FTIR characterization and physicochemical evaluation of cottonseed oil

Abstract

In present study cottonseed ( Gossypium ) varieties (RH-112, Lankart-57, K-25, F-20 and D-9) were evaluated for possible variation in quality attributes by using conventional and instrumental techniques (GC-FID and FTIR). Physiochemical characteristics of seed and oils varied as: weight of individual seed (0.069-0.085g), weight of 100 seeds (5.95-7.73g), width (0.461-0.544cm), length (0.736-0.915cm), moisture (6.2-8.5%), oil content (12.01 to14.55%), refractive index at 40 o C (1.4661-1.4665) iodine value (IV) (93.90-105.76gI 2 /100g), saponification value (SV) (181.83-190.55) mgKOH/g, peroxide value (PV) (1.0-6.0meq/Kg), free fatty acids (FFA) (17.30-38.80%) and  induction period (IP) (1.95 -2.65 h), respectively. Furthermore, GC-FID and FT-IR studies were carried out for quantitative and qualitative analysis of cottonseed oil. Analysis showed that most abundant fatty acid in each variety was linoleic acid (42.09-52.55 %) among unsaturated fatty acid, whereas palmitic acid (22.70-26.20 %) was major saturated fatty cid. Some band intensities of FTIR spectra highly correlated with the chemical properties of cottonseed oil such as IV, SV, PV, FFA and IP. In conclusion significant variation was observed among the physiochemical properties of cottonseed oil which can be associated with the specific genetic variability and climatic conditions.