Effects of malaxation temperature and harvest time on the chemical characteristics of olive oils.
The aim of the study was to determine the effects of harvest time and malaxation temperature on chemical composition of olive oils produced from economically important olive varieties with a full factorial experimental design. The oils of Ayvalik and Memecik olives were extracted in an industrial two-phase continuous system. The quality parameters, phenolic and fatty acid profiles were determined. Harvest time, olive variety and their interaction were the most significant factors. Malaxation temperature was significant for hydroxytyrosol, tyrosol, p-coumaric acid, pinoresinol and peroxide value. Early and mid-harvest oils had high hydroxytyrosol and tyrosol (maximum 20.7mg/kg) and pigment concentrations (maximum chlorophyll and carotenoids as 4.6mg/kg and 2.86mg/kg, respectively). Late harvest oils were characterized with high peroxide values (9.2-25meqO2/kg), stearic (2.4-3.1%) and linoleic acids (9.3-10.4%). Multivariate regression analysis showed that oxidative stability was affected positively by hydroxytyrosol, tyrosol and oleic acid and negatively by polyunsaturated fatty acids.
Izmir Institute of Technology, Department of Food Engineering, 35430 Urla-Izmir, Turkey. Electronic address: olusolajolaym@iyte.edu.tr.
Olusola Samuel
OS
Jolayemi
Izmir Institute of Technology, Department of Food Engineering, 35430 Urla-Izmir, Turkey. Electronic address: figentokatli@iyte.edu.tr.
Figen
F
Tokatli
Izmir Institute of Technology, Department of Food Engineering, 35430 Urla-Izmir, Turkey. Electronic address: banuozen@iyte.edu.tr.
Banu
B
Ozen
D005227:Fatty Acids / Q000032:analysis; D000069463:Olive Oil / Q000737:chemistry*; D010636:Phenols / Q000032:analysis; D013696:Temperature; D013997:Time Factors
D005227:Fatty Acids; D000069463:Olive Oil; D010636:Phenols
Classification; Fatty acid profile; Harvest time; Malaxation temperature; Multivariate regression; Olive oil composition; Oxidative stability; Phenolic profile