title: Retardation of Listeria monocytogenes growth in mozzarella cheese using antimicrobial sachets containing rosemary oil and thyme oil.
abstract: An antimicrobial sachet containing microcellular foam starch (MFS) with embedded rosemary oil and thyme oil was developed to reduce bacterial growth in shredded mozzarella cheese. The efficacy of the volatiles of oils at various concentrations in reducing Listeria monocytogenes as well as the release of the oils from the MFS have been also determined in this study. The cheese, inoculated with a cocktail of 5 strains of L. monocytogenes (approximately 3 log CFU/g), was packaged in a Nylon/EVOH/PE bag. A paper sachet containing MFS embedded with rosemary oil and thyme oil, separately or together, was inserted into the bag. Rosemary and thyme oil volatiles released from the sachet restricted the growth of L. monocytogenes, resulting in a 2.5 log CFU/g reduction on day 9 at 10 °C. The volatile oils also showed inhibitory effects on the growth of lactic acid bacteria (LAB) and total aerobic bacteria (TAB). After 15 d at 10 °C, the numbers of LAB and TAB in the samples containing the sachet with both oils experienced a 1.2 and 1.4 log CFU/g reduction, respectively, compared to untreated samples. Nonetheless, the sachet treatment produced a distinct odor, unfavorably received by the panelists. The results suggest the potential for application of the sachet system for the reduction of growth of L. monocytogenes, LAB, and TAB in food products.
authors.affiliation: Dept. of Food Science and Human Nutrition, Univ. of Illinois at Urbana-Champaign, Champaign, IL, 61821, U.S.A.; PepsiCo Inc, 7701 Legacy Dr., Plano, TX, 75024, U.S.A.
authors.forename: Jung H
authors.initials: JH
authors.lastname: Han
authors.forename: Dhaval
authors.initials: D
authors.lastname: Patel
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Sea C
authors.initials: SC
authors.lastname: Min
mesh_terms: D000328:Adult; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002611:Cheese / Q000382:microbiology*; D003116:Color; D003258:Consumer Behavior; D005260:Female; D005506:Food Contamination / Q000517:prevention & control; D005516:Food Microbiology; D006801:Humans; D008089:Listeria monocytogenes / Q000254:growth & development* / Q000302:isolation & purification; D008297:Male; D009812:Odorants; D009822:Oils, Volatile / Q000494:pharmacology*; D010938:Plant Oils / Q000494:pharmacology*; D013649:Taste; D046930:Thymus Plant / Q000737:chemistry*; D055815:Young Adult
chemical_list: D000890:Anti-Infective Agents; D009822:Oils, Volatile; D010938:Plant Oils; C053775:rosemary oil
keywords: Antimicrobial sachet; Listeria monocytogenes; essential oil; mozzarella cheese