Contents lists available at ScienceDirect Industrial Crops & Products journal homepage: www.elsevier.com/locate/indcrop Essential oil composition of purple basils, their reverted green varieties (Ocimum basilicum) and their associated biological activity Adolfina R. Koroch a , James E. Simon b , H. Rodolfo Juliani b, ⁎ a The City University of New York, Borough of Manhattan Community College, 199 Chambers St., Science Dept., 10007, NY, USA b New Use Agriculture and Natural Plant Products Program, Department of Plant Biology, School of Environmental and Biological Sciences (SEBS) Rutgers University, 59 Dudley Road, New Brunswick 08901, NJ, USA ARTICLE INFO Keyword: Basil Oil composition Bioactivity Eugenol Linalool Methyl eugenol ABSTRACT Essential oils provide the characteristic aroma notes to basil varieties and are partially responsible for basil biological activities. The search for new aromas and biological activities are important steps to find new applications for industrial crop and products. The objective of this study was to evaluate the chemical composition of the essential oils from purple basil varieties and their progeny that reverted to green varieties, and to compare the composition of these oils with other nonpigmented basil varieties. This work also evaluated selected biological activities of some of these green and basil varieties in search of new biological activities. The green purple varieties derived from Dark Opal and Osmin Purple varieties exhibited a remarkable similarity, suggesting that these plants reverted to the same green ancestor. Their aromatic volatile oils and their main components exhibited a wide range of antioxidant and antimicrobial activities, with several chemotypes (Sweet, Osmin Purple basils) expressing high antioxidant and antimicrobial activities. Some of the reverted green types, showed higher levels phenylpropanoids (e.g. higher in eugenol) compared with their parent types (Purple Ruffles). These biological activities of the aromatic oils appear to be related to their phenolic constituents and concentration of the oils (e.g. eugenol, methyleugenol). The results showed that the essential oils of these basils have a number of additional attributes and applications for the nutraceutical industry in addition to their aroma and flavor impact. 1. Introduction Purple basils (Ocimum basilicum, Lamiaceae) have been commer- cialized for both culinary and their ornamental value. The instability of purple basils, where a percentage of the progeny reverts to a green ancestor that same season of production, has limited their use as ornamental plants and also limited their potential applications for other markets. Phippen and Simon (2000) showed that Purple Ruffles basil varieties can have a reversion back to partially green sectoring on its leaves up to 35%. Basil essential oils are complex mixtures that can include over a hundred chemical constituents. However, only a few of these components are found in high relative concentrations, such as citral, 1,8-cineole, linalool, methyl chavicol, eugenol, methyl eugenol and methyl cinnamate and it is the blend or ratio of all the constituents that together provide the basis of the herbs aroma (Simon et al., 1990). Oils from aromatic plants have been known since antiquity to possess biological activity, mainly antibacterial, antifungal and anti- oxidant properties (Koroch et al., 2007). Previously, it was reported the antioxidant activity in leaves extracts of some Ocimum spp (Koroch et al., 2010; Juliani and Simon, 2002 Juliani and Simon, 2002). The objective of this study is to evaluate the chemical composition of purple basil essential oils and their progeny reverted to green varieties, and to compare the composition of these oils with other basil varieties. This work also seeks to evaluate the biological activities of some of these green and basil varieties in search of new biological activities. The search for new uses is an important strategy to find industrial crop applications for herbs and aromatic plants. This an expanded study of our previous work (Juliani and Simon, 2002) now centered on the reversion of purple varieties. 2. Materials and methods Seeds from purple Ocimum basilicum varieties: Dark Opal (DO), (Richters Seeds, Goodwood Ontario, Canada), Osmin Purple (OP), Purple Ruffles (PR) (Johnny’s Selected Seeds) and the corresponding green reversions varieties: Green Dark Opal (GDO), Green Osmin Purple (GOP) and Green Purple Ruffles (GPR) were grown in flats before http://dx.doi.org/10.1016/j.indcrop.2017.04.066 Received 15 February 2017; Received in revised form 17 April 2017; Accepted 19 April 2017 ⁎ Corresponding author. E-mail addresses: hjuliani@rutgers.edu, rodolfojuliani@yahoo.com.ar (H.R. Juliani). Industrial Crops & Products xxx (xxxx) xxx–xxx 0926-6690/ © 2017 Published by Elsevier B.V. Please cite this article as: Koroch, A.R., Industrial Crops & Products (2017), http://dx.doi.org/10.1016/j.indcrop.2017.04.066