The enzyme-controlled hygroscopicity of peptide powders during storage at room temperature may have a profound effect on their properties. The present study aims to elucidate hygroscopicity, proton dynamics, as well as effect on the microstructure of sea cucumber ovum peptides (SCOPs) powder produced with different enzymes during storage. The SCOPs produced with Alcalase exhibited the strongest moisture absorption capacity, which was significantly higher than those of SCOPs produced with papain, neutrase, and trypsin (P < .05). This might be attributed to the greater hydrolysis of Alcalase and producing more polar groups. Moreover, the proton dynamic and the transformations of water populations varied greatly among the SCOPs with different enzymes. Even so, the SCOPs exhibited a common water migration rule that free water was gradually transformed into immobilized water that was simultaneously converted into bound water after moisture absorption. The hygroscopicity induced morphological changes of SCOPs, which was converted from a smooth amorphous structure into different sizes of particle agglomerates. Moreover, the SCOPs produced with Alcalase displayed more and smaller agglomerates than those produced with papain, neutrase, and trypsin. This study provides a theoretical basis for quality assurance of peptide powders, particularly those produced with Alcalase.

在室温下储存过程中，肽粉的酶控制吸湿性可能对其性能产生深远影响。本研究旨在阐明在贮藏期间由不同酶产生的海参卵子肽（SCOPs）粉末的吸湿性，质子动力学以及对微结构的影响。用Alcalase生产的SCOP表现出最强的吸湿能力，明显高于用木瓜蛋白酶，中性酶和胰蛋白酶生产的SCOP（P < .05）。这可能归因于Alcalase的更大水解并产生了更多的极性基团。此外，在不同酶的SCOPs中，质子动力学和水种群的变化差异很大。即便如此，SCOP仍显示出通用的水迁移规则，即游离水逐渐转化为固定化水，吸收水分后，固定水又转化为结合水。吸湿性引起SCOP的形态变化，其从光滑的无定形结构转变成不同大小的颗粒团聚体。此外，与用木瓜蛋白酶，中性酶和胰蛋白酶产生的SCOPs相比，用Alcalase产生的SCOPs显示出更多和更小的附聚物。这项研究为肽粉，特别是用Alcalase生产的肽粉的质量保证提供了理论基础。