福州大学：《食品化学》课程教学资源（试卷习题）Midterm Examination 3（UC Davis）答案

9 This is the beginning of the SHORT ANSWER section of the examination. hethe trm or hepoe comyp Invert sugar and high fructose corn syrup are both mixtures of D-glucose and D-fructose aro zing sucrose to form an equal mixtur e o her hand,is pro sugars. tarch,whi to ,but can vary somew tto ive more网ructos tha an glucose

9 This is the beginning of the SHORT ANSWER section of the examination. (4 pts.) Briefly compare the compositions of invert sugar and high fructose corn syrup. Explain the reactions used in the formation of the two products. Invert sugar and high fructose corn syrup are both mixtures of D-glucose and D-fructose. Invert sugar is produced by hydrolyzing sucrose to form an equal mixture of both sugars. High fructose corn syrup, on the other hand, is produced from corn starch, which is hydrolyzed to form predominantly glucose. Some of the glucose is then isomerized to produce fructose. The amounts of glucose and fructose are usually comparable in high fructose corn syrup, but can vary somewhat to give slightly more or less fructose than glucose

FST 100A Midterm 1;October 27,2004 Page 10 (6 pts.)The first question pertains to the reaction below: A H H HC-NR H2C-NR C-OH C-0 HO-C-H HO-C-H HO-C-H HO-C-H H-C-OH H-C-OH CH2OH (1 pt.)What is reactant on the left(molecule A)called?an eneaminol (3 pts.)Show the resonance structure that results when reactant A loses a proton: H HC-NR O H HC-NR C-OH C0 0 HO-C-H HO-C-H HO-C-H HO-CH HO-C-H H H-C-OH H-C-OH HO-C H-C OH CH2OH CH2OH CH2OH (1 pt.)What is this reaction called?Amadori rearrangement (1 pt.)What is the product on the right(molecule B)called?Amadori product

FST 100A Midterm 1; October 27, 2004 Page 10 (6 pts.) The first question pertains to the reaction below: (1 pt.) What is reactant on the left (molecule A) called? an eneaminol (3 pts.) Show the resonance structure that results when reactant A loses a proton: (1 pt.) What is this reaction called? Amadori rearrangement (1 pt.) What is the product on the right (molecule B) called? Amadori product A B C C C C HC H H OH OH HO HO H CH2OH NR H C C C C H2C H H OH O HO HO H CH2OH NR H C C C C HC H H OH OH HO HO H CH2OH NR H C C C C HC H H OH O HO HO H CH2OH NR H C C C C HC H H OH O HO HO H CH2OH NR H _ _