Partial propane extraction of aromatic compounds from dehydrated basils (Ocimum Lamiaceae)

Abstract

Many conventional extraction methods for basils (Ocimum sp. Lamiaceae) produce only the extract as a usable product and leave the extracted herb as a waste product. We demonstrate partial extraction of chemically and morphologically diverse basil cultivars using propane at low temperature (20-27 °C) and pressure (950-1200 kPa) and evaluate the process for production of dual products, the extracted herb (raffinate) and the herb extract in terms of aromatic content and color. The extracts contained aromatic compounds that were characteristic of but not always identical in terms of relative abundance to the dehydrated herb. Extraction decreased total aromatics in the raffinate by 12-43% but the individual aromatic proportions remained essentially the same, preserving flavor characteristics of the raffinate. Color was mostly unchanged by the extraction process. Partial propane extraction resulted in two useful basil products (an extract and extraction raffinate). Aromatic extractability was tissue and cultivar dependent for basils. Therefore, partial extraction protocols should be optimized according to cultivar/plant tissue abundance to provide consistent aromatic intensity of these potential food products. © 2019 Society of Chemical Industry.