Stability of carotenoids in sweet corn: Part 2. Effects of blanching, freezing, and canning

Authors: Whent, Monica; HUANG, JHONGYAN - University Of Maryland; CHILDS, HOLLY - University Of Maryland; SLAVIN, MARGARET - University Of Maryland; Harrison, Dawn; Novotny, Janet; YU, LIANGLI - University Of Maryland; Pehrsson, Pamela; Wu, Xianli

Submitted to: ACS Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/14/2023
Publication Date: 8/28/2023
Citation: Whent, M.M., Huang, J., Childs, H., Slavin, M., Harrison, D.J., Novotny Dura, J., Yu, L., Pehrsson, P.R., Wu, X. 2023. Stability of carotenoids in sweet corn: Part 2. Effects of blanching, freezing, and canning. ACS Food Science and Technology. 3(9):1590-1599. https://doi.org/10.1021/acsfoodscitech.3c00273.
DOI: https://doi.org/10.1021/acsfoodscitech.3c00273

Interpretive Summary: Sweet corn is commonly consumed in canned or frozen forms in the US. This study evaluated the effects of blanching, freezing and canning on carotenoids in sweet corn. The raw materials were harvested from the field and were processed immediately to frozen or canned samples. The processed samples were stored at -20 °C or at room temperature for one month for the frozen and the canned samples, respectively. Carotenoids were analyzed by HPLC and LC-MS. The three processing methods reduced the levels of free carotenoids but increased that of the bound carotenoids. As a result, the total carotenoids in the processed samples were either remained unchanged or slightly lower than the unprocessed sample. The stabilities of individual carotenoids were determined by their chemical structures. In addition, cis isomers of lutein and zeaxanthin were formed during canning, which made total cis isomers a significant contribution of the total carotenoids in canned sweet corns. The data from this study provided important information for better use of sweet corn products for human health.

Technical Abstract: Sweet corn is commonly consumed in canned or frozen forms in the US. This study evaluated the effects of blanching, freezing and canning on carotenoids in sweet corn. The raw materials were harvested from the field and were processed immediately to frozen or canned samples. The processed samples were stored at -20 °C or at room temperature for one month for the frozen and the canned samples, respectively. Carotenoids were analyzed by HPLC and LC-MS. The three processing methods reduced the levels of free carotenoids but increased that of the bound carotenoids. As a result, the total carotenoids in the processed samples were either remained unchanged or slightly lower than the unprocessed sample. The stabilities of individual carotenoids were determined by their chemical structures. In addition, cis isomers of lutein and zeaxanthin were formed during canning, which made total cis isomers a significant contribution of the total carotenoids in canned sweet corns. The data from this study provided important information for better use of sweet corn products for human health.