Measurements of coalescence were obtained by pulsed field gradient NMR. Formation of the solid crystalline wax phase following emulsification resulted in emulsions more stable to flocculation and coalescence than samples containing the same amount of wax crystallized prior to emulsification. Analysis of emulsion samples with polarized light microscopy showed the wax crystals were associated with the water droplet interfaces rather than dispersed freely within the continuous oil phase. Another investigation employed similar experimental protocols but incorporated food-grade materials. Two different solid fats were used, chosen for their differing polymorphic (crystal habit) behaviour. Solid crystals of canola stearine (ß-tending) and cottonseed stearine (ß-tending) were compared in their abilities to stabilize emulsions at levels of addition between 0 and 2%. Each type of fat was incorporated into the emulsion in a pre-crystallized state, or while melted and crystallized following emulsification. Cottonseed stearine was found to be in the ß polymorph when quickly crystallized following emulsification from 45⁰ to 5⁰C over 6 minutes. Further calorimetric and X-ray diffraction investigations revealed this crystallization behaviour was a result of a solid-state transformation via an imperfectly formed ß̕ intermediate. With respect to the post-crystallized emulsions, where the polymorphism of the two fats were both in the ß-form, the canola stearine provided better stabilization against coalescence than the cottonseed stearine. This observation coincided with a stronger energy of interfacial attachment for crystallized canola than for cottonseed as calculated from measurements of contact angle and interfacial tension. With the pre-crystallized system, incorporation of cottonseed stearine resulted in reduced sedimentation and coalescence compared to samples containing pre-crystallized canola stearine. This difference was attributed to the presence of fine shards of ß̕-form crystals. The system that imparted the highest degree of overall stability incorporated the use of canola stearine srystallized following emulsification.
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Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».