Antioxidant activity and efficacy of Garcinia kola (bitter kola) oil on pathogenic and alteration microorganisms of attiéké

Abstract

Attiéké, the most widely consumed cassava product in Côte d'Ivoire, has a short shelf life. This is largely due to microbial contamination. The aim of this study was therefore to assess the antioxidant activity and effectiveness of Garcinia kola seed oil against pathogenic and spoilage strains of attiéké. This was possible through an extraction of Garcinia kola oil by maceration in hexane. The antimicrobial activity of the oil was assessed using an agar diffusion method. The antioxidant activity of Garcinia kola oil was assessed using the DiPhenyl Picryl Hydrazyl (DPPH) free radical scavenging test and the Ferric Reducing Antioxidant Power (FRAP) test. Garcinia kola oil showed significant antioxidant potential. A high percentage of DPPH radical inhibition was observed, with an IC50 of 2.57 mg/mL. Iron-reducing power was highest when the oil was used at a concentration of 100 %. Garcinia kola oil was able to inhibit the bacterial growth of Staphylococcus aureus, Escherichia coli at a concentration of 100, 50 and 25 % respectively from 22 ± 0.05 to 16 ± 0.00 mm and 20 ± 0.05 to 14 ± 0.08 mm and Salmonella typhimurium (12 ± 00 mm) at a concentration of 100 %. Candida albicans (20 ± 0.07 to 18 ± 0.01 mm), Aspergillus flavus (28 ± 1.41 to 16 ± 0.00 mm) and Aspergillus niger (21 ± 1.01 to 15 ± 0.02) were inhibited at concentrations ranging from 100 to 12.5 %. Bacillus cereus, on the other hand, was resistant to Garcinia kola oil. Based on the findings of this study, Garcinia kola seed oil could be used to extend the shelf life of attiéké.