Zn, Cu, and Fe Concentrations in Dehydrated Herbs (Thyme, Rosemary, Cloves, Oregano, and Basil) and the Correlation with the Microbial Counts of Listeria monocytogenes and Other Foodborne Pathogens

Comparison of Essential and Toxic Metals Levels in some Herbal Teas: a Systematic Review

In the present study, we reviewed the literature as a systematic review to investigate the concentration of some metals (essential, none essential, and toxic metals) in herbal teas and their health risks. The search extended the literature from the database, including Google Scholar, PubMed, and Scopus, using the terms "herbal teas" combined with "heavy metals, essential metals, thyme, rosemary, chamomile, and tea" also with "iron, zinc, aluminum, chromium, cobalt, nickel, manganese, arsenic, cadmium, and lead" in titles and abstracts. The search was limited to articles published from 2012 to 2023 years. Initially, 212 articles were found; by detailed consideration, only 49 papers fit the inclusion criteria and were selected for further study. The mean of metal concentration, standard deviation, data distribution, and sample size were applied to generate data from the articles. The results indicated that all commonly consumed herbal teas included metals. None of them meet the requirements of the WHO requirements. However, more than 70% of their health risks are acceptable. The risks of arsenic and lead in tea and cadmium in black tea were considerably higher than in others. According to the review results, it is important to prevent heavy metal contamination of herbal teas by modifying cultivation patterns and also to prevent to consumption of low-quality herbal teas.

GC–MS-Based Metabolites Profiling, In Vitro Antioxidant, Anticancer, and Antimicrobial Properties of Different Solvent Extracts from the Botanical Parts of Micromeria fruticosa (Lamiaceae)

The present study assessed the metabolites and bioactivities of Micromeria fruticosa plant parts extracted with various solvents (ethanol, n-hexane, and water) through the steeping extraction method. Thereafter, the extracts were analyzed using GC-MS. Moreover, the extracts were tested for their antioxidant, antimicrobial, and antitumor activities. The quali-quantitative analysis of Micromeria fruticosa crude extracts revealed the occurrence of 27 secondary metabolites. Some major bioactives identified were menthone, oleamide, pulegone, and menthol. Numerous antioxidant minerals, viz., Fe, Zn, and Mn, were present. The water extract of leaves exhibited the highest DPPH scavenging activity (89.73%), followed by the water extract of flowers (80.07%) at 100 μg/mL. The stems’ water extract demonstrated greater antimicrobial activity against all the bacteria species tested. The ethanolic leaf and aqueous stem extracts exhibited strong activity against C. albicans and E. coli. Flowers’ aqueous extract demonstrated the highest cytostatic effect on the colon cell line by reducing viability, followed by the leaves’ ethanol extract. The extraction solvents influenced the recovery of phytocompounds, and the highest pharmacological activities of the different extracts could be correlated to the presence of additional bioactives. Our results suggest that the Micromeria fruticosa plant is a favorable source of natural products with promising properties for potential nutraceutical and functional food applications.

Trace Elements as Contaminants and Nutrients

Knowledge about trace elements has evolved remarkably in recent decades, both in terms of their metabolism and their functions [...]

Ca and Mg Concentrations in Spices and Growth of Commonly Sporulated and Non-Sporulated Food-Borne Microorganisms According to Marketing Systems

Ca and Mg levels were determined in five spices according to marketing system (in bulk or commercialized in glass or polyethylene terephthalate (PET) containers) and correlated with microbial growth of commonly sporulated (Clostridium perfringens and Bacillus cereus) and non-sporulated (Listeria monocytogenes, psychrophilic and mesophilic bacteria, and yeasts and molds) food-borne pathogens present in them, when they were previously added to the microbial culture media. The basil had the highest mean Ca and Mg level and showed the highest microbial growth in the food-borne pathogenic microorganisms studied (p < 0.001). For Ca, the lowest levels were measured in cloves (p < 0.001), which had the lowest capacity for microbial contamination. Ca and Mg contents in spices correlated linear and positively (p < 0.05). Ca concentrations weakly and positively correlated (p < 0.05) with microbial counts for almost all studied microorganisms, and Mg levels for B. cereus, C. perfringens, and mesophilic bacteria (p < 0.05), possibly acting as a growing factor for some sporulated and non-sporulated foodborne pathogens. These relationships are especially significant when PET vs. glass was used as a packaging material for spices.