Impact of thermal treatment on the phytochemicals and bioactivities of single clove black garlic

Garlic contains bioactive compounds, including organosulfur, phenolics, and polysaccharide compounds, which are believed to contribute to health benefits. Black garlic is produced by aging fresh garlic at controlled temperatures. S-allyl-L-cysteine (SAC), a key bioactive compound in garlic, is commonly used to evaluate the quality of black garlic. This study used single clove black garlic (SCBG) to evaluate the effects of aging durations on bioactive compounds, antioxidants, and antibacterial activity of extract. The aging process was carried out at 80 ± 5 °C for 7, 14, 21, and 30 days. The samples were categorized according to the presence or absence of skin. The Soxhlet method with ethanol as a solvent was used for extraction. Based on the results, it was found that longer aging duration had beneficial effects, indicating that the longer aging duration improves the bioactive and functional qualities of SCBG. SCBG aged for 30 days with skin had the highest SAC content (66.183 ± 0.491 μg SAC/g sample), TPC (64.548 ± 0.189 mg GAE/g extract), and TFC (9.777 ± 0.420 mg QAE/g extract). Moreover, the extract also had a high antioxidant activity with an IC 50 value 192.863 ± 4.270 mg/L and antimicrobial activity, especially against Escherichia coli .