The aim of this study was evaluated the effect of selected bioactive substances and nanoparticles on the immunoreactivity of edible packages based on chitosan using the ELISA. The analysed protein ...was the tropomyosin. The results confirmed the presence of the tropomyosin (3.77 ± 0.79-5.75 ± 0.01 µg/g) in control samples. This study demonstrated that the bioactive substances in the form of grape (0.61 ± 0.34-0.43 ± 0.16 µg/g), blueberry (0.58 ± 0.32-0.39 ± 0.27 µg/g), and parsley extracts (2.09 ± 1.28-0.79 ± 0.40 µg/g) reduces immunoreactivity (p < 0.05) of the tropomyosin. The elder pollen had no significant effect (p > 0.05) on immunoreactivity. ZnO and TiO
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nanoparticles also demonstrated immunoreactivity reduction (p < 0.05). The exception was silver nanoparticles, where the immunoreactivity increased with increasing concentration of grape extract (1.29 ± 0.01-5.47 ± 0.25 µg/g). The results confirmed the inhibitory effect of bioactive substances on the immunoreactivity of the used ELISA and also showed the need to consider immunoreactive substances when interpreting ELISA results.
Respondents’ perception about the possible changes of best before date (BBD) to the date of the highest quality was the main aim of the survey. The survey consisted out of 1,107 respondents who were ...grouped according to their demographic characteristics and food labelling preferences. The results of the survey are indicating high acceptance rate towards new labelling, but without clear connection with their preferences. Another aspect of the research emphasised the respondents’ perception towards the price of healthier food commodities and revealed that education level has high impact ( P < 0.05) on their opinion and considerations. The survey gave important answers on possibility of changes of food labelling by which it would be affected food waste quantities. Certainly, each food type shelf life should be checked and labelled according to food perishability and consumers safeness. The changing of the BBD to the date of the highest quality according to our survey would be broadly accepted among all socio-demographic groups.
This study was aimedto evaluate the influence of carrageenan and pectin on jam color during 10 days of cold storage (+ 4 °C). Jam samples were prepared with cherry and apricot fruits and 3 ...concentrations of gelling agents (0.5 %, 1 % and 2 %). Cherry and apricot jam samples prepared without gelling agent were used as control samples. Pectin, κ-carrageenan and icarrageenan were used as gelling agents. The jams were stored in the refrigerator for 10 days. The color of jams was monitored by personal camera, with the usage of image analysis software in three intervals (first day, third day and tenth day). The significant (p<0.05) changes of color during 10 days of storage were measured in all prepared jam samples with emphasis that the lowest changes were observed in jams prepared with 1 % pectin, 0.5 % κcarrageenan and 2 % i-carrageenan. Otherwise, Principal component analysis (PCA) illustrated that only jam samples prepared with 1 % κ-carrageenan had different RGB parameters in comparison with other laboratory prepared jam samples._
Stagnant water bodies have generally received little attention regarding the presence of endocrine disruptive compounds, although they can integrate diverse pollutants from multiple different ...sources. Many compounds of anthropogenic as well as natural origin can contribute to the overall estrogenicity of surface waters and some of them can exhibit adverse effects on aquatic biota even in very low concentrations. This study focused on freshwater ponds and reservoirs affected by water blooms and determined the estrogenic activity of water by in vitro bioassay as well as concentrations of several important groups of estrogenic compounds (estrogenic hormones, alkylphenols, and phytoestrogens) by LC-MS/MS analyses. Estrogenic hormones were found at concentrations up to 7.1 ng.L−1, similarly to flavonoids, whose concentrations did not exceed 12.5 ng.L−1. Among alkylphenols, only bisphenol A and 4-tert-octylphenol were detected in levels reaching 100 ng.L−1 at maximum. Estrogenic activity of water samples varied from below the quantification limit to 1.95 ng.L−1. There does not seem to be any general causal link of the massive phytoplankton occurrence with the estrogenicity of water or concentration of phytoestrogens, since they showed no direct relationship with the phytoplankton abundance or composition across sites. The contribution of the analysed compounds to the estrogenic activity was calculated in three scenarios. In minimum scenario, just the compounds above quantification limit (LOQ) were taken into account and for most samples, only minor part (<6%) of the biological activity could be explained. In the mean and maximum scenarios, we included also compounds below LOQ into the calculations at the level of LOQ/2 and LOQ, respectively. In these cases, a considerable part of the estrogenic activity could be attributed to the possible presence of steroid estrogens below LOQ. However, for the samples with estrogenic activity greater than 1 ng.L−1, more than 50% of the estrogenic activity remained unexplained even in the maximum scenario. Probably other compounds or possible interactions between individual substances cause the estrogenic activity in these types of water bodies and in this case, the results of LC-MS/MS analyses cannot sufficiently predict the biological effects. A complex approach including bioassays is needed when assessing the estrogenicity of these types of surface waters.
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•Anthropogenic and natural estrogens co-occur at ng.L−1 levels in stagnant waters.•Estrogenic activity of stagnant waters up to 2 ng.L−1 of estrogen equivalent.•More than 50% of estrogenic activity of the most active samples unexplained.•Some compounds can significantly contribute even below quantification limit.•No direct relation of estrogenicity or estrogens with phytoplankton occurrence.
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