Effect of glycerol content and pH value of film-forming solution on the functional properties of protein-based edible films

The work is concerned with the effects of glycerol content and pH value of film forming solution on the functional properties of protein-based films. The films were produced of chicken breast proteins, dissolved under either acidic (pH 3) or alkaline (pH 11) conditions, with different concentrations of glycerol (35%, 50% and 65% w/w of protein content). Glycerol content affected significantly mechanical properties, water vapor permeability, color at pH 3 and film solubility (p<0.05). The pH value had significant influence on light transmission, color, transparency and film solubility (p<0.05). Considering the results of mechanical properties and film solubility, the obtained films are in the acceptable range for the use as a packaging material. It was estimated that water vapor permeability, color, light transmission and transparency need to be improved for the application

Effect of Origanum heracleoticum L. essential oil on food-borne Penicillium aurantiogriseum and Penicilium chrysogenum isolates

Molds are ubiquitously distributed in nature and their spores can be found in the atmosphere even at high altitudes. The difficulty of controlling these undesirable molds, as well as the growing interest of the consumers in natural products, have been forcing the industry to find new alternatives for food preservation. The modern trends in nutrition suggest the limitation of synthetic food additives or substitution with natural ones. Aromatic herbs are probably the most important source of natural antimicrobial agents. Origanum heracleoticum L. essential oil has been known as an interesting source of antimicrobial compounds to be applied in food preservation. In the this work, we have investigated the effect of essential oil obtained from O. heracleoticum on growth of six isolates of Penicillium aurantiogriseum and four isolates of Penicillium chrysogenum isolated from meat plant for traditional Petrovacka sausage (Petrovská klobása) production. The findings reveal that the essential oil of O. heracleoticum provides inhibition of all of fungal isolates tested. O. heracleoticum L. essential oil exhibited higher antifungal activity against the isolates of P. chrysogenum than the isolates of P. aurantiogriseum. O. heracleoticum essential oil showed a MIC value ranging from 25 to 100 μL/mL. The fungi cultivated in the medium with higher concentration of essential oil showed certain morphological changes. The alterations included lack of sporulation and loss of pigmentation

Mycopopulations and ochratoxin A: Potential contaminants of Petrovská klobása

Petrovská klobása is traditionally produced dry fermented sausage from the area of Bački Petrovac (Vojvodina Province, Serbia) that has been protected with designation of origin (PDO) according to Serbian legislation. Contamination of this kind of sausage casings by different mould species often occur during the production process, mainly during the ripening and storage. The aim of this study was to isolate and identify moulds that contaminate ingredients used for Petrovská klobása production and its casings during different phases of ripening and storage. Sampling was done during the production process and after 2, 6, 9, 11, 14, 34, 65, 90, 120, 217 and 270 days. Total mould counts in components ranged from 1.60 (mechanically mixed filling) to 4.14 (red hot paprika powder) log10 CFU/g, while the number of moulds isolated from sausage casing surfaces ranged from 0.01 (C3 sausage, 217th day) to 1.60 (C1 sausage, 270th day) log10 CFU/cm2. After total mould counts were determined, isolates were identified and classified in five genera for components (Penicillium - 7 species; Fusarium - 2 species; Aspergillus - 1 species; Alternaria - 1 species; Verticilium - 1 species) and 3 genera for casings surfaces (Penicllium - 3 species; Aspergillus - 1 species; Eurotium - 1 species). It was appointed that 83.33% of isolated species are potential producers of toxic metabolites. The analyses of ingredients and sausages on the presence of ochratoxin A, following the ELISA method, gave the negative results