WORLD JOURNAL OF ADVANCE
HEALTHCARE RESEARCH

Dima Aldiab*

ABSTRACT

Olive oil is one of the oldest plant oils. It has pleasant taste and high nutritional value, where it is considered the favorite component of Mediterranean countries diet. Extra virgin olive oil (EVOO) is the highest grade of olive oil. During storage and heat treatment (EVOO) is subjected to oxidation resulting in deterioration of its sensory quality and nutritional value. There is increasing interest to enhance oil stability and delay the oxidation during storage and heat treatment therefore many synthetic and natural antioxidants are used. Extracts from herbs -such as Rosmarinus officinalis L- are rich sources of natural antioxidants including phenolic compounds. Therefore, the aim of this study is to investigate the effect of Rosmarinus officinalis L. ethanolic extract (RE) on reducing EVOO oxidation compared to Butylated hydroxyanisole (BHA) during storage and heat treatment. The phenolic content of the dried ethanolic Rosmarinus officinalis L. extract was 95.18 ± 5.38 mg GAE/g. Peroxide Value (PV), p-Anisidine value (p-An-V) and totox value increased in EVOO and reached after 30 min in oven 43.02 ± 3.3 mEqO2/kg, 25.75 ± 1.84 and 111.79 ± 6.7, respectively. Similarly, PV, p-An-V and totox value increased in EVOO and reached after 30 min in microwave 52.57 ± 3.3 mEqO2/kg, 50.56 ± 1.84 and 155.7 ± 6.7, respectively. The addition of RE and BHT led to decrease PV, p-An-V and totox value compared to EVOO (p-value <0.05) both during microwave and conventional heat treatment. The oxidation process in microwave was clearly higher than traditional heating in oven (p-value <0.05). PV, p-An-V and totox value increased gradually in EVOO during storage and reached after 9 months 38.59± 2.99 mEqO2/kg, 39.56 ± 0.42 and 116.74± 4.8, respectively. The addition of RE and BHT decreased PV, p-An-V and totox value during storage compared to EVOO (p-value <0.05). The results indicate that the ethanolic extract of Rosmarinus officinalis L. decreased EVOO oxidation, which enable it to be used as natural antioxidant in olive oil instead of the synthetic antioxidant BHT.

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