Preliminary investigation of Dioclea reflexa seed gum as a food and potential pharmaceutical excipient

The chemical quality of natural gum determines its functionality and safe use. This study was to characterize some physicochemical properties and microbial load of gum obtained from Dioclea reflexa seed (DR), which has a history of folkloric use as a soup thickener in eastern Nigeria. The gum was extracted by aqueous maceration of DR. The microbial load was determined using the pour plate technique. The extract was screened for phytochemical constituents and analyzed for elemental content using atomic absorption spectroscopy (AAS) and scanning electron microscopy (SEM). Also, the morphology was viewed using SEM. The phytochemical screening indicated the presence of carbohydrates, starch, and simple sugars. The total viable aerobic bacterial and fungal counts were 2.0 x 101 and 1.0 x 100 (CFU/mL), respectively. The SEM micrograph showed that the polymer microstructure had dense and smooth surfaces, a property that has been associated with polysaccharides. The AAS elemental analysis showed the presence of several metals in the sample: Fe, Pb, Zn, Cd, Mg, Ca, and Na, in amounts generally within WHO permissible limits, except for Pb and Cd, whose levels were slightly above. The SEM analysis also showed the presence of K, Ca, Mg, Al, P, S, Na, and a preponderance of C and O. The presence of heavy metals could be associated with environmental pollution. DR gum's nature and chemical constituents present it as a potential food and pharmaceutical additive. Further studies should be done to validate the findings.