Recombinant protein detection and its content in total protein, lipids and toxic antinutritional substances in Mexican maize

Abstract

The engineering genetic technology has developed Bt maize events which contain recombinant protein that will be safe for the consumer. The aflatoxins are contaminants present in maize capable of producing cancer and decreasing the immune response in human, additionally contained polyphenols compounds considered non nutritive. The objective of this study was to identify the presence of recombinant protein in hybrid and local varieties of corn and evaluate the content of aflatoxins and tannins. 25 samples of white grain maize for human consumption were collected, 12 were for hybrid maize and 13 local varieties, from the states of Hidalgo, Mexico and Morelos. Samples were analyzed for Cry1Ab/Cry1Ac, using lateral flow strip method, crude protein and lipids by standard methods. Aflatoxins were assessed by comercial Elisa kit and tannins by spectroscopy method. The data were grouped in a completely random model and an analysis of variance was performed. The results indicated that 44.5% of hybrid corn was positive by Bt-Cry1Ab/1Ac proteins, containing 9.02% ± 2.5 lipids and 11.33% ± 2.2 crude protein, 189 ± 0.92 mg/g of tannins and 6.36 ± 3.3 µg·g −1 aflatoxins. The local maize samples (55.5%) were negative to Bt-Cry1Ab/ Cry1Ac, which protein content was of 8.68% ± 0.90, 6.14% lipids ± 2.3, 273 ± 0.40 mg/100g tannin and 7.15 ± 3.3 µg·g −1 of aflatoxins. In conclusion, we observed an improvement of nutrient composition in hybrid maize with Bt proteins, and decrease in tannins content comparing with some local varieties without Bt proteins. The effectiveness of Bt maize expressing the Cry1Ab/ Cry1Ac in reducing aflatoxin contamination was not observed, therefore, additive affects of aflatoxins contamination in maize Bt-Cry need to be further investigated in cancer disease development.