Isolation of Aflatoxin-Free Lutein from Aflatoxin-Contaminated Corn

Abstract

Lutein (3,3’-dihydroxy-alpha-carotene) has been identified by the Age-Related Eye Disease Study (AREDS) of the National Institute of Health (NIH) as a dietary compound with the ability to delay the onset and/or progression of age-related and/or diabetes-related vision loss. Lutein can also be useful in the prevention of other angiogenic diseases such as breast and colon cancer. Although marigold (Tagetes erecta) flowers are an excellent source of lutein, corn (Zea mays) has been identified as a very economical source of lutein because more value-added products, such as lutein, oil, and zein (known for its anti-microbial and anti-hypertensive activities) can be isolated from corn than marigold flowers. However, aflatoxin-contaminated corn has very low economic value to farmers and is banned for use in human food chain. The objective of this research was to isolate aflatoxin-free lutein from aflatoxin-contaminated corn. Aflatoxin-contaminated corn was fractionated for lutein using commercially available solvents. Aflatoxins in the aflatoxin-lutein mixture were converted into a water-soluble molecule and were displaced from the lipid environment. Extraction and quantification of aflatoxin in the aqueous and lutein-containing lipid phase were carried out using the AOAC multifunctional column method involving solid phase extraction and HPLC, respectively. Aflatoxins BB1B and BB2B were identified at 4888 and 368 ppb, respectively in the untreated aflatoxins-lutein extract. However, no peaks associated with either aflatoxin BB1B or BB2B were detected in the lipid phase containing lutein following aflatoxins displacement. Lutein concentration and stability following aflatoxins displacement was determined by HPLC. The HPLC results indicated the presence of one peak eluted at 21.0 minutes. Spiking with standard lutein confirmed the identity and stability of lutein isolated from aflatoxins-contaminated corn. This study has shown that corn growers and processors may generate additional income from aflatoxin-contaminated corn. The overall significance of this research is that, if approved by FDA, corn growers can still sell aflatoxins-contaminated corn at a competitive price since almost all the value-added products from corn can be recovered aflatoxins-free and more lutein will be available for disease prevention.