Extra virgin olive oil stored in different conditions: Focus on diglycerides

The effects of storage conditions of extra virgin olive oil (EVOO) on the isomerization of diglycerides (DGs) have been investigated. Aliquots of EVOO were stored for 14 months under four different conditions: at 20°C in darkness and in light, at 4-6°C in light and at 20°C in light with argon in the headspace. Samples were analysed bimonthly: 12 DGs with C34 and C36 (1,2 and 1,3 isomers) were tentatively identified and quantified by GC-FID. After 14 months, a clear tendency towards a decrease of 1,2-DGs and a significant increase of 1,3-DGs during storage was observed for all samples. 1,2-DGs were always predominant compared to 1,3-DGs and, for both types, C36 DGs were prevalent compared to C34 DGs. Overall, EVOO stored at 4-6°C in light showed the highest preservation of 1,2-DGs.

[1]  Elena Falqué,et al.  Effect of storage time and container type on the quality of extra-virgin olive oil , 2007 .

[2]  N. Costantini,et al.  Use of nitrogen to improve stability of virgin olive oil during storage , 2002 .

[3]  Joaquín Velasco,et al.  Oxidative stability of virgin olive oil , 2002 .

[4]  L. Cossignani,et al.  Analysis of isomeric diacylglycerolic classes to evaluate the quality of olive oil in relation to storage conditions , 2006 .

[5]  E. Valli,et al.  Study on the effects of heating of virgin olive oil blended with mildly deodorized olive oil: focus on the hydrolytic and oxidative state. , 2009, Journal of Agricultural and Food Chemistry.

[6]  P. Dais,et al.  Kinetics of diglyceride formation and isomerization in virgin olive oils by employing 31P NMR spectroscopy. Formulation of a quantitative measure to assess olive oil storage history. , 2004, Journal of agricultural and food chemistry.

[7]  Dimitrios Boskou,et al.  Olive oil: chemistry and technology. , 2006 .

[8]  Lorenzo Cerretani,et al.  STABILITY OF THE SENSORY QUALITY OF VIRGIN OLIVE OIL DURING STORAGE: AN OVERVIEW , 2009 .

[9]  W. Moreda,et al.  Effects of olive fruit quality and oil storage practices on the diacylglycerol content of virgin olive oils. , 2001, Journal of Agricultural and Food Chemistry.

[10]  T. Léonardis,et al.  Diacylglycerols in the evaluation of virgin olive oil quality , 1994 .

[11]  C. Sweeley,et al.  Gas-Liquid Chromatography of Trimethylsilyl Derivatives of Sugars and Related Substances , 2002 .

[12]  J. L. Guil‐Guerrero,et al.  Quality of extra virgin olive oil affected by several packaging variables , 2009 .

[13]  Francesco Caponio,et al.  Diacylglycerol isomers in extra virgin olive oil: Effect of different storage conditions. , 2013, Food chemistry.