TABLE 4.

Influence of light on growth and phytochemical quality of microgreens.

S.No	Microgreen	Light treatment	Trait/Aspect studied	Key findings	References
Vegetables
1	Brassica juncea ‘Red Lace’ (Mustard) and Brassica napus‘Red Russian’ (kale)	Blue:red light (LED)	Mineral nutrient content	Increase in blue light decreased elongation and enhanced accumulation of micro as well as macro nutrients	Brazaitytė et al. (2021)
2	Broccoli microgreens	Red:blue:green (1:1:1) LEDs	Growth and phytochemical content	Increased fresh weight, dry weight and moisture content, further, elevated chlorophyll and reduced carotenoid content with increasing light intensity. Contents of some other phytochemicals like vitamin C, soluble proteins and sugar, flavonoid, free amino acid, and glucosinolates except progoitrin also increased	Gao et al. (2021)
3	Amaranthus tricolor L. and Brassica rapa L. subsp. oleifera	White LED, Blue LED and Red LED	Yield and nutritional quality	Blue light is most effective in promoting growth and nutritional qualities. Red light had pronounced effects on accumulation of fresh biomass as well as growth of hypocotyl	Toscano et al. (2021)
4	Chinese Kale	Red, white, Blue LED and sunlight (control)	Growth and antioxidant system	Low intensity red light increased fresh weight ang hypocotyl growth. White LED promoted accumulation of phenolic compounds, glucosinolates and ascorbic acid	Tantharapornrerk et al. (2021)
5	Eruca sativa L.- Arugula, Brassica oleracea L. var. Capitata f. rubra - red cabbage, Brassica napus L. subsp. napus var. Pabularia - ‘Red Russian’ kale, Brassica juncea L. - ‘Mizuna’ mustard	LEDs supplying blue (5%–30%) and red light (70%–95%)	Phytochemical profiles	20% blue light enhanced ascorbate levels (both reduced and total) in arugula, mustard as well as kale microgreens. 30% blue light stimulated accumulation of phenols in Kale and mustard. Total anthocyanin content showed proportional increase with the % of blue light supplied up to 30 percent in all microgreens, except mustard	Ying et al. (2021)
6	Leafy vegetable amaranth and Red amaranth	LEDs	Growth and nutritional value	Red + blue in ratio 70R:30B (PPFD-280 μmol/m2/s1; Photoperiod- 16 h) improved fresh yield, vitamin C, content of photosynthetic pigments (carotenoids and chlorophylls), anthocyanins, and levels in both red amaranth and leafy vegetable amaranth microgreens. Further, total antioxidant capacity was also increased	Meas et al. (2020)
7	Amaranth, cress (edible herb), mizuna, purslane	Red, Blue, Blue-Red	Differences in productivity levels, polyphenolic and antioxidant profiles together with content of mineral–carotenoid	Higher nitrate accumulation, Increased concentrations of Na and K, while decreased calcium and magnesium concentration. Enhanced lipophilic antioxidant activity, β-carotene and lutein. Decreased polyphenolic content	Kyriacou et al. (2019b)
8	Brassica oleracea var. gongylodes (kohlrabi), Brassica rapa var. Japonica (mizuna) and Brassica oleracea (broccoli)	10 light spectrum comprising of red light (638 and 665 nm), far-red light (731 nm) and blue light (447 nm), or supplemented by yellow (595 nm), green light (520 nm), or orange (622 nm), LED source	Nutrient levels	Metabolic changes resulted in increase in essential nutrients like Iron, Magnesium, Calcium, beta carotene, soluble carbohydrates, ascorbic acid	Samuolienė et al. (2019)
	Brassica oleracea var. gongylodes—Kohlrabi, Brassica rapa var. Japonica—Mizuna and Brassica oleracea - Broccoli
9	Radish	White, Blue, UV-A and dark; light conditions combined with Hydrogen rich water (HRW)	Anthocyanin accumulation	Blue light and UV-A combined with HRW resulted in higher phenolic content. Increased content of anthocyanin compounds	Zhang et al. (2019)
10	Mustard, Beet and Parsley	Blue light treatment	Carotenoid and tocopherol content	Quantity of chlorophylls, carotenoids, alpha-carotenes and beta-carotenes, zeaxanthin, violaxanthin, and lutein, increased 1.2 to 4.3 folds	Samuolienė et al. (2017)
11	Brassica oleracea var. gongylodes—Kohlrabi, Brassica juncea ‘Garnet Giant´- mustard, and Brassica rapa var. Japonica - mizuna	SS- LEDs; % Ratios as follows: Red87:Blue13, Red84:Far Red7:Blue9,orRed74:Green18:Blue8	Phytochemical synthesis	Total carotenoids in mizuna and mustard microgreens lowered, as light intensities increased. Higher values of total integrated chlorophyll were observed in kohlrabi at Red87:Blue13compared to mustard microgreens at Red84:Far Red7:Blue9 and Red74:Green18:Blue8.Total concentration of anthocyanins also increased as light intensity increased	Craver et al. (2017)
12	Brassica rapa var. Chinensis—Red pakchoi, Brassica juncea L.—Mustard and Brassica rapa var. rosularis—Tatsoi	Pulsed LED	Phytochemical levels	Total phenolic content decreased in response to pulsed LED while total anthocyanin content increased	Vaštakaitė et al. (2017)
Herbs—Medicinal/Culinary
1	Chia (Salvia hispanica L.) (Dark grown)	Constant light (100 µmol photons/m2/s) for 24h and 48 h	Antioxidant activity and metabolic profile	Significant increase in antioxidant activity, chlorophyll and carotenoid synthesis, total soluble phenols and ascorbic acid content	Mlinarić et al. (2020)
2	Ocimumbasilicum L. (Acyanic and cyanic basil)	Light Emitting Diodes - Red andBlue	Microgreen morphometric parametres and bioactive compounds	Blue light illumination affected growth parameters resulting in increased cotyledon surface area, fresh weight, anthocyanin concentration and chlorophyll levels. Red light triggered synthesis of phenols and capacity to scavenge free radicals in green cultivar while in red cultivar blue light was found effective for same	Lobiuc et al. (2017)
Legumes
1	Soybean	LED light spectra	Growth, antioxidant capacity, phenolic compounds profile	Decreased seedling heightas well as yield while increase in phenols. UV-A and Blue light significantly increased antioxidant capacity, total phenols and total flavonoid content	Zhang et al. (2019)