Since 2005 campylobacteriosis has been the most commonly reported gastrointestinal infection in humans in the European Union with more than 200,000 cases annually. Also Campylobacter is one of the most frequent cause of food-borne outbreaks with 319 outbreaks reported to EFSA, involving 1,254 cases of disease and 125 hospitalizations in EU in 2019. Importantly poultry meat is one of the most common source for the sporadic Campylobacter infections and for strong-evidence campylobacteriosis food-borne outbreaks in EU.
The chemical composition of berries and berry pomaces is diverse, containing polyphenolic components that may have both antibacterial and antioxidative properties. In the present study, in vitro antibacterial effect of the extracts of chokeberry, blackcurrant, and rowan berries and berry pomaces against L. monocytogenes, S. aureus, E. coli, and C. jejuni was studied. In addition, the polyphenolic profile and antioxidant activity of these extracts were investigated. The polyphenolic profiles in the aqueous and 30% ethanolic extracts were determined chromatographically by HPLC-MS, and the total polyphenol content was estimated spectrophotometrically by HPLC-DAD-UV. The minimal inhibition concentrations (MICs) of the extracts against tested bacteria were determined by the broth microdilution method. The content of total polyphenols was highest and good antioxidative properties of the extracts were determined for chokeberry and blackcurrant berries and their pomaces. The highest proportions of total quercetin derivatives and anthocyanins were found in the extracts of chokeberry berry/pomace and blackcurrant berry/pomace, respectively. The sensitivity of tested microbes to the extracts of berries and berry pomaces was as follows: S. aureus > L. monocytogenes > E. coli and C. jejuni. In vitro antibacterial activity of tested extracts depended on the extraction solvent, mainly for the ethanolic extracts. Findings suggest that chokeberry and blackcurrant berries and their pomaces can be used as a good source of polyphenols with antioxidative properties, and they also have antibacterial activity against some foodborne pathogenic bacteria. It is important that the valuable compounds are extracted from juice press residues before their disposal.
Fast protein and metabolite liquid chromatography (FPLMC) was introduced years ago to enable the easy separation of high-molecular compounds such as proteins from small molecules and the identification of the low-molecular substances. In this paper, the method is applied for the rapid evaluation of freshness and monitoring the aging of animal meat and fish. A novel chromatographic sensor was developed with a deep UV LED-based photometric detection unit (255–265 nm), an original flow cuvette and registration scheme; the processing of a chromatogram with the sensor takes approximately 15 min. Strict isochronism between the elution of ATP metabolites, mainly hypoxanthine (Hx) and inosine monophosphate (IMP), and the time of maturation of meat or fish, was discovered. A new freshness index H* = [Hx]/[IMP] was introduced, which is proportional to the instrumental delay time in the FPMLC chromatograms: the H* index < 0.5 indicates the presence of inosine monophosphate (IMP) and the high quality of the meat or fish. Reasonably strong correlations were revealed between data obtained by FPMLC and total volatile basic nitrogen TVB-N (for fish) or volatile fatty acids VFA (for meat) content. Moreover, putative nucleotide salvage and an increase in the concentration of IMP were observed in fish after heat treatment using the FPMLC sensor and NMR technique.
The prevalence and numbers of Listeria monocytogenes in various categories of ready-to-eat (RTE) food products taken from retail outlets and food industries over a 5-year period are presented. A total of 30,016 RTE food samples were analyzed for L. monocytogenes prevalence, and 3.6% were found to be positive. The highest prevalence was found for RTE fish and fish products (11.6%), especially for lightly salted and cold-smoked fish products. The overall prevalence of L. monocytogenes in other food categories was low, within the range of 0 to 3.9%. In addition, 14,342 RTE food samples were analyzed to determine the numbers of L. monocytogenes. A food safety criterion of 100 CFU/g was exceeded for 0.3% of RTE food samples. Samples most often exceeding the legal safety limit were from the RTE salted and cold-smoked fish product categories. High prevalence, 28.6 and 26.5%, respectively, and high numbers of L. monocytogenes among salted fish and cold-smoked fish products indicate a risk of listeriosis,...
It is a challenge for scientists to find new plant-based food constituents simultaneously possessing antimicrobial and antioxidative properties to prolong the shelf life of meat products. In this study, various plant powders and their blends were added to minced pork to carry out a complex study of their effect on sensory characteristics, microbial growth, and lipid oxidation of the meat in raw and cooked forms during storage. Microbiological shelf life parameters were evaluated by determining the total counts of microorganisms, yeasts, and molds. The growth potential of Listeria monocytogenes was estimated by challenge testing. The impact on lipid oxidation processes was assessed using thiobarbituric acid reactive substances (TBARS) and high performance liquid chromatography (HPLC) methods. The results showed that the blend of rhubarb petioles and tomato powder added a pleasant color and a combined taste to the product, similar to the taste of salt. In raw samples, considerable microbial growth inhibition was achieved with rhubarb petioles, tomato, and their mixture. Nine treatments of cooked samples had a stronger inhibitory effect on microbial growth compared to control treatments. Among all plant powders, tomato was the most effective inhibitor of yeast and mold growth. However, the challenge test revealed that L. monocytogenes growth in cooked samples was not inhibited during shelf life. In raw samples, rhubarb roots combined with blackcurrant or chokeberry berries effectively inhibited lipid oxidation, and in cooked samples, rhubarb petioles showed a similar effect. In conclusion, it was found that powdered plant materials are well suited for use as antimicrobial and antioxidative agents in minced meat products.