Microbial Spoilage, Actions of Preservatives and Phytochemical Screening of Mango (Mangifera indica) Seed Powder

Abstract

The work was carried out to determine the organisms responsible for the microbial spoilage of kernels of Mangifera indica. A specialized kit was employed to confirm the Gram negative organisms present in the spoilt kernels of M. indica. The effects of chemical preservatives such as sodium benzoate, sodium acetate, citric acid and sodium chloride at different concentrations on the microbial counts and pH of mango seed powder stored at room temperature over a period of 12 weeks were studied. The mango seed kernel powder (MSK) was screened for phytochemicals. The bacteria isolated include: Bacillus subtilis, Staphylococcus aureus, Enterobacter clocae, Enterobacter asburiae and Stenotrophomonas maltophilia. The Gram negative organisms confirmed were Enterobacter clocae, Enterobacter asburiae and Stenotrophomonas maltophilia. The isolated fungus was Aspergillus niger. In the analysis of different chemical preservatives on mango seed powder, the most effective preservative was 3.0% sodium benzoate followed by 5% sodium acetate and 5% common salt. Citric acid was the least effective of all the preservatives used at equal concentrations. Sodium benzoate at 3% had the least bacterial count of 0.8 x 10³ CFU/ml which was maintained from the 8^th week to the last week of storage. Citric acid at 0.1% and 1.0% concentrations had bacterial counts of 3.50 x 10³ CFU/ml and 2.0 x 10³ CFU/ml respectively at the end of the 12 weeks of storage. The pH of the chemically preserved powdered kernels of M. indica from the 1^st to the 12^th week ranged from 2.70-6.01. The phytochemicals present in the mango seed powder included tannins, saponnins, polyphenol, alkaloids, flavonoids, cardiac glycosides and steroids.