Thymol, cardamom and Lactobacillus plantarum nanoparticles as a functional candy with high protection against Streptococcus mutans and tooth decay.

Due to the increasing resistance of microorganisms against antibiotics, the use of natural bioactive substances for the prevention of pathogenic bacteria is considered in food products. In this study, thymol, cardamom essential oil, L. plantarum cell-free supernatant (ATCC 14917), and their nanoparticle candies prepared and inhibition activities against S. mutans (ATCC 25175), which is important in causing tooth decay, was investigated. Moisture content, pH, and sensory analyzes of candies measured. Also, SEM and FTIR of treated candy samples were performed. All examined bioactive substances and their nanoparticles showed an inhibitory effect against S. mutans with different minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The prepared candies had pH 5.5 represented a bactericidal effect against S. mutans. SEM and FTIR results approved the antibacterial effects of prepared candies. According to the results, all of the prepared candies significantly decreased S. mutans in saliva compared to the control candy and they are suitable agents for S. mutans growth-inhibiting. Also, cardamom essential oil candy showed the most general acceptance in a sensory analysis by panelists.

Lactobacillus plantarum as a Probiotic Potential from Kouzeh Cheese (Traditional Iranian Cheese) and Its Antimicrobial Activity.

The aim of this study is to isolate and identify Lactobacillus plantarum isolates from traditional cheese, Kouzeh, and evaluate their antimicrobial activity against some food pathogens. In total, 56 lactic acid bacteria were isolated by morphological and biochemical methods, 12 of which were identified as Lactobacillus plantarum by biochemical method and 11 were confirmed by molecular method. For analyzing the antimicrobial activity of these isolates properly, diffusion method was performed. The isolates were identified by 318 bp band dedicated for L. plantarum. The isolated L. plantarum represented an inhibitory activity against four of the pathogenic bacteria and showed different inhibition halos against each other. The larger halos were observed against Staphylococcus aureus and Staphylococcus epidermidis (15 ± 0.3 and 14.8 ± 0.7 mm, respectively). The inhibition halo of Escherichia coli was smaller than that of other pathogen and some L. plantarum did not show any inhibitory activity against E. coli, which were resistant to antimicrobial compounds produced by L. plantarum. The isolated L. plantarum isolates with the antimicrobial activity in this study had strong probiotic properties. These results indicated the nutritional value of Kouzeh cheese and usage of the isolated isolates as probiotic strains.