Evaluation of Carrots (Daucus carota L.) Grown in Two Hydroponic Systems for Inclusion in NASA's Advanced Food Systems 2005-01-3114

In contribution towards the screening of eight hydroponically grown carrots, some biochemical, physical and sensory properties of the roots were evaluated. The carrots had been grown under two nutrient delivery systems, Nutrient Film Technique (NFT) and Microporous Tube Membrane nutrient delivery System (MTMS). Biochemical measures conducted included, moisture, fat and β-carotene contents, and the physical measures were texture and color. For the NFT- and MTMS-grown carrots, Nantes Touchan (91%) and Nanco Hybrid (87%), respectively, had the highest moisture contents. Fat contents for all the cultivars grown in both systems ranged from 0.1 to 0.4%. In the NFT-grown carrots, Baby Spike and Juwaroot had the highest and lowest β-carotene contents, 8777 and 248 µg/100 g, respectively. For the MTMS-grown carrots, Thumbelina had the highest β-carotene content (7840 µg/100 g). However, the lowest β-carotene value for the MTMS-grown carrots was 3059 µg/100 g. Baby Spike and Nantes Touchan grown in MTMS were the carrots lightest in color (L* = 63). Kandulus and Nanco Hybrid grown in MTMS and NFT, respectively, had the lowest L* values. For the NFT and MTMS-grown carrots, Juwaroot and Nantes Touchan, respectively, were the most firm carrots. Consumer survey revealed that most of the participants (82%) were not aware of hydroponic carrots. However, 61% indicated that they would buy hydroponic carrots if they are healthier. Out of the three hydroponic carrots tested, Baby Spike (MTMS) was most preferred by consumers. Overall, the commercial carrot was better than the hydroponic carrots in many aspects, though in some cases not by far.