Antioxidant and antimicrobial activity and potential of heather (Erica spp.) extracts in the control of Listeria monocytogenes

Abstract

Summary In this work, heather and its flowers were studied regarding their antioxidant and antimicrobial activities. Plants were subjected to ultrasound‐assisted methanolic extraction followed by fractionation. A phytochemical characterisation of extracts content in total phenols and flavonoids, and their antioxidant activity was performed. The antimicrobial activity was evaluated through the determination of minimum inhibitory concentration and by bioautography. Following, studies on the antilisterial potential were carried out by: time‐kill curves, inhibition of biofilm formation and tolerance of Listeria monocytogenes to adverse conditions. The results evidenced the antioxidant activity in both extracts, as well as, the antimicrobial activity against Gram‐positive bacteria. Concerning the evaluation of the antilisterial potential, a bacteriostatic behaviour and inhibition of biofilms formation ability were observed. Listeria monocytogenes showed an increased susceptibility to adverse conditions when preincubated with extracts. Thus, heather and its flowers may be a source of new compounds with antilisterial activity potential.

Control of Listeria monocytogenes biofilm on industrial surfaces by cell ‐ free extracts of Lactobacillus plantarum

“…As a result shown in Table 2, no significant differences were observed between the SS, PVC, and PC surfaces. Similarly, Santos et al (2018) showed that all The microscopic observations performed for L. monocytogenes 32 biofilms showed a dense three-dimensional structure in all surfaces (Figures 3a-5a), similar to the reports of other authors (Borucki et al, 2003;Dubravka et al, 2009). Using the scanning electron microscope, we established that L. monocytogenes 32 formed strong biofilm and that individual bacterial cells adsorbed to all three surfaces.…”

“…Similarly, Santos et al. (2018) showed that all concentrations tested a fraction of heather extracts led to statistically significant inhibition of biofilm formation of L. monocytogenes , with inhibition percentages as high as 91%. Overall, L. plantarum ‐derived CFE with its sub‐MIC values was found to be effective on all surfaces which are all resistant to acid and other sanitizer treatments (van der Veen & Abee, 2011) that makes routine disinfection in the food industry more difficult.…”

“…Examples of chemical or biological agent alternatives suggested removing biofilms have been accepted as environment‐friendly control strategies like enzymes and phages (Srey et al., 2013), natural compounds such as flavonoids extracted from plants (Koo et al., 2003), and bacterial products such as bacteriocins (Okuda et al., 2013). In particular, several studies (Nostro et al., 2016; Sandasi et al., 2010; Santos et al., 2018) have reported the activity of plant extracts in inhibiting the biofilm formation of L. monocytogenes . However, no unique strategy providing absolute biofilm control efficiency has been presented in the literature yet (Ciccio et al., 2012).…”

Chemical analysis and in vitro antioxidant and anticholinesterase activities of essential oils and extracts from different parts of Erica manipuliflora

“…Since ancient times, Erica species have been used as a traditional medicine for the treatment of burns and wounds by the local people in Anatolia. The studies have been showed that Erica species possess antiulcer [8,9], antimicrobial [10,11], antibacterial, cytotoxic [12][13][14][15] and antioxidant [16][17][18][19][20] activities. It has also been reported that Erica species have (poly) phenolic, flavonoid, coumarin and triterpenoid, compounds [21][22][23][24][25][26][27][28].…”

The Antioxidant Activity of Wild-Growing Plants Containing Phenolic Compounds in Latvia

“…This corresponds to our findings. C. vulgaris has many phenolic compounds with antioxidant activity, which could explain the high activity of its extracts [ 31 , 49 ]. Even C. vulgaris honey has antioxidant activities [ 50 ].…”