Phytochemical composition and antioxidant characteristics of traditional cold pressed seed oils in South India

Cold press extraction is the ultimate method to extract essential phytonutrients from oil seeds. Other extractions such as chemical and hot press extraction include processes like deodorizing and refining which affect the quality of phytocompounds (essential fatty acids, tocopherols and phytosterols). In this study, antioxidant capacity, tocopherol and fatty acid profiles of six cold-pressed oils (sesame, coconut, peanut, neem, castor and iluppai) were determined. Lipophilic extracts showed excellent DPPH-free radical scavenging activity compared to hydrophilic extracts. Lipophilic extract of sesame oil showed the highest antioxidant capacity in both DPPH (0.61 +/- 0.02 TEAC mu M/g dw) and ABTS (0.85 +/- 0.05 TEAC mu M/g dw) free radical scavenging assays. The presence of alpha (alpha), gamma (gamma) and delta (delta) tocopherols were detected and quantified in all the six seed oil samples through UPLC analysis. From the results it was confirmed that gamma-tocopherol content is predominant in castor (395.32 +/- 2.12 mg/kg), sesame (278.72 +/- 2.80 mg/kg) and peanut (104.11 +/- 2.86 mg/kg) oils. GC-MS analysis of all the six seed oil samples exhibited fatty acids such as myristic, palmitic, stearic, oleic and linoleic acid in various compositions. The highest levels of total saturated (SFA) in coconut oil, monounsaturated (MUFA) in castor oil and polyunsaturated (PUFA) in sesame oil were quantified at the range of 85.51%, 64.09%, and 31.72% respectively. In conclusion these phytoconstituents from cold pressed oil play a promising role in improving human health without side effects.