Biological Activity of Extracts from Aromatic Plants as Control Agents against Spoilage Molds Isolated from Sheep Cheese

• Main Authors: Nuria Muñoz-Tebar, Emilio J. González-Navarro, Teresa María López-Díaz, Jesús A. Santos, Gonzalo Ortiz de Elguea-Culebras, M. Mercedes García-Martínez, Ana Molina, Manuel Carmona, María Isabel Berruga
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Foods
• Subjects: <i>Penicillium</i>; <i>Aspergillus</i>; molecular identification; essential oils; ethanolic extracts from solid by-products; antifungal activity
• Online Access: https://www.mdpi.com/2304-8158/10/7/1576

The aim of this work was to assess the antifungal and antioxidant activity of essential oils and ethanolic extracts from distilled solid by-products from aromatic plants (<i>Artemisia</i> <i>dracunculus</i>, <i>Hyssopus</i> <i>officinalis</i>, <i>Lavandula</i> <i>stoechas</i>, <i>Origanum</i> <i>vulgare</i> and <i>Satureja</i> <i>montana</i>) against 14 fungi strains isolated from sheep cheese and identified at species level using DNA barcoding based on β-tubulin sequence analysis. In addition, capacity of fungi to produce ochratoxin A, patulin, cyclopiazonic acid and sterigmatocystin was analyzed. Of the isolates, 85.7% belonged to <i>Penicillium</i> (<i>P</i>. <i>commune</i>/<i>biforme</i>, <i>P</i>. <i>crustosum</i>) and 14.3% to <i>Aspergillus</i> (<i>A</i>. <i>puulaauensis</i> and <i>A</i>. <i>jensenii</i>), the first time that these <i>Aspergillus</i> species have been found in sheep’s cheese. All <i>P</i>. <i>commune</i> isolates were producers of cyclopiazonic acid, and the two <i>Aspergillus</i> strains produced sterigmatocystin, but the others did not produce any tested mycotoxin. Among the essential oils tested, oregano, savory and tarragon had a significant antifungal activity against all the isolated strains, but no ethanolic extract showed antifungal activity. By contrast, ethanolic extracts showed great potential as antioxidants. The identification of new molds in cheese will help the dairy industry to know more about those molds affecting the sector, and the use of aromatic plants in the control of fungal spoilage could be a suitable alternative to chemical preservatives used in the agri-food industry.