Gabriela Borilova

Combined antimicrobial effect of oregano essential oil and caprylic acid in minced beef.

Oregano essential oil (OEO) and caprylic acid (CA) are highly aromatic natural antimicrobials with limited individual application in food. We proved their combined additive effect when used in meat. Application of 0.5% CA and 0.2% OEO (v/w) with 0.1% of citric acid in vacuum packed minced beef inoculated with Listeria monocytogenes at a concentration of 5 log cells/g reduced counts of lactic acid bacteria by 1.5 log CFU/g and counts of psychrotrophic bacteria and L. monocytogenes by more than 2.5 log CFU/g at the end of storage at 3°C for 10 days. In sensory evaluation the samples with OEO showed during the whole experiment statistically better scores than control, whereas the samples treated with CA showed worse colour attributes.

Comparative study of DNA extraction methods from fresh and processed yellowfin tuna muscle tissue

ABSTRACT The most common techniques used to identify tuna species include methods based on the detection of specific DNA. The quality of species-specific DNA crucially affects the efficiency of amplification during the subsequent polymerase chain reaction (PCR). Detection of DNA in processed products can be adversely affected by DNA fragmentation during the processing steps and the use of ingredients that may inhibit the PCR reaction. In this study, several processing treatments applied to the muscle tissue of yellowfin tuna (Thunnus albacares) were evaluated. For DNA isolation three DNA extraction methods were compared. The concentration, purity, and amplificability of DNA were tested. The results revealed the variability among extraction procedures in terms of DNA quality and quantity in tuna muscle tissue processed under different processing technologies.