Sprouts and Microgreens-Novel Food Sources for Healthy Diets

Abstract

With the growing interest of society in healthy eating, the interest in fresh, ready-to-eat, functional food, such as microscale vegetables (sprouted seeds and microgreens), has been on the rise in recent years globally. This review briefly describes the crops commonly used for microscale vegetable production, highlights Brassica vegetables because of their health-promoting secondary metabolites (polyphenols, glucosinolates), and looks at consumer acceptance of sprouts and microgreens. Apart from the main crops used for microscale vegetable production, landraces, wild food plants, and crops' wild relatives often have high phytonutrient density and exciting flavors and tastes, thus providing the scope to widen the range of crops and species used for this purpose. Moreover, the nutritional value and content of phytochemicals often vary with plant growth and development within the same crop. Sprouted seeds and microgreens are often more nutrient-dense than ungerminated seeds or mature vegetables. This review also describes the environmental and priming factors that may impact the nutritional value and content of phytochemicals of microscale vegetables. These factors include the growth environment, growing substrates, imposed environmental stresses, seed priming and biostimulants, biofortification, and the effect of light in controlled environments. This review also touches on microgreen market trends. Due to their short growth cycle, nutrient-dense sprouts and microgreens can be produced with minimal input; without pesticides, they can even be home-grown and harvested as needed, hence having low environmental impacts and a broad acceptance among health-conscious consumers.

Keywords: biofortification; functional foods; health-promoting compounds; illumination; malnutrition; microgreens; microscale vegetables; phytonutrients; seed priming; sprouts.

Figure 2

Home-grown 3-day old pea (Pisum sativum) sprouts. Seed germination process and nutritional benefits of sprouted seeds:

Figure 3

Home-grown 9-day old pea (Pisum sativum) microgreens. Commonly recognized nutritional benefits of microgreens:

Figure 1

Dormant seed with stored reserves. A display of a seed mix for sprouting, consisting of quinoa (Chenopodium quinoa), lentil (Lens culinaris), and radish (Raphanus sativus) seed.

Figure 4

The antioxidant activity (%) in methanol extract (100 mg/mL) of raw seed, sprouts, and microgreens of Vigna radiata and Cicer arietinum; a graphical representation of data published by Kurian and Megha [42].

Figure 5

A comparison of selected phytochemical concentrations of red cabbage (Brassica oleracea var. capitata) at the microgreen and adult growth stage. FW = fresh weight; DW = dry weight; a graphical representation of data published by Choe et al. [95].