Antimicrobial activity of bottle gourd leaf extract and its effect on the quality of food

Abstract

A considerable interest has developed on natural foods preservatives as extend the shelf-life. There is a strong controversy about the safety aspects of synthetic preservatives since they are considered responsible for many teratogenic attributes and carcinogenic as well as residual toxicity. Therefore, the antimicrobial activity, total phenolic and flavonoids of bottle ground leaf extract were examined. And a descriptive detection of the extract was made, where it was found that they contain (phenols, flavonoids, alkaloids, glycosides, terpenes, saponins, phlobatanins, resins, tannins And steroids). 50% ethanolic extract exhibited the highest extraction ability for such phenolic and flavonoid compounds. The total phenolic was 406 mg gallic equivalent/g and the total flavonoid was 42.6 mg quercetin/g dry weight. The antimicrobial activity was studied using Agar well diffusion method and broth dilution method. Results indicated that Gram-negative bacteria E. Coli was more sensitive than Gram-positive bacteria S. aureus and B. subtilis against bottle ground leaf extract, were 25, 18 and 19 mm inhibitory zone for concentration 50mg/well respectively. MIC and MLC where determined, MICs test showed that the lowest concentration was 10 mg/ml against S. aureus, and was equal concentration on E. coli and B. subtilis (20 mg/ml). On the basis of this results bottle ground leaf extract was added to beef sausage at different concentrations (1%, 2%, and 4%) and stored for 90 days at 20-°C to study its effect on the quality of beef sausage. Results indicated a high stability against oxidation in sausage treated with the bottle ground leaf extract compared to control samples. Also, a decrease in microbial load of the treated sausage compared to the control was observed. Finally, it was evident that the bottle gourd leaf extract has a role in reducing the number of microbes, as well as their possession of natural antioxidants that prolongs shelf life of sausage.