Search

Microorganism food poisoning is one of the foodborne illnesses in the world. The interest in natural preservatives has increased since the lack of acceptability in using synthetic preservatives. Propolis, a resinous mixture, is a natural product produced by honey bees to protect their hives against microorganisms. It is considered a natural food supplement and preservative owing to its high antimicrobial and antioxidant activities. However, its resinous nature (not readily soluble in water), ethanol solubility, specific strong smell and taste limits its usage as a natural preservative. Encapsulation of propolis ethanol extract with natural polymers like alginate and pectin may overcome these limitations. Main aim of this study was to test powdered form of propolis as a natural preservative in ice cream as model food. For this purpose propolis, after extraction and characterization, was encapsulated by using pectin and converted into powdered form. Antimicrobial activity of prepared ice cream itself against S. aureus (ATCC 25923), E. coli (ATCC 28712), E. faecalis (ATCC 51299), K. pneumoniae (ATCC 700603) and B. cereus (patient isolate) was tested. Total phenolic content and ferric reducing antioxidant power of propolis were noted as 46.26 ±1.18 mg GAE/mL and as 0.27 ±0.07 µmol FeSO4.7H2O/mL, respectively. The encapsulation efficiency was found 95%. Encapsulation of propolis ethanol extract improved the homogenization of propolis active compounds in ice cream. This resulted in obtaining an ice cream with high antimicrobial and antioxidant activities. In conclusion, the use of encapsulated active compounds of propolis ethanol extract improved the both antimicrobial and antioxidant activity of the ice cream produced in a natural way. [ABSTRACT FROM AUTHOR]

Honey is the most important bee product. There are many secondary metabolites, carbohydrates, enzymes, and vitamins in honey, thus, honey has antimicrobial activity. In this study, in vitro antimicrobial activity of forty-two honey and eight propolis ethanolic extracts (PEE) were investigated against 16 microorganisms. Total phenolic content ranged between 20.00–124.10 mg GAE/100 g and 103–232 mg GAE/g for honey and raw propolis samples, respectively. Pine and oak honeydew honeys had higher antimicrobial activity than four different grades of Manuka Honeys up to 18 mm minimum inhibition zone diameters. The ethanolic propolis extracts showed much higher antimicrobial activity than the honey samples. Fungi species were inhibited by the propolis samples. Helicobacter pylorii (H. pylorii) was the most sensitive, whereas Streptococcus agalactiae was the most resistant bacteria among the studied microorganisms. Brazilian and Zonguldak propolis had the closest antimicrobial activity to ampicillin, streptomycin, and fluconazole. It can be concluded that both honey and propolis could be used in preservative and complementary medicine. [ABSTRACT FROM AUTHOR]

Monoamine oxidase (MAO) inhibitors are generally used in the treatment of depressive disorders and some neurodegenerative illnesses, such as Parkinson's disease and Alzheimer's disease. The aim of this preliminary study was to investigate the MAO [MAO (E.C.1.4.3.4)] inhibiting effect of various apitherapeutic products, such as chestnut honey, pollen and propolis. Extracts' MAO inhibition was measured using peroxidase-linked spectrophotometric assay in enzyme isolated from rat liver microsomes, and the values are expressed as the inhibition concentration (IC50) causing 50% inhibition of MAO. The antioxidant activity of the bee products was also determined in terms of total phenolic content (TPC) and ferric reducing/antioxidant power in aquatic extracts. All samples exhibited substantial inhibition of MAO, propolis having the highest. Inhibition was related to samples' TPCs and antioxidant capacities. These results show that bee products possess a sedative effect and may be effective in protecting humans against depression and similar diseases. [ABSTRACT FROM AUTHOR]

Three different honey extracts from the endemic plant in the Black Sea region Rhododendron ponticum, were investigated for their inhibitory effects against the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1), more precisely the human (h) isoforms hCA I and hCA II. Hexane, methanol, ethanol, and water solid-phase extractions (SPEs) showed inhibitory activity towards the two CA isozymes which were related to the total phenolic content. The highest inhibitory effects (0.036--0.039 mg/mL) were those of propolis methanolic extract. Among the three different samples investigated here, the aqueous extracts showed lower inhibitory effects compred to the organic solvent SPE extracts (in the range of 1.150-- 5.144 mg/mL). The studied honey extracts constitute an interesting source of phenolic derivatives that might serve to identify lead compounds, targeting the physiologically relevant enzymes CA I and CA II. [ABSTRACT FROM AUTHOR]