088: Profiling of Volatile Sulfur Compounds in Garlic and Its Processed Products

Introduction

Garlic (Allium sativum), a staple ingredient in many cuisines, is valued for its pungent flavor and health benefits, which are primarily attributed to volatile sulfur compounds (VSCs) such as diallyl trisulfide, diallyl sulfide, and allyl methyl disulfide. Garlic is consumed in various forms, including raw cloves and processed products such as black garlic, garlic juice, and garlic flakes. The composition of VSCs significantly varies depending on garlic type, origin, and processing method. This study characterizes VSC profiles in 26 garlic samples using HS-SPME-GC/MS with chemometric analysis.

Methods

Garlic samples (0.5–5 g) were ground under liquid nitrogen and placed into a 20 mL headspace vial containing internal standard (ethyl methyl sulfide, 4.16 µg/mL), and equilibrated at 45°C for 10 min. Headspace volatiles were extracted using a DVB/CAR/PDMS fiber for 40 min and thermally desorbed into the GC injector port. VSCs were separated on a DB-WAX column and identified by comparison of their mass spectra to authentic chemicals and the NIST library.

Results

The results showed that 25 VSCs, including 2 sulfides, 8 disulfides, 8 trisulfides, 3 thiophenes, and 4 other sulfur-containing compounds were identified and quantified in different garlic samples. The VSC content was significantly higher in the garlic clove (9.73 ~ 0.78 mg/100 g) compared to the peel (1.96 ~ 0.17 mg/100 g). Significant variations in VSC composition were observed in raw garlic across cultivation regions. Furthermore, black garlic (1.09 ~ 0.21 mg/100 g) exhibited lower VSC concentrations than fresh garlic, due to a reduction in VSC content during the aging process. Among processed products, garlic seasonings (1.15 ± 0.50 mg/100 g) and flakes (1.73 ± 0.23 mg/100g) had higher VSC levels than other garlic-derived products.

Significance

This study investigated the variations in VSC content of garlic and its derivatives, considering cultivar, origin, and processing techniques. The findings suggest that environmental, geographical, and processing factors could play a crucial role in determining composition of VSCs in garlic, thereby influencing its health benefits and sensory qualities.

Authors: Yuna Jeon, Samuel Park, Heon-Woong Kim, Chang Joo Lee, Jeehye Sung