Exopeptidase treatment combined with Maillard reaction modification of protein hydrolysates derived from porcine muscle and plasma: Structure-taste relationship.

Reduction of bitter taste in protein hydrolysates is a challenging task. The aim of this study was to apply a simple two-step approach to prepare low bitter hydrolysates and investigate the influence of peptide modifications on taste characteristics. Protein hydrolysates were prepared from porcine muscle and plasma through simultaneous hydrolysis using endo- and exo-peptidases combined with peptide glycation by glucosamine (GlcN). Spectroscopic analysis and quantification of major alpha-dicarbonyl compounds (α-DCs) indicated the relatively low extent of Maillard reaction in GlcN-glycated protein hydrolysates. Thermal degradation of high MW peptides (>10 kDa) might play a major role in Maillard reaction, reflected by the formation of more Maillard reacted peptides (1-5 kDa), especially in plasma samples. Sensory evaluation indicated that glycation by GlcN can alter taste profiles of protein hydrolysates, which may be attributed to the formation of Maillard reacted peptides and peptide modifications revealed by LC-MS/MS analysis.

Protein hydrolysates of porcine hemoglobin and blood: Peptide characteristics in relation to taste attributes and formation of volatile compounds.

The objective of this study was to investigate the impact of endo- and exo-peptidase treatment on certain structural characteristics of peptides and volatile compounds of porcine hemoglobin and whole blood hydrolysates. Porcine hemoglobin and whole blood were hydrolyzed by endo- and exo-peptidases. The presence of exopeptidases reduced the bitterness and altered the volatile profiles of protein hydrolysates. Exopeptidase treatment can release terminal amino acids from peptides, which in turn may contribute to formation of volatile compounds by Maillard reactions. In contrast, endopeptidases conferred a slightly bitter taste and different volatile profiles. For hemoglobin hydrolysates, principal component analysis revealed that proteases were categorized into three groups based on endo- or exo-peptidase activity. Whole blood is a more complex raw material, yet the proteases were still categorized in a similar fashion. This work contributes to understanding structural characteristics responsible for taste and volatile profiles of protein hydrolysates.

Consumer perception of snack sausages enriched with umami-tasting meat protein hydrolysates.

Adequate protein intake is necessary to maintain muscle mass and function. Nutritionally dense(r) products are increasingly sought after by consumers that need a heightened protein intake, such as active young and elderly individuals. This paper focuses on functional snack sausages enriched with umami-tasting meat protein hydrolysates (MPH), developed by systematically varying in recipe, meat type and MPH content. A consumer study (N = 100) was conducted where young and elderly consumers evaluated perceived acceptability and sensory quality of samples. Additionally, textural (Warner-Braztler shear test) and chemical (amino acids) analyses on the same samples were conducted to give a complete characterization of the functionality of the hydrolysates. Both the consumer test and the instrumental analyses consistently indicated that the enrichment with MPH had minor or no influence on the perceptual quality of the sausages, suggesting that this ingredient can be added to increase the nutritional density of a reference meat product without negatively affecting consumer acceptability.