摘要：Sunflower seed defatted meal (SM) is an underutilized source of protein due to the presence of chlorogenic acid (CGA) which imparts a greenish color to sunflower meal protein products. The aim of the present study was to prepare a (CGA) extract from SM and evaluate its biological activity. The study included extraction of phenolic compounds from SM, using 80% methanol, 80% ethanol and 80% acetone. The methods of extraction used included conventional extraction (CE), microwave assisted extraction (MAE) and ultrasound assisted extraction (UAE). Results proved that acetone achieved highest phenolic extraction, acetone-CE, acetone-MAE and acetone-UAE extracted 1802.76, 3668.81 and 3093.31 mg total phenolics/100 g meal. For safe nutritional reasons ethanol was chosen to continue the investigation. Ethanol concentrations 80, 70, 60, 50% were examined and results indicated 60% to be the most efficient. Using solvent mixtures with MAE-3 min and UAE-30 min proved effective. All phenolic extracts had a good antioxidant activity ranging between 86-95% as measured by free radical scavenging activity and between 74-93% as measured by the β-carotene bleaching method. Some of the above extracts were chosen for further investigation. The 60% ethanol-MAE-3 min and 60% ethanol-UAE-30 min extracts were effective for delaying oxidation of flaxseed oil. UV Spectroscopic analysis and HPLC analysis indicated that the chosen extracts contained between 687.22-1243.51 mg CGA/100 g as measured by UV-spectrophotometry and between 726.27-923.45 mg CGA/100 g as determined by HPLC. All chosen extracts showed potential as antimicrobial and anticarcinogenic agents. In conclusion the CGA extract was successfully prepared and proved to have antioxidant, antimicrobial and anticarcinogenic properties.
