Effect of Natural Preservatives (Ocimum Gratissimum and Zingiber Officinale) on Shelf Life And Storage Stability of Smoked African Catfish

Abstract

This study investigated the impact of various bio-preservatives on the proximate composition, quality deterioration, and sensory attributes of smoked catfish. Specifically, the effects of Scent leaves (Ocimum gratissimum), Ginger rhizome (Zingiber officinale), and their combination on smoked catfish were evaluated. The results demonstrated significant variations in proximate composition across different treatments. Ginger-treated fish exhibited the lowest moisture content (6.18%) and the highest protein content (61.74%). In contrast, Ocimum gratissimum treated fish showed the highest ash content (10.53%) and the highest fiber content when combined with ginger (1.83%). Fat content showed minimal variation, with ginger-treated fish showing the lowest fat content (10.50%). Quality deterioration parameters revealed that the combination treatment of Ocimum gratissimum and ginger had the lowest peroxide value (8.45 meq/kg) and total volatile base nitrogen (14.67 mg N/100g), indicating superior preservation of lipid quality. Thiobarbituric acid reactive substances (TBARS) values were also lowest in the combination treatment (5.27 mg malondialdehyde/kg). For spoilage indicators, ginger-treated fish exhibited the lowest total trimethylamine nitrogen (5.58 mg N/100g) and total viable count (1.81 x 10⁵ CFU/g), while yeast and mould counts were minimal in ginger-treated fish (1.14 x 10³ CFU/g). Sensory evaluation revealed that ginger-treated smoked catfish scored highest in aroma (7.05), taste (7.20), texture (7.95), appearance (7.73), and overall acceptance (7.83). These results indicate that ginger treatment significantly enhances the sensory quality of smoked catfish compared to others. This study highlights ginger as a particularly effective bio-preservative for improving the nutritional quality and sensory attributes of smoked catfish.