FORTIFICATION OF OLIVE OIL IN PALM OIL TO UPGRADE ITS QUALITY, STABILITY AND ACCEPTIBILITY

Abstract

Oil Blending has been expected as mainly important solutions in the production of vegetable oil with good quality storage Constance’s and most favorable fatty acid composition. The current study was carried out to identify the finest oil blend in terms of physicochemical properties between palm and olive oils. Laboratory experiment on the “Fortification of olive oil in palm oil to upgrade its quality, stability and acceptability” was carried out at Nuclear Institute for Food and Agriculture Tarnab, Peshawar and also at The University of Agriculture Peshawar KP-Pakistan during 2014-15. Olive/palm oils were treated in sole or admixture at various ratios. Samples were tested with potato food frying at monthly interval continued for three months. Data were recorded on Peroxide value (PV), Free fatty acids (FFA), Anisidine value (AV), Iodine value (IV), Color index (CI), Beta carotene (βC) and Fatty acid profile of the oils. The results showed considerable variations in all the studied parameters tested in different blends under various stress conditions. Maximum PV (10.76 meq/kg), FFA (2.44%), AV (2.29), IV (77.09 g/100g) and CI (0.609) were recorded in sole olive oil, while minimum PV (9.69 meq/kg), FFA (0.65%), AV (0.88), IV (53.40 g/100g) and CI (0.146) were noted in sole palm oil. The samples kept in sunlight showed maximum PV (12.82 meq/kg), FFA (1.32%) and AV (1.39), while maximum IV (63.10 g/100g), CI (0.371) and BC (11.30) value were observed in samples stored at ambient temperature. Storage conditions increased PV from 2.18 to 27.82 meq/kg, FFA from 0.88 to 1.47%, AV from 1.02 to 1.56, while decreased IV from 63.38 to 58.05 g/100g, CI from 0.392 to 0.337 and BC from 27.87 to 3.46.After the frying process, maximum PV (8.37 meq/kg), FFA (2.24%), AV (2.28) and IV (71.69 g/100g) were noted in sole olive oil, while minimum PV (7.05 meq/kg), FFA (1.32%), AV (1.28) and IV (51.01 g/100g) were recorded in sole palm oil. Maximum PV (12.44 meq/kg), FFA (2.12%), AV (2.10), CI (0.392), while minimum IV (53.11 g/100g) and BC (23.14) were recorded after 3rd frying. As saturated fatty acid, palmitic acid was higher as 4.70, 31.80, 26.77, 24.85, 21.77 and 19.94in OO, PO, 10:90%, 20:80%, 40:60% and 60:40% oil blends, respectively. While, Eicosadienoic acid was higher as 0.912, 0.905, 0.895, 0.889 and 0.880in PO, 10:90%, 20:80%, 40:60% and 60:40% oil blends, respectively. Oleic acid was higher as 44.897, 31.096, 26.17, 23.756, 18.020 and 18.885 in OO, PO, 10:90%, 20:80%, 40:60% and 60:40% oil blends, respectively. Saturated fatty acids decreased from 0.781 to 0.494, from i i 2.889 to 2.834, from 2.586 to 2.217, from 2.376 to 2.092, from 2.173 to 1.797, from 1.940 to 1.598 in OO, PO, 10:90%, 20:80%, 40:60% and 60:40% oil blends, respectively after 3rd frying. Unsaturated fatty acids decreased from 1.039 to 0.854, from 0.209 to 0.143, from 0.204 to 0.140, from 0.200 to 0.136, from 0.195 to 0.132, from 0.179 to 0.120 in OO, PO, 10:90%, 20:80%, 40:60% and 60:40% oil blends, respectively after 3rd frying. Cis fatty acids decreased from 15.77 to 8.47, from 8.73 to 7.10, from 7.35 to 5.97, from 6.69 to 5.63, from 6.88 to 2.76, from 5.47 to 4.49 in OO, PO, 10:90%, 20:80%, 40:60% and 60:40% oil blends, respectively after 3rd frying. Maximum appearance (6.90), taste (7.57), texture (8.00), color (7.67) and overall acceptability (7.56) were noted in 10:90% oil blend. It was observed that low temperature storage was beneficial for oil quality in addition to blending of OO:PO at 10:90% and 20:80% ratios showed low PV and FFA value. Fatty acid profile showed that it has high monounsaturated fatty acids conflicting to oxidation. It is concluded that OO:PO oils mixed at 10:90% and 20:80% ratios is more economical and acceptable for improving the quality and stability of edible oils.