Effects of Indigenous Reed (Typha latifolia) Salt and Iodized Commercial Salt on Total Phenolic and Total Flavonoid Contents and Antioxidant Activity of Garlic (Allium sativum L.)

Abstract

Aim: The use of natural food additives such as garlic, ginger, turmeric and indigenous reed salts is increasing over synthetic ones due to their availability, affordability and the mental picture that ‘‘natural is safe’’. Food is usually cooked in the presence of other additives such as salt. It has been established that food additives (such as salt) and their degradation products can interact with other food additives and food constituents (additive-additive, additive-micronutrient) to form an array of products and these can have positive or negative effects on the antioxidant activity of the other additives and the food. The aim of this study was to investigate the effects of indigenous reed salt (Typha latifolia) and iodized commercial salt (Kensalt) used in Kenyan culinary recipes on the total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity of garlic. Place and Duration of the Study: Garlic bulbs and iodized commercial salt (Kensalt) were purchased from Khethia supermarket and Food Plus mall of Eldoret town (Kenya), respectively. Indigenous reed salt was purchased from vendors in Busia County of Western Kenya. The samples were analyzed at Directorate of Government Analytical Laboratory, Kampala (Uganda) between August 2019 and January 2020.  Methodology: The TPC of fresh and salted garlic extracts were determined using the Folin-Ciocalteu assay, TFC by aluminum chloride colorimetric method and antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Results: The TPC, TFC and antioxidant activity of fresh aqueous garlic extract were 303.07 ± 6.58 mg gallic acid equivalent per 100 g, 109.68 ± 6.78 mg quercetin equivalent per 100 g and 56.60 ± 0.05%, respectively. Salt had a significant effect on TPC (P = .03) and antioxidant activity (P ˂ 0.05). However, the mean differences were insignificant for the effect of salt on TFC (P = .66). Changes in salt concentrations did not significantly affect the TPC, TFC and antioxidant activity of garlic. Conclusion: Cooking garlic with salt enhances the extraction of its phytochemicals, thereby increasing its antioxidant potential.