Aqueous garlic extract and its phytochemical profile; special reference to antioxidant status

Abstract

Garlic (Allium sativum L) has distinct nutritional profile with special reference to its bioactive components and is used in different diet-based therapies to cure various lifestyle-related disorders. For this purpose, characterization and extraction of garlic were carried out followed by antioxidant assays. Different solvents (50% aqueous ethanol, 50% aqueous methanol and water) at different time intervals (4, 5 and 6 h) at 60°C were used to optimize aqueous extraction efficiency of garlic. Among the solvents, water extract resulted in better extraction yield (31.85 ± 2.09 g/25 g) at 5 h. The antioxidant potential of all these solvents was estimated through in vitro studies. In this context, it was observed that higher amount of total phenolic contents was present in aqueous methanol 71.87 ± 1.69% at 45 min. Antiradical (1,1-diphenyl-2-picrylhydrazyl assay) and antioxidant activity showed that the maximum value was 73.80 ± 3.69 and 83.83 ± 0.16%, respectively, in methanolic extract at 45 min while glucose diffusion and ferric reducing antioxidant power were 97.00 ± 0.20 and 32.66 ± 0.72% at p < 0.05, respectively. Aqueous garlic extract was selected as the best treatment on the basis of percentage yield and safety modulation in human body absorption. Aqueous garlic extract was subjected to pH, acidity, total soluble solids (TSS) and colour. It was observed that the pH of aqueous garlic extract decreased with the passage of time while acidity increased. It was also concluded that storage affected the value of TSS and colour significantly. L* values for colour on 0 day were 34.18 ± 0.08, whereas those on 28th day were 38.84 ± 0.03. It was predicted that 28 days storage resulted in significant increase in L* value, while a* value decreased from 4.31 ± 0.01 to 0.32 ± 0.01 at the end of storage study.