TITLE:
Formulation, Shelf-Life, and Microbiological Quality Assessment of Spice Products
AUTHORS:
Prisca Nneka Onuoha, Peter Azikiwe Onwualu, John Eloyi Judith
KEYWORDS:
Spice Production, Sensory Evaluation, Microbial Quality Assessment, Shelf-Life Evaluation, Bioproducts
JOURNAL NAME:
Agricultural Sciences,
Vol.17 No.3,
March
18,
2026
ABSTRACT: The persistent reliance on imported ingredients for the formulation of Therapeutic Food in Africa undermines local food sovereignty and increases production costs. Additionally, microbial safety and shelf stability remain critical quality parameters for spice-based formulations intended for nutritional and functional applications. This study aimed to evaluate the microbial quality and shelf-life stability of a locally formulated all-purpose spice blend, with an emphasis on safety, storage resilience, and potential functional benefits such as supporting breast milk expression. A Microbial Quality Assessment (MQA) was performed using selective and differential culture media, including Sabouraud Dextrose Agar (SDA), MacConkey Agar (MCA), Tryptic Soy Agar (TSA), Salmonella Shigella Agar (SSA), Mueller Hinton Agar (MHA), Mannitol Salt Agar (MSA), and Eosin Methylene Blue Agar (EMB). Gram staining was used for preliminary species identification. Shelf-life stability was assessed under accelerated conditions in a stability chamber at 38˚C - 39˚C, with periodic evaluation of color, appearance, aroma, and sensory attributes. Fungal growth was detected on SDA for the S/J spice sample, with colonies labelled SA-SF. The total bacterial count on TSA was 7.3 × 104 CFU/mL, while the fungal count was 6.0 × 108 CFU/mL. No growth occurred on MCA, SSA, MSA, or EMB, and Salmonella spp. were absent. Probable isolates included Bacillus, Candida, and Staphylococcus species. Accelerated shelf-life testing revealed gradual changes in sensory characteristics, but the product retained acceptable quality for over four months. The findings demonstrate that the locally formulated spice blend is microbiologically safe, shelf-stable, and potentially offers functional health benefits. This supports the viability of locally sourced spice formulations as components in sustainable nutrition programs, reducing dependency on imports and enhancing local value chains.