Biopreservative Potential of the Spices; Piper Guineense (Uziza), Xylopia Aethiopica (Uda) and Tetrapleura Tetraptera (Oshorisho) in Fresh Fruit Juices

Abstract

This study demonstrates the antimicrobial activity of three spices, Piper guineense (Uziza), Xylopia aethiopica (Uda), Tetrapleura tetraptera (oshorisho) and their potential use as food biopreservatives. Essential oils of the spices seed were obtained and used in the agar-diffusion and tube dilution assays to determine their minimum inhibition (MIC) and bactericidal concentrations (MBC) against a common fruit juice spoilage organism (Bacillus cereus). MIC values of 50mg/ ml (Oshorisho) and 25mg/ml (Uziza and Uda) were obtained. Similarly, all spice extracts were bactericidal at a concentration of 100mg/ml. The spice extracts were utilized in the fortification of fresh fruit juice. Fortification of orange, pineapple and watermelon juices with extracts of the spices caused a reduction in the bacterial and fungi load of the juices over a period of 7 days in comparison to unpreserved controls. Orange juice preserved with uda had a fungal load of 1.9 x106 and bacterial load of 8.0 x106 compared to control with loads of 2.3 x107 and 1.1 x107 , respectively. Watermelon juice preserved with oshorisho had a fungal load of 1.2 x106 and bacterial load of 1.1 x107 compared to control with loads of 2.1 x107 and 8.8 x107 , respectively while pineapple juice preserved with uziza had a fungal load of 1.2 x107 and bacterial load of 1.6 x107 compared to control with loads of 2.7 x107 and 2.5 x108 , respectively. These results show that the spice extracts have potential for use as food preservatives for extending the shelf life of freshly prepared fruit juices. This is important as the demand for fresh foods free from chemical preservatives but microbiologically safe is on the increase.