Influence of Protein Type on the Antimicrobial Activity of LAE Alone or in Combination with Methylparaben

Abstract

The cationic surfactant Lauric arginate (LAE) has gained approval for utilization in meat products (limit: 200 mg/kg). However, as for other antimicrobials, its activity is reduced when applied to complex food matrices. The current study therefore aims to better understand protein-antimicrobial agent-interactions and their influence on the antimicrobial activity of (i) LAE and (ii) methylparaben against Listeria innocua and Pseudomonas fluorescens in defined model systems (pH 6). Antimicrobials were utilized alone or in combination with nutrient broth containing either no protein or 2% bovine serum albumin, whey protein isolate, or soy protein hydrolysate. LAE was found to form complexes with all proteins due to electrostatic attraction, determined using microelectrophoretic and turbidity measurements. Minimal lethal concentrations of LAE were remarkably increased (4–13 fold) in the presence of proteins, with globular proteins having the strongest impact. Combinations of LAE (0–200 µg/mL) with the less structure-sensitive component methylparaben (approved concentration 0.1%) remarkably decreased the concentrations of LAE needed to strongly inhibit or even kill both, L. innocua and P. fluorescens in the presence of proteins. The study highlights the importance of ingredient interactions impacting microbial activity that are often not taken into account when examining antimicrobial components having different structure sensitivities.

Ethyl lauroyl arginate: An update on the antimicrobial potential and application in the food systems: a review

“…Parabens, also known as para-hydroxybenzoic acid esters, are a class of antimicrobial preservatives allowed for use in foods. It is proven that LAE exhibits higher antibacterial and antifungal activities in combination with methylparaben (Li et al, 2018;Loeffler et al, 2020). As reported by Loeffler et al (2020), the MIC values of LAE against L. innocua and P. fluorescens in nutrient broth with 2% bovine serum albumin (BSA) were 300 and 200 μg/ml, respectively.…”

“…It is proven that LAE exhibits higher antibacterial and antifungal activities in combination with methylparaben (Li et al, 2018;Loeffler et al, 2020). As reported by Loeffler et al (2020), the MIC values of LAE against L. innocua and P. fluorescens in nutrient broth with 2% bovine serum albumin (BSA) were 300 and 200 μg/ml, respectively. However, the MIC values of LAE against L. innocua or P. fluorescens decreased to 175 and 125 μg/ml, respectively, when combined with 0.1% methylparaben in the same testing condition.…”

“…Several benefits have be resulted from the combination of LAE with other antibacterial agents, such as methylparaben (Li et al, 2018;Loeffler et al, 2020), ε-polylysine (Kozak et al, 2017;Martínez-Ramos et al, 2020), nisin (Pattanayaiying et al, 2014;Soni et al, 2014), potassium lactate and sodium diacetate (Martin et al, 2009), organic acid salts (Luchansky et al, 2005;Suksathit and Tangwatcharin, 2013), and peracetic acid (Shen et al, 2021).…”

“…LAE may interact with other components within foods and beverages, such as starch (Ma et al, 2013), proteins (Loeffler et al, 2020), polysaccharides (Loeffler et al, 2014), and lipids (Ziani et al, 2011;Magrinyà et al, 2015), causing a significant decrease in its antimicrobial activity. In general, many studies confirm that the concentration of LAE required to inactivate microorganisms in foods is higher than that needed for in vitro tests.…”

Insights into a novel pathway of paraben-induced endotoxin affecting human sperm quality: Parabens’ dual effects of antibacterial and estrogenic activity

“…A rat study provided initial evidence that postnatal low-dose exposure to MeP was capable of modifying the gut microbiota in adolescent rats [43]. G+ (such as Staphylococcus aureus) are more sensitive to PBs with longer alkyl chains than G− (such as Escherichia coli) [44,74], due to the signi cant differences in lipid composition of plasma membranes between G + and G − bacteria [75]. When PBs inhibited G+, the abundance of G − increased, and more LPS was released.…”