Unlocking Nutritional Potential: First Profile of Ricebean (Vigna umbellata) Grown as Microgreens

The Philippines is home to diverse plant species, yet many remain underexplored and underutilized. One of these is ricebean (Vigna umbellata), locally known as tapilan. It is commonly used as an animal feed, but it holds huge nutritional potential as its seeds are protein rich. Therefore, this study explored the potential of ricebean as microgreens, an emerging commodity in the Philippines. Microgreens is a commodity grown and harvested in just a short amount of time, typically ranging from 7-21 days. Most species are classified as microgreens with the presence of the first two true leaves. In this study, ricebean seeds were sorted based on their seed coat color, namely, yellow-green (RBYG), light greyed-orange (RBAO), and dark greyed-orange (RBRB). These morphotypes were grown in a two-layered microgreen tray with moist sterilized coco coir, maintained under ambient temperature (27±2°C), and subjected to white and red-blue light-emitting diodes (LED) lights. Following the extended BBCH scale for dicotyledon plants, harvesting was done prior to the first trifoliate leaf formation 5 days after sowing at BBCH 13. Among the three seed morphotypes, RBYG and RBAO exhibited an average of 98% germination with vigorous seedlings. Proximate analysis revealed that RBRB (1.2100±0.01 g 100g-1) has the highest ash content followed by RBYG (1.0933±0.01 g 100g-1) and RBAO (1.0233±0.03 g 100g-1). In addition, RBYG (0.8933±0.09 g 100g-1) and RBRB (0.7900±0.08 g 100g-1) crude fat content is significantly higher than RBAO (0.5667±0.03 g 100g-1). Overall, 100g of fresh ricebean microgreens contain 6.44±0.60 g crude protein, 4.65±0.59 g total carbohydrate, 0.76±0.22 g crude fat, 0.99±0.12 g ash-1, and 87.5±0.50% moisture content which are comparable to mungbean microgreens. Further validation with additional ricebean seedlots is needed to refine the findings of this exploratory study and establish guidelines for microgreens production at the household level.