Search

In an increasingly interconnected world facing global challenges such as climate change and social inequality, citizenship education plays a critical role in preparing young people for responsible democratic participation and sustainability. This study aims to develop a model to explain factors influencing Latvian students' perceptions of global threats, comparing data from the International Association for the Evaluation of Educational Achievement (IEA)'s International Civic and Citizenship Study (ICCS) cycles in 2016 and 2022, to assess how these opinions have evolved and their implications for promoting sustainability through civic education. Confirmatory factor analysis is used to test the latent factor structure modeling the students' perceptions of environmental and economic threats to the world's future. A multi-group structural equation model is constructed and used with the corresponding descriptive statistics to analyze various background factor effects on students' sustainability concerns. The results of the study indicate that citizenship knowledge, as well as various student-level background factors, have an impact on environmental and economic sustainability concerns among 13-year-old students. In some instances, these effects are mediated by students' civic knowledge level, while in other instances, they are directly attributed to the background factors. The findings show that there may have been some shift in students' perceptions of sustainability threats, and the role of civic education may have changed in this respect. Furthermore, the varying levels of knowledge across various levels of background factors may suggest that content in lessons must be differentiated according to the needs of groups to support their understanding of the importance of sustainability. [ABSTRACT FROM AUTHOR]

Traditional biochemical methods are resource- and time-consuming; therefore, there is a need for cost-effective alternatives. A spectral analysis is one of the non-destructive techniques that are more widely used for fruit quality determination; however, references are needed for traditional methods. In this study, visible and near-infrared (Vis-NIR) spectroscopy was used to analyze the internal quality attributes of tomatoes. For the first time, 80 varieties with large differences in fruit size, shape, color, and internal structure were used for an analysis. The aim of this study was to develop models suitable to predict a taste index, as well as the content of lycopene, flavonoids, β-carotene, total phenols, and dry matter of intact tomatoes based on Vis-NIR reflectance spectra. The content of phytochemicals was determined in 80 varieties of tomatoes. A total of 140 Vis-NIR reflectance spectra were obtained using the portable spectroradiometer RS-3500 (Spectral Evolution Inc.). Partial least squares regression (PLS) and multiple scatter correction (MSC) were used to develop calibration models. Our results indicated that PLS models with good prediction accuracies were obtained. The present study showed the high capability of Vis-NIR spectroscopy to determine the content of lycopene and dry matter of intact tomatoes with a determination coefficient of 0.90 for both parameters. A regression fit of R2 = 0.86, R2 = 0.84, R2 = 0.82, and R2= 0.73 was also achieved for the taste index, flavonoids, β-carotene, and total phenols, respectively.

Tomatoes (Solanum lycopersicum L.) are a widely used vegetable in the human diet throughout the year, both fresh and in various processed products. Tomatoes contain compounds important to human health and are an important source of vitamins, antioxidants, and mineral elements. Performing biochemical analyses is an expensive, environmentally unfriendly and time-consuming process; therefore, a way to determine the biochemical composition of tomatoes using non-destructive methods is being sought. The study includes 45 varieties of tomatoes with different colors - red, pink, orange, brown, yellow, and bicolor tomato fruits. The content of dry matter, soluble dry matter, titratable acidity, lycopene, ß-carotene, total phenol, and flavonoids was determined by standard biochemical procedure. Reflectance spectrums of tomato fruits were obtained with Remote Sensing Portable Spectroradiometer RS-3500 (Ltd. Spectral Evolution, Haverhill, MA, USA) at the wavelength 350-2,500 nm with a 1 nm interval. In order to determine the content of various biochemical parameters in tomatoes, the vegetation indices found in the literature were used, and new ones were developed. The research demonstrated that the developed vegetative indices allow to detect lycopene and ß-carotene content non-destructively. For the determination of the dry matter, soluble solids and phenolic content, indices designed for detecting water content can be used, but their correlation coefficients with chemical methods are moderately high - 0.65, 0.56 and 0.57, respectively. It was found that the best correlation between biochemically detected parameters and vegetation indices is for lycopene > ß-carotene > dry matter> total phenols = titratable acidity = soluble solids > taste index > flavonoids. [ABSTRACT FROM AUTHOR]

Tomatoes (Solanum lycopersicum L.) are good source of several biologically active compounds and antioxidants, especially lycopene, phenolic compounds, and vitamins. Tomatoes are found all over the world and are cultivated in a wide variety of environmental conditions. Light-emitting diode (LED) lamps are increasingly being used in the cultivation of tomatoes due to their cost-effectiveness and wide range of possibilities to adapt the spectrum of light emitted to the needs of plants. The aim of this study is to evaluate the effect of different additional lighting used in the greenhouse on the accumulation of biologically active compounds in different varieties of tomato fruit. Chemical composition—content of organic acids, lycopene, total carotenoids, total phenolics and flavonoids as well as dry matter, soluble solids content, and taste index were determined in five tomato cultivars (“Bolzano F1,” “Chocomate F1,” “Diamont F1,” “Encore F1,” and “Strabena F1”), which were cultivated in greenhouse in an autumn-spring season by using additional lighting with 16 h photoperiod. Three different lighting sources were used: LED, induction (IND) lamp, and high-pressure sodium lamp (HPSL). Experiments were performed during 3 years. Results showed that tomato varieties react differently to the supplemental lighting used. Cultivars, such as “Encore” and “Strabena,” are the most unresponsive to supplemental light. Experiments have shown that HPSL stimulates the accumulation of primary metabolites in tomato fruit. In all the cases, soluble solids content was 4.7–18.2% higher as compared to other lighting sources. As LED and IND lamps emit about 20% blue-violet light, the results suggest that blue-violet light of the spectrum stimulates the accumulation of phenolic compounds in the fruit by 1.6–47.4% under IND and 10.2–15.6% under LED compared to HPSL. Red fruit varieties tend to synthesize more β-carotene under supplemental LED and IND light. An increase of blue promotes the synthesis of secondary metabolites.