Led lighting intensity effect on biochemical composition of microgreens of white cabbage

Abstract

In recent years, there has been a trend in Belarus towards a significant increase in demand for the products of microgreens of vegetable crops, including white cabbage, as a source of a wide range of useful substances. At the same time, an important aspect when growing microgreens in a closed controlled environment is lighting, which is both a signal for growth and development and a source of energy for higher plants. Plants adapt to the conditions of the light environment not only via changes in morphophysiological parameters, but also via restructuring their light-collecting complex. One of the most important parameters of the lighting mode is the photon flux density – the intensity of illumination, which significantly affects both the growth of biomass and the accumulation of secondary metabolites. The results of a comparative study of the influence of the intensity of LED lighting are presented (50, 100, 150, 200, 250 μm/m2·s) for the content of chlorophylls, carotenoids and ß-carotene, dry, tannin and pectin substances, free organic, ascorbic and hydroxy acids in the samples of white cabbage microgreens, soluble sugars, the main groups of bioflavonoids – mainly anthocyanins, leucoanthocyanins, catechins, flavonols and the indicator of the sugar acid index. It has been determined that the leading position in the experiment in terms of the integral level of nutritional vitamin value of this product, exceeding that in the control by 1.4 times, belonged to the variant of the experiment with a minimum intensity of LED lighting of 50 μm/m2·s, whereas for the variant with an intensity of lighting of 150 μm/m2·s, a lag in this regard from the control by 1.1 times and, accordingly, from more successful variants of the experiment by 1.2–1.6 times, which allowed to consider it ineffective. The novelty of the research lies in the fact that for the first time in the conditions of the republic, a comprehensive biochemical study of samples of white cabbage grown at different intensities of LED lighting was carried out, which made it possible to recommend this vegetable crop for industrial production of micro-greenery.