Effect of Moisture Content on the Quality and Quantity of Screw-Pressed Flax Seed Oil

Abstract

Healthy foods and green processing are currently in the focus of scientific attention. Flax is considered a superfood that includes numerous beneficial ingredients. Its oil is a great source of polyunsaturated fatty acids. However, the heat-sensitive futures of the polyunsaturated fatty acids require low-temperature methods. Screw pressing can produce oils at lower temperatures, but a lower oil capacity makes it less advantageous. Pre-treatment of seeds as a crucial pre-processing stage affects the quality and quantity of oil. This research featured the effect of moisture content in flax seeds on the quantity and quality flax seed oil. The study involved local flax (Linum usitatissimum L.) from the Qashqadaryo Region, Uzbekistan. Standard methods were used to define the quality parameters of oil, i.e., acid value, free fatty acids content, peroxide value, oil recovery, and sediment content. Regression equations were obtained using the method of regression analysis. The highest oil recovery of 40.99% was observed at the moisture content of 9.56%. At 7.55%, the oil recovery dropped by 3.17%. The sediment content in the oil increased at lower moisture contents in the flax seeds (14.62–5.55%). The acid value, peroxide value, and free fatty acid content demonstrated both downward and upward trends when the moisture content increased. The moisture content in flax seeds affected the quality and quantity profile of screw-pressed oil. The optimal parameters of oil processing can yield health-beneficial and highly nutritional oil.

Keywords

• screw pressing
• moisture content
• oil recovery
• sediment content
• peroxide value
• acid value
• free fatty acids