Dehydration of PDO Genovese basil leaves (Ocimum basilicum maximum L. cv Genovese Gigante) by direct osmosis

Starting from a registered patent, the aim of the present study was to improve the osmo-dehydration (OD) process of Protected Designation of Origin (PDO) Genovese basil leaves by composite experimental design. The contemporary optimization of both process variables and mixture composition allowed enhancing the quality of the dried product. A tentative substitution in the osmo-dehydration brine of the polyalcohol sorbitol with the novel food trehalose was also performed. Sensorial techniques and head space analysis were applied to monitor changes in appearance, texture, flavour and colour. The best appearance and aroma of dried leaves were obtained at 67.5 °C with a dipping time of 55 seconds in a brine containing 65% water; 20% sorbitol and 15% NaCl. Using trehalose did not lead to a significant improvement of the quality of the final product. This experimental approach could be successfully used, also on industrial scale, for the optimization of similar OD processes.