Evaluation of Organoleptic and Preservative Properties of Neem Leaf Extract as a Natural Preservative in Tomato Paste

Synthetic preservatives used in commercially produced tomato paste have attracted growing consumer concern due to potential long-term health effects. Natural plant extracts offer promising alternatives given their established antimicrobial and antioxidant activities. This study evaluated the preservative and organoleptic effects of neem (Azadirachta indica) leaf extract at concentrations of 0, 0.5, 1.0, and 1.5 percent (w/v) in locally produced tomato paste. Neem leaves were obtained from Zaria, Kaduna State, and aqueous extract was prepared using standard maceration. Tomato paste was produced from fresh Roma tomatoes and stored at room temperature for eight weeks. Parameters assessed at two-week intervals included total viable count, yeast and mould count, pH, lycopene content, colour, and sensory acceptability. Results showed that tomato paste with 1.0 percent neem extract exhibited significantly lower microbial counts throughout the storage period compared to the unsupplemented control. Lycopene content was better preserved in neem-treated samples. However, sensory evaluation revealed that the 1.5 percent concentration imparted a detectable bitter aftertaste, reducing acceptability scores. The 1.0 percent concentration maintained acceptable organoleptic attributes while demonstrating antimicrobial efficacy comparable to the benzoate-preserved control. The study supports further investigation into neem extract as a partial synthetic preservative replacement in Nigerian food processing. Keywords: neem extract, natural preservative, tomato paste, antimicrobial, sensory evaluation.