Bioactive lipids, radical scavenging potential, and antimicrobial properties of cold pressed clove (Syzygium aromaticum) oil

Application of Vegetal Oils in Developing Bioactive Paper-Based Materials for Food Packaging

A major disadvantage of conventional food packaging materials is the difficulty in disposal and recycling, due to their high stability to environmental and thermal stress. The trend now is to develop new eco-friendly food packaging that can substitute fossil fuel derived materials. Cellulose, the main constituent of paper-based food packages, is a favorable starting material for such purpose. In this study we present a new method to obtain bioactive paper based materials suitable for food packaging applications. By combining eco-friendly activation processes (cold plasma or gamma irradiation) and bioactive plant oils (clove essential oil and rosehip seeds vegetal oil) for modification of kraft paper, new materials with antioxidant and antibacterial activity were obtained. The oil-loaded bioactive paper based materials presented increased hydrophobicity (from 97° contact angle in the case of kraft paper to 115° for oil-loaded sample) and decreased water adsorption (a one-quarter decrease). Due to various interactions with the functional groups of plant oils, the modified kraft paper presents different antibacterial and antioxidant properties. Essential clove oil imprinted higher antioxidant activity (owing to the high content in eugenol and eugenol acetate phenolic compounds) and was more efficient in reducing the bacterial growth on fresh beef meat and on fresh curd cheese. The cold pressed rosehip seeds oil acted as aslightly better antibacterial agent against Listeria monocytogenes (+), Salmonella enteritidis (−) and Escherichia coli (−) bacterial strains. Thus, the newly developed bioactive paper could be used as effective packaging material that can help preserving food quality for longer time.

Phytosterol, Lipid and Phenolic Composition, and Biological Activities of Guava Seed Oil

Plant seeds have been found to contain bioactive compounds that have potential nutraceutical benefits. Guava seeds (Psidium guajava) are by-products in the beverage and juice industry; however, they can be utilized for a variety of commercial purposes. This study was designed to analyze the phytochemicals of the n-hexane extract of guava seed oil (GSO), to study its free-radical scavenging activity, and to monitor the changes in serum lipids and fatty acid profiles in rats that were fed GSO. The GSO was analyzed for phytochemicals using chromatographic methods. It was also tested for free-radical scavenging activity in hepatoma and neuroblastoma cells, and analyzed in terms of serum lipids and fatty acids. GSO was found to contain phenolic compounds (e.g., chlorogenic acid and its derivatives) and phytosterols (e.g., stimasterol, β-sitosterol and campesterol), and exerted radical-scavenging activity in cell cultures in a concentration-dependent manner. Long-term consumption of GSO did not increase cholesterol and triglyceride levels in rat serum, but it tended to decrease serum fatty acid levels in a concentration-dependent manner. This is the first study to report on the lipid, phytosterol and phenolic compositions, antioxidant activity, and the hepato- and neuro-protection of hydrogen peroxide-induced oxidative stress levels in the GSO extract.

Antifungal and Synergistic Effects of the Ethyl Acetate Extract of Tanacetum vulgare (L.) Against Candida albicans

BACKGROUND With the continued demand for new, effective, and safe endodontic therapies, the aim of this study was assessment of efficiency of the ethyl acetate (EthOAc) extract of Tanacetum vulgare (L.) against Candida albicans. MATERIAL AND METHODS The antifungal effectiveness of the EthOAc extract of T. vulgare was determined using the agar disk diffusion method. The inhibition zones induced by the EthOAc extract were compared after 5 minutes, 60 minutes, and 24 hours to those induced by standard solutions (2% chlorhexidine, saturated calcium hydroxide, and 2% sodium hypochlorite). Statistical analysis of the results was performed using the Kruskal-Wallis test and one-way ANOVA. RESULTS The inhibition zone of chlorhexidine against C. albicans was 30.3-19.3 mm, but in combination with EthOAc extract (100 mg/mL) of T. vulgare, this inhibition was from 32.7-30 mm, indicating that this combination exerted a marked synergistic effect against C. albicans. The inhibition zone of sodium hypochlorite (69.7-65 mm) was higher than the inhibition zone of EthOAc extract and chlorhexidine. The combination of EthOAc extract with sodium hypochlorite resulted in a loss of antifungal activity. Furthermore, the activity of the EthOAc extract against C. albicans was decreased after mixing the extract with dentine at a concentration of 25 mg/50 µL (30.3-20.7 mm). The EthOAc extract did not show a genotoxic effect on lymphocyte cells. CONCLUSIONS The EthOAc extract of T. vulgare may be a useful tool to discover natural bioactive agents that have antifungal activity against C. albicans and could be used as endodontic therapies.

Role of fatty acids in Bacillus environmental adaptation

The large bacterial genus Bacillus is widely distributed in the environment and is able to colonize highly diverse niches. Some Bacillus species harbor pathogenic characteristics. The fatty acid (FA) composition is among the essential criteria used to define Bacillus species. Some elements of the FA pattern composition are common to Bacillus species, whereas others are specific and can be categorized in relation to the ecological niches of the species. Bacillus species are able to modify their FA patterns to adapt to a wide range of environmental changes, including changes in the growth medium, temperature, food processing conditions, and pH. Like many other Gram-positive bacteria, Bacillus strains display a well-defined FA synthesis II system that is equilibrated with a FA degradation pathway and regulated to efficiently respond to the needs of the cell. Like endogenous FAs, exogenous FAs may positively or negatively affect the survival of Bacillus vegetative cells and the spore germination ability in a given environment. Some of these exogenous FAs may provide a powerful strategy for preserving food against contamination by the Bacillus pathogenic strains responsible for foodborne illness.