Can Light Spectrum Composition Increase Growth and Nutritional Quality of Linum usitatissimum L. Sprouts and Microgreens?

Martina Puccinelli,Marco Santin,Luciana G Angelini,Antonella Castagna,Marco Landi,Luca Incrocci,Silvia Tavarini,Rita Maggini

doi:10.3390/horticulturae8020098

Abstract

Flaxseed could be suitable for obtaining high-quality sprouts and microgreens thanks to high amounts of nutrients and antioxidant, antidiabetic, and anticancer compound content in its seeds. Recent studies highlighted that seedling growth, nutritional compound, and secondary metabolite content can be strongly managed by regulation of the light spectrum used during germination. The present study intended to shed light on flaxseed as emerging and novel species for sprouts and microgreens and to evaluate the effect of light, with different spectrum compositions (100% blue, 100% red, 100% green, and red:green:blue—1:1:1) on the performance of flax microgreens and sprouts grown indoors under controlled conditions. Microgreens showed, compared to sprouts, a higher chlorophyll (+62.6%), carotenoid (+24.4%), and phenol content (+37.8%), antioxidant capacity (+25.1%) and a lower dry matter content (−30.7%). Besides, microgreens treated with 100% blue light were characterized by the highest content of flavonoids (2.48 mg CAE g−1 FW), total phenols (3.76 mg GAE g−1 FW), chlorogenic acid (1.10 mg g−1 FW), and antioxidant capacity (8.06 µmol TEAC g−1 FW). The paper demonstrates the feasibility of obtaining flax sprouts and microgreens indoors with a considerable antioxidant capacity and health-promoting compounds by modulating the light spectrum.

Highlights

Sprouts and microgreens have gained an ever-increasing popularity over the last few decades as emerging types of specialty vegetable and new functional foods
The dry matter content of flax sprouts was higher than the values reported by Wang et al [18,35] and Wu et al [36], and lower than those reported by Narina et al [17], showing that the dry matter content of flax sprouts could be quite variable, ranging from 5.5 [36] to 24% [17]
The lower dry matter content observed in our study in comparison with Narina et al [17] could be due to the older sprouts harvested in our experiment (7 vs. 4 days in [17])

Summary

Introduction

Sprouts and microgreens have gained an ever-increasing popularity over the last few decades as emerging types of specialty vegetable and new functional foods. Sprouts are young seedlings obtained from seed germination with a very short growth cycle (4–10 days), while microgreens (a marketing term) are young and tender greens without roots that are harvested 10–14 days from sowing, after the development of the cotyledon leaves, and first true leaves [1]. Beside their unique taste and flavor, both sprouts and microgreens have a higher nutritional and health profile compared to seeds or mature plants, thanks to the germination process.

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Discussion

Conclusion