Controlled light intensity efficiently enhances micronutrient content and composition in chia sprouts.

Light-based biofortification can enhance the micronutrient content of sprouts under controlled environments. To evaluate the effect of light intensity and the light/dark phase on chia (Salvia hispanica), sprouts were grown in darkness for 3 days and then exposed to three light intensities (50, 100, and 150 μmol/m2/s) and two light/dark phases (12/12 h and constant light) for 48 h. Natural light and darkness were also assessed. Medium-intensity constant light was the optimal treatment for boosting micronutrients overall; it increased pro-vitamin A content by 4.5-fold compared to natural light (from 13.5 to 61.4 μg/g FW). Several minerals (copper, iron, magnesium, manganese, sulfur, and zinc) also increased (by between 1.5- and 1.3-fold) under this light regime. It was estimated that 137-176 g of biofortified chia sprouts may theoretically meet vitamin A requirements. This demonstrates that light intensity and phase differentially reshape chia micronutrients and provide a cost-effective approach for their optimization.