Microbiological and physical properties of pennywort (Centella asiatica) leaves using pulsed light technology

Siti Zaharah R., . and Noranizan M., . and Son R., . and Roselina K., . and Yusof N. L., . and Koh P. C., . and Nor Hasni H., . Microbiological and physical properties of pennywort (Centella asiatica) leaves using pulsed light technology. pp. 16-27. ISSN 2231-7546

Pennywort (Centella asiatica) is a herbaceous vegetable commonly consumed raw as ulam or salad. Consumption of raw leafy green vegetables is one of the pathogenic mechanisms that could cause foodborne outbreaks. The aim of the present work was therefore to investigate the effect of pulsed light (PL) treatment at fluences of 1.5 4.2 6.9 9.6 and 12.3 J/cm on the microbiological and physical quality of pennywort stored at 4 1C. Escherichia coli (E. coli) were inoculated onto the pennywort leaves before being exposed to PL and viewed using scanning electron microscopy (SEM). PL fluences of 6.9 9.6 and 12.3 J/cm significantly reduced the microbial count; however the highest inactivation was obtained by using fluences of 9.6 and 12.3 J/cm. The color of pennywort was not significantly affected by PL treatment applied at lower fluences of 1.5 4.2 and 6.9 J/cm; however at higher fluence 9.6 and 12.3 J/cm the color was affected. PL at 1.5 4.2 6.9 and 9.6 J/cm was able to retain the texture appearance of the leaves. To conclude PL at 6.9 J/cm showed the best fluence to reduce total aerobic mesophilic count while retaining the physical properties of pennywort leaves and extend the shelf life to about four days. The inactivation of E. coli population was significantly higher at PL fluence of 6.9 J/cm. It was observed that PL caused the destruction to the surface of E. colis cell membrane. The reductions of samples inoculated with E. coli were better than those achieved in native microbiota. Furthermore the present work also demonstrated that PL treatment was able to reduce the microbial count on pennywort leaves.

Full text available from: Official URL: http://www.ifrj.upm.edu.my/27%20(01)%202020/02%20-...

Abstract

Pennywort (Centella asiatica) is a herbaceous vegetable commonly consumed raw as ulam or salad. Consumption of raw leafy green vegetables is one of the pathogenic mechanisms that could cause foodborne outbreaks. The aim of the present work was therefore to investigate the effect of pulsed light (PL) treatment at fluences of 1.5 4.2 6.9 9.6 and 12.3 J/cm on the microbiological and physical quality of pennywort stored at 4 1C. Escherichia coli (E. coli) were inoculated onto the pennywort leaves before being exposed to PL and viewed using scanning electron microscopy (SEM). PL fluences of 6.9 9.6 and 12.3 J/cm significantly reduced the microbial count; however the highest inactivation was obtained by using fluences of 9.6 and 12.3 J/cm. The color of pennywort was not significantly affected by PL treatment applied at lower fluences of 1.5 4.2 and 6.9 J/cm; however at higher fluence 9.6 and 12.3 J/cm the color was affected. PL at 1.5 4.2 6.9 and 9.6 J/cm was able to retain the texture appearance of the leaves. To conclude PL at 6.9 J/cm showed the best fluence to reduce total aerobic mesophilic count while retaining the physical properties of pennywort leaves and extend the shelf life to about four days. The inactivation of E. coli population was significantly higher at PL fluence of 6.9 J/cm. It was observed that PL caused the destruction to the surface of E. colis cell membrane. The reductions of samples inoculated with E. coli were better than those achieved in native microbiota. Furthermore the present work also demonstrated that PL treatment was able to reduce the microbial count on pennywort leaves.

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Item Type:	Article
AGROVOC Term:	Leafy vegetables
AGROVOC Term:	Herbaceous plants
AGROVOC Term:	Pulsed lighting
AGROVOC Term:	Microbiological analysis
AGROVOC Term:	Physical properties
AGROVOC Term:	Escherichia coli
AGROVOC Term:	Electron microscopy
AGROVOC Term:	Sampling
AGROVOC Term:	Experiments
AGROVOC Term:	Water analysis
Depositing User:	Mr. AFANDI ABDUL MALEK
Last Modified:	24 Apr 2025 00:54
URI:	http://webagris.upm.edu.my/id/eprint/8968

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