Efficient and selective method to separate triterpene acids by direct treatment of apple peels with alkaline ethanol
ABSTRACT Triterpene acid extraction from dried apple peels of Fuji and Gala varieties in 2%NaOH/ethanol at room temperature, followed by filtration and acidification (pH 3) was investigated, comparing to a classical exhaustive extraction (Soxhlet, 2 h, with ethanol and methanol, >97% recovery) Alkali ethanol process yielded 4.35 6.86% (w/w) of whitish extracts, up to 15 times less than Soxhlet but with same recovery (P 0.05) of ursolic and oleanolic acids. Alkaline extraction of previously defatted peels led to same recovery (P 0.05) but the yield increased slightly (P 0.01) The cost effective and environmental friendly procedure prepares triterpene rich extracts from apple peels at high recovery, directly eliminating the cutin and avoiding prior treatments with hazardous organic solvents.