Control of Listeria monocytogenes and Escherichia coli O157:H7 in enoki mushrooms (Flammulina velutipes) by combined treatments with organic acids, nisin, and ultrasound. (November 2021)

• Record Type: Journal Article
• Authors: Yoon, Jae-Hyun; Jeong, Do-Young; Lee, Su-Bin; Kim, Se-Ri
• Is Part Of: Food control. Volume 129(2021)
• Publication Date: 2021-11
• Subjects: Enoki mushroom -- Listeria monocytogenes -- Lactic acid -- Nisin -- Synergistic effect -- Ultrasound; Food -- Quality -- Periodicals; Food -- Analysis -- Periodicals; Food handling -- Periodicals; Food industry and trade -- Quality control -- Periodicals; Aliments -- Industrie et commerce -- Qualité -- Contrôle -- Périodiques; Aliments -- Qualité -- Périodiques; Aliments -- Analyse -- Périodiques; Hygiène alimentaire -- Périodiques; Food -- Analysis; Food handling; Food -- Quality; Periodicals; Electronic journals; 664.07
• DOI: 10.1016/j.foodcont.2021.108204
• Languages: English
• ISSNs: 0956-7135

Abstract

Abstract: This study was undertaken to evaluate the combined effect of organic acids, nisin, and ultrasound (US) on the reduction of Listeria monocytogenes and Escherichia coli O157:H7 in enoki mushrooms stored at 5 °C. Each bacterium was treated with 1–3% organic acids, 0.1% nisin, and 40 kHz US in enoki mushrooms individually or in combination at 25 °C for ≤30 min. Lactic acid (LA) was superior to malic acid, acetic acid, and nisin, decreasing L . monocytogenes and E. coli O157:H7 in enoki mushrooms by more than 3.00 log CFU/g at 25 °C for 30 min. US alone failed to inactivate L . monocytogenes and E . coli O157:H7 in enoki mushrooms. Particularly, L . monocytogenes and E . coli O157:H7 diminished to below the detection limits (<1.55 log CFU/g) in enoki mushrooms after dipping in 3% LA and 0.1% nisin incorporated with 40 kHz US at 25 °C for 30 min and remained constant incapable of growing in samples stored at 5 °C for 120 h. A transmission electron microscopy analysis presented collapse of peripheral cytoplasm layers with formation of local pores and breakage of cell wall structures in L . monocytogenes exposed to combined treatments with 3% LA, 0.1% nisin, and 40 kHz US. A combination of LA, nisin, and US exerted strong synergistic effects for controlling the mushroom carriage of L. monocytogenes and E . coli O157:H7.