β-Carotene biofortification of chia sprouts with plant growth regulators.

Chia (Salvia hispanica) is a native plant species from South America that is very appreciated for its oleaginous seeds in the agri-food field. Chia seeds are natural sources of many bioactive compounds which provide benefits to human health. Nevertheless, chia sprouts have better nutritional properties than seeds, such as antioxidants, essential amino acids, and phenolic compounds. Among all these beneficial compounds, β-carotene has not been studied in chia sprouts. β-carotene is a precursor of vitamin A, which contributes to maintaining our health status. In this study, to improve β-carotene content in chia sprouts, some plant growth regulators (abscisic acid, methyl jasmonate and methyl salicylate) were applied exogenously to germinating chia seeds. Gibberellins A4/A7 and cytokinin 6-benzyladenine (Promalin®) were also applied, combined with the other regulators, to antagonize a possible inhibition in the germination. Seeds were grown in darkness for 4 days, then seeds were exposed to a short light stimulus (30') and finally to a continued light stimulus (48h). β-carotene, xanthophylls, chlorophylls, de-epoxidation status of xanthophyll cycle (DPS), germination rate, and sprouts fresh weight were analysed. The results show that sprouts treated with methyl salicylate in-creased 2,35 fold their β-carotene content when they were exposed to light for 30'+48h. Sprouts fresh weight and germination were not affected by methyl salicylate. Although more research is needed before industrial application, it is concluded that methyl salicylate can be used to improve β-carotene contents in chia sprouts.