乳清分离蛋白掩蔽花椒苦味机制研究

Study on the Mechanism of Whey Protein Isolate Masking Bitterness of Zanthoxylum bungeanum Maxim.

花椒是我国重要的香辛料及药用植物,因含有7-甲氧基香豆素而具有明显的苦味。花椒的苦味限制了花椒产品的开发和利用。本实验旨在探索乳清分离蛋白对花椒苦味的掩蔽效果及作用机制。选用花椒油树脂为基质,通过感官实验和电子舌考察了乳清分离蛋白对花椒苦味的掩蔽效果,采用分子对接技术探究了乳清分离蛋白对花椒苦味的掩蔽机制。结果表明,乳清分离蛋白可显著降低花椒油树脂的苦味,且花椒油树脂的苦味降低值与乳清分离蛋白的添加量存在质量浓度-效应关系;当其用量为1.00%,花椒油树脂溶液浓度为0.5%时,苦味降低值ΔBI为1.8,说明苦味掩蔽效果较好。分子对接模型显示7-甲氧基香豆素与β-乳球蛋白在第二个聚类具有20个对接构象,最低结合自由能为-5.90 kcal/mol,是两者发生相互作用最有可能的结合区域。因此,乳清分离蛋白是通过与7-甲氧基香豆素结合后阻止其与苦味受体结合而减少苦味的产生,该研究结果可为花椒加工产品的矫味提供参考依据。

Zanthoxylum bungeanum Maxim.is an essential spice and medicinal plant in China.Zanthoxylum bungeanum Maxim.has a distinct bitterness due to 7-methoxylcoumarin.The bitterness of Zanthoxylum bungeanum Maxim.restricted the development and utilization of its products.This study aimed to explore the masking effect and mechanism of whey protein isolate on the bitterness of Zanthoxylum bungeanum Maxim..The masking mechanism of the bitterness of Zanthoxylum bungeanum Maxim.by whey protein isolate was investigated using the method of sensory evaluation,electronic tongue and molecular docking technique with Zanthoxylum bungeanum Maxim.oleoresin as the matrix.The results indicated that whey protein isolate could significantly mask the bitterness of Zanthoxylum bungeanum Maxim.oleoresin.Furthermore,there was a mass concentration-effect relationship between bitterness reduction values of Zanthoxylum bungeanum Maxim.oleoresin and the additive amount of whey protein isolate.When the dosage of whey protein isolate was 1.00%and the concentration of Zanthoxylum bungeanum oleoresin was 0.5%,the reduction value ofΔBI was 1.8,indicating that the bitterness masking effect was good.The molecular docking model showed that 7-methoxycoumarin andβ-lactoglobulin had 20 docking conformations in cluster 2,and the lowest binding free energy was-5.90 kcal/mol.Hence,cluster 2 was the most likely binding region for their interaction.It could be concluded that whey protein isolate could mask the bitterness of Zanthoxylum bungeanum Maxim.oleoresin by binding to 7-methoxycoumarin and preventing it from binding to bitter receptors.The results may provide a reference for the taste correction of Zanthoxylum bungeanum Maxim.products.