Effect of the distribution of saturated fatty acids in the melting and crystallization profiles of high-oleic high-stearic oils

Thermal and chemical characterization of fractions from Syagrus romanzoffiana kernel oil

The Jerivá (Syagrus romanzoffiana) kernel oil (JKO) has a pleasant coconut-like smell, with about 33% lauric acid and 28% oleic acid. The oil also contains bioactive compounds, such as phenolics, carotenoids, and tocopherols. JKO has a solid consistency at low temperatures, but has a low melting point and low solid content at room temperature. Thus, this work aimed to evaluate the thermal properties related to crystallization and fusion, as well as the chemical and oxidative characteristics of JKO fractions, olein and stearin, obtained from dry and solvent fractionation. In general, stearins had higher crystallization and melting temperatures, and higher solid fat content, unlike oleins, which may be associated with the concentration of high melting triglycerides in the stearins. No statistically significant difference was found for fatty acid profile or oxidative stability of the fractions. The type of fractionation influenced the chemical and thermal properties of JKO fractions. The solvent process promoted the most relevant differentiation of fractions. An olein was obtained with 7% less solid fat at 25 °C which remained visually liquid at 2 °C below the oil, as well as a stearin with 17% more solid fat at 25 °C which remained visually solid at 3 °C above the oil.

Chemical characterization and thermal properties of kernel oils from Tunisian peach and nectarine varieties of

A comparative study was conducted to determine the fatty acids, triacylglycerol compositions and thermal properties of Tunisian kernel oils from the Prunus persica varieties, peach and nectarine, grown in two areas of Tunisia, Gabes and Morneg. Qualitatively, the fatty acids composition and triacylglycerol species were identical for all samples. Oleic acid (67.7-75.0%) was the main fatty acid, followed by linoleic (15.7-22.1%) and palmitic (5.6-6.3%) acids. The major triacylglycerol species were triolein, OOO (38.4-50.5%), followed by OOL (18.2-23.2%), POO (8.3-9.7%) and OLL (6.3-10.1%). The thermal profiles were highly influenced by the high content of triolein due to the importance of oleic acid in these oils. Moreover, the fatty acids distribution in TAG external positions was determined as corresponding to an α asymmetry coefficient that was between 0.10 and 0.12, indicating a high asymmetry in the distribution of saturated fatty acids in the position sn-1 and sn-3 in the TAG species of all samples.