Impact of the seed storage time on the quality of cold-pressed sunflower oil

The objective of this study was to investigate the impact of seed storage time on the quality of cold-pressed sunflower oil. The quality and oxidative stability of oil was determined in samples of domestic varieties of sunflower hybrid, linoleic type seeds, obtained from fresh seeds and from seeds stored in silo cell for 6 and 12 months at temperature below 30oC and in good ventilation conditions. It was found that the longer storage time of seeds had a negative impact on many quality aspects of the oil, such as flavor, odor and aroma, primarily on the sensory profile. Chemical characteristics and oxidative stability of oil were also influenced by the storage time, which was confirmed by increased values of the acid value (AV) and peroxide value (PV) of the oil samples. Fresh seed oil had an AV of 0.49±0.01 mgKOH/g, while oils that were obtained from one-year old seeds had an AV of 1.95±0.02 mgKOH/g. Content of the primary oxidation products in the oil obtained by cold-pressing of the fresh seeds was 1.73±0.02 mmol/kg (measured as PV), and 2.22±0.07 mmol/kg in that from the seeds stored for 12 months. The anisidine value for the oil obtained from the seeds stored for 12 months was 0.86±0.04 (100A1% 350nm).[ Projekat Ministarstva nauke Republike Srbije, br. TR 31014

Effect of seed quality on oxidative stability of cold-pressed sunflower oil

The objective of this study was to investigate the impact of the storage time, content of the husk and impurities in the seed mass on the oxidative stability of the cold pressed sunflower oil. The oxidative stability of oil was analyzed by the RSM (Response Surface Methodology), where the response value (output) of the model was the content of oxidation products measured via specific absorbance at 232 nm for conjugated dienes and 270 nm for conjugated trienes. Analyses were performed on the fresh oil samples and oil samples tempered under the Schaal-Oven’s test conditions (96 h at 63±2ºC). It was concluded that the seed storage time had significant impact on the primary (A1%232nm) and secondary (A1%270nm) oil oxidation products, both before (b1-p<0,001; b1-p=0,021) and after (b1-p=0,048; b1-p=0,033) the heating of oil. The content of impurities and husks in the seeds used for pressing also had an influence of the conjugated dienes and trienes contents in both, fresh and heated oil samples. However, their impact was not statistically significant. Interaction of seed storage time, the content of impurities and husks also exert some effect on the values of these quality parameters in the fresh oil as well as in the oil after the heat treatment, even though their influence is not significant. The obtained results have shown that the cold pressed sunflower oil had a good oxidative stability at temperatures up to 63±2ºC