A novel photometric method for evaluation of the oxidative stability of virgin olive oils.
The Oxitester method, a novel, simple, and fast photometric method for the evaluation of the antioxidant capacity of olive oils, was validated and compared to the official oil stability index (Rancimat) method. The Oxitester method appeared to be a good alternative to the Rancimat method with adequate correlation for a wide range of virgin olive oil samples, including extrissima virgin olive oils (correlation coefficient 0.88), and extra virgin olive oils of increased acidity (free fatty acids >0.45%, correlation coefficient 0.89). Other quality factors (flavor, free fatty acids content, specific absorbance at 270 and 232 nm, peroxide value, and content of oleic, linoleic, and linolenic acids) were also measured and correlated to the antioxidant capacity values of the Oxitester and Rancimat methods. The Oxitester method, in contrast to the Rancimat method, was indicative of the flavor characteristics of the olive oils and the content of linolenic acid.
Kamvissis
Vassilis N
VN
Minerva S.A. Edible Oils Enterprises, Analytical Laboratory Department, 165 Tatoiou and Odisseos Str, 14452 Metemorfosis Attica, Factory: 32009 Schimatari Viotias, Greece. vkamvi@minerva.com.gr
Barbounis
Emmanouil G
EG
Megoulas
Nikolaos C
NC
Koupparis
Michael A
MA
D000975:Antioxidants / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D009812:Odorants / Q000032:analysis; D000069463:Olive Oil; D010084:Oxidation-Reduction; D010783:Photometry; D010938:Plant Oils / Q000737:chemistry*; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet; D013649:Taste; D017962:alpha-Linolenic Acid / Q000032:analysis
D000975:Antioxidants; D007202:Indicators and Reagents; D000069463:Olive Oil; D010938:Plant Oils; D017962:alpha-Linolenic Acid