**3. Results**

### *3.1. Morphometric and Yield Characteristics*

Microgreens were harvested 23 days after sowing. Borage provided the highest amount of fresh product per cultivated surface and a largely higher dry biomass (Table 1). In our controlled conditions, yield was highly correlated with the harvested dry mass (r = 0.99; *p* < 0.001; Pearson two-tails). On the other hand, the percentage of dry matter was higher for purslane.

**Table 1.** Fresh yield, dry weight, dry matter, and hypocotyl length of the two microgreens growing in controlled conditions. Means were statistically separated using a two-tailed Student's *t*-test. \*\*: *p* < 0.01; \*\*\*: *p* < 0.001.


### *3.2. Mineral Content*

Regardless of the higher percentage of dry matter, purslane had a higher amount of 13 mineral elements out of the 18 analyzed, with only Se and Cu (not detected in purslane) present in higher percentage in borage (Table 2). In relative terms, the largest difference was observed for Mo (+461%), followed by Zn (+297%) for the microelements, and for K (+127%) and Mg (+98%) among the macro-elements. B, Al, and Pb did not display a significant variation between the species. As expected, K was the most abundant mineral element for both species. In addition, the Na/K ratio was not significantly different between purslane and borage (not shown), being K approximately 10 × higher than Na.

**Table 2.** Mineral composition of the microgreens growing in controlled conditions. Means were statistically separated using a two-tailed Student's *t*-test. ns: Not significant; \*: *p* < 0.05; \*\*: *p* < 0.01; \*\*\*: *p* < 0.001; nd: Not detected.


### *3.3. Radical Scavenging Activity*

Purslane microgreens had significantly higher antioxidant properties as indicated by the activities measured in the plant extracts with the three different assays (Table 3). Specifically, the different methodologies gave a comparable ranking of antioxidant activities, consistently higher (around 40%) in purslane.

**Table 3.** Antioxidant activities in microgreen extracts. Means were statistically separated using a two-tailed Student's *t*-test. \*\*: *p* < 0.01; \*\*\*: *p* < 0.001.


### *3.4. Ascorbic Acid, Chlorophyll, Lutein, and β-Carotene*

The total ascorbic acid differed significantly between the two microgreen genotypes studied (Table 4). Interestingly, purslane had significantly more total ascorbic acid (more than 3 times higher than that of borage), while determinants of the leaf color (i.e., chlorophylls and carotenoids) were not different between the two species (Table 4). The data implied that the different colors of the microgreens (Supplementary Figure S1) are mainly due to other components, such as chromogenic phenolic compounds (see below). In absolute terms, β-carotene was more abundant than lutein for both species (Table 4). Nonetheless, the β-carotene/lutein ratio was significantly higher for purslane (*p* < 0.01; *t*-test).

**Table 4.** Total ascorbic acid, total chlorophylls, and carotenoids (lutein and β-carotene) in microgreen extracts. Means were statistically separated using a two-tailed Student's *t*-test. ns: Not significant; \*\*\*: *p* < 0.001.

