The Biofortification Preparation And Application Of Iron-enriched Germinated Corn

In this dissertation,0～100μg/mL ferrous sulfate solution and Fe^Ⅲ-EDTA are used as iron culture solution,and the four varieties of corn seeds（Jinhai 13,Zheng Dan 958,Jundan 20,Jinyu 1233）soaked in ultrapure water for 10 hours,carry out biofortification germination to prepare iron-enriched germinated corn.The growth parameters of the germinated corn seeds were measured,and the effects of different culture solutions and concentrations on the growth parameters such as the germination rate,sprout length and root length of corn seeds were analyzed.Measured the contents of Fe,Zn,Mn,Cu trace elements in corn seeds by FAAS method,compared the changes of the four trace elements contents after germination or iron biofortification,and explore the effects of different culture solutions and concentrations on Fe,Zn,and Zn in corn seeds.The influence of Mn and Cu element contents,and the in vitro digestion and dialysis method was used to analyze the bioavailability of iron in iron-enriched germinated corn.Ultraviolet spectrophotometry was used to measure the changes of total flavonoids,carotenoids,and anthocyanins in different varieties of corn under different culture solutions and concentrations,and explored the effects of germination or iron biofortification on the nutritional value of corns.Finally,FRAP method and DPPH free radical scavenging method were used to evaluate the antioxidant capacity of iron-enriched germinated corn.The main conclusions are as follows:（1）By soaking the four kinds of corn seeds with ultrapure water and then germination or iron biofortification,the germination rate of the four kinds of corn is higher than that of the ultrapure water control group,and the germination rate is up to90%.The root length and shoot length of the germinated corn after biofortification by iron culture solution changed significantly（p<0.05）.High concentration of iron culture solution would inhibit the root and shoot growth of germinated corn. Low-concentration iron solution is conducive to the growth of roots and shoots of germinated corn.（2）After germination with ultrapure water,the four trace elements in germinated corn all slightly changed.Iron element increased slightly,zinc element basically remained flat or decreased slightly,manganese element leaked a lot,copper element was basically the same.After the iron culture solution biofortification,the low-concentration iron culture solution had no significantly influence on the iron contents in the germinated corn.When the concentration exceeded 20μg/mL,the iron contents in the germinated corn increased significantly（p<0.05）.The effect of iron culture solution on zinc contents in germinated corn was not significantly,and there were no significantly influences on zinc contents in germinated corn cultivated at various concentrations（p>0.05）.However,the iron-enriched germination corn caused a sharp drop in the contents of manganese.Different iron culture solutions have different effects on the content of copper in germinated corn.When Fe^Ⅲ-EDTA was culture solution,caused the loss of copper,while when Fe SO₄ was culture solution,caused the accumulation of copper in the germinated corn.（3）After germination,the total flavonoid contents,anthocyanin contents and carotenoid contents in the four germinated corns were increased compared with raw seeds.After iron biofortification,the three nutrient contents of four iron-enriched germinated corns were significantly increased compared with raw seeds（p<0.05）.Among them,the highest total flavonoid contents reached 2163.83 mg/kg,the highest anthocyanin contents reached 377.31 mg/kg,and the highest carotenoid contents reached 215.2 mg/kg.In addition,Fe^Ⅲ-EDTA was culture solution had more conducive to the synthesis of total flavonoids in germinated corn.However,the effect of two different iron culture solution on the carotenoid contents in germinated corns was not significantly（p>0.05）.（4）The in vitro digestion and dialysis model showed that the bioaccessibility of the four germinated corns increased after germination by iron culture solution.Among the four kinds of iron-enriched germinated corn,the iron bioaccessibility rate increased by 139.59%,129.95%,143.82%,and 142.74%of Jinhai 13,Zheng Dan 958,Jundan 20,Jinyu1233 compared with the ultrapure water germination group, respectively.Regarding the biologically acceptable amounts of iron in germinated corn,the highest bioaccessible amounts of four iron-enriched germinated corns were66.34μg/g,88.73μg/g,79.21μg/g and 65.89μg/g,respectively.（5）The FRAP method was used to determine the total antioxidant capacity of germinated corns.It was found that Zhengdan 958 had the strongest total antioxidant capacity among the four raw seeds,reaching a maximum of 138.30μg VC/g DW.After iron biofortification,the strongest total antioxidant capacity is Jundan 20,with a maximum of 243.86μg VC/g DW.By the DPPH free radical scavenging method,the DPPH free radical scavenging rate of the four raw seeds had no significantly influence（p>0.05）.After iron biofortification,the DPPH free radical scavenging rates of the four raw seeds were all significantly increased（p<0.05）,the highest DPPH free radical scavenging rate reached 87.63%.