OPTIMAL EXTRACTION OF PURE ANTHOCYANINS FROM FRUITS OF SAMBUCUS NIGRA

Natural plant products contain numerous matrix components, such as sugars, phenols, organic acids, proteins, salts and flavonoids that will be extracted along with anthocyanins during solid-liquid extraction. Liquid-liquid extraction and solid phase extraction can be used to further purify anthocyanins in solution. In this study, we optimized extraction of anthocyanins from elderberry fruits, Sambucus nigra, using adsorbent C₁₈ silica gel which was reported as optimal in several studies. During initial purification experiments (solid phase extraction) we experienced significant losses of anthocyanins (up to 83%). The losses can be reduced to 15% by increasing the volume of 70% ethanol-water 1% citric acid solvent which was used for flashing of solid adsorbent. Our experiments were carried out to determine the number of extractions with the same fruit sample needed to extract the major portion of anthocyanins. Total amount of anthocyanins was determined by differential spectrophotometry. After three extractions, using 70% ethanol-water with 1% citric acid for 30 min, we have obtained anthocyanins in an amount near 0.98% of fresh plant weight (expected 0.664-1.816% wt.).