A study is reported on shelf-life of extra virgin olive oil packaged in bottles having different oxygen barrier properties and stored in the dark at room temperature (RT) and at 37°C for 12 months. Five different materials were tested: polyethyleneterephthalate (PET), PET including 1% "oxygen scavenger" (PETA), PET including 3% "oxygen scavenger" (PETB), PET coated with high barrier resin (PETC) and PET coated with high barrier resin including "oxygen scavenger" (PETD); glass was used as the control. The following quality indices were monitored during storage: acidity, peroxide value, K 232, K 270 organoleptic assessment and the (E)-2-hexenal/hexanal ratio. A significant influence of the package on the quality decay kinetics of oil was found. Acidity did not change during storage, except for oil packaged in glass stored at 37°C, where about a 50% increase was observed. K 232 and peroxide values of the samples packaged in glass, PETC and PETD were lower than those of oil packaged in PET, PETA and PETB. K 270 increased in all samples, whereas the sensory score decreased from 7.69 (initial value) to about 6.5, for oils stored at RT, and to about 6.0, for those stored at 37°C. The value of the (E)-2-hexenal/hexanal ratio remained above 1, indicating the absence of off-flavours. The results indicate that the materials having higher oxygen barrier properties slow down the quality decay kinetics of extra virgin olive oil, suggesting that PETC and PETD could replace the traditional glass bottles compatible with the mechanical performance, which needs to be carefully tested.
Shelf-life of extra virgin olive oil stored in packages with different oxygen barrier properties
GAMBACORTA, Giuseppe;FACCIA, Michele;
2004-01-01
Abstract
A study is reported on shelf-life of extra virgin olive oil packaged in bottles having different oxygen barrier properties and stored in the dark at room temperature (RT) and at 37°C for 12 months. Five different materials were tested: polyethyleneterephthalate (PET), PET including 1% "oxygen scavenger" (PETA), PET including 3% "oxygen scavenger" (PETB), PET coated with high barrier resin (PETC) and PET coated with high barrier resin including "oxygen scavenger" (PETD); glass was used as the control. The following quality indices were monitored during storage: acidity, peroxide value, K 232, K 270 organoleptic assessment and the (E)-2-hexenal/hexanal ratio. A significant influence of the package on the quality decay kinetics of oil was found. Acidity did not change during storage, except for oil packaged in glass stored at 37°C, where about a 50% increase was observed. K 232 and peroxide values of the samples packaged in glass, PETC and PETD were lower than those of oil packaged in PET, PETA and PETB. K 270 increased in all samples, whereas the sensory score decreased from 7.69 (initial value) to about 6.5, for oils stored at RT, and to about 6.0, for those stored at 37°C. The value of the (E)-2-hexenal/hexanal ratio remained above 1, indicating the absence of off-flavours. The results indicate that the materials having higher oxygen barrier properties slow down the quality decay kinetics of extra virgin olive oil, suggesting that PETC and PETD could replace the traditional glass bottles compatible with the mechanical performance, which needs to be carefully tested.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
