The Effect of Selected Herbal Extracts on Lactic Acid Bacteria Activity

Abstract

This study aimed to investigate the effect of plant extracts (valerian Valeriana officinalis L., sage Salvia officinalis L., chamomile Matricaria chamomilla L., cistus Cistus L., linden blossom Tilia L., ribwort plantain Plantago lanceolata L., marshmallow Althaea L.) on the activity and growth of lactic acid bacteria (LAB) during the fermentation and passage of milk through a digestive system model. The tested extracts were also characterized in terms of their content of polyphenolic compounds and antioxidant activity. It was observed that the addition of the tested herbal extracts did not inhibit the growth of LAB in fermented milk drinks, such as yogurts. However, they can gradually inhibit fermentation when added at concentrations above 2% by weight, and hence should be used in limited amounts. The microflora of yogurts containing the tested herbal extracts did not die during digestion in model digestive juices, and no stimulating effect of the added plant extracts was noted either. Nevertheless, due to the antioxidant properties, a slight addition of the herbal extracts containing polyphenols to different kinds of food products can increase the nutritional quality, thus making them functional foods.

Antioxidant and Antibacterial Activity of Extracts from Selected Plant Material

“…Our results indicate that the extract of C. incanus herb contained the highest content of phenolic compounds, reaching a value of 363.61 ± 2.29 mg GAE/g of extract and that the extract of A. archangelica root contained the lowest (20.35 ± 0.37 mg GAE/g of extract). In contrast to our study, Bernacka et al [35] and Ziarno et al [2] showed lower phenolic content in water infusions prepared from C. incanus leaves. The differences may be due to the different preparation of the extract, the part of the plant material used and its origin and time of harvest.…”

“…Plant material is a source of many value components, such as phenolic compounds, which may scavenge free radicals and thus reduce oxidative stress [1][2][3]. Phenolic compounds showing antioxidant properties include flavonoids, phenolic acids, lignans and stilbenes.…”

“…not detected;2 References compound, the diameter of commercial disc containing 0.03 mg of Nitrofurantoin was 6 mm (Mast Diagnostics, Merseyside, UK). Means with different lowercase letters ( a-j ) indicate significant difference at the significance level of 0.05.…”

Studies Regarding the Pharmaceutical Potential of Derivative Products from Plantain

“…Antimicrobial activities of different bioproducts obtained in various solvents are reported for microorganisms such as E. coli , S. aureus , P. aeruginosa , K. pneumoniae , P. mirabilis , C. albicans , and various Streptoccosus species as S. aglactiae , S. pneumoniae , S. bovis , S. mutans , S. sobrinus , S. parasanguinis , and S. viridans [ 46 ]. Ziarno and collab [ 47 ] in studies performed on aqueous extract obtained from Plantago lanceolata, which contains 41.84 mg GAE/g, did not find an inhibitory effect of the polyphenolic content on the bacterial population of S. thermophilus or L. delbruecki spp. bulgaricus in the field of concentrations ranging between 0.2–1.4% during 4 h of fermentation.…”

“…bulgaricus in the field of concentrations ranging between 0.2–1.4% during 4 h of fermentation. If the concentration of aqueous extract increased to 3% in the culture media, the bacterial population decreased slightly with (0.5–0.6) logarithmic units for each microorganism involved in the study [ 47 ]. Beara and collab.…”