TITLE:
Antilisterial Activity of Lactose Fatty Acid Esters in Milk
AUTHORS:
Seung-Min Lee, Brian Nummer, Brian Nummer, Ashwini Wagh, Marie K. Walsh
KEYWORDS:
Lactose Monodecanoate, Lactose Monolaurate, Antilisterial Activity, Milk, Fat, Temperature
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.10 No.7,
July
19,
2019
ABSTRACT: Carbohydrate fatty acid esters have been shown to inhibit the growth of
bacteria in growth media. In this study, the antilisterial activities of the carbohydrate esters lactose monodecanoate (LMD) and lactose monolaurate (LML) were tested in milk samples with variable
fat content (up to 10%) and at different temperatures (37°C, 24°C and 5°C) after inoculation with a 5-strain Listeria monocytogenes cocktail. Both LMD and LML demonstrated antilisterial properties against L.
monocytogenes in milk, with the observed log reductions in the LMD
milk samples being higher than those in the LML samples at all tested
temperatures. LMD in 1% and 2% fat milk was found to be bactericidal with no Listeria growth by day 6. LMD showed significant antilisterial activity in milk samples containing up to 9%
fat at 37° and in samples with up to 3.5% fat at 24°C and in milk samples with up to 2% fat at 5°C.
LML showed significant Listeria log reductions at 37°C
with milk containing up to 9% fat but showed no microbial inhibition in milk in
any samples at 24°C and 5°C. Although carbohydrate fatty acid esters have
proven microbial bactericidal/bacteriostatic properties in growth media, their antimicrobial properties are reduced in a food system containing
fat and at temperatures lower than 37°C. The significance of this research is identifying food constituents and storage temperatures that limit the microbial
inhibitory properties of lactose esters to ensure appropriate use as potential
food grade antilisterial agents.