Abstract

This study intends to investigate the feasibility of using a local preservative under ambient environmental conditions to minimise the deterioration of Moringa oleifera seed extract in terms of pH fluctuations and coagulation properties. The effect of Trona solution on the pH stability of M. oleifera seed extract was evaluated by observing varying concentrations (0.5 to 2%) of mixtures of seed extract and Trona solution over a period of 19 days. Using an incremental dosage of 0.1g Trona added into 6 sets of 1 g/100 mL seed extract powder suspension and observing the respective pH for a period of seven days, the minimum amount of Trona solution required for a stable solution was determined to be at a dosage of 0.5 g. This was chosen as the minimum dosage required and consequently, preserved M. oleifera seed extracts of varying concentrations (2 to 15% w/v) were prepared containing Trona dosages of 0.5 g and above. The pH values were recorded over a 19 day period from which it was observed that for constant M. oleifera extract concentration, more pH stability was achieved at higher Trona dosages, that is. highest stability was achieved at a Trona dosage of 2.0 g/100 mL. While for constant Trona dosage, more pH stability was achieved at lower concentrations of M. oleifera extracts that is highest stability was achieved at 2% extract concentration. The Trona solutions maintained a consistently alkaline pH with an overall average variance of 0.0006. As little as 0.5 g/100 mL concentration of the preservative is capable of slowing the deterioration of a 1% (w/v) M. oleifera seed powder suspension. Therefore the possibility of using Trona, a locally available preservative, to extend the shelf life of a locally available coagulant, M. oleifera seed extract, appears to be very feasible.`

Key words: M. oleifera seed extract, Trona, preservative, stability, deterioration.