Assessment of the Phytochemical Contents and Antioxidant Activities of Some Herbs and Spices in South-Eastern Nigeria

The phytochemical contents and the antioxidant activities of extracts of some herbs and spices (Glycyrrhizaglabra, Tetrapleuratetraptera Monodoramyristica, Xylopiaaethiopica, and Gongronemalatifolium) consumed mostly in South East, Nigeria, were assessed. The determination of the antioxidant capacities of the group of phytochemicals present in the selected culinary herbs and spices was based on different radicals and mechanisms of reaction, using AOAC methods and common assays. The assays include 2-2 Diphenyl - 1- picrylhydrazyl (DPPH) free radical scavenging activity and Ferric Reducing Antioxidant Power (FRAP). The phytochemicals assessed and the range of values obtained in mg/100g were: Flavonoid (0.095 to 0.493); Phenol (0.082 to 0.285); Tannin (18.08 to 39.74); Anthocyanin (0.002 to 0.0053); Carotenoid ( 0.11 to 0.33); Alkaloid (0.013 to 0.063); Phytate (0.22 to 0.55); Oxalate ( 0.013 to 0.02); and Saponin (3.4 to 5.00). These phytochemical values differed significantly (P>0.05) among the herbs and spices with except Anthocyanin. The extracts from the Tetrapleuratetraptera (Aidan fruit) had the highest value for tannin, carotenoid, alkaloid, and oxalate. Out of the five samples evaluated Xylopiaaethiopica (92.5mg/100g) had the best free radical scavenging activity followed by Gongronemalatifolium (88.7mg/100g) and Monodoramyristica (77.6mg/100g). The FRAP values (217.15 – 675.42) mg/ml varied significantly among the herbs and spices. The FRAP analysis indicated that Aidan fruit had the highest antioxidant activities thus is capable of scavenging free radicals and reducing the risk of cancer and chronic diseases. The study, therefore, recommends the greater use of the Aidan fruit extract in food applications.

Keywords: Herbs, Spices, Phytochemicals, Antioxidant, Activities.