บทบาทของเหล็กและสังกะสี ต่อการเจริญเติบโตและปริมาณธาตุอาหารในผักสลัด ที่ปลูกในระบบไฮโดรโพนิกส์

Abstract

Nowadays, consumers have a demand for hydroponic lettuce which is safe from pesticide and contain beneficial nutrition. Especially iron and zinc are necessary for plants and the human body, and an inadequate daily intake of iron and zinc is a widespread problem. The objective of this study was to investigate the effects of iron and zinc fortification in the hydroponic system on the growth, nitrate, and nutrient content of lettuce and the effect of iron and zinc fortified lettuce on human primary colon cells (T4056). The experiment design was a completely randomized design, CRD with 3 experiments 1) Effect of iron-fortified with B-Veggie bio-agent on lettuce growth in flood roots system. 2) Effect iron and zinc fortified on the growth and quality of lettuce in the deep root floating technique, DRFT system. 3) Effect of nutrient fortified lettuce on primary human colon cells. The result showed that the B-Veggie bio-agent promotes lettuce growth and increases their high iron tolerance ability. Green oak and frillice iceberg, with the use of B-Veggie bio-agent, fortified with iron at 8.83 mg/L can grow normally compared to the unfortified green oak and frillice iceberg. Iron-fortified (8.83 mg/L) increased iron content in 5 lettuces (green cos, frillice iceberg, green oak, red oak, and butterhead) 1.10-1.27 times, with frillice iceberg obtaining the highest iron content (16.70 mg/kg fresh weight), but the amount of nitrogen, phosphorus, potassium, calcium, magnesium, and zinc tends to decrease. Zinc fortified (21.15 mg/L) increased zinc content in 5 lettuces 4.68-6.05 times, with green oak the highest zinc content (16.70 mg/kg fresh weight), but the amount of nitrate and iron tends to decrease. Iron with zinc fortified (4.42 mg/L and 10.58 mg/L, respectively) make butterhead growth and iron content similarly to the unfortified one and increased the zinc content of butterhead around 2 times. With the MTT cytotoxicity test, the extract of 3 lettuces (green oak, red oak, and butterhead) at 0 0.15 0.31 0.62 1.25 2.5 and 5 mg/mL with nutrients fortified and unfortified management. The result showed that the survival of human primary colon cells at the lowest level remains as high as 79.04% (the safety extract must not decrease the cell viability to less than 50%). It indicated the safety of lettuce for consumption. Green oak extract keeps the percentage of cell survival in the range of 90.19%-112.26%. The zinc fortified green oak extract at 2.5 mg/mL evoked cells to the highest growth level. Red oak extract keeps the percentage of cell survival in the range of 79.04%-118.20%. The iron-fortified red oak extract at 0.62 mg/mL evoked cells to the highest growth level, but the zinc-fortified red oak extract at the highest concentration decreased the percentage of cell survival by 20.96%. Butterhead extract keeps the percentage of cell survival in the range of 99.63%-154.40%. The iron-fortified butterhead extract at the highest concentration evoked cells to the highest growth level. In conclusion, iron and zinc fortified lettuce grows normally with high quality and high iron and zinc content, along with the low potassium content and nitrate below the EFSA standard. The fortified lettuce was also safe for the primary colon cells cell. It could be upgraded to a functional vegetable in the future.