title: Composition, diffusion, and antifungal activity of black mustard (Brassica nigra) essential oil when applied by direct addition or vapor phase contact.
abstract: In this study, we characterized the essential oil (EO) of black mustard (Brassica nigra) and quantified its antimicrobial activity, when applied by direct contact into the liquid medium or by exposure in the vapor phase (in laboratory media or in a bread-type product), against the growth of Aspergillus niger, Aspergillus ochraceus, or Penicillium citrinum. Allyl-isothiocyanate (AITC) was identified as the major component of B. nigra EO with a concentration of 378.35 mg/ml. When B. nigra EO was applied by direct contact into the liquid medium, it inhibited the growth of A. ochraceus and P. citrinum when the concentration was 2 μl/ml of liquid medium (MIC), while for A. niger, a MIC of B. nigra EO was 4 μl/ml of liquid medium. Exposure of molds to B. nigra EO in vapor phase showed that 41.1 μl of B. nigra EO per liter of air delayed the growth of P. citrinum and A. niger by 10 days, while A. ochraceus growth was delayed for 20 days. Exposure to concentrations ≥ 47 μl of B. nigra EO per liter of air (MIC) inhibited the growth of tested molds by 30 days, and they were not able to recover after further incubation into an environment free of EO (fungicidal effect). Adsorbed AITC was quantified by exposing potato dextrose agar to B. nigra EO in a vapor phase, exhibiting that AITC was retained at least 5 days when testing EO at its MIC or with higher concentrations. Mustard EO MIC was also effective against the evaluated molds inhibiting their growth for 30 days in a bread-type product when exposed to EO by vapor contact, demonstrating its antifungal activity.
authors.affiliation: Departamento de Ingeniería Química, Alimentos y Ambiental, Universidad de las Américas Puebla, Sta. Catarina Mártir, San Andrés Cholula, 72810, Puebla, Mexico.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Mejía-Garibay
authors.affiliation: Departamento de Ingeniería Química, Alimentos y Ambiental, Universidad de las Américas Puebla, Sta. Catarina Mártir, San Andrés Cholula, 72810, Puebla, Mexico.
authors.forename: Enrique
authors.initials: E
authors.lastname: Palou
authors.affiliation: Departamento de Ingeniería Química, Alimentos y Ambiental, Universidad de las Américas Puebla, Sta. Catarina Mártir, San Andrés Cholula, 72810, Puebla, Mexico. aurelio.lopezm@udlap.mx.
authors.forename: Aurelio
authors.initials: A
authors.lastname: López-Malo
mesh_terms: D001230:Aspergillus / Q000187:drug effects; D001234:Aspergillus niger / Q000187:drug effects / Q000254:growth & development; D001939:Bread / Q000382:microbiology; D005658:Fungi / Q000187:drug effects / Q000254:growth & development; D005659:Fungicides, Industrial / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D009149:Mustard Plant / Q000737:chemistry*; D009822:Oils, Volatile / Q000494:pharmacology; D010407:Penicillium / Q000187:drug effects; D010938:Plant Oils / Q000008:administration & dosage* / Q000737:chemistry*; D014835:Volatilization
chemical_list: D005659:Fungicides, Industrial; D009822:Oils, Volatile; D010938:Plant Oils; C027793:mustard oil