An innovative solid-liquid extraction technology: use of the naviglio extractor ® for the production of lemon liquor

Abstract

This document is a review on solid-liquid extractive techniques and describes an innovative solid-liquid extraction
technology using the Naviglio Extractor®. Also explained is an application for the production of alcoholic extract from
lemon peel. The alcoholic extract, mixed with a sugar and water solution in the right proportions is used to make a
well known Italian lemon liquor commonly named "limoncello". Lemon liquor is obtained utilizing the Naviglio
Extractor®; the procedure used is fast and efficient and uses about half the weight of lemon peel per volume of ethyl
alcohol used for the extraction of the odorous and taste responsible compounds, compared to the commonly used
extraction procedures. To test the consumer’s preference and compare the taste of the liquor obtained with that
obtained by peel maceration from the same lot of lemons and obtained using the traditional recipe, a consumer test
has been carried out. One hundred people, chosen from among frequent consumers of limoncello, tasted the two
lemon liquors, and evaluated intensity of aroma, colour, alcohol taste and sweetness. In about 81% of the preferences,
the liquor obtained using the Naviglio Extractor® was preferred. The extraction process used allows the ethanol from
used up lemon peel to be totally recovered so that these can be disposed of as non toxic waste or used in agriculture
or as cattle feed.