The solid–liquid phase diagrams of binary mixtures of consecutive, even saturated fatty acids: differing by four carbon atoms

Label-free imaging of fatty acid content within yeast samples

“…Fig. 3 (left panel) demonstrates the normalized SRL spectral profile of a mixture containing 80% palmitoleic acid and 20% palmitic acid (by molar mass), with peaks fitted to match the following Raman bands in the C-H stretch region: 2845 cm -1 , 2855 cm -1 , 2895 cm -1 , 2900 cm -1 and 2935 cm -1 which correspond with symmetric and antisymmetric ʋ(C-H) vibrations of CH3 and CH2 groups, while the 3006 cm -1 band is characteristic of unsaturated bonds in fatty acids resulting from ʋ(=C-H) vibrations [16]- [18] .…”

“…However, the C-H stretching modes are sensitive to both temperature and phase transition [16] which can complicate this analysis. Additionally, lipid droplets also contain small amounts of protein, which also contribute to the C-H spectral profile [4] .…”

Trends and demands in the solid–liquid equilibrium of lipidic mixtures

“…This complexity is 40 especially due to the inherent ability of the fatty crystals to selfassemble into stable and metastable structures in their multiple solid phases [4][5][6][7] . Also, in a mixture, fatty components can also present mutual miscibility or even total immiscibility in the solid phase 8,9 . Consequently, apart from the fact that such phenomena 45 largely affect microstructural changes and, therefore, the set of industrial quality requirements of products, numerous operational and economical reasons emphasize the importance of a critical thermodynamic evaluation of the fatty systems for process design and optimization.…”

“…Some works suggest to interpret such 25 phenomenon as a chemical reaction so that the original components form a product according to a specified stoichiometry. If the new compound crystallizes independently of the mixture's compounds the phase diagram behavior is that presented in Figure 2 the appearance of peritectic profiles in binary mixtures of fatty acids and some systems composed by methyl esters 9,39,40,54 . Despite the classification of many fatty mixtures into the typical four phase diagrams shown in Figure 2, the understanding of the phase behavior of the fatty systems is still far from 5 complete.…”

“…Since different crystal lattices are observed in these cases, namely hexagonal, orthorhombic and 50 triclinic, different transition temperatures and enthalpies are also observed. Crystalline structure of fatty acids, alcohols and esters can also pack into different polymorphic forms, usually in temperatures very close to the most stable form 9,37,39,40 . Knowing that the polymorphism phenomena can be managed by 55 particular thermal treatments, the parameters of the processes to which mixtures are submitted, time and temperature, can define the profile of the final product.…”