Biofortification and antioxidant improvement of onion bulbs using calcareous algae and storage

Abstract

Along the line that health-beneficial foods must also be accompanied by sustainable agricultural practices, the red alga Lithothamnium sp. (Rhodophyta), frequently used for animal and human nutrition, it was shown that it could be a biofertilizer, regarding their bioactive humic acid content, released by micronization. Also, onions present well-known benefits to health and are among the main vegetable crops grown worldwide. Thus, the objective this work was to evaluate the effects of foliar sprays with micronized Lithothamniun sp. on yield, mineral nutrients, flavonoids, phenolic content, and antioxidant activity before and after storage of bulbs of two organically grown onion cultivars. The yield, mineral content, antioxidant activity, and phenolic and flavonoid content in onion bulbs were improved through sprays, highlighting the dose of 1.5 g L-1 of Lithothamnium sp. in solution. Genotype interactions and storage effects were observed. The benefits with the use of Lithothamnium sp. as biofertilizer were towards the biofortification of organically grown onions by improving mineral nutrient acquisition as it was followed by upgrading antioxidant capacity.