Cultural management and consumer sensory evaluation of common ice plant (Mesembryanthemum crystallinum L.) as an edible succulent leafy green
Common ice plant (Mesembryanthemum crystallinum L.) is a novel edible plant with succulent and savory flavor. It has high nutritional value for humans and is used as medical treatment, in therapeutic cosmetics and as food. Ice plant as a leafy green with its unique flavor may become an important new, high-value crop in controlled environment agriculture (CEA). However, limited information on cultural practices of ice plant is available. No information was previously available on the consumer liking and sensory evaluation of ice plant. The objective of this study was to develop increased knowledge about cultural management during hydroponic production to optimize the yield potential of this plant as well as to determine consumer sensory responses. This study began with evaluating the response of ice plant to sodium chloride (NaCl) concentration in the hydroponic nutrient solution, because ice plant is an obligatory halophyte that requires NaCl for optimal growth. Four-week old seedlings were established in hydroponics with a base nutrient solution and one of five NaCl concentrations (0, 0.05, 0.10, 0.20, 0.40 M NaCl). Optimum yield (fresh weight, dry weight, and leaf surface area) was obtained at 0.05 M and 0.10 M NaCl in hydroponic nutrient solution which performed better than control (0 M). Quantitative analysis of Na and Cl uptake also indicated the potential of ice plant to be used in bioremediation of saline soil and hydroponic wastewater. The second part of this study focused on lighting control which is a common practice in CEA. Ice plant was evaluated in response to five photoperiod/daily light integral (DLI) treatments (8/6.3, 12/9.5, 16/12.7, 20/15.8, 24/19.0 hr/mol·m-2·d-1 ) and it exhibited better plant performance with increased photoperiod/DLI up to 20 hr/15.8 mol·m-2·d-1 and negative effect of continuous lighting treatment. The NaCl and lighting research could effectively inform greenhouse and plant factory production of edible ice plant. The third part of this study focused on consumer sensory evaluation of ice plant. Ice plant received a moderate overall liking score and the score decreased slightly with increasing salt level. Increasing salt also led to slightly increased fishiness and sourness and slightly decreased green flavor but had no effect on sweetness and bitterness. Salt level did not affect appearance and texture of ice plant. Overall familiarity and intent to purchase ice plant was low suggesting more work is needed to familiarize consumers to this new edible crop.