Bio-Preservative Potential of Calotropisprocera extract on Tomato (Lycopersicumesculentummill.) Fruits Sold in Ago-Iwoye Market, Southern Nigeria and its Microbial Spoilage

Calotropisprocera extract has been established to possess antimicrobial properties against microorganisms of medical importance. This study investigated the effect of the exudates on post-harvest spoilage of tomato fruits and also studied the microorganisms associated with its spoilage. Fresh and wholesome tomato fruits were purchased from Ago-Iwoye metropolitan market, Southern Nigeria. One hundred (100) pieces of epicarp intact tomato fruits were sorted and distributed into nine (9) small baskets each and treated with 10%, 15%, 20% and 25% C. procera extract with leaves underlain covering and without leaf respectively including a control set up. They were monitored every other day for eight weeks and spoilt fruit samples were enumerated and microbiological analysis was conducted. Samples without leaf significantly enhanced the shelf life as level of spoilage set in at 11th, 13th, 21st and 15th day with 4%, 5%, 5% and 4% spoilage respectively. However, less than 50% of the 20% concentration maintained wholesome freshness till 35th day whereas control started on the 3rd day and by 15th day all got spoilt. Total of nine species of microorganisms were identified as Escherichia coli, Micrococcus sp., Staphylococcus aureus, Corynebacterium sp., Mucorsp., Aspergillusniger, A. fumigatus, Alternaria sp. and Saccharomyces cerevisiae. Mucorsp. had the highest rate of occurrence 43 (51.2%) and the lowest was Alternaria sp. 2 (2.4%). The results therefore established a good support for the application of this biopreservative metabolite in food processing industries.

Keywords: Tomato fruits; Calotropisproceraextract; bio-preservative, microorganisms, spoilage, AgoIwoye.