Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/5/2007
Publication Date: 12/12/2007
Citation: Zheljazkov, V.D., Callahan, A.N., Cantrell, C.L. 2007. Yield and Oil Composition of Thirty-Eight Basil (Ocimum basilicum L.) Accessions Grown in Mississippi. Journal of Agricultural and Food Chemistry. 56(1):241-245. Interpretive Summary: Sweet basil (Ocimum basilicum L.) is a widely grown aromatic crop cultivated either for production of essential oil, dry leaves for the fresh market, or as an ornamental. Within this species, there is a significant variation in phenotype and chemotype as oil content and oil composition. Historically, due to its pleasant aroma that suppresses other scents, basil has been widely used in religious rituals in various cultures and times. Fresh basil is used as an ingredient in various dishes and food preparations, especially in the Mediterranean cuisine. Due to its antimicrobial and insecticidal activity and very pleasant aroma, basil essential oil is widely used in the food, pharmaceutical, cosmetic, and aromatherapy industries. Although there has been substantial research on basil essential oil content and composition, most studies in other countries have been limited to either locally grown cultivars or (in the case of the U.S.) mostly in the northern U.S. It is well know that environmental conditions and agricultural practices may modify significantly productivity, oil content, and composition of sweet basil. This study is the first study to compare productivity, oil content and composition of a large number of O. basilicum accessions (38 in total) grown side by side in the Mississippi climate.
Technical Abstract: Sweet basil (Ocimum basilicum L.) has been grown as an essential oil crop in many countries; however, the herbage yield, oil content, composition, and bioactivity of basil grown in Mississippi and other Southern U.S. states has not been explored. The hypothesis of this study was that certain basil genotypes may be better suited for growth in Mississippi as a high-value essential oil crop. A field experiment was conducted to assess yield, oil content and composition of 38 genotypes of Ocimum basilicum L. All basil accessions grew very well under Mississippi conditions without any major pests or diseases. Overall, biomass yields were high and comparable to those reported in the literature. Basil genotypes differed significantly with respect to oil content and composition. Oil content of the tested accessions varied from 0.07 to 1.92% in dry herbage. Based on the oil composition, basil accessions were divided into seven groups: (1) high-linalool chemotype, (2) linalool-eugenol chemotype (six chemotypes with 27-65% linalool and 4-29% eugenol), (3) methyl chavicol chemotype (six accessions with 20-71% methyl chavicol and no linalool), (4) methyl chavicol- linalool chemotype (five accessions with 8-24% methyl chavicol and 8-52% linalool), (5) methyl eugenol – linalool chemotype (two accessions with 36 and 91 % methyl eugenol and 60 and 15% linalool), (6) methyl cinnamate – linalool chemotype (one accession with 9.7% methyl cinnamate and 31% linalool), and (7) bergamotene chemotype (one accession with begamotene as major constituents, 5% eucalyptol and less than 1% linalool). Our results demonstrated that basil could be a viable essential oil crop in Mississippi. The availability of various chemotypes offers the opportunity for production of basil to meet the market requirements of specific basil oils or individual compounds such as linalool, eugenol, methyl chavicol, methyl cinnamate, or methyl eugenol.