Difference Between Gelatinization and Retrogradation

Thekey differencebetween gelatinization and retrogradation is that胶质化是指制造或变成凝胶状的行为，而逆行是指逆行方式。

The terms gelatinization and retrogradation describe the properties of淀粉。淀粉是一种聚合物碳水化合物，由许多glucose糖苷键连接的单位。它是一个polysaccharide这是由大多数绿色植物作为能源存储物质生产的。

内容

1.Overview and Key Difference
2.What is Gelatinization
3.What is Retrogradation
4.并排比较 - 胶质化与表格形式的逆行
5.概括

What is Gelatinization?

Gelatinization is the breaking down of intermolecular bonds between starch molecules, allowing the hydrogen bonding sites to engage more water molecules. Generally, we use this term to describe starch, so it’s normally known as starch gelatinization. When there are water and heat, the intermolecular bonds between starch molecules tend to breakdown and, the hydrogen bonding sites gain the ability to hold more water molecules in these sites. Then, the starch granules become dissolved in water irreversibly and act as a plasticizer.

Difference Between Gelatinization and Retrogradation

Figure 01: Rice Starch seen on Light Microscope

The process of gelatinization occurs in three steps: starch granule swelling, melting, andamyloseleaching. When we heat the starch sample, swelling occurs due to the absorption of water into the amorphous space of starch. Thereafter, the water enters the tightly bound areas of starch granules, which contain helical structures of amylopectin. Normally, water cannot enter this region, but heating allows this to occur. Then the penetration of water increases the randomness of starch granules, which leads to the disintegration of starch.

有些因素会影响胶质化过程，包括获得淀粉的植物类型，培养基中存在的水量，pH，盐浓度，培养基，糖，蛋白质和脂肪含量。

What is Retrogradation?

逆行是一种化学反应，在冷却淀粉样品时，在煮熟的胶质化淀粉重新调整中的淀粉酶和淀粉蛋白链时发生的化学反应。换句话说，这是这些聚合物链的运动以逆行方式。

If we heat starch and dissolve it in water, it causes the destruction of the crystalline structure of amylose and amylopectin molecules, which leads to hydration and forms a viscous solution. If we cool this viscous solution or leave it in a low temperature, the linear molecules (amylose) and the linear parts of amylopectin molecules tend to retrograde and rearrange themselves again, forming a more crystalline structure. The linear parts of the molecules tend to place themselves in a parallel manner, forming hydrogen bridges. In this process, we can observe that the amylose crystallization is faster than the amylopectin crystallization.

Furthermore, retrogradation can cause the expel of water from the polymer network. This process is called syneresis. However, we can observe a small amount of water on the top of the gel. This retrogradation process is directly related to staling or ageing of bread. Moreover, retrograded starch is less digestible. However, the chemical modification of starch can lead to the reduction or enhancement of the retrogradation process. Additives such as fat, glucose, sodium nitrate, etc. can reduce the retrogradation process of starch.

胶质化和逆行之间有什么区别？

Gelatinization and retrogradation are properties of starch that vary with heat. Gelatinization is the breaking down of intermolecular bonds between starch molecules, allowing the hydrogen bonding sites to engage more water molecules. Retrogradation, on the other hand, is a chemical reaction that takes place when amylose and amylopectin chains in cooked, gelatinized starch realign themselves when cooling the starch sample. The key difference between gelatinization and retrogradation is that gelatinization refers to the act of making or becoming gelatinous, whereas retrogradation refers to the motion in a retrograde manner.

Below infographic tabulates more differences between gelatinization and retrogradation.

摘要 - 胶质化与逆行

Gelatinization and retrogradation are properties of starch that very with heat. The key difference between gelatinization and retrogradation is that gelatinization refers to the act of making or becoming gelatinous, whereas retrogradation refers to the motion in a retrograde manner.