Effect of moisture on the oil extraction sunflower collets and its minor compounds content

E.E. PEREZ; E.R. BAÜMLER; M.E. CARRIN; G.H. CRAPISTE; A.A. CARELLI

Concordia, Entre Rios

Congreso; International Conference on Food Innovation INNOVA; 2014

Universidad Nacional de Entre Ríos (UNER) (Argentina), Universidad Politécnica de Valencia (UPV) (Spain) and Instituto Universitario de Ingeniería de Alimentos para el Desarrollo (S

It is known that the oil yield obtained is associated with the moisture content and that it increases with decreasing moisture content of the raw material. Studies found in the literature dating from the ´40s and ´50s, neverthelessthey not report how moisture content influences the extraction of oil sunflower minor components and their profiles. This work aims to analyze the effect of moisture on sunflower oil extraction, wax, phospholipids and tocopherols content and their profiles. Oil was extracted from low-protein sunflower collets in a batch device stirred with a magnetic agitator; the oil extraction was carried out at 50ºC for 2 hours using n-hexane as solvent. Samples were conditioned at three moisture levels (6, 12 and 18% db), prior to oil extraction. The oil content was measured gravimetrically. The tocopherols content was measured by HPLC and fluorescence detector using AOCS method. Quantitative determination of phospholipids was carried out by enrichment using a diol solid-phase extraction cartridge and subsequent analysis by HPLC?UV. The wax fraction was isolated by column chromatography in a glass column with a solid stationary double phase of silica gel and silver nitrate-impregnated silica gel.The analysis of the first fraction eluted was performed by capillary GLC equipped with an on-column injection system,flame ionization detector (FID) detector and internal standard method. All assays were performed in triplicate independent samples. Statistical analysis was carried out by analysis of variance (ANOVA) followed by comparisons between means with Fisher´s LSD test, at 5% significance level.The increasing moisture content caused the decrement of oil yield, they were statistically different for each sample tested (p = 0.003). The waxes contents were between 572 and 741 ppm, they were composed mainly by esters with C44 and C60 carbon atoms, being their esters profiles distributed differently according to the moisture content considered. The presences of alpha- and beta-tocopherols and alpha-tocotrienol were detected in all the samples, being the level of alpha-tocopherol higher than 93% and easier to extract at 12% db of moisture content.Furthermore, the oil phospholipid content increased with moisture content.