Antioxidant activity of monoterpenes and synergist antioxidant effect with BHT

P R QUIROGA; M LARRAURI; C M ASENSIO; P MARTÍN; C G RIVEROS; N R GROSSO; V NEPOTE

New Orleans

Congreso; IFT Annual Meeting and food expo; 2014

Institute of Food and Thecnology

Synthetic antioxidants are used in many foods. Their health safety is questioned. Monoterpenes obtained from essential oils have shown antioxidant activity. The objective of this study was to evaluate the preserving effect of monoterpenes: thymol, carvacrol, and sabineno hydrate acting as antioxidant additives. The antioxidant activity of monoterpenes were evaluated in a storage study of roasted sunflower seeds. The following samples were prepared: roasted sunflower seeds (RS-C) as control sample and roasted sunflower seeds with addition of BHT (RS-BHT) and thymol (RS-T), carvacrol (RS-Car), and sabinene hydrate (RS-S) monoterpenes. Samples were stored during 35 days at room temperature. Peroxide (PV) and p-anisidine (AV) values were measured every 7 days. The synergist antioxidant effect between monoterpenes and BHT was evaluated in canola oil stored during 14 days at 60 C. A binary combination of each monoterpene with BHT (0:100, 20:80, 40:60, 60:40, 80:20, and 100:0, monoterpene:BHT) were prepared and added to canola oil at 0.02% w/w. PV value was measured in all canola oil samples. Statistical analysis was performed on the data (ANOVA and Fisher-LSD test). Chemical indicators increased during storage in roasted sunflower seed samples. After 35 days of storage, PV value was 27.74, 58.05, 89.12, 98.95, and 145.35 meq O2/Kg in RS-BHT, RS-S, RS-T, RS-Car, and RSC, respectively. The AV at storage day 35 was 2.71, 5.95, 5.45, 6.48, and 9.05 in RS-BHT, RS-S, RS-Car, RS-T, and RS-C, respectively. A synergist antioxidant effect was observed in the combinations 20:80 between the monoterpenes thymol and sabinene hydrate with BHT (lowest PV in canola oil samples). Carvacrol:BHT combinations did not have synergist effect. Thymol and sabinene hydrate exhibiten better antioxidant effect in roasted sunflower seeds and show synergist antioxidant effect with BHT in canola oil. Monoterpenes as thymol, carvacrol and sabineno hydrate can be used as natural antioxidant in food products.