Monovarietal extra virgin olive oils: correlation between thermal properties and chemical composition.
Thermal properties of monovarietal extra virgin olive oils were evaluated by means of differential scanning calorimetry (upon cooling) and related to their chemical composition (triacylglycerols, diacylglycerols, total and free fatty acids, oxidation status). The overall crystallization enthalpy did not significantly differ among samples and did not account for the differences observed in chemical compositions. On the contrary, a higher degree of unsaturation in the lipid profile induced a shift of the crystallization onset towards lower temperatures and narrowing of the crystallization temperature range. The presence of triacylglycerol lysis and lipid oxidation products shifted the crystallization towards higher temperatures and the phase transition developed over a larger temperature range. Differential scanning calorimetry thermograms were deconvoluted into three constituent exothermic peaks for all samples. The area of the two lower-temperature exotherms was found to be statistically correlated with the amount of triunsaturated and monosaturated triacylglycerols present in the oil. Thermal properties of extra virgin olive oil were found to be affected by oil chemical composition.
Dipartimento di Ingegneria Industriale, Università degli Studi di Parma, viale Usberti 181/A, I-43100, Parma, Italy.
Emma
E
Chiavaro
Elena
E
Vittadini
Maria Teresa
MT
Rodriguez-Estrada
Lorenzo
L
Cerretani
Matteo
M
Bonoli
Alessandra
A
Bendini
Giovanni
G
Lercker
D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D004075:Diglycerides / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis; D005230:Fatty Acids, Nonesterified / Q000032:analysis; D006358:Hot Temperature; D000069463:Olive Oil; D010938:Plant Oils / Q000737:chemistry*; D013816:Thermodynamics; D014280:Triglycerides / Q000032:analysis
D004075:Diglycerides; D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D000069463:Olive Oil; D010938:Plant Oils; D014280:Triglycerides