The hydrolysis of whey protein isolate with low purity enzymes was studied with application of ultrasound pre-treatment. The aim was to increase the degree of hydrolysis and produce new biologically active peptides. The experiments were carried out with hydrolysis times up to 24 h. The influence of temperature, pH, enzymes (pepsin and papain), substrate concentration, and use or not of the ultrasonic probe was investigated. The peptide's structure and profile were examined after exposure to ultrasound. The highest degree of hydrolysis occurred with the use of pepsin for 10 h, 37 °C, and pH 2.5. The ultrasound pre-treatment allowed a reduction of 6 h in the process. After partial enzymatic hydrolysis and ultrasound pretreatment a higher proportion of low molar mass peptides were observed at 1000–2000 g.mol^-1. In vitro simulated digestion showed slight differences in peptide profile indicating that active compounds were preserved intact with a slight impact on bioactivity.

通过超声预处理研究了低纯度酶对乳清分离蛋白的水解作用。目的是增加水解程度并产生新的生物活性肽。实验进行了长达24小时的水解时间。研究了温度，pH，酶（胃蛋白酶和木瓜蛋白酶），底物浓度以及超声探头使用与否的影响。暴露于超声后检查该肽的结构和概况。使用胃蛋白酶持续10 h，37°C和pH 2.5时，水解程度最高。超声预处理可以减少6小时的时间。经过部分酶水解和超声预处理后，在1000–2000 g.mol ^-1处观察到更高比例的低摩尔质量肽。体外模拟消化显示肽谱略有不同，表明活性化合物完整保存，对生物活性有轻微影响。