Enhanced antimicrobial effect of ultrasound by the food colorant Erythrosin B. (October 2017)

• Record Type: Journal Article
• Authors: Bastarrachea, Luis J.; Walsh, Martin; Wrenn, Steven P.; Tikekar, Rohan V.
• Is Part Of: Food research international. Volume 100 Part 1(2017)
• Page Start: 344
• Page End: 351
• Publication Date: 2017-10
• Subjects: Low-frequency ultrasound -- Food colorants -- Microbial inactivation -- Nonthermal technologies; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2017.07.012
• Languages: English
• ISSNs: 0963-9969

Abstract

Abstract: The synergistic combination of the food colorant Erythrosin B (E-B, FD&C 3) (0, 25, and 50 μM) and low-frequency ultrasound (20 kHz, 0.86–0.90 W mL − 1 ) was evaluated against Listeria innocua . Although E-B was antibacterial by itself, the inactivation rate significantly increased in a concentration-dependent manner upon exposure to ultrasound and followed a sigmoidal behavior. The enhanced antimicrobial effect of E-B in the presence of ultrasound can be explained in part from a microbubble disappearance study in which it was confirmed that the presence of E-B enhances inertial cavitation, thereby enhancing the antimicrobial effect of ultrasound. The inactivation rate in a sequential treatment, where L. innocua was sonicated for 4 min followed by exposure to 25 μM Erythrosin B, was comparable to that obtained by the simultaneous treatment, indicating complementary mechanisms of inactivation. Fluorescence microscopy showed attachment of E-B to the cells, which may explain its intrinsic antimicrobial property. Other mechanism may include the confirmed decrease in the cavitation threshold of water by addition of E-B, resulting in more effective cavitation. The study offers a proof-of-concept of a novel approach to complement ultrasound treatment for enhanced microbial inactivation. Graphical abstract: Highlights: Erythrosin B is able to increase inertial cavitation under ultrasound exposure. Erythrosin B shows an intrinsic antimicrobial effect against Listeria innocua . Intrinsic antimicrobial effect of Erythrosin B is independent of its concentration. With ultrasound, antimicrobial effect increases with Erythrosin B concentration. L. innocua previously exposed to ultrasound is more sensitive to Erythrosin B.