Volume 12 (2019): Issue 1 (December 2019)

Selenium (Se) is an essential micronutrient, and the ability of some crops to accumulate Se is crucial for human and animal nutrition and health. Se deficiency can cause white muscle disease characterized by muscle weakness, heart failure, unthriftiness, and death in livestock. This study was undertaken to investigate the effect of sulphur (S) on Se concentration in alfalfa (Medicago sativa L. cv. Verko) as a nonhyperaccumulator plant. Alfalfa plants grown in the field were treated foliarly with 3 g Se ha⁻¹ solutions of selenate, 3 g S ha⁻¹ sulphate, and both. The concentration of Se in both the leaves and stems of plants was similar in the control and S-treated plants. Se concentration in plants treated with S was undetectable, as expected. S was shown to enhance Se accumulation in alfalfa. Furthermore, although foliar Se + S spray increased biomass, photosynthetic pigments decreased peroxidase activity and malondialdehyde content. Overall, results suggested that foliar Se + S spray can be applied as a biofortification to improve alfalfa plants with appropriate amounts of Se and better nutritional as well as functional quality.

The recent years have seen a great number of instances when ultraviolet (UV) radiation was used in the preservation process of all sorts of foods. Since the purine and pyrimidine bases of DNA and RNA absorb well the 254 nm radiation, its application with the use of a correct dosage can result in disinfections of various orders of magnitude. It can be particularly effective in cases where technology does not allow a more intensive heat treatment. When used properly, UV treatment can be a competitive procedure in the case of foodstuffs where the large surface area allows for UV rays to penetrate the entire volume of the substance. Incorrectly applied UV treatment may change the composition of foods. Free-radical as well as photochemical reactions can digest the proteins, damage the antioxidants, oxidize the lipids, make changes to the colour and substance, and produce undesirable flavourings and odorous substances. Some vitamins are particularly sensitive to UV irradiation in the course of which losses could reach even 50%. Photosensitive water-soluble vitamins are vitamin C, B₁₂, B₆, B₂ and folic acid, while vitamins A, K and E are the fat soluble sensitive to light, carotene being the only provitamin with such properties. On the other hand, UV treatment can be a useful tool of food safety because of the photosensitivity of fungal toxins.

Earlier we determined the colostrum and milk composition of cows after single- and twin-calving as well as the changes in the composition as a function of postpartum time. It was established that the dry matter, protein, whey protein, and immunoglobulin-G (IgG) content of the first-milked colostrum immediately after calving was significantly higher with twin-calving cows than with single-calving animals. As regards the other components, there were no significant differences among the animals. During the last years, we managed to collect the first-milked colostrum from five cattle after triplet-calving. The composition of these samples were determined by the methods we used earlier at twin-calving animals, and the results were compared to the colostrum composition of single- and twin-calving animals. It was found that although as an effect of triplet-calving the protein and IgG content of colostrum increased, the difference was not significant between twin- and triplet-calving animals. We are aware that others have not reported data from the point of view of the colostrum composition of twin-calving, and in the case of tripletcalving our results are unique in the world. In our publication, we report on the results of our investigations.

Fermented meat products represent an important segment of our alimentation. Obtaining these products is based on beneficial microorganism activity. In the case of traditional food products, these are commercial starters or autochthonous microflora. Fermentation of raw materials is mainly done by sugar metabolization of lactic acid bacteria (LAB). In addition, these microorganisms can have other beneficial properties too such as probiotic properties, antimicrobial compound production abilities, etc.

In order to meet consumer demands, starter cultures are continuously developed to produce high-quality, healthy, and tasty products, thus contributing to guaranteeing microbiological safety and to improving one or more sensory characteristics, technological, nutritional, or health properties of the fermented products. The aim of our research is to determine the technological properties of autochthonous lactic acid bacteria originated from commercial fresh sausages in order to select and use them as potential starter cultures in the meat industry. In our work, we determined the relevant characteristics (such as salt tolerance, proteolytic activity, antimicrobial activity, and antibiotic resistance) of bacteria isolated from 16 fresh sausages. Based on our results, the studied bacterial isolates originated from sausages could be potentially used as autochthonous meat starter cultures.

Carrot is one of the most important root vegetables rich in bioactive compounds such as carotenoids and dietary fibres, with appreciable levels of several other functional components and having significant health-promoting properties. Therefore, it is cultivated on a large scale throughout the world. The by-product (pomace) resulted during carrot juice production is used mainly as animal feed although it contains many valuable components and could therefore be used profitably in the food industry, too. Carrot pomace needs to be preserved by drying as otherwise it deteriorates rapidly. In our research, we studied the infrared drying kinetics of carrot pomace at various temperatures, the obtained data being very important in the drying practice.

The manufacture of dairy products is an important sector of the food industry. From milking to processing, a number of hygiene rules must be strictly followed. During processing, dairy products can be contaminated with different microorganisms, causing spoilage, infectious diseases, and alterations in the sensory characteristics. There are strict requirements for the quality assurance of milk products. In spite of this, there occur infections linked to milk and dairy product consumption. The analysis of the microbiological quality of these products is a health concern, and it also has an economic impact. The increase and development of the global market of processing technologies require rapid monitoring and controlling systems for food products. In our study, we investigated the microbiological quality of some fresh dairy products with the Soleris^® test system. For instrument setting, calibration curves were realized with test bacterial strains. With known initial microbial load of the samples, the microbial growth versus time was measured by the above-mentioned system. The occurrence of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus was evaluated in ten dairy products. Results obtained by the Soleris system showed that the system is efficient for this purpose. Calibration curves with high correlation coefficients permitted the quantitative determination of the aimed bacteria in the dairy product samples.

Heat resistant thermophilic spore-forming bacteria, such as Aeribacillus (A.) pallidus, may contaminate the surfaces in food facilities resulting food spoilage of the products. The aim of this work was to determine the heat and disinfectant resistance of an A. pallidus strain that was isolated from a canning factory environment. Compared to other heat-resistant spore-forming bacteria, it did not prove to be very resistant to heat with a D₁₀-values of A. pallidus from 12.2 min to 2.4 min (at 102 °C and at 110 °C), with a calculated z-value of 11.6 °C. Not only spores but vegetative cells showed resistance against all investigated disinfectants.

Energy drink (ED) consumption, even mixed with alcohol, is popular among adolescents and young adults. The side effects of ED are attributed to their active ingredients and their cumulated effect. A cross-sectional study to identify university students’ ED consumption habit was realized. A small sample size (n = 10) experiment examining the effect of ED consumption on arterial blood pressure and heart rate was carried out.

From the total number of 240 interviewed students, 87.1% consumed ED at least once, and one third of them did so on a monthly basis. Students consume energy drinks mainly for its taste, very rarely for studying. Differences in consumption place preferences were observed between sexes, females preferring bars, while males the dormitory. We have demonstrated the increase of systolic blood pressure (SBP) for one type of energy drink in young and healthy volunteer students. Other changes in blood pressure and heart rate were not observed.