Bìa tạp chí

 

009bet

Survey on the level of Listeria monocytogenes infection on gotu kola and fresh gotu kola juice in Nha Trang, Khanh Hoa province

Nguyen Thi Thanh Hai Le Nha Uyen Pham Thu Thuy
Published 10/04/2022

Article Details

How to Cite
Nguyen Thi Thanh Hai, Le Nha Uyen, Pham Thu Thuy. "Survey on the level of Listeria monocytogenes infection on gotu kola and fresh gotu kola juice in Nha Trang, Khanh Hoa province". Vietnam Journal of Food Control. vol. 5, no. 3, pp. 525-532, 2022
PP
525-532
Counter
354

Main Article Content

Abstract

Gotu kola is often used to make fresh juice without heating. In Nha Trang, gotu kola drinks are usually prepared and refrigerated while being traded. Listeria monocytogenes is a bacterium capable of growing at cold temperatures; whereas the pathogenicity is low, mortality rate can be up to 25 - 30%. Therefore, the assessment of the level of L. monocytogenes contamination on raw gotu kola and in gotu kola juice during cold storage is crucial to ensure food safety and hygiene. This study has shown that the prevalence of L. monocytogenes infection on raw gotu kola cultivated in Nha Trang accounted for 15% of the samples with an average infection density of 24.2 MPN/g, in which gotu kola grown in wastewater field had the highest density of bacteria. Soaking raw vegetables in a solution of potassium permanganate 10 ppm/10 minutes has appeared to reduce the amount of L. monocytogenes by 56%. During the first 6 hours of storage, the amount of L. monocytogenes in gotu kola juice was stable at low level. After 24 hours of storage, the number of bacteria increased tenfold (on gotu kola juice without sugar) and twentyfold (on gotu kola juice with sugar) depending on storage temperature. Noticeably, the addition of sugar in gotu kola juice may have increased the growth of bacteria. Test results of forty-five samples of gotu kola juice sold on the streets of Nha Trang have revealed that the infection rate of L. monocytogenes was 6.67% and the average bacterial density was 5.43 MPN/mL. Thus, consumers need to pay attention to the origin and the manufacturing process of crude materials and should not use this herbal beverage from 6 hours after storage to reduce the possibility of disease caused by L. monocytogenes.

Keywords:

Food preservation, Listeria monocytogenes, gotu kola juice, gotu kola.

References

[1]. FAO/WHO, “Risk Assessment of Listeria monocytogenes in ready-to-eat foods: Interpretative Summary,” Microbiological Risk Assessment Series, 2004.
[2]. D. Liu, “Identification, subtyping and virulence determination of L. monocytogenes, an important foodborne pathogen,” Journal of Medical and Microbiology, vol, 55 (Pt 6), pp. 645-649, 2006.
[3]. R. B. Larry, “Listeria monocytogenes: Incidence on vegetables,” Food Control, vol.7, no. 415, pp. 223-228, 1996.
[4]. P. Jeyaletchumi, R. Tunung, S. P. Margaret, R. Son, M. G. Farinazleen, Y. K. Cheah, N. Mitsuaki, N. Yoshitsugu, and K. M. Pradeep, “Listeria monocytogenes in raw salad vegetables sold at retail level in Malaysia,” Food Control, vol. 21, no. 5, pp. 774-778, 2010.
[5]. A. Miceli, and L. Settanni, “Influence of agronomic practices and pre-harvest conditions on the attachment and development of Listeria monocytogenes in vegetables,” Annals Microbiology, vol. 69, pp.185-199, 2019.
[6]. Directorate for standards, metrology and quality, TCVN 9778: 2013 (CAC/GL 61: 2007) “Guidelines on the Application of General Principles of Food Hygiene to the Control of Listeria monocytogenes Foods,” 2013.
[7]. D. H. Anthony, J. Karen, and Y. Chen, “Detection and Enumeration of Listeria monocytogenes in Foods, in Bacteriological Analytical Manual,”, Food and Drug Administration (FDA), 2017.
[8]. N. T. T. Hai, N. T. T. My, and N. M. Tri, “The situation of Listeria monocytogenes infection on lettuce in Nha Trang,” Journal of fisheries science and technology-Nha Trang University, vol. 1/2012, pp. 36-40, 2012.

 Submit