ASHS 2024 Conference

Economic opportunities have arisen to increase the production of specialty crops catering to ethnically diverse consumers. Opportunities to capture anticipated niche market growth for ethnic crops continue to grow. Amaranthus viridis L. (amaranth), a highly nutritious leafy vegetable, eaten cooked or raw, with a nutritional value similar to spinach, is widely cultivated, highly nutritious, and has medicinal properties. Studies were conducted to 1) evaluate two thermo-processing (steam and water blanching) and three drying methods (freeze, hot air, and infrared drying) for the development of amaranth value-added products and 2) analyze the effective thermo-processing and drying methods to maximize the phytonutrient contents and minerals in the vegetable. Two thermo-treatments, steam blanch (SB) and hot water (HB), and the control (C), three drying treatments, freeze-dried (FD), hot air dried (HAD), and infrared dried (ID) were used. The treatments were T1:FD(C), T2:HAD(C), T3:ID(C), T4:FD(SB), T5:HAD(SB), T6:ID(SB), T7: FD(HW), T8: HAD(HW), T9: ID(HW). Amaranth was harvested once per week and processed three times throughout the growing season (1st harvest (28 days after transplanting (DAT)), 2nd harvest (56 DAT) in the middle of the growing season, and the 3rd harvest (84 DAT) at the end of the growing season). Phytonutrients, ascorbic acid and β-carotene, rehydration capacity, and sensory evaluation were analyzed. Significant differences in phytonutrients (total phenolic content (TPC) and total flavonoid content (TFC)) were observed among treatments and harvest times, with the FD(C) treatment being significantly higher in TPC and TFC during the 1st and 2nd harvest when compared to the other treatments. Ascorbic acid was significantly higher in FD(C) and HAD(C) (419.33 mg/100g, dm and 203.3 mg/100g, dm, respectively). ID(C), ID(SB), ID(HW) and HAD(SB) were significantly lower in ascorbic acid when compared to the other treatments. Significant differences were also observed in β-carotene among treatments. For rehydration capacity, rehydration at 9 minutes showed the highest water absorbance for all treatments, with FD(C) and HAD(C) being significantly higher, while HAD(HW) and ID(HW) were significantly lower in water absorbance for the rehydration times of 3, 6 and 9 minutes. For the sensory evaluation, 59%, 73%, and 54% of respondents indicated that the rehydrated samples were just right for flavor, color, and texture, respectively; and 45% of respondents indicated that the overall quality of the rehydrated sample was good. This study provides valuable insights for the development of value-added products catering to ethnically diverse consumers.