Assessment of Phenolic Contents and Antioxidant and Antibacterial Activities of Extracts from Four Varieties of Iranian Date Palm (Phoenix dactylifera L.) Seeds

  Background and objective: Every year, large quantities of date palm seeds are produced as byproducts in date processing and packaging industries, which is discarded or used as low-value materials for animal feeds and composts. However, these bioresources may include potentials to produce high-value added products in food industries. The major aim of the current study was to assess phenolic profiles and contents and antioxidant and antibacterial activities of four Iranian date palm seed extracts, namely Zahedi, Kabkab, Mazafati and Rabbi.Material and methods: Total phenolic contents, phenolic compounds profile and antioxidant and antibacterial activities of extracts from four Iranian date palm seeds were assessed using Folin-Ciocalteu, reversed-phase high-performance liquid chromatography, 2, 2-diphenyl-1picrylhydrazyl radical scavenging, agar disc diffusion and broth microdilution methods, respectively.Results and conclusion: Total phenolic contents varied 1480-3380 mg GAE 100 g-1 dw. cinnamic, chlorogenic, caffeic and 3, 5-dihydroxybenzoic acid included the primary phenolic compounds, respectively. Of the varieties, Kabkab and Mazafati seed extracts with IC50 values of 16.56 and 22.6 µg ml-1 demonstrated the highest and lowest radical scavenging activity, respectively. Results obtained from disc diffusion method revealed that all extracts included inhibitory effects against Staphylococcus aureus, but not against Escherichia coli. Minimum inhibitory concentration and minimum bactericidal concentration of the extracts ranged 1.563.125 and 3.125-12.5 mg ml-1 for Staphylococcus aureus, respectively. Based on the findings, Iranian date seeds are good sources of extractable phenolic compounds with notable antioxidant activities, which can be used as natural additives in formulations of various products such as functional foods and dietary supplements. Furthermore, these seeds can be converted to value added products through biotechnological processes.Conflict of interest: The authors declare no conflict of interest.   

Utjecaj esencijalnog ulja biljke Echinophora platyloba i primarnog kondenzata dima na suzbijanje rasta bakterije Staphylococcus aureus u goveđem mesu

In the current study, the antibacterial effect of Echinophora platyloba essential oil and common liquid smoke (individually and in combination) against Staphylococcus aureus in beef meat samples is investigated. Using an automated microbiological growth analyser and the turbidimetric technique, the minimum inhibitory concentrations (MIC) and the minimum bactericidal concentrations (MBC) of the essential oil and liquid smoke were determined. Anti-S. aureus activity of essential oil and liquid smoke (individually and in combination) was defined by disk diffusion assay, generation time and cell constituent release. Apart from that, the interactions between these two compounds were measured by the checkerboard assay and by calculating the fractional inhibitory concentration (FIC) indices. Related MIC values of essential oil and smoke were found to be 7200 and 5500 mg/L, and MBC values were 8500 and 8000 mg/L, respectively. The conducted organoleptic assay showed that the addition of 0.05 g of essential oil and 0.6 g of liquid smoke to 100 g of meat samples did not have adverse effect on the overall acceptance. Weaker antibacterial effect against Staphylococcus aureus was observed when only Echinophora platyloba essential oil was used than when it was used in combination with liquid smoke.U radu je ispitan pojedinačni i zbirni učinak esencijalnog ulja biljke Echinophora platyloba i primarnog kondenzata dima na suzbijanje rasta bakterije Staphylococcus aureus u uzorcima goveđeg mesa. Pomoću automatskog sustava za detekciju mikrobiološkog rasta i turbidimetrije određene su minimalna inhibicijska koncentracija i minimalna baktericidna koncentracija esencijalnog ulja i primarnog kondenzata dima. Pojedinačni i zbirni antibakterijski učinak esencijalnog ulja i primarnog kondenzata dima ispitani su disk difuzijskom metodom, određivanjem generacijskog vremena i mjerenjem apsorbancije otpuštenog staničnog sadržaja bakterije Staphylococcus aureus. Osim toga, ispitana je interakcija između ta dva antimikrobna agensa mikrorazrjeđenjem u bujonu (tzv. checkerboard testom) i određivanjem indeksa interakcije. Minimalna inhibicijska koncentracija esencijalnog ulja bila je 7200 mg/L, a primarnog kondenzata dima 5500 mg/L, dok je minimalna baktericidna koncentracija esencijalnog ulja bila 8500 mg/L, a primarnog kondenzata dima 8000 mg/L. Ispitana su organoleptička svojstva uzoraka mesa i utvrđeno je da dodatak 0,05 g esencijalnog ulja i 0,6 g kondenzata dima u 100 g uzorka nije utjecao na prihvatljivost proizvoda. Esencijalno ulje biljke Echinophora platyloba imalo je slabiji učinak na suzbijanje rasta bakterije Staphylococcus aureus od kombinacije esencijalnog ulja i primarnog kondenzata dima

The anti-staphylococcus aureus effect of combined echinophora platyloba essential oil and liquid smoke in beef

In the current study, the antibacterial effect of Echinophora platyloba essential oil and common liquid smoke (individually and in combination) against Staphylococcus aureus in beef meat samples is investigated. Using an automated microbiological growth analyser and the turbidimetric technique, the minimum inhibitory concentrations (MIC) and the minimum bactericidal concentrations (MBC) of the essential oil and liquid smoke were determined. Anti-S. aureus activity of essential oil and liquid smoke (individually and in combination) was defined by disk diffusion assay, generation time and cell constituent release. Apart from that, the interactions between these two compounds were measured by the checkerboard assay and by calculating the fractional inhibitory concentration (FIC) indices. Related MIC values of essential oil and smoke were found to be 7200 and 5500 mg/L, and MBC values were 8500 and 8000 mg/L, respectively. The conducted organoleptic assay showed that the addition of 0.05 g of essential oil and 0.6 g of liquid smoke to 100 g of meat samples did not have adverse effect on the overall acceptance. Weaker antibacterial effect against Staphylococcus aureus was observed when only Echinophora platyloba essential oil was used than when it was used in combination with liquid smoke551117124CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ324027 429

The Anti-Staphylococcus aureus Effect of Combined Echinophora platyloba Essential Oil and Liquid Smoke in Beef

In the current study, the antibacterial effect of Echinophora platyloba essential oil and common liquid smoke (individually and in combination) against Staphylococcus aureus in beef meat samples is investigated. Using an automated microbiological growth analyser and the turbidimetric technique, the minimum inhibitory concentrations (MIC) and the minimum bactericidal concentrations (MBC) of the essential oil and liquid smoke were determined. Anti-S. aureus activity of essential oil and liquid smoke (individually and in combination) was defined by disk diffusion assay, generation time and cell constituent release. Apart from that, the interactions between these two compounds were measured by the checkerboard assay and by calculating the fractional inhibitory concentration (FIC) indices. Related MIC values of essential oil and smoke were found to be 7200 and 5500 mg/L, and MBC values were 8500 and 8000 mg/L, respectively. The conducted organoleptic assay showed that the addition of 0.05 g of essential oil and 0.6 g of liquid smoke to 100 g of meat samples did not have adverse effect on the overall acceptance. Weaker antibacterial effect against Staphylococcus aureus was observed when only Echinophora platyloba essential oil was used than when it was used in combination with liquid smoke

Evaluation and comparison of SYBR Green I RealTime PCR and TaqMan RealTime PCR methods for quantitative assay of Listeria monocytogenes in nutrient broth and milk Evaluation and comparison of SYBR Green I Real-Time PCR and TaqMan Real-Time PCR methods for

Specific traditional plate count method and real-time PCR systems based on SYBR Green I and TaqMan technologies using a specific primer pair and probe for amplification of iap-gene were used for quantitative assay of Listeria monocytogenes in seven decimal serial dilution series of nutrient broth and milk samples containing 1.58 to 1.58×10 7 cfu /ml and the real-time PCR methods were compared with the plate count method with respect to accuracy and sensitivity. In this study, the plate count method was performed using surface-plating of 0.1 ml of each sample on Palcam Agar. The lowest detectable level for this method was 1.58×10 cfu/ml for both nutrient broth and milk samples. Using purified DNA as a template for generation of standard curves, as few as four copies of the iap-gene could be detected per reaction with both real-time PCR assays, indicating that they were highly sensitive. When these real-time PCR assays were applied to quantification of L. monocytogenes in decimal serial dilution series of nutrient broth and milk samples, 3.16×10 to 3.16×10 5 copies per reaction (equals to 1.58×10 3 to 1.58×10 7 cfu/ml L. monocytogenes) were detectable. As logarithmic cycles, for Plate Count and both molecular assays, the quantitative results of the detectable steps were similar to the inoculation levels

Antibacterial activity of Carum copticum essential oil against Escherichia Coli O157:H7 in meat: Stx genes expression

This work were aimed to (a) determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Carum copticum essential oil (EO) against Escherichia. coli O157:H7 in vitro Trypticase Soy Broth, (TSB) and in ground beef; (b) evaluation of the effect of sub-inhibitory concentrations (sub-MICs) of EO on the growth of bacterium in TSB over 72 h (at 35 A degrees C) and ground beef over 9 days (at 4 A degrees C); and (c) investigation of gene expression involved in Shiga toxins production using relative quantitative real-time PCR method. The MIC in broth and ground beef medium were determined as 0.05 (v/v) and 1.75 % (v/w), respectively. In comparison with control cultures, the EO concentration of 0.03 % in broth caused reduction of colony counting as 1.93, 1.79, and 2.62 log(10) CFU ml(-1) after 24, 48, and 72 h at 35 A degrees C, and similarly EO (0.75 %) in ground beef resulted to reduction of colony counting as 1.03, 0.92, 1.48, and 2.12 log(10) CFU g (-1) after 2, 5, 7, and 9 days at 4 A degrees C, respectively. An increase and decrease in gene expression were observed as result of EO addition (0.03 %) to broth and (0.5 %) to ground beef was noticed, respectively732265272CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ324027429

Essential oil composition and antioxidant capacity of carum copticum and its antibacterial effect on staphylococcus aureus, enterococcus faecalis and escherichia coli O157:H7

Antibacterial activity, also antioxidant capacity of Carum copticum was evaluated; in addition, a mechanism for its antibacterial action against both Gram positive and Gram negative bacteria were introduced. Presence of antimicrobial constituents (thymol, p‐cymene, γ‐terpinene) were confirmed by gas chromatography/mass spectrometry. Micro‐well dilution and disk diffusion assays were applied to assess the antibacterial activity of C. copticum against Staphylococcus aureus, Enterococcus faecalis and Escherichia coli O157:H7. The mechanism of the antibacterial activity was also evaluated by scanning electron microscopy. Total phenolic concentration of EO was 831.16 ± 3.75 mg of gallic acid equivalents per gram of oil. The minimum inhibitory concentrations of EO against S. aureus, E. faecalis and E. coli O157:H7 were 0.044%, 0.07% and 0.05%, (vol/vol) respectively. Moreover addition of C. copticum EO to minced beef at concentrations of 0.75 and 1% significantly enhanced fresh meat odor and color413CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ302763/2014-7; 190178/2013-