|GU, XIN - Monsato Seed Company
|LEE, THOMAS - Monsato Seed Company
|GENG, TAO - Monsato Seed Company
|LIU, KANG - Monsato Seed Company
|THOMA, RICHARD - Monsato Seed Company
|CROWLEY, KATHLEEN - Monsato Seed Company
|EDRINGTON, THOMAS - Monsato Seed Company
|WARD, JASON - Monsato Seed Company
|WANG, YONGCHENG - Monsato Seed Company
|BELL, ERIN - Monsato Seed Company
|GLENN, KEVIN - Monsato Seed Company
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2017
Publication Date: 2/5/2017
Citation: Gu, X., Lee, T., Geng, T., Liu, K., Thoma, R., Crowley, K., Edrington, T., Ward, J., Wang, Y., Flint Garcia, S.A., Bell, E., Glenn, K. 2017. Assessment of natural variability of maize lipid transfer protein using a validated sandwich ELISA. Journal of Agricultural and Food Chemistry. 65:1740-1749. doi: 10.1021/acs.jafc.6b03583.
Interpretive Summary: Food allergens pose a risk to human health, and foods containing the most common allergens require labelling. While corn (maize) is not one of the eight major food groups that currently requires labelling in the US, the primary allergen in maize has been identified as lipid transfer protein (LTP). Little is known about the range of variability in LTP in maize can be attributed to growing environment versus maize variety. Here we develop an assay to quantify LTP in maize, and conduct studies to assess the variability in LTP content in diverse maize hybrids from around the world and determine the relative contribution of growing environment on LTP content in commercial varieties grown across the US. We found a five-fold range in LTP content across diverse maize, indicating that variety grown certainly affects LTP content. We also determined that the majority of LTP variability can be attributed to variety effects and that environmental effects were negligible. These outcomes indicate that the location where the corn is grown is not as important as the variety that is grown. This information is useful to food scientists and regulators as they address food allergies and labelling requirements.
Technical Abstract: Lipid transfer protein (LTP) is the main causative agent for rare food allergic reactions to maize. This report describes a new, validated ELISA that accurately measures LTP concentrations from 0.2 to 6.4 ng/ml. The levels of LTP ranged from 171 to 865 µg/g grain, a 5.1 fold differences, across a set of 49 samples of maize B73 hybrids derived from the Nested Association Mapping (NAM) founder lines and a diverse collection of landrace accessions from North and South America. A second set of 107 unique samples from 18 commercial hybrids grown over two seasons in 10 U.S. states showed a comparable range of LTP level (212 to 751 µg/g grain). Statistical analysis showed that genetic and environmental factors contributed 63% and 6%, respectively, to the variance in LTP levels. Therefore, the natural variation of maize LTP is up to five-fold across a diverse collection of varieties that have a history of safe cultivation and consumption.