美拉德反应改善熟化马铃薯冻融酶解汁液风味

Maillard Reaction Improves the Flavor of Frozen-thawed Enzymatic Juice Derived from Cooked Potato

以熟化马铃薯冻融酶解汁液为原料,通过添加外源糖类进行美拉德反应,改善其风味。以感官评分和美拉德反应强度为指标,使用单因素结合正交设计法优化酶解汁液反应条件,比较反应前、后汁液中的香气成分、游离氨基酸含量及其体外抗氧化活性变化。结果表明:美拉德反应最优条件为:以木糖和果糖为复配外源糖,质量比1∶3,复配外源糖添加量3.0%,反应体系初始pH 6.0,110℃反应50 min。该条件下制备的马铃薯美拉德反应液挥发性物质种类显著增加,烃类物质、醇类物质含量减少甚至消失,生成较多的糠醛、二甲基丁醛、苯甲醛、苯乙醛等挥发性香气成分及吡嗪、吡啶等坚果香、烤肉香气杂环类化合物;游离氨基酸总含量减少22.52%,鲜味氨基酸和甜味氨基酸相对含量分别提高了2.88%和0.85%,苦味氨基酸相对含量降低了3.72%;美拉德反应汁液体外抗氧化活性增强,总还原力提高3.35倍,DPPH自由清除率和ABTS自由基清除率分别提高了55.82%和33.12%。添加外源木糖和果糖进行美拉德反应可改善马铃薯酶解液风味,增强体外抗氧化活性。

In this present study,enzymatic hydrolysis and Maillard thermal reaction by adding exogenous sugars were employed to produce Maillard reaction products(MRPs)for flavor improvement of enzymatic hydrolyzed juice by-product derived from cooked potatoes prepared by frozen-thawing process.Single-factor experiments combined with orthogonal experiments were employed to optimize the enzymolysis liquid reaction conditions.Changes of volatile favor compounds,free amino acids and antioxidant activity of Maillard treated juice were analyzed.Results showed that the optimal parameters for Maillard reaction were:3.0%mixed xylose and fructose with a mass ratio of 1∶3,initial pH 6.0,and reaction at 110℃for 50 min.The types of volatile substances in MRPs were increased significantly,the content of hydrocarbons and alcohols were decreased or even disappeared.Moreover,furfural,dimethyl butyraldehyde,benzaldehyde,phenylacetaldehyde,pyrazine,pyridine characterized nutty and barbecue aroma formed,and therefore contributed to the flavor improvement of potato juice.In addition,the total content of free amino acids was decreased by 22.52%,the umami acids and sweet amino acids increased by 2.88%and 0.85%,the bitter amino acids was decreased by 3.72%.In terms of antioxidant activity in vitro,ferric ion reducing antioxidant power increased by 3.35 folds,the DPPH free scavenging activity increased by 55.82%,and the ABTS free radical scavenging rate increased by 33.12%.Overall,the application of Maillard reaction by adding exogenous xylose and fructose can be used a promising strategy for improving flavor and antioxidant activity of the enzymatic hydrolyzed potato juice by-product.