Selenium Biofortification Impacts the Nutritive Value, Polyphenolic Content, and Bioactive Constitution of Variable Microgreens Genotypes

Abstract

Selenium (Se) is considered essential for human nutrition as it is involved in the metabolic pathway of selenoproteins and relevant biological functions. Microgreens, defined as tender immature greens, constitute an emerging functional food characterized by overall higher levels of phytonutrients than their mature counterparts. The nutraceutical value of microgreens can be further improved through Se biofortification, delivering Se-enriched foods and potentially an enhanced content of bioactive compounds. The current study defined the effect of sodium selenate applications at three concentrations (0, 8, and 16 μM Se) on the bioactive compounds and mineral content of coriander, green basil, purple basil, and tatsoi microgreens grown in soilless cultivation. Analytical emphasis was dedicated to the identification and quantification of polyphenols by UHPLC-Q-Orbitrap-HRMS, major carotenoids by HPLC-DAD, and macro micro-minerals by ICP-OES. Twenty-seven phenolic compounds were quantified, of which the most abundant were: Chlorogenic acid and rutin in coriander, caffeic acid hexoside and kaempferol-3-O(caffeoyl) sophoroside-7-O-glucoside in tatsoi, and cichoric acid and rosmarinic acid in both green and purple basil. In coriander and tatsoi microgreens, the application of 16 μM Se increased the total phenols content by 21% and 95%, respectively; moreover, it improved the yield by 44% and 18%, respectively. At the same Se dose, the bioactive value of coriander and tatsoi was enhanced by a significant increase in rutin (33%) and kaempferol-3-O(feruloyl)sophoroside-7-O-glucoside (157%), respectively, compared to the control. In green and purple basil microgreens, the 8 μM Se application enhanced the lutein concentration by 7% and 19%, respectively. The same application rate also increased the overall macroelements content by 35% and total polyphenols concentration by 32% but only in the green cultivar. The latter actually had a tripled chicoric acid content compared to the untreated control. All microgreen genotypes exhibited an increase in the Se content in response to the biofortification treatments, thereby satisfying the recommended daily allowance for Se (RDA-Se) from 20% to 133%. The optimal Se dose that guarantees the effectiveness of Se biofortification and improves the content of bioactive compounds was 16 μM in coriander and tatsoi, and 8 μM in green and purple basil.

Selenium biofortification in the 21st century: status and challenges for healthy human nutrition

“…Seedlings of edible vegetables supplemented with selenate seem to preferentially accumulate organic Se, and their nutritional value is generally ameliorated by Se enrichment (D'Amato et al 2018b(D'Amato et al 2020Islam et al 2020;Pannico et al 2020). In fact, Ávila et al (2014) screened Se-enriched cultivars from the six largely consumed Brassica vegetables and found that all were able to accumulate MeSeCys and contained higher levels of GLS, especially glucoraphanin.…”

Sensory Attributes and Consumer Acceptability of 12 Microgreens Species

“…Microgreens are also regarded as fresh "super foods" [4,9,10] due to their innate fortification with plant secondary metabolites [9,[11][12][13]. Additionally to carotenoids, ascorbic acid, phylloquinone, γ-tocopherols, and phenolic compounds, microgreens are also a source of macro and micro-minerals.…”

“…Additionally to carotenoids, ascorbic acid, phylloquinone, γ-tocopherols, and phenolic compounds, microgreens are also a source of macro and micro-minerals. Such nutritive and functional values enhance human diet and prevent a range of common diseases [4,9,10,12,14]. Indeed, microgreens enclose a greater load of essential phytonutrients compared to their mature counterparts [3,4,6,10,13].…”

“…Such nutritive and functional values enhance human diet and prevent a range of common diseases [4,9,10,12,14]. Indeed, microgreens enclose a greater load of essential phytonutrients compared to their mature counterparts [3,4,6,10,13]. Suchlike dense phytochemical composition has garnered the attention of nutrition researchers [6,15] and gained them prevalence among food technologists, urban farmers, and consumers [15].…”

The Use of a Nutrient Quality Score is Effective to Assess the Overall Nutritional Value of Three Brassica Microgreens

“…It is important to note that the duration of the growing cycle of microgreens is intermediate between sprouts and "baby leaf" vegetables. Thanks to their flexibility in cultivation, several growing techniques have been applied to microgreens in order to modulate the content of nutritional compounds to obtain tailored food products [13,[17][18][19][20][21].…”