11Purple-fleshed sweet potato P40 has been shown to prevent colorectal cancer in a murine 12 model. This study is to identify anthocyanins by using HPLC/MS-MS and assess the stability 13 during various cooking conditions. P40 possesses a high content of anthocyanins up to 14 mg/g 14 dry matter. Total 12 acylated anthocyanins are identified. Top three anthocyanins, e.g., cyanidin 15 3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside, peonidin 3-caffeoyl sophoroside-5-16 glucoside, and cyanidin 3-(6'' -caffeoyl-6''-feruloylsophoroside)-5-glucoside, account for half 17 of the anthocyanin contents. Over 80% of anthocyanins measured by acid hydrolysis were 18 cyanidin derivatives, indicating P40 is unique when compared with other purple-fleshed sweet 19 potatoes that usually contain more peonidin than cyanidin. Steaming, pressure cooking, 20 microwaving, and frying but not baking significantly reduced 8-16% of total anthocyanin 21 contents. Mono-acylated anthocyanins showed a higher resistance against heat than di-and non-22 acylated. Among of which, cyanidin 3-p-hydroxybenzoylsophoroside-5-glucoside exhibited the 23 best thermal stability. The stable acylated and cyanidin-predominated anthocyanins in P40 may 24 provide extra benefits for cancer prevention. 25Keywords: Anthocyanins / purple-fleshed sweet potato / cancer prevention / stability / cooking 26 conditions 27

Heterocyclic amines (HCAs), potent mutagens and a risk factor for human cancers, are produced in meats cooked at high temperature. The aim of this study was to determine the HCA content in cooked meat products (beef, chicken, pork, fish) prepared by various cooking methods (pan frying, oven broiling, and oven baking at 170 to 230 °C) that are preferred by U.S. meat consumers. The primary HCAs in these samples were PhIP (2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine) (1.49-10.89 ng/g), MeIQx (2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline) (not detected-4.0 ng/g), and DiMeIQx (2-amino-3,4,8-trimethyl-imidazo [4,5-f]quinoxaline) (not detected-3.57 ng/g). Type and content of HCAs in cooked meat samples were highly dependent on cooking conditions. The total HCA content in well-done meat was 3.5 times higher than that of medium-rare meat. Fried pork (13.91 ng/g) had higher levels of total HCAs than fried beef (8.92 ng/g) and fried chicken (7.00 ng/g). Among the samples, fried bacon contained the highest total HCA content (17.59 ng/g).

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Fifteen Fusarium species were analyzed by high-performance liquid chromatography for the production of six mycotoxins in corn grits cultures. Production of mycotoxins ranged from 66 to 2,500 g/kg for fumonisin B 1 , 0.6 to 1,500 g/g for moniliformin, 2.2 to 720 g/g for beauvericin, and 12 to 130 g/g for fusaproliferin. Fumonisin B 2 (360 g/kg) was produced by two species, fumonisin B 3 was not detected in any of the 15 species examined, and Fusarium bulbicola produced none of the six mycotoxins that we analyzed.

The effects of rosmarinic acid and a rosemary antioxidant powder were evaluated on the reduction and mutagenicity of MeIQx, PhIP, and comutagens norharman and harman in beef patties fried at 375 °F for 5 min each side and 400 °F for 7.5 min each side. Both rosemary extracts were found to effectively decrease the formation and overall mutagenic activity of heterocyclic amines (HCAs) due to their antioxidative characteristics. At the lower temperature, rosmarinic acid was able to reduce MeIQx by up to 64% and PhIP by 48%, while rosemary powder reduced the formations of MeIQx up to 69% and PhIP up to 66%. The effects of the rosemary extracts were more dramatic when cooking temperature and time were increased, as rosmarinic acid was able to reduce MeIQx formation up to 70% and PhIP up to 64%; also, rosemary powder significantly reduced MeIQx up to 57% and PhIP up to 77%. The overall mutagenic activity was evaluated by the Ames Salmonella assay and both rosemary extracts were capable of reducing mutagenicity in beef patties at the higher cooking temperature of 400 °F. At 375 °F there was an insignificant trend of the rosemary extracts decreasing the number of Salmonella revertants. There was no significant inhibiting effect by any of the rosemary extracts on the formation of either norharman and harman as measured in this study.