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The antioxidant and antimicrobial potential of artichoke extract (AE) in raw beef patties (RBPs) was evaluated during the storage. The RBPs were prepared with the addition of 500 and 1000 ppm AE. Also, Escherichia coli ATCC25922 and Listeria monocytogenes ATCC19118 were inoculated to each RBP to follow the antimicrobial activity. An evaluation of the instrumental colour, pH, total phenolic content (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, TBARS and microbiological properties was carried out during storage. The evaluation revealed that the a* value decreased significantly, so that the reduction level of the AE500 and AE1000 samples during storage was  35, 57, and 56%, respectively, in the control. AE addition slightly decreased the pH of RBPs, which varied between 5.72 and 5.96. The TPC and DPPH values of samples with added 500 and 1000 ppm AE were 2 to 3-fold and 3 to 7-fold higher than in the control, respectively. Also, the TBARS values were determined as 43 and 54% lower than in the control at the end of storage when 500 and 1000 ppm AE were used. The AE in RBP inhibited the viability of total aerobic psychrophilic bacteria, coliform bacteria and yeast-mould in a concentration-dependent manner. AE prevented the growth of E. coli ATCC25922 and L. monocytogenes ATCC19118 inoculated to the RBPs. In conclusion, 1000 ppm AE was sufficient for antioxidant and antimicrobial activity in RBP. To our knowledge, this is the first study that presents the antioxidant and antimicrobial activity of AE used in a food model system.

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Tarhana is a traditional cereal product fermented by lactic acid bacteria (LAB) and yeast strains that has gained special interest recently as an infant nutrition. Tarhana contains wheat flour, yogurt, and various vegetables that might create a microbiological toxicological risk, especially for Bacillus cereus and Staphylococcus aureus. In this study, characterization of the metabolites responsible for antibacterial activity of Pediococcus acidilactici PFC69 and Lactococcus lactis PFC77 strains obtained from tarhana was performed, and antibacterial effects were detected against B. cereus ATCC 11778 and S. aureus ATCC 29213 during the fermentation. A total of 12,800 AU/mL antibacterial activity was observed for the supernatants of the PFC69 and PFC77 strains that were found to be stable at high temperature and in low pH conditions and sensitive to proteases, suggesting the antimicrobial metabolite is a bacteriocin. These bacteriocins were further purified and their molecular sizes were determined as 4.5 and 3.5 kDa, respectively. Importantly, inoculation of PFC69 and PFC77 to tarhana dough significantly decreased B. cereus ATCC 11778 and S. aureus ATCC 29213 amounts from the fifth day of fermentation compared to the control dough samples. P. acidilactici PFC69 and L. lactis PFC77 strains were concluded as bioprotective cultures for tarhana and these strains were offered for other cereal-based fermentations.

BackgroundThe novel amido and O-ferrocenyldithiophosphonates [FcP(S)(SH)(NHR1)] (Fc = Fe(η5-C5H5)(η5-C5H4), R1 = 1-(4-fluorophenylethyl and benzyloxycyclopentyl) and [FcP(S)(OR2)S−][H3N+C(CH3)3] (R2 = myrtanyl) were synthesized by the reaction of [(FcPS2)]2 (Fc = Fe(η5-C5H5)(η5-C5H4)) and chiral amines, such as (S)–(−)-1-(4-fluorophenylethyl) amine and (1S,2S)-(+)-benzyloxycyclopentyl amine, and of (1S), (2S), (5S)-myrtanol in toluene. The reaction of ferrocenyldithiophosphonates and [Cu(PPh3)2]NO3 or AgNO3 and PPh3 gave rise to copper(I) and silver(I) complexes in THF. [Ag2{FcP(OMe)S2}2(PPh3)2] and [Cu(PPh3)2]NO3 were embedded into nanofibers and their antimicrobial activities on fibers were also investigated.ResultsThe compounds have been characterized by elemental analyses, IR, NMR (1H-, 31P-) spectroscopy as well as MS measurements. Nanofibers were obtained by electrospinning method which is the simplest and most effective method to produce nanoscale fibers under strong electrical field. Antimicrobial activity of the compound 5, [Ag2{FcP(OMe)S2}2(PPh3)2], and [Cu(PPh3)2]NO3 on fibers were studied.ConclusionsIn this study, the new dithiophosphonate ligands were synthesized and utilized in the preparation of copper(I) and silver(I) complexes with ferrocenyldithiophosphonate and triphenylphosphine. Then, the compounds [Ag2{FcP(OMe)S2}2(PPh3)2] and [Cu(PPh3)2]NO3 were added into the PAN solutions (Co-PAN dissolved in dimethylacetamide) and the solutions were electrospun onto microscope slides and PP meltblown surfaces. Antimicrobial activity of the compounds [Ag2{FcP(OMe)S2}2(PPh3)2] and [Cu(PPh3)2]NO3 on fibers were determined in vitro against two indicator strains; M. luteus NCIB and E. coli ATCC25922. The obtained results indicated that these metals showed moderate level antimicrobial activities.