The high-throughput 96-well plate method proved to be as robust and reproducible as the conventional method for determining total phenolic content, flavonoid content and DPPH-scavenging capacity in either sorghum bran or flour.

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).

Alkylcyclobutanones have been recognized as chemical markers of irradiated lipid-containing foods since 1970. They are important because they are produced solely as a result of irradiation and not any other processing method. This study investigated the formation of 2-dodecylcyclobutanone (2-DCB) and 2-tetradec-5'-enylcyclobutanone (2-TDCB) in irradiated ground beef patties from commercial and noncommercial sources. Patties were irradiated using a (60)C source (gamma-irradiation) and electron beam irradiation, at five targeted absorbed doses of 0.5, 1.0, 2.5, 5.0, and 7.0 kGy. Commercially available irradiated patties were also studied. A supercritical fluid extraction (SFE) procedure was optimized and used for the extraction and isolation of the alkylcyclobutanones. Samples can be used for extraction without a prior cleanup step, which makes this procedure rapid and convenient to use. Identification and quantitation of the cyclobutanones were done by gas chromatography-mass spectroscopy. 2-DCB was detected in all of the irradiated samples (including commercial patties), and its concentration increased linearly with the irradiation dose. Electron beam irradiation produced a greater amount of 2-DCB compared to gamma-irradiation at dose levels >2.5 kGy. 2-TDCB was detected only at the two higher irradiation doses, whereas both marker compounds were not detected in the non-irradiated samples.

Heterocyclic amines (HCAs) are suspected human carcinogens formed in muscle foods during high temperature grilling or cooking. Inhibition of HCAs by commercial marinades rich in polyphenolic antioxidant containing spices was evaluated with beef round steaks cooked at 204 degrees C (400 degrees F). Treatment effects on the levels of 4 HCAs were investigated: 2-amino-3,8-dimethylimidazo[4,5-flquinoxaline (MeIQx), 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP), 1-methyl-9H-pyrido[4,3-b]indol (harman), and 9H-pyrido[4,3-blindol (norharman). The marinades were formulated according to the package label instruction in an oil, water, and vinegar mixture, and the steaks were treated for 1 h prior to grilling. All 3 marinades, Caribbean, Southwest, and herb, significantly decreased the imidazo-azaarene HCAs (MeIQx, PhIP) as contrasted to controls and liquid blanks. The Caribbean mixture showed the highest decrease in the total HCA content (88%), followed by the herb (72%) and Southwest (57%). With a few exceptions there were significant decreases in HCAs for treatments with only the marinade bases (ingredients without any spices/herbs). As measured by high-performance liquid chromatography (HPLC), the marinades contained considerable amounts of the polyphenolic antioxidants carnosic acid, carnosol, and rosmarinic acid with Caribbean being the highest. Commonly available spice-containing marinades can be effective inhibitors of HCA formation and provide reduced exposure to some of the carcinogens formed during grilling.