RESUMEN

Chlorpyrifos (CPF) is an organophosphorus pesticide used in poultry to prevent and/or kill insects and such as preserving agents of poultry feed. Exposure continues to CPF can promote its accumulation at trace concentrations in animal tissue. The toxicological effects of these residues (carcinogenicity, genotoxicity, and neurological disorders) have been related to oxidative stress. Nevertheless, it is still unknown if these trace concentrations might promote oxidative stress in muscle proteins since chicken meat proteins are susceptible to undergo oxidation reactions. Moreover, protein oxidation has been related to a decrease in the nutritional value in of meat. To investigate the oxidative effect of CPF on chicken breast proteins, peptidomics and proteomics analysis were used. For this, chicken breast samples were exposed to CPF and subjected to simulated gastrointestinal digestion. The identification of oxidized peptides from digested and undigested proteins were performed by LC MS/MS (nanoESI qQTOF). Prior to mass analyses undigested proteins were trypsinated. Data were analysed using MASCOT and ProteinPilot v 4.5 software. In this study, 90 and 107 oxidized peptides from digested proteins of control and exposed samples were identified, respectively. These peptides corresponding to 12 oxidized proteins. Meanwhile, 260 and 324 oxidized peptides from undigested proteins (control and exposed samples) were identified, which corresponding to 19 and 17 proteins, respectively. Collagen was protein more susceptible to oxidation promoted by chlorpyrifos in digested and undigested proteins. Identification of these oxidized proteins from simulated digestion provides an important insight about the impact of substances like certain veterinary drugs at trace concentrations on the nutritional value of chicken breast meat.

RESUMEN

The typical Spanish dry-cured ham has a particular sensory quality that makes it a distinctive food, highly appreciated for consumers worldwide. Its particular physicochemical properties, such as high salt content and reduced water activity contribute to their shelf-stability. However, post-processing actions carried out for the commercialization of these products such as slicing may increase the risk of development of pathogenic microorganisms as Listeria monocytogenes. During ripening, muscle proteins are hydrolyzed by muscle peptidases releasing peptides and free amino acids. Some of these peptides have been described to exert biological activities such as antioxidant and ACE-inhibition. In this study, a peptidomic strategy using mass spectrometry techniques has been used to identify and sequence those naturally generated peptides showing antilisterial activity. One hundred and five peptides have been identified in active fractions and some synthesized and their MIC calculated. Ten peptides were able to inhibit the growth of L. monocytogenes, being the pentapeptide RHGYM the most effective showing a MIC value of 6.25 mM. This study proves for the first time the potential antimicrobial action against L. monocytogenes of certain naturally generated peptides obtained from Spanish dry-cured ham.

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RESUMEN

Angiotensin I converting enzyme (ACE) inhibitory activity of peptides derived from the hydrolysis of sarcoplasmic and myofibrillar porcine proteins by the action of Lactobacillus sakei CRL1862 and Lactobacillus curvatus CRL705 (whole cells+cell free extracts) was investigated at 30°C for 36 h. The protein hydrolysates were subjected to RP-HPLC in order to fractionate the extracts for further evaluation of ACE inhibitory activity. Bioactive fractions were only found from the hydrolysis of sarcoplasmic proteins by both assayed lactobacilli strains. Identification of peptides contained in the bioactive fractions was carried out by tandem mass spectrometry using a nanoLC-ESI-QTOF instrument and the mascot search engine. From the four most active fractions obtained, a total of eighteen and fifty peptides were characterized from L. sakei CRL1862 and L. curvatus CRL705 protein hydrolysates, respectively. The sequence FISNHAY was generated by the proteolytic activity of the two lactobacilli species. Sequence similarity analyses between the peptides identified in this study and those previously identified as ACE inhibitory peptides and detailed in the BIOPEP database were outlined. Results suggest that meat-borne Lactobacillus were able to generate peptides with ACE inhibitory activity, highlighting their potential to be used in the development of functional fermented products. BIOLOGICAL SIGNIFICANCE: The results of this study would enable the obtention of porcine functional foods by applying lactic acid bacteria generating bioactive peptides. ACE inhibitory peptides obtained by the hydrolytic action of L. curvatus CRL705 and L. sakei CRL1862 on sarcoplasmic proteins were analyzed. Among them, the peptide FISNHAY exhibited the highest activity and its sequence has not yet been reported.

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