二氢杨梅素对大米淀粉回生的抑制作

淀粉是大米中的主要成分，其回生程度直接影响大米制品的品质与货架期。该研究将属于多酚类化合物的二氢杨梅素（Dihydromyricetin，DMY）添加到大米淀粉中，研究不同添加量的DMY与大米淀粉的相互作用以及DMY对大米淀粉的溶解度、膨胀度、回生焓值、微观结构的影响，以期改善大米淀粉的回生特性。结果表明，随着二氢杨梅素的添加，大米淀粉的溶解度从4.49%增加至12.83%，膨胀度11.41%降至10.12%；淀粉表面由原来的紧密结构变化为疏松多孔结构；红外光谱1 047 cm-1/1 022 cm-1的比值从0.87降至0.78。较未添加的DMY的大米淀粉相比，低浓度的DMY已经显著影响大米淀粉回生特性。当DMY的添加量为5%时，大米淀粉的回生焓值、回生率以及相对结晶度分别下降了68.75%、71.86%、59.07%。总体而言，二氢杨梅素可以抑制大米淀粉的回生。因此，在淀粉制品加工时，可考虑添加DMY来调控淀粉基食品的回生现象。

Inhibitory Effect of Dihydromyricetin on Rice Starch Retrogradation

Starch is the main ingredient in rice, and the quality and shelf life of rice products are directly affected by its retrogradation degree. Dihydromyricetin (DMY), a polyphenolic compound, was added to rice starch to improve the retrogradation properties of rice starch. The effects of different amounts of DMY on the solubility, expansion, retrogradation enthalpy, and microstructure of rice starch were investigated, and the interaction between DMY and rice starch was analyzed. With the addition of DMY, the solubility of rice starch increased from4.49%to12.83%, and expansion decreased from 11.41% to 10.12%. The starch surface changed from a compact to a loose and porous structure. The FT-IR ratio of 1 047 cm-1/1 022 cm-1 decreased from 0.87 to 0.78. Compared with rice starch without DMY, a low concentration of DMY significantly affected the retrogradation characteristics of rice starch. When the amount of DMY was 5%, the retrogradation enthalpy, retrogradation rate, and relative crystallinity of rice starch decreased by 68.75%, 71.86%, and 59.07%, respectively. In general, rice starch retrogradation was inhibited by DMY. Therefore, DMY can be used to regulate the retrogradation of starch-based foods during the processing of starch products.