Optimising the extraction of natural flavouring from ‘Satsum’ mandarin (Citrus unshiu Marc.)

Approximately 18% of ‘Satsuma’ mandarins produced in the Eastern and Western Cape of South Africa are discarded because of strict export standards. The demand for natural flavourants presented an opportunity to extract a unique flavourant from ‘Satsuma’ mandarin rind for liqueur production. In this study the yield and consistency of the extraction of the flavourant was optimised against aroma intensity while maintaining a unique flavour proposition. The highest aroma intensity, minimum variability and maximum tolerable rancidity was achieved at a yield of 61 % using rind with a moisture content of 25%, an ETOH extractant concentration = 90% (v/v), a ratio of rind to extractant (m/v) ranging from 20 to 30% and a maceration period of 360 h. The valuable heart fraction was distilled between 60 to 80% ETOH content (v/v). Methyl-n-methylanthraniiate content was investigated as a biochemical marker to monitor processing quality. This parameter only accounted for 30% of the variation observed and proved unreliable. In comparing the flavour profile of the ‘Satsuma’ mandarin extract with that of the internationally renowned Mandarine Napoléon Grande Liqueur, the extract presented a unique citrus-like aroma profile that could contribute to blending a proudly South African liqueur.