Selection of Leafy Green Vegetable Varieties for a Pick-and- Eat Diet Supplement on ISS


Several varieties of leafy vegetables were evaluated with the goal of selecting those with the best growth, nutrition, and organoleptic acceptability for ISS. Candidate species were narrowed to commercially available cultivars with desirable growth attributes for space (e.g., short stature and rapid growth). Seeds were germinated in controlled environment chambers under conditions similar to what might be found in the Veggie plant growth chamber on ISS. Eight varieties of leafy greens were grown: ‘Tyee’ spinach , ‘Flamingo’ spinach , ‘Outredgeous’ Red Romaine lettuce , ‘Waldmann’s Dark Green’ leaf lettuce, ‘Bull’s Blood’ beet, ‘Rhubarb’ Swiss chard, ‘Tokyo Bekana’ Chinese cabbage, and Mizuna. Plants were harvested at maturity and biometric data on plant height, diameter, chlorophyll content, and fresh mass were obtained. Tissue was ground and extractions were performed to determine the tissue elemental content of Potassium (K), Magnesium (Mg), Calcium (Ca) and Iron (Fe). Following the biometric/elemental evaluation, four of the eight varieties were tested further for levels of anthocyanins, antioxidant (ORAC-fluorescein) capacity, lutein, zeaxanthin, and Vitamin K. For sensory evaluation, ‘Outredgeous’ lettuce, Swiss chard, Chinese cabbage, and Mizuna plants were grown, harvested when mature, packaged under refrigerated conditions, and sent to the JSC Space Food Systems Laboratory. Tasters evaluated overall acceptability, appearance, color intensity, bitterness, flavor, texture, crispness and tenderness. All varieties received acceptable scores with overall ratings greater than 6 on a 9-point hedonic scale. Chinese cabbage was the highest rated, followed by Mizuna, ‘Outredgeous’ lettuce, and Swiss chard. Based on our results, the selected varieties of Chinese cabbage, lettuce, Swiss chard and Mizuna seem suitable for a pick-and-eat scenario on ISS with a ranking based on all factors analyzed to help establish priority.


Bellevue, Washington
Raymond M. Wheeler, NASA, Kennedy State Center, USA
Gioia D. Massa, NASA, Kennedy State Center, USA
Gary W. Stutte, ESC Advanced Life Support Laboratories, Kennedy State Center, USA
Jeffrey T. Richards, ESC Advanced Life Support Laboratories, Kennedy State Center, USA
LaShelle E. Spencer, ESC Advanced Life Support Laboratories, Kennedy State Center, USA
Mary E. Hummerick, ESC Advanced Life Support Laboratories, Kennedy State Center, USA
Grace L. Douglas, NASA, Johnson Space Center, USA
Takiyah Sirmons, Wyle Integ. Sci. & Eng- Lockheed Martin, Johnson Space Center, USA
The 45th International Conference on Environmental Systems was held in Bellevue, Washington, USA on 12 July 2015 through 16 July 2015.