美拉德反应改良四角蛤蜊酶解液的风味

以四角蛤蜊酶解液为原料，通过美拉德反应对其进行风味改良。通过研究还原糖的种类、复合比例与添加量、反应温度、反应时间和反应体系初始pH值对感官评分、反应程度及色差的影响，确定酶解液美拉德反应风味改良工艺，并分析反应前后酶解液中氨基酸和挥发性风味成分的变化。结果表明，还原糖的种类、复合比例与添加量、反应温度、反应时间和反应体系初始pH值均对四角蛤蜊酶解液风味具有显著影响（P＜0.05）。较优的反应条件为：选用木糖与葡萄糖复合添加，质量比1∶2，还原糖添加量（质量分数）4.0%，反应体系初始pH?6.5，100?℃反应90?min。美拉德反应后，酶解液中18?种氨基酸均有不同程度的损失，其中丙氨酸、甘氨酸、牛磺酸和谷氨酸的损失率较大，其次是组氨酸、精氨酸、蛋氨酸、苯丙氨酸、亮氨酸、赖氨酸，说明这些氨基酸可能是参与美拉德反应并对反应产物风味起主要作用的氨基酸。反应前后挥发性化合物的种类和相对含量有所差异，其中醛类、酮类、酯类物质相对含量增加，烯烃类物质相对含量降低。

Flavor Improvement of Enzymatic Hydrolysate of Mactra veneriformis by Maillard Reaction

The aim of this work was to improve the flavor of an enzymatic hydrolysate of Mactra veneriformis by Maillard reaction. The effects of sugar type, mixing ratio and amount of sugars, reaction temperature, time and initial pH on sensory score, the degree of reaction and the color difference were investigated to obtain the optimal reaction conditions. Meanwhile, the changes of free and total amino acids, and volatile compounds before and after reaction were also analyzed. The results showed that all the reaction parameters significantly influence the flavor of the enzymatic hydrolysate (P < 0.05). The optimal conditions of Maillard reaction were obtained as follow: ratio of xylose to glucose 1:2, 4.0% reducing sugar, initial pH 6.5, temperature 100 ℃ and time 90 min. The Maillard reaction resulted in loss of all 18 amino acids especially alanine, glycine, taurine and glutamic acid followed by histidine, arginine, methionine, phenylalanine, leucine and lysine in the hydrolysate, indicating that these amino acids may take part in the Maillard reaction and contributed to the flavor of reaction products. The species and relative contents of flavor components were different after the Maillard reaction. The contents of aldehydes, ketones and esters increased, while those of hydrocarbons decreased.