Comparative Analysis of Volatile Components and Sensory Profiles of Four Basil Varieties Based on HS-SPME and SD Coupled with GC-MS

Abstract

This study utilized gas chromatography-mass spectrometry (GC-MS) to analyze the volatile components and sensory profiles of four basil varieties, both in their fresh state and as essential oils (EOs) extracted via steam distillation (SD). By employing headspace solid-phase microextraction (HS-SPME) and SD/GC-MS, a comprehensive comparison was conducted to elucidate the changes in volatile profiles before and after drying and extraction processes. In total, 47 volatile components were identified in fresh basil samples. Methyl chavicol was predominant in Thai basil (66.53%), lemon basil (90.18%), and sweet basil (89.19%), whereas linalool (58.56%) was the major component in purple basil. For EOs, 66 volatile components were detected, with methyl chavicol remaining significant in Thai basil (65.27%) and lemon basil (81.03%), though its proportion decreased in sweet basil (29.34%). Purple basil EOs showed a higher proportion of alcohols (54.54%) and terpenoids (31.31%), with the notable presence of linalool (20.08%) and τ-juniper alcohol (18.18%). Multivariate analyses, including principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA), revealed significant variations in volatile profiles among basil varieties. Sensory evaluation, supported by radar fingerprinting, demonstrated that the drying and extraction processes notably impacted the aroma profiles. Distinctive aroma profiles revealed that Thai basil was noted for its aniseed aroma, lemon basil for its lemon scent, sweet basil for its pungency, and purple basil for its floral notes. These findings highlight the diverse applications of basil varieties and their EOs, providing valuable insights into flavoring, fragrance, and therapeutic products based on their volatile compositions and sensory attributes.