Evaluation of phyt exponent® concentrations as natural spray preservative for extending the shelf-life of tomatoes (solanum lycopersicum)

Abstract

Tomatoes (Solanum lycopersicum) are highly perishable crops that experience postharvest losses due to microbial spoilage, moisture loss and rapid physiological deterioration during storage. The increasing concerns associated with synthetic chemical preservatives have created a need for safer and environmentally friendly natural alternatives. This study therefore evaluated the effectiveness of Phyt Exponent® as a natural spray preservative for extending the shelf-life of tomatoes under normal storage conditions. A Completely Randomized Design (CRD) consisting of four treatments was used to conduct the experiment with the treatments named T0 (control-0%), T1 (1%), T2 (3%) and T3 (5%) Phyt Exponent® concentrations. These treatments were replicated five times. The tomatoes were assessed over a 14-day storage period for physical attributes including weight loss, firmness and colour change. The chemical attributes of tomatoes were also assessed and these were pH and total soluble solids (TSS). In addition, antimicrobial activity was determined through the measurement of zone of microbial inhibition against two spoilage microorganisms (fungi and bacteria). The results showed that Phyt Exponent® significantly reduced weight loss and maintained fruit’s firmness compared to untreated control (p < 0.05). The best preservation effect was produced with the 5% concentration throughout the storage period. Significant differences in pH and TSS were also observed from day 7 onwards for the physical attributes. The tomato fruits which were treated have maintained lower pH and slowed increase in TSS respectively as compared to the control. However, in colour change there were no significant differences that were observed among all the treatments. Moreover, the spray preservative demonstrated a concentration-dependent antimicrobial activity against spoilage microorganisms (Erwinia carotovora and Botrytis cinerea) producing measurable zones of inhibition ranging from 8 mm at 1% to 17 mm at 5% with no inhibition observed in the untreated control (F = 261.90; p ≤ 0.001). This study contributes to the field of postharvest technology and food preservation by providing evidence on the effectiveness of Phyt Exponent® as a natural spray preservative for tomatoes (S. lycopersicum) especially to smallholder farmers. Based on these findings, the study recommends the application of Phyt Exponent® at the 5% concentration for the effective postharvest preservation of tomatoes, particularly among smallholder farmers lacking cold-chain infrastructure.