Qualitative phytochemical and GC-MS analysis of fermented castor seed (Ogiri Igbo)

Abstract

The aim of this study was to investigate the phytochemicals present in fermented castor seed (ogiri Igbo). 1kg of castor seed was dehulled and cleaned after which seeds were wrapped in banana leaves and boiled for 6-8 h. The boiled seeds which were still wrapped in the leaves were left to ferment for 4-6 days. Later, the seeds were mixed with ash from oil palm bunch and ground into paste. Subsequently, the condiment (ogiri Igbo) formed was wrapped in leaves in small portions.Phytochemical and GC-MS analysis were performed on the condiment using standard methods. Phytochemicals investigated were tannins, saponins, flavonoids, steroids, terpenoids, cardiac glycosides, phlobactannins, phenols, proteins, reducing sugars and anthraquinones. While steroids, reducing sugars and anthraquinones were absent in the condiment, flavonoids, phlobactannins, and alkaloids were present in abundance (++), the least abundant being the terpenoids, cardiac glycosides and phenols (+) and the most abundant phytochemicals reportedly present in the condiment were saponins and proteins. GC-MS analysis performed on the fermented castor seed (ogiri Igbo) showed that forty eight compounds were present in the said condiment and while the most abundant compound reported was 9,12-Octadecadienoic acid (Z,Z)-methyl ester (17.43%), the least abundant was 2-t-Butyl-3,6-dimethyl pyrazine (0.35%). In conclusion, although some of the relevant phytochemicals may have been lost to fermentation, the condiment still retains some health aiding phytoconstituents in appreciable amounts.