ULTRASOUND-ASSISTED EXTRACTION OF PHENOLICS COMPOUNDS FROM CHIA (Salvia hispanica L.) SEEDS AND THEIR ANTIOXIDANT ACTIVITY

Extraction of phenolic compounds from chia (Salvia hispanica L.) seeds using two solvents (methanol and n-hexane) was performed with or without high intensity ultrasound assistance. Conventional solid-liquid extraction and ultrasonic-assisted extraction at 50, 75 and 100 % of maximum power (400 W) were performed using chia seeds mixed with solvent (1:10 w/v) at three extraction times (5, 10 and 15 min). The highest phenolic concentration and the best antioxidant capacity were obtained using methanol as extraction solvent for both methods. When using the regular procedure, higher phenolic contents in both methanol and hexane, extracts were obtained at shorter extraction times, whereas antioxidant capacity increased with time. Efficiency of ultrasound-assisted extraction of phenolics increased with time and power output. Methanolic extracts obtained at the maximum power (100 %, 15 min) did not exhibit the best antioxidant capacity. The ultrasound-assisted process showed better extraction ability than conventional methods, which means that the extraction yield of phenolic compounds from chia seeds increased. This increase may lead to a wider application of S. hispanica L. as a high-quality functional ingredient in several industrial processes. Therefore, the ultrasound-assisted technique could be a reliable and novel method for phenolic compounds and antioxidants extraction from chia seeds, due to increases and improves extraction yield.