Investigating the Short Peptidome Profile of Italian Dry-Cured Ham at Different Processing Times by High-Resolution Mass Spectrometry and Chemometrics

Abstract

Short peptides have been spiking interest owing to their significant contribution to the taste and functional properties of dry-cured ham. In this study, a suspect screening approach based on high-resolution mass spectrometry was employed for the comprehensive characterization of the short endogenous peptidome in dry-cured ham samples at different processing stages (14, 22, and 34 months). After careful manual spectra interpretation, a chemometric approach based on principal component analysis was employed for highlighting the differences between the three sets of samples. A total of 236 short peptide sequences was tentatively identified, including 173 natural short peptides and 63 sequences containing non-proteinogenic amino acids, the highest number ever reported for endogenous sequences in dry-cured ham. Samples in the latest processing stages presented a generally higher abundance of dipeptides, indicating residual proteolytic activity. Moreover, the several annotated modified short peptides, mainly pyroglutamination and lactoyl conjugation, allowed hypothesizing several reactions occurring over time. For the first time, several lactoyl-dipeptides were tentatively identified in dry-cured ham samples with maximum concentration in the late processing stage samples. The presented results significantly contribute to the understanding of the reaction involving short peptides that affect the sensory and functional properties of dry-cured ham.

Profile Assessment of Bioactive Peptides in the Greek Traditional Cheese “Tsalafouti”

“…SCPs (short-chain peptides) have been demonstrated as health-promoting substances that can be directly absorbed by the human organism, therefore the abundance of endogenous SCPs in foods can reflect their nutritional value [51]. Short peptides show a more remarkable resemblance to polar metabolites than longer peptides for their low molecular weights and wide range of physicochemical properties (acid-base properties and polarity) [52]. Pepsin, pancreatic trypsin, elastase, chymotrypsin, carboxypeptidase, and brush border peptidases are among the digestive proteases and peptidases found in the digestive tract [53], which would inevitably result in the generation of massive amounts of small-chain peptides during macromolecular protein digestion, moreover, these SCPs with multiple bioactivities have a higher likelihood of surviving these digestive enzymatic actions and permeating intestinal epithelial cells [54].…”

Impact of oxidation on the cardioprotective properties of the bioactive dipeptide AW in dry-cured ham

“…In the same line, most Italian dry-cured ham-derived dipeptides such as NW, Lac-FH, Lac-L(I)-F, Pyr-L(I)-F, γ-EW, and Pyr-EY, have been reported to reach higher concentrations at 22 months of processing in comparison with 14 months. However, a decrease was pointed out about other peptides such as L/I-F, HF, WQ, EE and EF at 34 months of elaboration (Cerrato et al, 2022). Other agreeing studies determined increasing concentrations with the processing time of dipeptides such as PG from Norwegian dry-cured ham and AH, PL and AR, between others, from Jinhua ham; and AA, β-AK, EE, GG and GL from Prosciutto-like processing dry-cured ham (Degnes et al, 2017;Sugimoto et al, 2020;Zhu et al, 2017).…”

Bioactive and Sensory Di- and Tripeptides Generated during Dry-Curing of Pork Meat

“…Thus, the strong link between the proteolysis degree and the aging time may turn these dipeptides into effective markers of long-aged dry-cured meat products [ 81 , 92 ]. More recently, γ-EF, γ-EW, and γ-EY have also been reported in Prosciutto dry-cured hams [ 93 ]. These results, in joint with the fact that the enzyme γ-glutamyl-transferase has also been found in different tissues of the pig [ 115 ], suggest that this enzymatic activity might occur during the processing of dry-cured ham, contributing to the development of the typical taste.…”

“…As it has been signaled in the Kokumi section, γ-glutamyl peptides γ-EF, γ-EI, γ-EL, and γ-EY have been quantified in Parma dry-cured ham [ 81 , 92 ], and γ-EF, γ-EW, and γ-EY were detected in Prosciutto dry-cured hams [ 93 ]. Actually, a greater amount of these peptides has been found in digested samples of dry-cured ham compared with non-digested samples, so it can be hypothesized that γ-glutamyl residues are bound to N-terminal amino acids in peptide chains and then released from them by enzymatic digestion [ 92 ].…”