Excessive bitterness, pastiness, and adhesiveness are the main organoleptic and textural defects of dry‐cured ham, which often cause a lot of financial losses to manufacturers and seriously damage ...the quality of the product. These sensory and textural defects are related to the protein degradation of dry‐cured ham. Proteomics shows great potential to improve our understanding of the molecular mechanism of sensory and textural defects and identify biomarkers for monitoring their quality traits. This review presents some of the major achievements and considerations in organoleptic and textural defects of dry‐cured ham by proteomics analysis in the recent decades and gives an overview about how to correct sensory and textural defects of dry‐cured ham. Proteomics reveals that muscle proteins derived from myofibril and cytoskeleton and involved in metabolic enzymes and oxygen transport have been identified as potential biomarkers in defective dry‐cured ham. Relatively high residual activities of cathepsin B and L are responsible for the excessive degradation of these protein biomarkers in defective dry‐cured ham. Ultrasound‐assisted mild thermal or high‐pressure treatment shows a good correction for the organoleptic and textural defects of dry‐cured ham by changing microstructure and conformation of muscle proteins by accelerating degradation of proteins and polypeptides into free amino acids.
The processing of dry-cured ham results in an intense proteolysis that leads to the generation of peptides of different sizes and composition, which have been shown to be biologically active. In this ...study, a total of ninety-three peptides mainly derived from actin, β-enolase, myosin heavy chain, and creatine kinase proteins have been identified from a size-exclusion chromatography (SEC) fraction that resulted as antioxidant by using matrix-assisted laser desorption/ionisation time-of-flight (MALDI-ToF) and nESI-ion trap mass spectrometry. Several of the identified peptides have been synthesised and their antioxidant activity tested in vitro by using DPPH radical-scavenging assay and reducing power analysis. The peptide with sequence SNAAC showed the best results with an IC50 of 75.2μM in DPPH radical-scavenging assay and 205μM in ferric-reducing antioxidant power analysis, very good when comparing with the positive control 2,6-di-tert-butyl-4-methyl phenol (BHT) that showed an IC50 of 358.5μM and 90.3μM, respectively, in the different assays. These results suggest that Spanish dry-cured ham represents an important source of powerful antioxidant peptides which due to their natural characteristics may represent a highly valuable alternative in human health.
•Novel antioxidant peptides extracted, purified and identified in dry-cured ham.•Ham peptides analysed through advanced proteomics tools.•Spanish dry-cured ham as a source of antioxidant peptides.
Protein degradation occurs during the processing of dry‐cured ham, which has important influences on the flavor and quality of products. The aim of this work was to study the degradation kinetics of ...myofibrillar proteins (MPs) and sarcoplasmic proteins (SPs) extracted from the biceps femoris muscle during the processing of Xuan'en ham. A relationship between protein degradation and the flavor formation was found. During the processing of Xuan'en ham, MPs and SPs were mainly degraded in the salting stage and incipient fermentation. Accompanied by protein degradation, the content of carbonyl group in SPs increased gradually, but in MPs, it first increased and then decreased. Interconversion between sulfhydryl and disulfide bonds was investigated during this processing. Oxidation, degradation, and thermal effects significantly affected the surface hydrophobicity of proteins. More than one hundred volatile compounds have been identified at each stage of ham preparation. Among them, organic acids were the predominant group, followed by hydrocarbons, aldehydes, alcohols, ketones, and esters.
•The metabolites and metabolite pathway were evaluated in spoiled dry-cured ham.•Amino acid derivatives and oligopeptides were the key components to distinguish spoiled and normal hams.•N-acetyl-Met, ...Ile-Pro, and Ile-Lys-Thr-Lys were responsible for the low scores of overall acceptance in spoiled ham.•Purine metabolism, pyrimidine metabolism and protein degradation were the main metabolic pathways in spoiled ham.
The spoiled dry-cured ham commonly shows unpleasant taste and odour. To deepen the understanding in the formation mechanism of unpleasant taste in spoiled ham, sensory attributes, texture parameters, protein degradation, metabolites were investigated between normal and spoiled hams; the relationship between the sensory quality and metabolites of dry-cured ham was further evaluated by partial least square discriminant analysis (PLS-DA). The scores of richness and overall acceptance were significantly lower in spoiled ham, and more than 12.5-fold values in adhesiveness were found in spoiled ham than normal ham. Myofibrillar proteins including actin, troponin-T and myosin light chain showed excessive degradation in spoiled ham. Forty-two kinds of metabolites mainly derived from protein degradation were identified by LC-MS/MS, and amino acid derivatives and oligopeptides were the key components to distinguish spoiled and normal hams demonstrated by PLS-DA. Purine metabolism, pyrimidine metabolism and protein degradation were the main metabolism pathways in spoiled ham.
NIR spectroscopy combined with chemometric methods has been used to develop a prediction models of the most influential parameters in curing process of two types of hams (140 hams) using different ...salting techniques, lean hams salted on a tray and fatty hams in a tub, in which sodium is partially replaced. Spectral data were examined by principal component analysis and cross-validated calibration equations were developed using partial-least squares regression. Calibration errors for each parameter, obtained from cross validation (RMSECV), were similar to those obtained by reference method. For lean and fatty hams the RMSECV values were: Moisture 0.78% and 0.80; Fat 2.5 and 1.2%; Protein 0.7 and 1.7%; water activity 0.008 and 0.006; Proteolysis Index 1.6 and 1.7%; Sodium 0.11 and 0.10%; and Potassium 0.04 and 0.10. Results allow the prediction of the parameters involved in ham curing process, demonstrating the viability of the proposed method for the control and monitoring of the different stages until obtaining the final product.
•Evaluation of curing process of ham with low sodium content by NIR spectroscopy•Development of prediction models of the influential parameters in ham curing process•NIRS shows viability for control and monitoring of the stages in ham curing process.
The use of proteomics in food science has permitted both a better characterization of the food products and the control of their final quality despite the fact that food systems are under continuous ...changes during processing and consumption. Ham is a very popular meat product frequently consumed in Mediterranean countries after a dry‐curing processing that results in the generation of large amounts of peptides that contribute to its texture, flavor, and final quality. Proteolysis is the main biochemical mechanism occurring throughout the dry‐cured ham processing and a better knowledge of this phenomenon is essential to give an extra value to the product and produce regular batches. In this regard, peptidomics has become an important tool for the characterization of dry‐cured hams in order to identify and quantify bioactive peptides and potential biomarkers, study their stability under processing conditions or gastrointestinal digestion, and search for post‐translational modifications that could affect the quality of dry‐cured hams. This manuscript is reviewing from the first uses of comparative proteomics in dry‐cured ham approaches to the most modern peptidomic studies and their contribution to the advance in meat science.
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•The crude peptides extracted from the three types of ham have antioxidant activity.•UPLC-Q-TOF-MS/MS was used for peptide composition analysis.•The peptides in the three types of ham ...were mainly derived from myosin.
The aim of the study was to evaluate antioxidant activity of crude peptides with molecular weight less than 3 KDa extracted from Xuanwei ham, Jinhua ham and mutton ham. UPLC-Q-TOF-MS/MS was used for composition analysis of peptides and homologous protein matching. Further, crude peptide (<3 KDa) was purified using G-15 gel filtration chromatography, and the main antioxidant peptide identified. Analysis showed that mutton ham peptide (MHP) has the highest Fe2+ chelating ability, whereas Jinhua ham peptide (JHP) had the highest ABTS and DPPH free radical scavenging ability (P < 0.05). A total of 346, 203 and 296 peptides were identified in JHP, Xuanwei ham peptides (XHP) and MHP, respectively. Most of the peptides were derived from myosin, accounting for 21.97% in JHP, 18.72% in XHP, and 21.96% in MHP. Myosin, actin, myoglobin, troponin, tropomyosin and pyruvate kinase proteins were the main source of peptide differences in the three types of dry cured ham.
In order to study the effect of low salt on lipid oxidation and volatile flavor of dry-cured ham, a formula containing 18% potassium lactate, 12% lysine and 70% NaCl was used as an alternative salt ...for curing ham. The control group using 100% NaCl as pickled formulation dry-cured ham.
The results showed that low salt significantly increased peroxide value (POV) and thiobarbituric acid value (TBARS) (P < 0.05). Acid lipase, neutral lipase, and phospholipase enzyme activity, as well as the amount of free fatty acids (FFAs), were all considerably higher in the low salt group than in the full salt group (P < 0.05). The volatile flavor compounds of dry-cured ham were determined by GC-MS, and 14 differential metabolites were screened out by using OPLS-DA analysis based on P < 0.05 and VIP >1. The enrichment analysis showed that low salt mainly affected low molecules fatty acids (palmitic acid, stearic acid, linoleic acid and myristic acid). Meanwhile, low salt treatment also influenced biosynthesis of unsaturated fatty acids, linoleic acid metabolism, fatty acid biosynthesis, fatty acid elongation and fatty acid degradation. This study demonstrates that low salt promotes the formation of ham flavor quality by affecting lipid oxidation and hydrolysis.
•Low-salt processing promotes the primary and secondary oxidation of ham lipids.•Lipase viability was significantly increased throughout the low-salt processing period.•Low salt processing produced dry-cured hams with 14 different lipid oxidation metabolites than salt processing.•Low salt affects five metabolic pathways of lipid oxidation, including the biosynthesis of unsaturated fatty acids.
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