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Fat, composed mainly of triacylglycerols and phospholipids, and protein, composed of amino acids, constitute major components of meat. Carbohydrate, in the form of glycogen, is present in very low amounts. This article describes the main methodologies available for the analysis of these substances, discusses their advantages and disadvantages, and gives recommendations for the choice of methods.

Peptides and free amino acids are naturally generated in dry-cured ham as a consequence of proteolysis phenomenon exerted by muscle peptidases. The generation of bioactive peptides in different types of dry-cured ham produced in Spain, Italy and China is reviewed in this manuscript. Major muscle proteins are extensively hydrolysed firstly by endogenous endo-peptidases followed by the successive action of exo-peptidases, mainly, tri- and di-peptidylpeptidases, aminopeptidases and carboxypeptidases. Such proteolysis is very intense and consists of the generation of large amounts of free amino acids and a good number of peptides with different sequences and lengths, some of them exerting relevant bioactivities like angiotensin converting enzyme inhibitory activity, antioxidant activity, di-peptidylpeptidase IV inhibitory activity among other and in vivo antihypertensive, hypoglycemic or anti-inflammatory activity. This manuscript reviews the recent findings showing that dry-cured ham constitutes a good source of natural bioactive peptides that have potential benefit for human health., The research leading to these results received funding from Grant AGL2017-89831-R from the Spanish Ministry of Economy, Industry and Competitivity and FEDER funds The Ramón y Cajal postdoctoral contract to LM is also acknowledged.

This study is focused on the characterization of the proteolysis occurred during the processing of Pastırma, a traditional Turkish dry-cured meat product, which is responsible for its final characteristics. Thus, the evaluation of naturally generated free amino acids and peptides present at 0, 2, 5, 10, and 21 days of processing and the bioactivity of peptide fractions have been approached. Peptides were examined by MALDI-TOF and results showed differences in the amount of generated peptides at different times of processing, and a total of 29 peptides were newly generated at Day 21 in comparison with Day 2 during processing. The water soluble fraction of Pastırma at the end of the curing period (Day 21) was also analyzed by size-exclusion chromatography and some of the collected fractions demonstrated strong ACE-inhibitory and antioxidant activities. In fact, Pastırma showed an ACE inhibitory activity higher than 86% from 220 to 270 mL corresponding to molecular masses between 900 and 1500 Da, and also a DPPH radical-scavenging activity above 60% at 250 to 300 mL corresponding to molecular masses between 700 and 2000 Da. Thus, Pastırma represents a good source of natural ACE-inhibitory and antioxidant peptides which might be due to the proteolysis occurred by endogenous enzymes and the contribution of the çemen paste used in production., Grant AGL2014-57367-R from MINECO (Spain) and FEDER funds and JAEDOC-CSIC postdoctoral contract of L.M. cofunded by European Social Funds are acknowledged. The research fellowship grant provided by Erasmus + KA1 Student Mobility Programme for Higher Education for the author Ebru Deniz is also gratefully acknowledged.

Amino acids are natural constituents of proteins and peptides present in foods that are known to contribute to many relevant functions in an organism. The knowledge of the amino acid profile or the essential amino acids contents in foods and the limiting amino acids in a protein is very important for the characterization of their biological value and how their nutritional benefits may be affected by food processing or during storage. There are many available methods for the analysis of amino acids in foods that are summarized in this article.

Bioactive peptides are known to contribute relevant bioactive functions during postmortem processing of muscle foods. They can influence the metabolism and prevent diseases exerting their functions on the cardiovascular, immune, gastrointestinal, and nervous systems in human bodies. The identification and quantitation of these peptides in foods are very important for the characterization of its biological value and its benefits for consumers' health. Their importance is mainly based on the lower amount of secondary effects produced by the natural peptides, in contrast to the nondesirable effects observed when synthetic peptides are used. This article describes the main sources to obtain bioactive peptides, their most studied properties, and their occurrence in foods.

Histidine-containing dipeptides carnosine, anserine, and balenine are natural constituents in mammalians, which are known to contribute to relevant bioactive functions during postmortem processing of muscle foods. The knowledge of the content of these dipeptides in meat, poultry, and seafood is very important for the characterization of its biological value in different muscles and cuts and how its antioxidant benefits may be affected by processing or during the storage. This article is describing the importance for health, the availability, and the occurrence of histidine-containing dipeptides in meat, poultry, and seafood as well as the description of the main available methods for their analysis in foods.

Proteolysis is a complex and dynamic process which takes place throughout the whole dry-cured processing due to the action of endogenous muscle peptidases, and results in the generation of a high number of small peptides and free amino acids responsible for the final quality of dry-cured ham. In this study, a total of sixty-eight peptides derived from the ubiquitin-60S ribosomal protein have been identified in dry-cured ham at 2, 3.5, 5, 6.5, and 9 months of processing using various chromatographic separations and a quadrupole/time-of-flight mass spectrometer in tandem. Some of the identified peptides have been detected during the whole process, whereas a total of fourteen of them were exclusively identified at 9 months of curing. The presence of any of these peptides could be a good indicative that dry-cured ham pieces have reached a minimum curing process of 9 months. The study of the generated peptides has contributed both to a better knowledge of proteolysis evolution and the endogenous enzymes participating, and to determine their potential to be used as quality markers to monitor the processing time., Grant PROMETEO/2012/001 from Conselleria d'Educació, Formació i Ocupació of Generalitat Valenciana (Spain) is fully acknowledged. FPI Scholarship BES-2011-046096 from MINECO (Spain) to M.G. and JAEDOC-CSIC postdoctoral contract to L.M. are also acknowledged. Mass spectrometry analysis was performed in the SCSIE_University of Valencia Proteomics Unit, a member of ISCIII ProteoRed Proteomics Platform.

All rights reserved. In this study, a peptidomic approach has been used in the identification of naturally generated peptides during a dry-curing process, showing methionine (Met) oxidation in their sequence. A total of 656 peptides derived from major myofibrillar proteins in Protected Designation of Origin (PDO) Teruel dry-cured ham have been identified by nanoliquid chromatography coupled to tandem mass spectrometry (nLC-MS/MS), including 120 peptides showing methionine oxidation. The percentage of oxidised peptides in the studied proteins ranged from 6% to 35%, being peptides derived from nebulin, titin, myosin heavy chains, and troponin I proteins, those showing the highest number of oxidised methionine. The identification of the peptide sequence incorporating the oxidised amino acid provides valuable information of neighbouring amino acids, degree of hydrolysis of the sample, and characteristics of the peptide, which might be very useful for a future better understanding of the oxidation mechanisms occurring in dry-curing processing., Grant AGL2013-47169-R from MINECO (Spain) and FEDER funds and FPI Scholarship BES-2011-046096 from MINECO (Spain) to M.G. are fully acknowledged. JAEDOC-CSIC postdoctoral contract and support from European Social Funds to L.M. are also acknowledged.

Peptidomics is a necessary alternative in the analysis of naturally generated peptides in dry-fermented processing. The intense proteolysis occurred during the processing of dry-fermented sausages is due to the action of endopeptidases and exopeptidases from both, endogenous muscle origin and lactic acid bacteria (LAB) added in the starter. Sodium caseinate is frequently used as an additive in this type of products because of its emulsifying properties, and consequently influences the protein profile available during the proteolysis. In this study, a mass spectrometry approach has been used to determine the impact of added sodium caseinate in the final peptide profile as well as to analyse its possible influence in the presence of certain previously described casein-derived bioactive peptides.

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., HEFCE infrastructure funding is acknowledged for MS equipment to PDF. LM and PDF are grateful to the EU-FP7 Marie Curie IEF scheme (FOOSAF project) for the financial resources. FPI Scholarship from Spanish Ministry of Science and Innovation to E.E. and grant AGL2010-16305 from Spanish Ministry of Economy and Competitiveness and FEDER funds are fully acknowledged.

[EN] Simultaneous brine thawing/salting process was applied as an alternative to traditional pile salting process using 51 frozen Iberian hams. The effect of this type of salting process on endogenous enzyme activity and sensory quality of Iberian dry-cured hams was analysed. The frozen hams were simultaneously thawed and salted with saturated brine, with and without vacuum pulses, and were compared to hams thawed under refrigeration and traditionally salted. The peptidase and lipase activities were measured at the end of salting and post-salting stages. The activity of cathepsin B+L was reduced in the two brine salted batches while few differences among batches were observed for the other peptidases. Several lipase activities were significantly reduced in the two brine salted batches. The brine thawed processing affected the free fatty acid content at the different stages although the differences were more appreciated at the beginning of the process and no differences were observed at the end. The long ripening time makes these differences negligible and the consumer did not appreciate any differences between the sensory quality of Iberian brine/thawed hams and traditional Iberian thawed pile salted hams. (C) 2011 Elsevier Ltd. All rights reserved., Financial support from PETRI by the Ministry of Science and Innovation (PTR-1995-0754-OP-03) is fully acknowledged. Work was carried out under the Unidad Asociada IIAD (UPV) - IATA (CSIC) framework. The authors are grateful to M. Lozano and MI. Nadal for technical assistance.

This work describes the correlation found along 10 days between potentiometric measurements obtained by using an electronic tongue and the variation in certain physicochemical, microbial and biochemical parameters measured on a whole piece of pork loin stored under refrigeration. The electronic tongue consists of a set of six electrodes made of Au, Ag, Cu, Pb, Zn and C, and a reference electrode. Through the use of various multivariate analysis techniques, such as: PCA and two types of artificial neural networks (i.e. multilayer perceptron (MLP) and fuzzy ARTMAP) it was found that it is possible to determine the time elapsed in relation to the degradation of the loin by using simple potentiometric measurements. Additionally, in the same pork sample used to measure redox potentials with the electronic tongue, the following parameters were also determined; pH, microbial count, concentrations of inosine 5'-monophosphate (IMP), inosine (Ino) and hypoxanthine (Hx). Through the use of PLS analysis, it was found a rather good correlation between pH and the potentiometric data. Also a remarkable correlation was observed between the measures carried out with the electronic tongue and the so-called K-index that simultaneously measures the variation in the adenosine triphosphate (ATP) degradation products. These results suggest that this simple, or a similar electronic tongue, could be useful for the undemanding qualitative or semi-quantitative evaluation of freshness in meat samples in a wide range of situations. © 2010 Elsevier Ltd. All rights reserved., We would like to thanks the Spanish Government for support (Project CTQ2006-15456-C04-01/BQU and AGL2007-65379-C02-01 and 02/ALI). This work has been partially carried out under Associated Unit framework between IIAD (UPV) and IATA (CSIC).

Proteolytic events taking place during prok meat ageing and curing processes are described. Muscle cathepsins and calpains provide suitable substrate for muscle peptidases and aminopeptidases which ultimately generate small peptides and free amino acids. The levels of small peptides and free amino acids in all meats are higher after processing than before as a result of intense action of those proteases. Increases of the free essential amino acids such as valine, methionine, isoleucine, leucine, phenylalanine, tryptophan and lysine are observed along the conditioning of meat and are especially large in the processing of dry-cured ham. Thus, aged meat but very especially dry-cured ham have an important nutritional significance when the energy intake is low or in poor nutritional quality diet.

Many flavor peptides in raw pork meat and dry-cured ham are generated as a consequence of muscle protein degradation. Low molecular mass peptides (Mr