Effect of Roasting and Boiling Techniques on Chemical Composition of Local Safflower (Carthamus tinctorius L.) Seed and its Oil Stability

Abstract

The objective of this study was to determine the effect of roasting and boiling processing techniques on compositional and stability parameters of safflower seeds. The chemical composition, minerals, and amino acids of safflower seeds roasted and boiled were evaluated and compared with those of control samples. The fatty acids and oxidative stability by peroxide value of safflower seed oil were also conducted. The moisture content, carbohydrates, and fibers decreased with roasting and boiling treatments while fat increased from 34.1 (g/100g) in raw sample to more than 36.0 (g/100g) in samples prepared by roasting and boiling techniques. The protein content increased slightly from 13.2 (g/100g) in raw samples to 13.6 in SSR 180/10, and 13.7 in SSR 180/20, and 13.8 in SSR 180/30 and 13.4 in boiled sample. The fatty acid composition of safflower oils of roasted and boiled samples changed slightly compared with control samples. The major fatty acid was linoleic acid (80%). The amino acids changed by boiling and roasting compared with control sample. The peroxide value increased by roasting and boiling with value higher in roasting than boiling compared with raw sample. The concentration (on ppm wet basis) of major elements (Ca, K, and Mg) in raw safflower seeds (110, 750 and 183ppm) were significantly (P>0.05) higher than roasted safflower seeds (90, 745, and 122 ppm) and boiled seeds (94, 750 and 119 ppm). And of minor elements (Pb, Ni, Mn, Cu, Na, and Fe) was also affected by roasting and boiling. In addition, Fourier Transform Infra Red (FTIR) spectroscopy was used to monitor the peak changes during the thermal oxidation. The peak intensities (absorbancies) of control oil were changed in comparison with oil subjected to boiling and roasting indicating clear effect of boiling and roasting temperatures on safflower oil.