Influence of food matrices on the stability and bioavailability of abrin

Authors: Tam, Christina; Henderson, Thomas; Stanker, Larry; Cheng, Luisa

Submitted to: Toxins
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/23/2018
Publication Date: 12/1/2018
Citation: Tam, C.C., Henderson II, T.D., Stanker, L.H., Cheng, L.W. 2018. Influence of food matrices on the stability and bioavailability of abrin. Toxins. 10(12):52. https://doi.org/10.3390/toxins10120502.
DOI: https://doi.org/10.3390/toxins10120502

Interpretive Summary: Abrin, one of most potent toxins known to man, is a potential bioterror weapon. Work from both our laboratory and others have shown that abrin is highly resistant to both thermal and pH inactivation methods. We sought to evaluate the effectiveness of some food processing thermal inactivation conditions against abrin in four economically important food matrices (whole milk, non-fat milk, liquid egg, and ground beef). The effectiveness of inactivation was evaluated with different in vitro cell free assay, a Vero cell culture cytotoxicity assay, and the mouse bioassay. For both whole milk and non-fat milk, complete inactivation could not be achieve using regular pasteurization or the high temperature short time pasteurization (HTST). Toxin inactivation in liquid egg required temperatures of higher than suggested temperatures for scrambled eggs and plain whole egg. Additionally, the ground beef (80:20%) matrix was found to be inhibitory for full toxin activity in the mouse bioassay while retaining some activity in both the cell free translation assay and Vero cell culture cytotoxicity assay. A better understanding of the bioavailability of toxins would help in risk assessments for different agencies charged to protect our food supply.

Technical Abstract: Abrin, one of most potent toxins known to man, is a potential bioterror weapon. Work from both our laboratory and others have shown that abrin is highly resistant to both thermal and pH inactivation methods. We sought to evaluate the effectiveness of some food processing thermal inactivation conditions against abrin in four economically important food matrices (whole milk, non-fat milk, liquid egg, and ground beef). The effectiveness of inactivation was evaluated with an in vitro cell free translation (CFT) assay, a Vero cell culture cytotoxicity assay, and an in vivo mouse bioassay. For both whole milk and non-fat milk, complete inactivation was achieved at temperatures of 80 °C for 3 min or 134 °C for 60 sec which were higher than the normal vat/batch pasteurization or the high temperature short time pasteurization (HTST). Toxin inactivation in liquid egg required temperatures of 74 °C for 3 min higher than suggested temperatures for scrambled eggs (22% solids) and plain whole egg. Additionally, the ground beef (80:20%) matrix was found to be inhibitory for full toxin activity in the mouse bioassay while retaining some activity in both the cell free translation assay and Vero cell culture cytotoxicity assay.