Aqueous extraction of oil from flaxseed and evaluation of its storage stability and physicochemical properties during storage

The aim of this study is to investigate aqueous extraction process as a safe and environmentally friendly method for extracting oil from flaxseed. For this purpose, flaxseeds were first roasted (at 120 °C for 45 minutes), then ground and the extraction process was performed. In the aqueous extraction process, temperature (25-70 ° C), time (1.5-5.5 hours) and pH (4-7) conditions were applied and qualitative characteristics (acid value, peroxide value and oil extraction yield) were measured. The results showed that, with increasing extraction time and temperature, the obtained oil yield also increased, so that the maximum yield related to extraction time of 3 hours, extraction temperature of 70 °C and pH=4. Also acid and peroxide values increased by increase of the extraction time and temperature. According to the results of the acid value, peroxide value and extraction oil yield, extraction at 70 °C, 2.45 h and pH=4 was selected as the optimal treatment and quality characteristics of the extracted oil was evaluated during storage. The results showed that, chlorophyll, carotenoids and total phenol content significantly decreased (p≤0.05) during storagemouseout="msoCommentHide('_com_1')" onmouseover="msoCommentShow('_anchor_1','_com_1')">[U1] . Also, acid and peroxide values had a significant increase during storage (p≤0.05) and the maximum observed at 60th day storage. It was concluded that aqueous extraction of oil from flaxseed despite its relatively low efficiency, improved quality characteristics and can be a good alternative to conventional methods.