Effect of Traditional Fermentation Time on Total Phenolic Content and In vitro Antioxidant Activity of Kocho: Ethiopian Fermented Food from Enset (Ensete ventricusum welw. Chessman)

Abstract

Ensete ventricusum, locally known as Enset, is the main crop of a sustainable food source that ensures food security in Central ,South and South West Ethiopia. It has been used as a food and local medicine for thousands of years. Kocho is a product of matured Enset prepared traditionally by fermenting (for few weeks to some months) a mixture of pulverized pseudostem and corm in pit. The objective of this study was to evaluate the effect of traditional fermentation period on the total phenolic content and antioxidant activity of Kocho. The sample was fermented in the pit for 15, 30, 45, 60, 75, 90, 105 and 120 days. Oven dried Kocho powder was extracted with methanol followed by water. Total phenolic content of the extract was determined by the Folinciocalteu method. Antioxidant activities of the extracts were evaluated with 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and total antioxidant activity using phosphomolybdenum assay. The results revealed that Kocho showed greater total phenolic content and antioxidant activities than unfermented product. Methanol extract of Kocho fermented for 45 days showed the highest amount of total phenolic content (9.27 ± 0.44 milligram of gallic acid equivalent per gram of dried extract). In comparison of DPPH scavenging and total antioxidant, methanol extracts were also superior to aqueous extracts. Methanol extract of Kocho fermented for 60 days exhibited the strongest DPPH scavenging activity (IC₅₀ = 0.15 ± 0.02 mg/mL) and total antioxidant activity (0.43 ± 0.04 milligram of ascorbic acid equivalent per gram of dried extract). Thus fermentation offers a tool to further increase the bioactive compounds and antioxidant potential of Kocho.

Keywords: antioxidant activity, Ensete ventricusun, , fermentation, Kocho, total phenolic

DOI: 10.7176/FSQM/91-05

Publication date:October 31^st 2019