PRODUCTION OF MICROGREENS FROM LOCAL PLANT SPECIES IN THAILAND

Microgreens production from indigenous Thai plant species was studied as part of a development project started in 2009. The project focused on the production and utilization of local Thai vegetables and was conducted by the Rajamangala University of Technology Suvarnabhumi (Ayutthaya). The selected local plant species were: leaf mustard (Brassica juncea (L.) Czern.), rat-tailed radish (Raphanus sativus Linn. var. caudatus Alef) and sano (Sesbania javanica Miq). One-week seedling heights were 6.18, 11.58, and 10.36 cm, 100-seedling fresh weights were 5.49, 16.34 and 11.47 g; and fresh weight yields of microgreens were 2.21, 1.84 and 1.30 kg m^-2 for B. juncea, R. sativus var. caudatus and S. javanica, respectively. Monitoring of consumer acceptance during the distribution of fresh microgreens on a trial basis at local supermarkets revealed acceptance scores ranging from 4.4 to 4.9 on a 1 to 5 scale. The respective nutritional contents per 100 g of edible portion of microgreens from B. juncea, R. sativus var. caudatus and S. javanica were: protein 6.55, 6.83 and 6.97 g; fiber 3.94, 3.70 and 3.12 g; vitamin C 31, 28 and 3 mg; beta-carotene 1540, 569 and 366 μg. Chlorophyll contents were 0.324, 0.445 and 0.159 mg g^-1 fresh weight, respectively. Evaluation of antioxidant capacity revealed that B. juncea had the highest capacity of 0.79, R. sativus var. caudatus was intermediate at 0.42, and S. javanica exhibited the lowest level of 0.04 mmol Trolox equivalent g^-1 dry matter basis. Following seven days of storage at 5°C, microbial populations were evaluated: populations of yeast, mould, E. coli and Salmonella were all determined to be at a safe level.