酶促和非酶褐变之间的差异| Compare the Difference Between Similar Terms

Thekey differencebetween enzymatic and nonenzymatic browning is that theenzymatic browning involvesenzymessuch as polyphenoloxidaseand catechol oxidase whereas the nonenzymatic browning does not involve any enzymatic activity.

The terms enzymatic and nonenzymatic browning is very important in describing the food browning. They differ according to their mechanism of action. Food browning is the process of turning a food such as fruits and vegetables into a brown color due to the chemical reactions that take place in that food. This has many implications for the food industry, especially regarding the cost.

内容

1.Overview and Key Difference
2.什么是酶褐变
3.What is Nonenzymatic Browning
4.Side by Side Comparison – Enzymatic vs Nonenzymatic Browning in Tabular Form
5.概括

什么是酶褐变?

酶褐变是由于该食物中发生的酶催化的化学反应而导致食物变成褐色的过程。We can see this in fruits, vegetables and seafood as well. It affects the taste, color and the value of the food. These reactions involve enzymes such as polyphenol oxidase and catechol oxidase. These enzymes create melanin and benzoquinone from natural phenols. Another name for this process is “oxidation of food”. This process requires the exposure to oxygen.

图01：酶褐变

酶褐变会以苯酚氧化酶氧化为喹酮的氧化引发。这些奎因酮很强electrophileswhich cause high susceptibility to nucleophilic attacks from other proteins. These quinones can polymerize via a series of reactions. Eventually, it results in brown colored pigments on the surface food. Therefore, if we need to inhibit this process, we have to focus on hindering the polyphenol oxidase activity. However, sometimes this browning has positive effects as well. For example, it develops the color and flavor in coffee, cocoa beans and tea.

What is Nonenzymatic Browning?

非酶褐变是由于没有由酶催化的化学反应，因此食物变成棕色的过程。It also produces brown pigments in food. There are two main types of this reaction as caramelization and Mallard reaction.

Figure 02: Nonenzymatic Browning

焦糖涉及pyrolysisof sugar. Therefore, this process is useful in cooking to get a nutty flavor and brown color. In this process, volatile chemicals release producing the characteristic caramel flavor. In Mallard reaction, a chemical reaction takes place between the amine group of free amino acid and the carbonyl group of reducing sugar. Further, this reaction occurs with the addition of heat. The sugar reacts with the amino acid producing a variety of odors and flavors. Hence, this reaction is responsible for the production of flavor after we cook food. Moreover, this reaction is important in producing artificial flavors for processed food. The type of amino acid that involves the reaction determines the flavor of the end product.

What is the Difference Between Enzymatic and Nonenzymatic Browning?

酶褐变是由于该食物中发生的酶催化的化学反应而导致食物变成褐色的过程。它涉及诸如多酚氧化酶和儿茶酚氧化酶之类的酶。此外，它以苯酚氧化酶氧化为喹酮的氧化启动，然后聚合以产生棕色的色素。非酶褐变是由于没有由酶催化的化学反应，因此食物变成棕色的过程。它不涉及任何酶活性。除此之外，它还涉及游离氨基酸胺组与碳碳糖基团减少糖之间的化学反应。以下信息图显示了表格形式的酶促和非酶褐变之间的差异。