الفهرس | Only 14 pages are availabe for public view |
Abstract -----------------------------------ABSTRACT ABSTRACT F our Eucalyptus species as a source of natural antioxidant were used named Eucalyptus camaldulensis (Sinai), E.camaldulensis (valley), E.citriodora, and E.gomphocephala. The defatted leaves were extracted with three different sui vents named diethyl ether, chloroform and 80% ethanol. Different concentrations (0.01 %, 0.02% and 0.03%) of the three extracts of four Eucalyptus species were added individually to soybean oil and compared with (0.02%) TBHQ. Samples were stored in a thermostatically controlled oven at 60°C for 20 days.Samples were periodically withdrawn every 2 days for the determination of the PV, TBA value, oxygen electrode test, refractive index, antioxidant effectiveness, and GLC analysis. The important obtained results could be summarized as follow. All of treated soybean oil with 0.03% concentration of ethanol extracts of E. gomphocephala and E. camaldulensis (Sinai) was more stable than 0.02% TBHQ. The concentration of 0.03% ethanol extract of all plants was more effective as antioxidant agent than other two solvents, (0.03%ether and- 0.03%chloroform). The antioxidant effectiveness of each extract of the four Eucalyptus species in comparison with TBHQ was fllowing the order E. gomphocephala >E. camaldulensis (Sinai» TBHQ> E. camaldulensis (valley» E. cetriodora. GC-MS analysis of ethanol extract of E.camaldulensis (Sinai) indicated that there are 12 components in the sample and GC-MS analysis of ethanol extract of E.gomphocephala indicated that there are 14 components in the sample a-pinene, p-cymene, Aromadendrene, lemonene , Allo Aromadendrene , a-terpineol, Benzene-l-ethyl 2, 4 dimethyl, Methyleugenol , Trans-pinocarveol , 1,8 cineol, crypton , spathulenol, and carvone . could be responsible for the antioxidant effectiveness ~ -----------------------------------ABSTRACT ABSTRACT F our Eucalyptus species as a source of natural antioxidant were used named Eucalyptus camaldulensis (Sinai), E.camaldulensis (valley), E.citriodora, and E.gomphocephala. The defatted leaves were extracted with three different sui vents named diethyl ether, chloroform and 80% ethanol. Different concentrations (0.01 %, 0.02% and 0.03%) of the three extracts of four Eucalyptus species were added individually to soybean oil and compared with (0.02%) TBHQ. Samples were stored in a thermostatically controlled oven at 60°C for 20 days.Samples were periodically withdrawn every 2 days for the determination of the PV, TBA value, oxygen electrode test, refractive index, antioxidant effectiveness, and GLC analysis. The important obtained results could be summarized as follow. All of treated soybean oil with 0.03% concentration of ethanol extracts of E. gomphocephala and E. camaldulensis (Sinai) was more stable than 0.02% TBHQ. The concentration of 0.03% ethanol extract of all plants was more effective as antioxidant agent than other two solvents, (0.03%ether and- 0.03%chloroform). The antioxidant effectiveness of each extract of the four Eucalyptus species in comparison with TBHQ was fllowing the order E. gomphocephala >E. camaldulensis (Sinai» TBHQ> E. camaldulensis (valley» E. cetriodora. GC-MS analysis of ethanol extract of E.camaldulensis (Sinai) indicated that there are 12 components in the sample and GC-MS analysis of ethanol extract of E.gomphocephala indicated that there are 14 components in the sample a-pinene, p-cymene, Aromadendrene, lemonene , Allo Aromadendrene , a-terpineol, Benzene-l-ethyl 2, 4 dimethyl, Methyleugenol , Trans-pinocarveol , 1,8 cineol, crypton , spathulenol, and carvone . could be responsible for the antioxidant effectiveness ~ |