Evaluation and comparison of the content of total polyphenols and antioxidant activity in garlic (Allium sativum L.)

Garlic (Allium sativum L.) is one of the oldest cultivated plants in the world and highly valued throughout the ages as a culinary spice. It is a hardy perennial belonging to the Alliaceae family. The garlic bulb is the most commonly used portion of the plant, composed of 5 - 20 individual. It is a very good source of manganese, selenium, vitamin C and vitamin B6 (pyridoxine). In addition, garlic is a good source of other minerals, including phosphorous, calcium, potassium, iron and copper. Many of the perceived therapeutic effects of garlic are thought to be due to its active ingredient allicin. This sulphur-containing compound gives garlic its distinctive pungent smell and taste. Garlic possesses antiviral, antibacterial, anti-fungal properties allowing it to stand against all infections. This work has focused on the evaluation and comparison of total content of polyphenols and antioxidant activity in five varieties of garlic - Mojmír, Záhorský, Lukan, Havran and Makoi. Samples of plant material were collected at the stage of full maturity in the area of Nitra. The total content of polyphenols was determined using the spectrophotometric method of Folin-Ciocalteu agents. Determined the content of total polyphenols in garlic were in the range 621.13 mg.kg-1 (Záhorský) to 763.28 mg.kg-1 (Havran). Total polyphenols content in garlic declined in the following order: Havran >Mojmír >Makoi >Lukan >Záhorský. Antioxidant activity was measured by the spectrophotometric method using a compound DPPH (2.2-diphenyl-1-picryhydrazyl). Statistically significant highest value of antioxidant was recorded in 20.22% (Mojmír) and the lowest value was in 13.61% (Záhorský). The values of antioxidant activity observed in the varieties of garlic may be arranged as follows: Mojmír >Havran >Lukan >Makoi >Záhorský. In all the analysed varieties of garlic was confirmed by the strong dependence of the antioxidant activity and the total content of polyphenols.