No abstract

Antibiotics are low molecular-weight molecules produced as secondary metabolites, mainly by microorganisms that live in the soil. Microbial secondary metabolites have been a major source of clinically useful antibiotics. Members of the genus Bacillus are known to produce a wide arsenal of antimicrobial substances, including peptide and lipopeptide antibiotics. These peptides can be classified into two different groups based on whether they are ribosomally (bacteriocins) or nonribosomally (polymyxins and iturins) synthesized. The present paper provides a general overview of antimicrobial peptides derived from Bacillus species, including their structure and classification, as well as several extraction and purification methods used to obtain these bioactive compounds.

Salmonella Enteritidis is the major cause of foodborne salmonellosis affecting human health. The light emitting diodes (LEDs) is a novel approach to inactivate of the foodborne pathogens. The aim of this study was to determine the antibacterial effect of 405 nm LEDs illumination on S. Enteritidis and S. Enteritidis PT4. The irradiance of the 405 nm LEDs was 27.7 mW/cm 2 . Bacterial cultures suspended in tryptic soy broth were illuminated by 10-watt LEDs at a distance of 4.5 cm for 24 hours at 4 °C, 25 °C and 37 °C. Approximately 7-log reduction in colony forming unit (CFU) counts of both S. Enteritidis and S. Enteritidis PT4 at each temperature were observed following exposure after 7.5 hours to the LEDs, concluding that temperature did not affect the inactivation of the bacteria. The decimal reduction times (D-values) for the serotypes ranged from 55.78 to 67.88 min at 4, 25 and 37 °C after 405 nm LEDs illumination. No significant difference in D-values was observed among both the serotypes and temperatures, except for S. Enteritidis which had lower D-value at 4 °C. The LEDs technology has shown antibacterial efficacy and can be implemented in the food processing for reducing S. Enteritidis.

The present study aimed to investigate major volatile compounds, organic acid, phenolic and mineral contents, and antiradical and antimicrobial properties of home-made apple/grape vinegar. Grape vinegar showed higher total acidity, organic acid content, total phenolic content (TPC), antiradical activity and lower minimum 2 2 inhibitory concentration (MIC) values compared to apple vinegar. While acetic and tartaric acids were the most abundant organic acids in grape vinegar, acetic and succinic acids were the most abundant organic acids in apple vinegar. The most abundant phenolic compound was gallic acid in both grape and apple vinegar. A total of 18 and 9 volatile compounds were determined in grape vinegar samples and apple vinegar samples, respectively. The most abundant volatile compounds were acetic acid and acetoin in grape vinegar, acetic acid, ethyl acetate and 2,4,5-trimethyl-1,3-dioxolane in apple vinegar. K, Ca and Na were common minerals in both vinegar and more in the grape vinegar compared to apple vinegar. Although MIC value for grape vinegar was at 6.25% with minimum bactericidal concentration (MBC) values ranged from 6.25% to 12.50%, MIC value for apple vinegar was at 12.50% with MBC values ranged from 12.50% to 25.00% for all test bacteria. The antiradical and antibacterial activities of the vinegar samples were correlated with their TPC and organic acid contents.

No abstract

Salmonella Enteritidis is amongst the most common causes of foodborne salmonellosis. Multi-drug resistant Salmonella strains has been associated with treatment failures. Plant-derived phytochemicals may be an alternative to antibiotics in combating these bacteria. The purpose of this study is to investigate the antibacterial activity of curcumin, carvacrol and styrax liquidus on S. Enteritidis and S. Enteritidis PT4.Minimum inhibitory concentration (MIC) values of these substances were detected at 1.5, 3, 7.5 and 24 h by broth microdilution method to evaluate their time-dependent antibacterial activities. The findings of the present study showed that MIC values of carvacrol, curcumin and styrax liquids for both S. Enteritidis and S. Enteritidis PT4 were 125.0 µg/mL, 132.5 µg/mL, 31.3 mg/mL for 24 h, respectively. Also, a time-dependent change was observed in the MIC values of curcumin. Carvacrol, curcumin and styrax liquidus can be used to provide antimicrobial effect on S. Enteritidis and S. Enteritidis PT4 in food applications, taking into account the MIC values and contact times.

No abstract

Bee pollen is a honey bee product containing over 250 biologically active substances such as phenolic bases, amino acids, carbohydrates, lipids, enzymes and coenzymes, vitamins and bio-elements. The composition of bee pollen may vary due to plant sources and its botanical and geographical origin. Bee pollen has been used since ancient times in traditional medicine for its therapeutic effects such as wound healing and hepatoprotective. Bee pollen has been reported to possess antioxidant and radical scavenging activities usually attributed to the presence of phenolic acids and flavonoids which are plant-derived polyphenolic substances. The antioxidant capacity of bee pollen depends on the content of total polyphenolic substances. This review presents an overview of chemical composition and antioxidant activity of bee pollen.