Assessment of natural vegetal extracts in the inhibition of leuconostoc mesenteroides MS1

Abstract

The present study focuses on the assessment of natural vegetal extracts in the inhibition of bacteria altering Vienna sausages whose growth becomes evident in the vacuum packed product after two to three weeks of refrigerated storage causing packages to swell. The different natural extracts were obtained by means of steam stripping, microwave assisted extraction and ultrasound assisted extraction. Apart from these extracts, commercial essential oils, pure compounds present in the vegetal kingdom and solutions were also evaluated. For each of the extracts, microbial sensitivity tests were carried out in order to assess the inhibitory/bactericidal effect against Leuconostoc mesenteroides MS1. It has been found that the essential oils obtained from Citrus lemon peels and Aloysia polystachya, Eucalyptus cinerea and Laurus nobilis leaves can be used as bactericides against the growth of Leuconostoc mesenteroides MS1. In addition, it has been found that eugenol/sunflower oil concentrations greater than 18.5% w/w, 0.75% w/w salicylic acid, 0.75% w/w hydroquinone; and Just commercial essential oils of lavender, peppermint and geranium also presented a bactericidal effect against it. These natural extracts used as natural antimicrobials represent an alternative to common chemical food preservatives against the Leuconostoc mesenteroides MS1 strain.

El presente estudio se focaliza en la evaluación de extractos vegetales naturales en la inhibición de bacterias que alteran las salchichas de Viena, cuyo crecimiento se evidencia en el producto envasado al vacío después de dos o tres semanas de almacenamiento refrigerado, lo cual produce hinchazón en los envases. Los diferentes extractos naturales fueron obtenidos mediante extracción con vapor de agua, extracción asistida por microondas y extracción asistida por ultrasonido. Además, se evaluaron aceites esenciales comerciales, compuestos puros presentes en el reino vegetal y soluciones. Para cada uno de los extractos se realizaron ensayos de sensibilidad microbiana para evaluar el efecto inhibitorio/bactericida contra Leuconostoc mesenteroides MS1. Se ha encontrado que los aceites esenciales obtenidos de cáscaras de Citrus lemon y de hojas de Aloysia polystachya, Eucalyptus cinerea y Laurus nobilis, pueden ser utilizados como potenciales bactericidas contra el crecimiento de Leuconostoc mesenteroides MS1. Además, concentraciones de eugenol/aceite de girasol mayores a 18.5 % p/p, ácido salicílico 0.75 % p/p, hidroquinona 0.75 % p/p; aceites esenciales comerciales Just de lavanda, menta y geranio presentaron efectos bactericidas contra la misma. Estos extractos naturales utilizados como antimicrobianos naturales representan una alternativa a los conservantes comunes de alimentos de síntesis química contra la cepa Leuconostoc mesenteroides MS1.