顆粒形狀和大?。?/p>

Particle shape and size:

蠟質(zhì)玉米顆粒的形狀多為多角形，此外，還有圓形，其表面較為粗糙，無(wú)裂紋；普通玉米淀粉顆粒表面光滑，多為多角形；馬鈴薯淀粉顆粒多為卵形，表面光滑、顆粒完整；甘薯淀粉顆粒形狀多為圓形，此外還有多角形，表面光滑，無(wú)裂紋。其粒徑如表1所示：

The shape of waxy corn granules is mostly polygonal, and in addition, they are also round, with a rough surface and no cracks; The surface of ordinary corn starch granules is smooth and mostly polygonal; Potato starch granules are mostly oval shaped, with a smooth surface and intact granules; Sweet potato starch granules are mostly circular in shape, in addition to being polygonal, with a smooth surface and no cracks. Its particle size is shown in Table 1:

透明度的凝沉性：

The coagulation of transparency:

淀粉糊的透明度是食品加工上的重要品質(zhì)因素之一，和老化度也有很大的相關(guān)性。一般易老化者透明度較差。例如，普通玉米淀粉呈半透明白色糊，馬鈴薯淀粉糊和蠟質(zhì)玉米淀粉則非常透明。目前常用透光度來(lái)反應(yīng)淀粉糊透明度的高低，從而顯示其與水結(jié)合能力的強(qiáng)弱。一般來(lái)說(shuō)，蠟質(zhì)玉米淀粉的透光率要好于馬鈴薯淀粉和普通玉米淀粉。

The transparency of starch paste is one of the important quality factors in food processing, and it is also closely related to aging degree. Generally, people who are prone to aging have poor transparency. For example, regular corn starch appears as a semi transparent white paste, while potato starch paste and waxy corn starch are very transparent. At present, transparency is commonly used to reflect the transparency of starch paste, thereby demonstrating its ability to bind with water. Generally speaking, the transparency of waxy corn starch is better than that of potato starch and regular corn starch.

淀粉受熱，其顆粒吸水膨脹、破裂而發(fā)生糊化，在冷卻過(guò)程中，淀粉分子進(jìn)行重排，分子鏈之間以氫鍵結(jié)合，使淀粉分子脫水收縮，其粘附性能下降，保水性減弱。沉降體積越小，表示該淀粉越易凝沉。一般來(lái)說(shuō)普通淀粉的凝沉性很強(qiáng)，而蠟質(zhì)玉米淀粉和馬鈴薯淀粉的凝沉性很低，這是因?yàn)橹辨湹矸鄢舒湢罱Y(jié)構(gòu)，在溶液中空間障礙小，易于取向，故易回生，尤其是中等長(zhǎng)度的直鏈淀粉易回生，而馬鈴薯淀粉中直鏈淀粉的鏈較長(zhǎng)，取向困難，回生慢。蠟質(zhì)玉米淀粉中基本是直鏈淀粉，支鏈淀粉呈樹(shù)狀結(jié)構(gòu)，在溶液中空間障礙大，不易取向，故不易凝沉。

When starch is heated, its particles absorb water, expand and rupture, resulting in gelatinization. During the cooling process, starch molecules rearrange, and hydrogen bonds bind between molecular chains, causing starch molecules to dehydrate and contract, resulting in a decrease in adhesive properties and weakened water retention. The smaller the sedimentation volume, the easier it is for the starch to coagulate. Generally speaking, ordinary starch has strong retrogradation, while waxy corn starch and potato starch have low retrogradation. This is because linear starch has a chain like structure, with small spatial barriers in solution and easy orientation, making it easy to retrogradation, especially for medium length linear starch. However, in potato starch, linear starch has longer chains, difficult orientation, and slow retrogradation. Waxy corn starch is mainly composed of straight chain starch and branched chain starch with a tree like structure. It has large spatial barriers in solution and is not easy to orient, so it is not easy to coagulate.

膨潤(rùn)力和溶解度

Swelling power and solubility

淀粉加水分散后，一旦受熱會(huì)吸水膨脹形成糊狀，這種糊化現(xiàn)象由于淀粉種類(lèi)的不同而有差異。一般來(lái)說(shuō)，馬鈴薯淀粉的糊化溫度低，但吸水膨潤(rùn)速率；而普通玉米淀粉恰恰相反。馬鈴薯淀粉在60-60℃低溫下的吸水膨潤(rùn)力可達(dá)70%以上，而蠟質(zhì)玉米淀粉于68-85℃間的膨潤(rùn)力急速增加。普通玉米淀粉則需到90℃以上的高溫才有25%的膨潤(rùn)力。

After starch is dispersed with water, once heated, it will absorb water and expand to form a paste, which varies depending on the type of starch. Generally speaking, potato starch has a low gelatinization temperature but a high water absorption and swelling rate; However, ordinary corn starch is the opposite. The water absorption and swelling power of potato starch can reach over 70% at low temperatures of 60-60 ℃, while the swelling power of waxy corn starch increases rapidly between 68-85 ℃. Ordinary corn starch requires a high temperature above 90 ℃ to have 25% swelling power.

糊黏度性質(zhì)

Paste viscosity properties

相同濃度下，蠟質(zhì)玉米淀粉糊液的黏性比馬鈴薯低，但高于普通玉米淀粉。

At the same concentration, the viscosity of waxy corn starch paste is lower than that of potatoes, but higher than that of ordinary corn starch.

蠟質(zhì)玉米淀粉乳在PH接近中性時(shí)，糊的黏度較高且比較穩(wěn)定，在較高的PH或較低的PH小，糊的黏度穩(wěn)定性差。說(shuō)明蠟質(zhì)玉米淀粉糊的抗酸堿能力差。

Wax corn starch emulsion has a high and stable viscosity when its pH is close to neutral, but its viscosity stability is poor when its pH is high or low. The waxy corn starch paste has poor acid and alkali resistance.

在食品制造過(guò)程中常加入糖品，使用在其中的淀粉會(huì)受到其中糖品的影響。由于蔗糖分子中有多個(gè)羥基極易溶于水，糖溶于淀粉乳中，相對(duì)地減少了淀粉糊膨脹糊化的水分，使淀粉猶如在比較少的水中糊化，顆粒膨脹困難，難以糊化，故糊化溫度升高，黏度也隨時(shí)增大。隨著蔗糖用量的增加，對(duì)淀粉顆粒膨脹和糊化的抑制作用增強(qiáng)，黏度達(dá)到一定極限后也隨之下降。

Sugar is often added in the food manufacturing process, and the starch used in it will be affected by the sugar content. Due to the presence of multiple hydroxyl groups in sucrose molecules that are highly soluble in water, sugar dissolves in starch milk, which relatively reduces the amount of water needed for starch paste to expand and gelatinize. This makes starch gelatinize as if it were in relatively little water, making it difficult for the particles to expand and gelatinize. As a result, the gelatinization temperature increases and the viscosity also increases at any time. With the increase of sucrose dosage, the inhibitory effect on starch particle expansion and gelatinization is enhanced, and the viscosity also decreases after reaching a certain limit.

氯化鈉的存在使蠟質(zhì)玉米淀粉的糊化溫度有所提高。食鹽與蔗糖一樣，會(huì)降低水分活度，影響淀粉分子與水分子的作用，阻礙淀粉的糊化性能，食鹽的量越大，淀粉越難糊化，淀粉糊凝沉更快。

The presence of sodium chloride increases the gelatinization temperature of waxy corn starch. Salt, like sucrose, can reduce water activity, affect the interaction between starch molecules and water molecules, and hinder the gelatinization performance of starch. The larger the amount of salt, the harder it is for starch to gelatinize, and the faster the starch paste settles.