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Liquid-Liquid Extraction for the Enrichment of Edible Oils with Phenols from Olive Leaf Extracts

Japon-Lujan, R., Luque de Castro, M.D.
Journal of agricultural and food chemistry 2008 v.56 no.7 pp. 2505-2511
extraction, enriched foods, food enrichment, phenols, olives, leaves, Olea europaea, plant extracts, food analysis, food composition, olive oil, sunflower oil, soybean oil
A liquid-liquid extraction method to enrich edible oilsolive, sunflower, and soy oilswith phenols from olive leaf extracts is proposed. After microwave assistance to remove the phenols from three varieties of olive leaves, concentrations in the extracts between 12921 and 5173 mg/L of oleuropein, between 488 and 192 mg/L of apigenin-7-glucoside, between 444 and 219 mg/L of luteolin-7-glucoside, and between 501 and 213 mg/L of verbascoside were obtained, which clearly depended on the target variety. After optimization of the liquid-liquid extraction step, the concentrations in oils were 442, 162, and 164 mg/L of oleuropein, respectively, which were also enriched in apigenin-7-glucoside (between 8 and 15 mg/L, depending of the oil), lutelin-7-glucoside (between 11 and 12 mg/L), and verbascoside (between 11 and 13 mg/L). The oil-extract distribution factor of these compounds was also calculated for all olive leaf varieties and edible oils using different extracts concentrations and also different oil-extract volume ratios. Thus, a door is open to enrichment of any oil with olive phenols at preset concentrations using extracts preconcentrated as required and taking into account the distribution factor of the target compounds between the oil and the extracts.