Assessment of the physicochemical properties and biological activity of Vietnamese single-bulb black garlic

• Published in: Food bioscience 2022-10, Vol.49, p.101866, Article 101866
• Main Authors: Hue, Cao Thi, Tan, Luc Quang, Van Hung, Hoang, Le, Quynh Thi Ngoc, Nguyen, Thanh Hoa, Huong, Nguyen Thi Lan, Ha, Nguyen Manh, Trinh, Dinh Kha
• Format: Article
• Language: English
• Subjects: Antimicrobial activity; Antioxidant activity; Antioxidant content; Different temperature; Physicochemical; Single-bulb black garlic
• ISSN: 2212-4292; 2212-4306
• DOI: 10.1016/j.fbio.2022.101866

This study assessed the quality and biological activity of Vietnamese single-bulb black garlic (SBG) by investigating the effect of different temperatures (60, 65, 70, and 75 °C) on physicochemical properties during the heat treatment process. The optimal treating conditions accounted for the highest concentration of antioxidants were 70 °C for 42 days. The SBG.70 had a higher content of reducing sugar, protein, flavonoid, and polyphenol in comparison with the white garlic and the others. Antioxidant activity of single-bulb white garlic and SBG were measured via DPPH, phosphomolybdenum, and H2O2 radicals, as well as a reduction potential. The antimicrobial activity was assessed by the multi-concentration dilution method; the sample treated at 70 °C displayed the strongest activity against four microbial strains with MIC values for S. aureus, P. aeruginosa, B. cereus, and C. albicans of 64, 128, 128, and 64 μg/mL, respectively. Additionally, only two SBG samples aged at 70 °C and 75 °C were bacteriostatic to E. coli with MIC values of 32 and 64 μg/mL, respectively. •Black garlic was prepared from single-bulb white garlic at various temperatures.•The sample aged at 70 °C during 42 days showed the highest quality.•The black garlic samples displayed strong antioxidant and antibacterial activities.•Two samples prepared at 70 and 75 °C exhibited capacity against E. coli.