The Effect of Essential Oils on the Survival of Bifidobacterium in In Vitro Conditions and in Fermented Cream

Microscopic Droplet Size Analysis (MDSA) of "Five Thieves' Oil" (Olejek Pięciu Złodziei) Essential Oil after the Nebulization Process

Nowadays, due to a higher resistance to drugs, antibiotics, and antiviral medicaments, new ways of fighting pathogens are intensively studied. The alternatives for synthesized compositions are natural products, most of which have been known in natural medicine for a long time. One of the best-known and intensively investigated groups are essential oils (EOs) and their compositions. However, it is worth noting that the method of application can play a second crucial part in the effectiveness of the antimicrobial activity. EOs possess various natural compounds which exhibit antimicrobial activity. One of the compositions which is based on the five main ingredients of eucalyptus, cinnamon, clove, rosemary, and lemon is named "five thieves' oil" (Polish name: olejek pięciu złodziei) (5TO) and is used in natural medicine. In this study, we focused on the droplet size distribution of 5TO during the nebulization process, evaluated by the microscopic droplet size analysis (MDSA) method. Furthermore, viscosity studies, as well as UV-Vis of the 5TO suspensions in medical solvents such as physiological salt and hyaluronic acid, were presented, along with measurements of refractive index, turbidity, pH, contact angle, and surface tension. Additional studies on the biological activity of 5TO solutions were made on the P. aeruginosa strain NFT3. This study opens a way for the possible use of 5TO solutions or emulsion systems for active antimicrobial applications, i.e., for surface spraying.

Effect of the Addition of Selected Herbal Extracts on the Quality Characteristics of Flavored Cream and Butter

Herbs have been used for centuries in order to enrich food as preservatives, flavorings, and medicinal agents. The aim of this work was to study the effect of the addition of selected herbal extracts (dried leaves of Thymus vulgaris L., Origanum vulgare L., Satureja hortensis L., Rosmarinus officinalis L., and Ocimum basilicum L.) on selected parameters of fermented flavored cream (counts of starter culture bacteria and pH value) and the resulting flavored butter (water content, water distribution, butter plasma pH, butter fat acidity, and oxidative stability), preceded by a study of the activity of the herbal extracts against starter lactic acid bacteria determined using the well diffusion method. The extracts did not inhibit the starter lactic acid bacteria at a fixed level. The presence of the herbal extracts contributed to a shorter fermentation course and influenced the counts of starter culture bacteria during fermentation and refrigerated storage (at 5 °C) for 21 days. The extract additives did not affect the water content or the degree of its dispersion, the butter plasma pH, or the butter fat acidity. The positive effect of the rosemary and thyme extract addition was only noted when analyzing the oxidative stability of the milk fat of the butter.

Special Issue on Application of Instrumental Methods for Food and Food By-Products Analysis

The application of various analytical procedures and methods determining the properties and safety of food and food constituents is a particularly important topic when dealing with food and food by-product analyses [...]