Aqueous extraction of limonin from Citrus reticulate Blanco

Abstract

The replacement of organic solutions in the extraction of limonin from citrus seeds with an alkaline solution was investigated. This method was based on the reversible conversion of limonin to limonoate A-ring lactone via ring-opening of D-ring lactone at different pH values. The extraction conditions, optimised using Taguchi experimental design, were as follows: pH 11, temperature 70°C, alkaline solution/seeds ratio 20:1 (v/w), ultrasonic power 800 W for 30 minutes. A yield of 7.5 mg/g (limonin/citrus seeds) of 98% pure limonin was obtained.