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Research background. While it is clear that SARS CoV-2 coronavirus is the primary respiratory virus, there are no entirely clarified ways of transmission. Foodborne transmission has remained an unexplained path. Therefore, the goals of this paper are to examine and present an assessment of the most appropriate of the four selected kits for RNA extraction for the testing and detection of SARS-CoV-2 on food packaging surfaces, food surfaces, and in food. This will enable to indicate the possibility of infection through contact or direct food consumption. Experimental approach. Finding the best technique is vital as RNA extraction is one of the essential elements in detecting SARS-CoV-2. This was achieved through an experiment with four commercial kits following the original manufacturers' protocols, and with a modification of the original protocols that included the use of ethanol and isopropanol. The selected kit was used for RNA extraction from the swabs of packaging surfaces, food surface, and ready-to-eat food samples. The coronavirus was then identified using real-time reverse transcription-polymerase chain reaction (RT-PCR) assays to determine whether the SARS-CoV-2 virus or viral particles are present in the food chain with the overall purpose of demonstrating the possibility that food can contribute as a vehicle for the transmission of the virus. Results and conclusions. The findings of this investigation made the most effective extraction kit and protocol stand out. The results of the applicability of the kit indicated a significant share of positive samples of viral SARS-CoV-2 virus particles on surfaces from the environment where infected persons with 'silent' COVID-19 infection, with mild symptoms or no symptoms, were present. However, according to the findings of the second part of the study, the virus was not detected on the examined samples of food packaging surfaces, food surfaces, and food. Novelty and scientific contribution. The presented results distinguished one of the most suitable protocols for isolating RNA from environmental surface samples. The main contribution of the study is in the presentation of the results, that is, the examination of samples that are primarily related to the food chain, food packaging, food surfaces, and ready--to-eat food. The results of this study could also be helpful for further determination of the potential of food as a vector for the transmission of coronaviruses. [ABSTRACT FROM AUTHOR]

Research background. Cheese in a sack is a traditional cheese produced in Croatia. Types of cheese with similar production technology are made in other countries but chemical and microbiological composition varies between regions. Traditionally, cheese in a sack is produced without the addition of starter cultures. Addition of beneficial probiotic cultures to numerous dairy products has documented advantages. Effects that the addition of probiotic bacteria to traditional cheese have on aroma compounds and sensory properties have not been fully investigated. The aim of this study is to determine the sensory properties and differences in the aromatic profiles between cheese samples ripened in a lambskin sack, produced traditionally without the addition of any starter culture, or with the addition of probiotic bacteria. Experimental approach. In this study, cheese in a sack was produced with the addition of probiotic cultures Lactobacillus plantarum B and L. lactis ssp. lactis S1. During ripening volatile aroma compounds were analysed with a solid-phase microextraction gas chromatography-mass spectrometry. Sensory properties were evaluated by trained tasters who are familiar with the traditional taste of the cheese from a sack. The results of aroma composition and taste scores were then compared using factorial and principal component analyses. Results and conclusions. Chromatography showed differences in the composition of aroma compounds and the sensory properties between the cheese produced with Lactobacillus starter cultures and the control cheese, traditionally produced without a starter culture. The addition of probiotic cultures L. plantarum B and L. lactis ssp. lactis S1 resulted in products with better sensory properties and chemical profile of volatile aromatic compounds. Novelty and scientific contribution. This study investigates the usage of naturally present probiotic cultures as starter cultures in cheese in a sack production. Their effects on aroma profiles and sensory characteristics have been compared for the first time using factorial and principal component analyses. [ABSTRACT FROM AUTHOR]

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Lactobacillus plantarum O1 was isolated from the gut of sea bream (Sparus aurata) and identified with the API biochemical test and MALDI-TOF MS. This strain was further characterised according to the selection criteria for lactic acid bacteria as starter cultures for aquatic food production. L. plantarum O1 showed good antimicrobial activity against pathogenic test microorganisms. Further investigation confirmed it as the producer of the bacteriocin plantaricin. This strain also showed good growth at a wide range of temperatures (from 4 to 45 °C) and a wide range of pH (2-12), even in the presence of 3.5 % NaCl. Its viability was also good after lyophilisation and in simulated gastric and small intestinal juice. The strain is a promising probiotic, and our further research will focus on its application in the biopreservation of fresh fish and shellfish. [ABSTRACT FROM AUTHOR]

In this paper the effect of aflatoxin B , ochratoxin A and zearalenon on morphology, growth parameters and metabolic activity of yeasts Saccharomyces cerevisiae, Saccharomyces uvarum, Candida utilis and Kluyveromyces marxianus was determined. The results showed that the three mycotoxins affected the morphology of all these yeasts, primarily the cell diameter, but not their final cell count. Fourier transform infrared spectroscopy showed that the yeast membranes bound the mycotoxins, C. utilis in particular. The cell membranes of most yeasts underwent denaturation, except S. uvarum exposed to ochratoxin A and zearalenone. In the early stage of fermentation, all mycotoxin-exposed yeasts had lower metabolic activity and biomass growth than controls, but fermentation products and biomass concentrations reached the control levels by the end of the fermentation, except for C. utilis exposed to 20 μg/ mL of zearalenone. The adaptive response to mycotoxins suggests that certain yeasts could be used to control mycotoxin concentrations in the production of fermented food and beverages. [ABSTRACT FROM AUTHOR]

In this study, the effect of an isolated and well-characterised autochthonous starter culture, glucose and maltodextrin (w=0.8 %) and temperatures of 12 and 20 °C on fermentation and quality of Slavonian kulen produced using the traditional technology and recipe were investigated. Physicochemical and microbiological analyses were carried out aft er 20 days of fermentation. Upon the completion of the production process (90 days), a sensory analysis was carried out. Furthermore, pH value was continuously measured throughout the twenty-day fermentation period. The addition of an autochthonous starter culture and sugars and different fermentation temperatures significantly (p<0.05) affected the instrumental colour and texture parameters of the Slavonian kulen. The fermentation was most intense in the samples with added autochthonous starter culture and 0.8 % glucose, and fermented at 20 °C. Microbiological analysis showed that samples with added autochthonous starter culture and fermented at higher temperature contained a higher number of lactic acid bacteria and coagulase-negative staphylococci and were safe. Sensory evaluation confirmed the outcomes of physicochemical and microbiological analyses and showed differences among samples fermented at two different temperatures and with added glucose or maltodextrin and an autochthonous starter culture. [ABSTRACT FROM AUTHOR]

The benefits of probiotic bacteria have been widely explored. However, fermented foods and digestive system of humans and animals are an inexhaustible source of new potentially probiotic microorganisms. In this study we present three new Lactobacillus plantarum strains isolated from different dairy products: cow's cheese, sheep's cheese and whey. In order to determine the antibacterial activity of yet unexplored L. plantarum strains against Salmonella enterica serotype Typhimurium, in vitro competition and co-culture tests were done. Furthermore, adhesion of these strains to Caco-2 cells and their influence on the adhesion of Salmonella were tested. Results showed the potential probiotic activity of isolated strains. L. plantarum strains survived in the presence of 1% bile salts, they possessed acidification ability, antibacterial activity and significantly att enuated the growth of S. Typhimurium in brain heart infusion broth. All tested L. plantarum strains were able to adhere to Caco-2 cells and significantly impair the adhesion of S. Typhimurium. All three L. plantarum strains exhibited significant probiotic potential and anti-Salmonella activity; therefore, further testing on in vivo models should follow. [ABSTRACT FROM AUTHOR]

As in the traditional production of cheese in lambskin sacks raw cow's or sheep's milk is mostly used, the purpose of this study is to see how the production affects the microbiological quality of the cheese. To do that, we tested 39 samples of raw cow's and sheep's milk, curd, ripened cheese (15, 30 and 45 days) and lambskin sacks for native microbial popu lation. Two-thirds of the milk, curd and cheese samples had higher counts of staphylococci and enterobacteria than permitted by regulations. Not a single sample had Salmonella and Listeria monocytogenes, but we did find Escherichia coliin sheep's milk and cheese, and yeast and mould in both types of milk and cheese. Staphylococcus xylosus prevailed in lambskin sacks. Despite the high incidence of S.aureus, even in the final product, staphylococcal enterotoxin was detected in only two sheep's cheese samples. Among the lactic acid bacteria, Lactococcus lactis and Lactobacillus paracasei prevailed in cow's cheese, whereas Leuconostoc mesenteroides and Lactobacillus plantarum prevailed in sheep's cheese. In the lambskin sacks Leuconostoc mesenteroides and Lactobacillus plantarum were predominant. Our findings give an important insight into the fermentation and microbial ecology of the cheese in lambskin sacks. [ABSTRACT FROM AUTHOR]

The study focuses on developing novel cott age cheese containing spices with acceptable sensory properties, increased biological value and extended shelf life. Thirty types of cheese with added fresh or dried parsley, dill, pepper, garlic and rosemary were produced. Characterisation of phenolic compounds, antioxidant capacity and antibacterial activity of spices and cheese samples were evaluated. The cheese containing fresh pepper and fresh and dried herbs showed excellent sensory properties, with the best results obtained with fresh sweet red pepper. Dry rosemary had the highest antioxidant and antibacterial activity due to high mass fractions of caff eic and rosmarinic acids as well as high mass fractions of fl avones and phenolic diterpenes. The plant extracts examined in vitro and in situ eff ectively reduce numbers of foodborne pathogens like Salmonella typhimurium, Escherichia coli, Staphylococcus aureus and Listeria monocytogenes, and therefore have potential as natural preservatives and antioxidants. [ABSTRACT FROM AUTHOR]

The aim of this study is to identify and characterise potential autochthonous functional starter cultures in homemade horsemeat sausage. The dominant microflora in the samples of horsemeat sausage were lactic acid bacteria (LAB), followed by micrococci. Among the LAB, Lactococcus lactis ssp. lactis and Lactobacillus plantarum were the dominant species, and since the first is not common in fermented sausages, we characterised it as a potential functional starter culture. Lactococcus lactis ssp. lactis produced a significant amount of lactic acid, displayed good growth capability at 12, 18 and 22 °C, growth in the presence of 5 % NaCl, good viability after lyophilisation and in simulated gastric and small intestinal juice, antimicrobial activity against test pathogens, and good adhesive properties in vitro. [ABSTRACT FROM AUTHOR]

The aim of this research is to use isolated and characterized autochthonous functional starter cultures from traditional Croatian dry sausages and to evaluate their capacity for industrial production of five sausages (Cajna sausage, Zimska sausage, Becka sausage, Sri-jemska sausage and Slavonski kulen). These defined autochthonous functional starter cultures (combination of Lactobacillus and Staphylococcus strains) were used to produce five different industrial sausages which were compared by a panel. The viability of introduced autochthonous Lactobacillus and Staphylococcus strains and their effect on the final product characteristics, namely microbiological, physicochemical and sensory properties were monitored. The obtained results indicate that autochthonous starter cultures survived industrial production of sausages and can be used for production of sausages under controlled conditions. Autochthonous starter cultures obtained better results in the organoleptic evaluation, microbial safety and prolonged shelf-life in comparison with commercial starter cultures. [ABSTRACT FROM AUTHOR]