Scapania nemorea liverwort extracts: Investigation on volatile compounds, in vitro antimicrobial activity and control of Saccharomyces cerevisiae in fruit juice

•Study of volatile chemical composition and antimicrobial potential of Scapania nemorea.•Dominant compounds in S. nemorea were β-bazzanene, isobazzanene, aromadendrene.•MIC of S. nemorea were 0.5-3 mg/mL (3 bacteria) and 0.2-1 mg/mL (7 yeasts).•The use of S. nemorea and mild heat as preservative for fruit juices was explored.•S. nemorea enhanced thermal inactivation of Saccharomyces cerevisiae in fruit juice.

This study was focused on chemical characterisation of liverwort Scapania nemorea extracts and their antimicrobial activity against pathogenic and food-spoiling yeasts and bacteria. The chemical composition of three different extracts of the liverwort S. nemorea was determined by solid phase microextraction gas chromatography-mass spectrometry (SPME GC-MS). The dominant compounds in extracts were sesquiterpenes β-bazzanene (11%, 17.9% and 14.6%), isobazzanene (10.2%, 15.8% and 11.7%) and aromadendrene (8.8%, 12.9% and 10.6%) in the methanol, ethanol and ethyl acetate extracts, respectively. Antimicrobial potential of S. nemorea extracts against food spoiling yeasts and bacteria was determined in vitro by microdilution method. The Minimum Inhibitory Concentration (MIC) varied from 0.5 to 3 mg/mL for bacteria, and from 0.2 to 1 mg/mL for yeasts. Moreover, the combined effects of dry methanol extract of S. nemorea and heat processing on the survival and growth of a spoilage yeast in an apple/orange-based beverage, have been assessed through a Central Composite Design. Changes in color and flavor of the beverages were considered acceptable also after one week of storage at 25 °C. The results provide evidence of antimicrobial potential of S. nemorea extracts and suggest its potential as natural antimicrobial agent for food preservation.