Chenopodium quinoa Willd. is a halophytic plant valued for its nutritional and nutraceutical properties, as well as its adaptability to diverse soil and climatic conditions. Biostimulant application enhances plant quality and resilience under adverse environmental conditions. The effects of microalgae extracts (Ettlia pseudoalveolaris and Chlorella vulgaris) and salt stress (NaCl 100, 200, 300 mM) were evaluated on 7-day-old seedlings of two quinoa varieties, ‘Tunkahuan’ and ‘Regalona’. The analysis focused on the content of antioxidant molecules (total phenolics and flavonoids), total antioxidant capacity (measured by DPPH, 2,2-Diphenyl-1-picrylhydrazyl, and FRAP, Ferric Reducing Antioxidant Power, assays), reactive oxygen species (ROS), the levels of lutein, β-carotene, chlorophyll a and b. Microalgae extracts and salt stress treatments significantly increased antioxidant molecules in both quinoa varieties. The highest antioxidant activity, measured by the DPPH assay, was observed in ‘Regalona’, while a dose-dependent increase in antioxidant capacity, by the FRAP assay, was evident in ‘Tunkahuan’ treated with Ettlia. ROS level was reduced by Ettlia in ‘Tunkahuan’ but not in ‘Regalona’. Pigment content increased with higher salt concentrations but decreased with the addition of biostimulants. These findings suggest that the application of microalgae extracts enhances bioactive compounds, improving salinity resistance and increasing the nutraceutical value of quinoa sprouts.

The study of different processing techniques, such as sprouting, cooking and fermentation, can help to develop new products for human health. In this work, raw, cooked and fermented seeds and germinated seeds of Chenopodium quinoa Willd. var. Tunkahuan and Amaranthus caudatus L. var. Alegrìa were compared for the content of antioxidant molecules, total antioxidant capacity and mineral elements. Fermentation was induced spontaneously, with the yeast Saccharomyces cerevisiae, with the bacterium Lactobacillus plantarum and with both microorganisms, for 24 and 48 h. The increase in antioxidant molecules and antioxidant activity was induced by germination, by 24 h of spontaneous fermentation (polyphenols and flavonoids) and by 24 h of L. plantarum fermentation (total antioxidant activity) for both species. Germinated seeds of the two plants showed higher values in respect to seeds of macroelements and microelements. No genotoxic but rather protective effects were determined for seed and germinated seed extracts using the D7 strain of S. cerevisiae, a good tool for the evaluation of protection from oxidative damage induced by radical oxygen species (ROS) in cells and tissues. Therefore, the two varieties could be very suitable for their use in human diet and in supplements, especially as germinated seeds or as fermented foods.

We report the spectrophotometric determination of total polyphenols, flavonoids, glucosinolates and antioxidant activity in seeds, seedlings and leaves of Tuscan black kale. The highest content of phytochemicals was observed in 10 days sprouts and antioxidant activity was maximum in 2, 4 days seedlings. Identification and characterisation of phytochemicals were performed by mass spectrometry (MS), high resolution and tandem MS with electrospray ionisation mode. Low-molecular-weight metabolites were evidenced in seeds while metabolites at high m/z range were detected in cotyledons and leaves. MS spectra evidenced different phenolic compounds (flavonoid caffeoyl glucose, hydroxycinnamic acid sinapine) and glucosinolates (glucoerucin, glucobrassicin and glucoraphanin) in function of developmental stage; galactolipids ω3 and ω6 were observed in leaves. Identification of stages with the highest phytochemicals content encourages the consumption of black kale sprouts and young leaves. Our research can support food and pharmaceutical industries for production of health promoting products from black kale.