Impact of Ultrasound Pretreatment and Enzyme Concentration on Taste and Biological Activities of Porcine Lung Hydrolyzates

The revalorization of porcine meat by-products is necessary to reduce their environmental and economic impact. Porcine lungs are usually discarded or used for low-value purposes despite their richness in collagen, elastin, or phospholipids. Enzymatic hydrolysis, in combination with ultrasound pretreatment, improves the generation of hydrolyzates with biological and taste-enhancing properties. The main objective of this study was to evaluate the impact of ultrasound pretreatment and enzyme concentration in the development of functional and taste-rich porcine lung hydrolyzates. Ultrasound pretreatments significantly increased the degree of hydrolysis and the antioxidant activity in 1:100 Enzyme: Substrate (E/S) ratio hydrolyzates. On the other hand, the combination of 1:20 E/S concentration with ultrasound pretreatment significantly increased the umami free amino acids content and Equivalent Umami Concentration (EUC), being the last one comparable with other umami-rich foods and ingredients. In silico predictions showed that the use of ultrasound pretreatment enhances the percentage of potential bioactive peptides according to PeptideRanker, whereas the bioinformatics tools UMPred-FRL and BERT4Bitter showed more umami peptides than bitter in all the hydrolyzates. These results suggest the combination of ultrasound pretreatment with 1:20 E/S can be a good strategy to revalorize porcine lung by producing hydrolyzates that could be used as a functional ingredient.