The paper presents the results of an evaluation of the quality of eggs from laying hens kept in caged and free range systems using traditional methods and ultra-weak luminescence (USL). It was found that the tested eggs were fresh and were characterized by the required quality, as demonstrated by analysis of the egg white and egg yolk. Eggs from free-range laying hens were characterized by an eight-fold higher emission of photons compared to eggs from caged hens, and they had over three times higher content of natural antioxidants in the form of carotenoids. Most probably, the higher number of photons emitted is associated with a higher content of biologically active substances in the material under study. Photon emission also varies in different ways depending on the specific hen breeding system. Differences in time in the identified maximum values of photon emission result from the composition of individual parts of the egg. Different times in which the emission peaks occurred for free-range eggs and for caged eggs were observed. The application of the USL method in order to confirm its usefulness in the assessment of food quality requires further research.

The paper presents the results of influence the light of different wavelengths and pulsed electric fields on the content of carotenoids. Seeds germination was carried out in a climatic chamber with phytotron system. The experiment was carried out under seven growing conditions differing in light-emitting diode (LED) wavelengths and using pulsed electric fields (PEFs) with different strength applied before sowing. Cultivation of the sprouts was carried out for seven days at relative humidity 80% and 20 ± 1 °C. Different light wavelengths were used during cultivation: white light (380–780 nm), UVA (340 nm), blue (440 nm), and red (630 nm). In addition, the pulsed electric field (PEF) with three values of strength equal to 1, 2.5 and 5 kV/cm, respectively, was applied to three series of sprouts before sowing. Sprouts treated with the PEF were grown under white light (380–780 nm). The light exposure time for all experimental series of sprouts was 12/12 h (12 h light, 12 h dark for seven days). Lutein is the dominant carotenoid in germinating red clover seeds, the content of which varies from 743 mg/kg in sprouts grown in red light, 862 mg/kg in sprouts grown in UVA, to 888 mg/kg in sprouts grown in blue light. Blue light in the cultivation of red clover sprouts had the most beneficial effect on the increase of carotenoids content and amounted to 42% in β-carotene, 19% in lutein, and 14% in zeaxanthin. It confirms that modelling the content of carotenoids is possible using UVA and blue light (440 nm) during seed cultivation. An increase in the content of β-carotene and lutein in red clover sprouts was obtained in comparison to the test with white light without PEF pre-treatment, respectively by 8.5% and 6%. At the same time a 3.3% decrease in the content of zeaxanthin was observed. Therefore, it can be concluded that PEF pre-treatment may increase mainly the content of β-carotene.

An innovative issue in food engineering is using the impulse electric field (PEF) in modeling the content of biologically active compounds in plant raw materials, including seeds. In the described experiment it was shown that it is possible to modify the carotenoid content in germinating seeds of red clover (Trifolium pratense L.) by treating the seeds with PEF before cultivation. The research material was the seeds of red clover ‘Rozeta’ variety. As a result of the conducted research, an increase in the content of lutein and zaaxanthin by 10% and β-carotene by 16% was obtained after the sprouts were subjected to a field of 5 kV/cm intensity.

The colour of wine is one of the key indicators of its quality. The influence of impulse electric field PEF on grapes, which will be used for wine production, is still a novel issue on a global scale. Grapes (Marechal Foch variety) were subjected to a pulsed electric field for 10 s, at a frequency of 20 pulses per second and two values of electric field strength of 3.3 kV/cm and 5 kV/cm, followed by fermentation in accordance with the procedures used in the wine industry. In the produced wines, the colour was determined using the CIELab method, obtaining L, * a, * b values, which are the axes of a three-dimensional colour space. It has been shown that the pulsed electric field PEF has a positive effect on the colour of red wine. The share of red parameter (*a) in wines (WMF 2, WMF 3) is respectively higher by 15% and 24% in relation to wine produced in typical conditions without additional pretreatment (WMF 1). The obtained results indicate a higher productivity of extraction of colour compounds from grapes under the influence of PEF. This is beneficial because the more intense wine colour correlates with the higher content of coloured antioxidant pro-health compounds.