| Chapter I provides an overview of the topic of acrylamide in food (discovery, formation mechanisms, food processing aspects, interactions with biomolecules, and biomedical and safety implications).; Chapter II reports the Correlation of Acrylamide Generation in Thermally Processed Model Systems of Asparagine and Glucose with Color Formation, Amounts of Pyrazines Formed, and Antioxidative Properties of Extracts. Acrylamide formation reached a maximum value after 20-30 min. of heating, followed by elimination. Color intensity and pyrazine formation increased steadily with temperature and heating time. There is a very strong, power law-type correlation between acrylamide formation and browning level. Acrylamide levels are linearly correlated with pyrazine levels in the initial stages of the Maillard reaction. The low yield of acrylamide formation afforded by excess asparagine is associated with increased antioxidant activity.; Chapter III presents the effect of cysteine on the formation of acrylamide, color, flavor, and antioxidants in an asparagine/glucose model system. The addition of cysteine reduced acrylamide level in a linear fashion via competition for the carbonyl fragments derived from glucose. Color intensity was decreased by 60%. Pyrazine formation was reduced by 50-80%, at the expense of the formation of thiophenes and thiazoles. Antioxidant activity generally decreased with increasing temperature and heating time. Cysteine inhibited the thermal decomposition of acrylamide. Michael addition of acrylamide to functional groups of amino acids does not occur at elevated temperatures and neutral pH.; Chapter IV describes the role of lipids in the formation of acrylamide. Amounts of acrylamide formed upon the heating of asparagine with dietary oils or animal fats at elevated temperatures corresponded to the degree of unsaturation of the oils and animal fats. Acrylic acid, a three-carbon unit formed from lipids by oxidation produced acrylamide with amino acids upon heating.; Chapter V covers antioxidative activities of major compounds formed in the asparagine/glucose reaction system and that of representative components of barley and wheat essence, determined by the hexanal/hexanoic acid assay and the conjugated diene assay. Significant antioxidant activity has been found for N-methyl-l-butanamine, 2-furanmethanol, and 4-hydroxy-2,5-dimethyl-3(2H)-furanone from the asparagine/glucose system, and for 3-methyl-2-butenal, 2,4-hexadienal, benzothiazole, and vanillin from essences of barley and wheat. |
