Natural deep eutectic solvents (NADESs) have been shown to be selective and environmentally friendly solvents for the extraction of bioactive compounds. However, studies on the solubility of low-molecular-weight carbohydrates (LMWCs) in NADESs are scarce. In this work, new solubility data of LMWCs in NADESs are provided and a new approach based on the use of these solvents for the efficient fractionation of bioactive carbohydrates was explored for the first time. Several mono- and disaccharides and three NADESs based on choline chloride (ChCl) and different donors (2-ethylene glycol (EtG), glycerol (Gly) and ethanedioic acid dihydrate (Eth)) were considered. While the degradation of carbohydrates, mainly ketoses, was detected with ChCl:Eth due to its acidic nature, ChCl:EtG and ChCl:Gly were found to be useful alternatives for selectively separating bioactive ketoses and their corresponding aldoses (e.g., lactulose/lactose and tagatose/galactose) present in equimolar binary mixtures. In addition, the usefulness of ChCl:EtG for the selective enrichment of lactulose to be used as food ingredient or nutraceutical was proven (from a 25% in the reaction mixture to a 56% in the purified sample). NADESs could be used for the selective fractionation of value-added carbohydrates from interfering sugars for several applications, including food science, engineering or pharmaceuticals.

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.

The growing production volume of the meat industry has increased the need for revalorization of meat by-products to reduce economic and environmental impacts. Enzymatic hydrolysis of protein-rich meat by-products is an effective strategy for producing hydrolyzates with bioactive potential. Combining sequential enzymatic hydrolysis with γ-glutamyl transpeptidase activity can promote the formation of γ-glutamyl peptides associated with koku perception, a sensory attribute that increases taste intensity, continuity, and palatability. This study aimed to develop porcine liver hydrolyzates enriched in koku-related peptides through enzymatic hydrolysis followed by post-treatment with the transpeptidase Protana Uboost. Substrate specificity assays showed that a 0.2 U/mL enzyme concentration maximized γ-glutamyl dipeptide formation. Sequential hydrolysis using Alcalase and Protana Prime followed by Protana Uboost post-treatment generated the highest levels of koku-related peptides. Moreover, post-treatment significantly enhanced antioxidant capacity in the resulting hydrolyzates, supporting their potential as a functional ingredient.

Taste strongly influences food acceptance and purchase intention. Beyond the five basic tastes, oral sensations such as astringency or koku modulate overall taste perception. Both umami and koku act as taste enhancers, increasing mouthfeel and savoriness. While the taste of most proteogenic amino acids is well established, non-proteogenic amino acids and related protein derivatives remain insufficiently characterized. This study analyzes the taste profile of seventeen underexplored amino acids and protein derivatives using the PredMol in silico tool and quantitative descriptive analysis (QDA), with particular emphasis on their umami and koku potential. In silico evaluation identified bitterness and sweetness as the predominant tastes and predicted carnosine, theanine, citrulline, and ornithine to have koku potential with values higher than 0.44. Principal Component Analysis of the QDA revealed that sweetness, bitterness, and sourness were the main drivers of sample differentiation. Ornithine, glutamine, citrulline, pyroglutamic acid, and theanine exhibited a positive dose–response in umami perception, with potential synergistic effects observed in the presence of 0.5 mmol/L IMP. Additionally, theanine, citrulline, and ornithine enhanced koku-related attributes, particularly aftertaste and continuity, in aqueous model solutions. Overall, these findings suggest that these compounds can have a taste influence in food products and potential to be used as taste enhancers.