Authors:N. Mohamed, A. Mariod, S. Yagoub, and Y. Dagash
The objective of this study was to determine the effect of different irrigation intervals (every 7 and every 14 days) and fertilizers (farmyard manure, pellet granules and urea) on the composition of safflower seed and its oil stability. Fertilizers have a significant effect on the carbohydrate, fat, ash and protein contents of safflower seed oil. Pellet granules slightly increased the carbohydrate content, while farmyard manure increased the fat and oil contents of safflower seed oil. On the other hand, urea and farmyard manure increased the fibre content compared with pellets, which slightly decreased it. Irrigation every 7 days increased the protein content. Farmyard manure significantly (P < 0.05) increased the mineral content (iron, potassium and calcium). The use of FTIR spectroscopy revealed that the period of storage significantly (P < 0.05) affects oil stability. The peak intensities (absorbencies) recorded for oil stored at zero time changed after storage for 1, 2 and 3 days, indicating a clear effect of storage time on the oil, and the bands 3008, 2923, 2854, 1747, 1654, 1463, 1377, 1238, 1163, 1099 and 723 exhibited a clear decrease in the intensity of the individual group vibrations, indicating a decrease in oil stability.