Introduction: Nowadays, there is a growing interest in adding natural antioxidants instead of the synthetic ones to improve oxidative stability of vegetable oils [1,2]. Various authors have reported the addition of carotenoids to different edible oils [3]. A carotenoid-rich extract from L. barbarum berries was added to Extra Virgin Olive Oil (EVOO) to improve the oxidative stability during storage. Methods: Chemical changes of EVOO and EVOOCar (added with a carotenoid-rich extract from Lycium barbarum L. berries) were monitored during storage of 6 months at room temperature. Traditional methods, as peroxide and acidity values, specific extinction values, were used. The fatty acid composition was obtained by HRGC-FID, while α-tocopherol and carotenoid contents were evaluated by HPLC-DAD-MS. Results: Targeted analysis showed that the most abundant carotenoid of L. barbarum extract was zeaxanthin dipalmitate, estimated to be > 80% of the total carotenoid extract. As regards traditional analysis, peroxide value was higher in EVOO (3.3-13.8 mEqO2/kg) in respect to EVOOCar (1.3-11.5 mEqO2/kg), during the storage. Regarding fatty acid composition, at the end of the storage EVOO and EVOOCar samples did not shown any significantly differences (P˃0.05). The results of HPLC-DAD-MS analysis showed that the level of α-tocopherol in the unheated oils (time zero) was 25.5 and 25.2 mg/100 g for EVOO and EVOOCar, respectively. This content significantly decreased in EVOO (19.4 mg/100) in respect to EVOOCar (24.4 mg/100 g) at the end of storage. The content of lutein remains fairly constant, while slight decrease in zeaxanthin dipalmitate was observed over time. Conclusions: The enrichment with health-promoting goji carotenoids might represent a valuable strategy to improve healthy properties while promoting oil stability. The enriched oil showed a good stability during storage of 6 months at room temperature. The addition of goji extract to EVOO makes possible the formulation of a new functional food, characterized by the well-known healthy properties of carotenoids. References 1. Zeb, A., & Murkovic, M., Food Chemistry, 127, 1584 (2011). 2. Blasi F., Rocchetti G., D. Montesano D. et al., Food Research International 105, 507 (2018). 3. Limón, P., Malheiro, R., Casal S. et al., Food Chemistry, 175, 203 (2015).
Chemical stability of extra-virgin olive oil added with carotenoids from Lycium barbarum L. during long-term
Blasi F.;Montesano D.;Simonetti M. S.;Cossignani L.
2018
Abstract
Introduction: Nowadays, there is a growing interest in adding natural antioxidants instead of the synthetic ones to improve oxidative stability of vegetable oils [1,2]. Various authors have reported the addition of carotenoids to different edible oils [3]. A carotenoid-rich extract from L. barbarum berries was added to Extra Virgin Olive Oil (EVOO) to improve the oxidative stability during storage. Methods: Chemical changes of EVOO and EVOOCar (added with a carotenoid-rich extract from Lycium barbarum L. berries) were monitored during storage of 6 months at room temperature. Traditional methods, as peroxide and acidity values, specific extinction values, were used. The fatty acid composition was obtained by HRGC-FID, while α-tocopherol and carotenoid contents were evaluated by HPLC-DAD-MS. Results: Targeted analysis showed that the most abundant carotenoid of L. barbarum extract was zeaxanthin dipalmitate, estimated to be > 80% of the total carotenoid extract. As regards traditional analysis, peroxide value was higher in EVOO (3.3-13.8 mEqO2/kg) in respect to EVOOCar (1.3-11.5 mEqO2/kg), during the storage. Regarding fatty acid composition, at the end of the storage EVOO and EVOOCar samples did not shown any significantly differences (P˃0.05). The results of HPLC-DAD-MS analysis showed that the level of α-tocopherol in the unheated oils (time zero) was 25.5 and 25.2 mg/100 g for EVOO and EVOOCar, respectively. This content significantly decreased in EVOO (19.4 mg/100) in respect to EVOOCar (24.4 mg/100 g) at the end of storage. The content of lutein remains fairly constant, while slight decrease in zeaxanthin dipalmitate was observed over time. Conclusions: The enrichment with health-promoting goji carotenoids might represent a valuable strategy to improve healthy properties while promoting oil stability. The enriched oil showed a good stability during storage of 6 months at room temperature. The addition of goji extract to EVOO makes possible the formulation of a new functional food, characterized by the well-known healthy properties of carotenoids. References 1. Zeb, A., & Murkovic, M., Food Chemistry, 127, 1584 (2011). 2. Blasi F., Rocchetti G., D. Montesano D. et al., Food Research International 105, 507 (2018). 3. Limón, P., Malheiro, R., Casal S. et al., Food Chemistry, 175, 203 (2015).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
