Submitted to: American Oil Chemists' Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/13/1998
Publication Date: N/A
Technical Abstract: Limiting aflatoxin B1 (AFB1) contamination is an important part of food safety. In corn, the germ is the principle site of AFB1 synthesis and the main nutrients in germ are triglycerides (TGs) and sucrose. Results are reported for the effect of sucrose, corn oil (CO), TGs, and selected glycolysis metabolites on AFB1 biosynthesis by A. flavus. Interaction between sucrose and TGs was assessed in medium with sucrose at 0-8% levels in combinations with CO at 0-16%. On sucrose alone, AFB1 increased as the sugar level increased from 0.5% to 8%. Toxin on CO alone increased up to 16%. Mixtures of CO and sucrose resulted in decreasing utilization of CO for AFB1 as sucrose level increased. A maximum decrease of 60% in toxin occurred at 2% sucrose and 16% CO. AFB1 level on 16% CO was 296 ug/mL and 136 ug/mL with 2% sucrose. A mixture of TGs with a composition similar to CO, composed of 31% trioleate, 56% trilinoleate and 13% tripalmitin gave results similar to those obtained with CO. TGs of 18:1, 18:2, and 18:3 used alone gave similar amounts of AFB1. Trilinolenate was not inhibited by glucose nor were saturated TGs. Other sugars and metabolites could stimulate or inhibit TG utilization regardless of whether they supported AFB1 production by themselves. The utilization of triglycerides for aflatoxin biosynthesis is markedly affected by the level and type of sugar available and could be important in some oil seeds which are hosts for A. flavus.