Preparation of active antimicrobial methyl cellulose/carvacrol/montmorillonite nanocomposite films and investigation of carvacrol release

Methyl cellulose (MC)/carvacrol (CRV)/montmorillonite (MMT) nanocomposite films were prepared to obtain active antimicrobial packaging materials. The characterization of film samples by X-ray diffraction and transmission electron microscopy showed that composite films were of nano structures. CRV addition to the MC film and MC/MMT nanocomposite films led to a decrease in the thickness and opacity values of them, whereas MMT addition to the film matrix caused an increase in these values. Thermal stability of films slightly increased with increasing MMT concentration in film matrix. CRV release from films was investigated at different temperatures for 30 days. An increase in the MMT concentration matrix caused a decrease in CRV release at 25.0 ± 0.5 °C and in 60 ± 4% relative humidity (RH). CRV release increased with temperature at a constant RH. The antimicrobial activities of films were tested against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by the microatmosphere method and these organisms were completely inhibited on the nutrient broth/bacteriological agar medium when film samples containing 11.1 ± 0.2 mg CRV were present. MC/CRV film and MC/CRV/MMT-60% nanocomposite films on sausage reduced E. coli and S. aureus counts by 0.9 and 0.7 log cfu/mL, respectively, compared to the control film. The amount of CRV release from developed antimicrobial films can be controlled by MMT concentration within the film matrix and by the storage temperature of film.     

Application of failure mode and effect analysis model to foodservice systems operated by chefs in practice and by chefs from a culinary school in Turkey

Failure mode and effect analysis (FMEA) methodology has been applied for the risk assessment of basic foodservice systems operated by the “chefs in practice” and by the “chefs from a culinary school” in Turkey. Firstly, the preliminary hazard analysis was done to predict the potential failure modes in the food flow of basic foodservice systems. Each step in the process, from receiving of raw ingredient to table, was analyzed. The risk priority numbers (RPN) were calculated for each failure mode. The corrective actions were suggested to lower the RPN values below the acceptable limit of 120. The data collected in this study compared to the data from a study carried out with “chefs in practice” about basic food safety issues. The significant difference was observed between “the chefs in practice” and “the chefs with formal culinary education”. Majority of chefs from a culinary school have scored better in many food safety issues, so thus the corrective actions in the FMEA table. The results clearly point out the urgent need for FMEA integration and for food handler education in current foodservice establishments in Turkey.     

Polycyclic aromatic hydrocarbons in cereal products on the Turkish market

The contamination level of four EU marker polycyclic aromatic hydrocarbons (PAHs) in some cereal-derived products was surveyed in this study. Thirty-eight samples, 20 bread and 18 breakfast cereals, were purchased from retail shops and local markets of East Black sea region in Turkey. The samples were analysed for four EU marker PAHs, using ultrasonic extraction, solid-phase extraction (SPE) clean up and stable-isotope dilution gas chromatography with mass-spectrometric (GC/MS) detection. The method was validated with the parameters linearity, accuracy, precision, limit of detection (LOD), limit of quantitation (LOQ) and uncertainty. Total content of the four PAHs in bread varied from 0.19 to 0.46 µg kg^?1 and in breakfast cereals from 0.10 to 0.87 µg kg^?1.     

Effects of heat treatment and in vitro digestion on the Angiotensin converting enzyme inhibitory activity of some legume species

In this study, potential Angiotensin Converting Enzyme (ACE) inhibitory activity of common dry beans, dry pinto beans and green lentils were determined and the effects of different heat treatment periods were investigated. In vitro gastrointestinal digestion was applied after heat treatment, and stability of the ACE inhibitory activity was determined. Crude protein extracts of legume samples showed 4.08–28.54% ACE inhibition activities. 30-min heat treatment caused a decrease in ACE inhibitory activity; however, 50-min heat treatment was observed to be beneficial for the release of ACE inhibitory peptides from the three legume species (p < 0.05). In vitro digestion process increased ACE inhibitory activities of the samples (p < 0.05), mainly green lentil digests by a factor of 10.91–23.65 against ACE in comparison with raw sample. It was observed that IC₅₀ values of common beans, pinto beans and green lentils after digestion were 0.78–0.83, 0.15–0.69 and 0.008–0.89 mg protein/mL, respectively.