Evaluación de la calidad de las paletas curados de diferentes líneas genéticas de cerdos Ibéricos

En este trabajo se estudió la calidad comparativa de las paletas curados de diferentes líneas genéticas: Retinto x Entrepelado RxT (n = 6), TxT Torbiscal (n = 6), Entrepelado ExE (n = 10), Retinto RxR (n = 6) Y Entrepelado x Torbiscal TxE/ExT (n = 8). Las paletas curadas se evaluaron con el método EVACAL, un método original del SiPA. Este método incluye análisis físico-químicos (humedad, grasa intramuscular, proteínas, NaCl, mioglobina, perfil de ácidos grasos, compuestos volátiles y oxidación de lípidos), análisis instrumental (color instrumental, pH y textura) y análisis sensorial. Los resultados obtenidos revelaron que el lote RxR muestra una relación más alta en oleico / estérico y MUFA/SAT, que se relaciona con una alta calidad. Esto se confirmó en el análisis sensorial con altas puntuaciones de fluidez grasa y brillo del magro. El lote TxE/ExT se caracteriza por presentar unos valores elevados de mioglobina que producen grandes cantidades de compuestos volátiles a partir de aminoácidos (2-metilbutanal y 3-metilbutanal). Esto hecho se mostró en los resultados del análisis sensorial con una mayor persistencia de sabor y mayor jugosidad en comparación con los otros lotes. Por otra parte, el lote RxE revela una gran cantidad de grasa intramuscular y mayores puntuaciones en atributos sensoriales en cuanto a la apariencia (fluidez grasa), textura (jugosidad) e intensidad de olor en comparación con los otros lotes. Podemos concluir que existen tres líneas genéticas que pueden producir productos de alta calidad. La conveniencia de utilizar uno de estos depende de otros aspectos como la prolificidad.

Effect of the partial replacement of sodium chloride by other salts on the formation of volatile compounds during ripening of dry-cured ham

The effect of the partial NaCl replacement by other salts (potassium, calcium, and magnesium chloride) on the formation of volatile compounds through the processing of dry-cured ham was studied using solid-phase microextraction (SPME). Three salt formulations were considered, namely, I (100% NaCl), II (50% NaCl and 50% KCl), and III (55% NaCl, 25% KCl, 15% CaCl(2), and 5% MgCl(2)). There was an intense formation of volatile compounds throughout the processing of dry-cured hams, particularly during the "hot-cellar" stage. The differences between treatments were found to be more remarkable at the end of the curing process. Hams from formulations I and II had significantly higher amounts of lipid-derived volatiles such as hexanal than hams from formulation III, whereas the latter had significantly higher amounts of Strecker aldehydes and alcohols. Plausible mechanisms by which salt replacement may affect the generation of volatile compounds include the influence of such replacement on lipid oxidation and proteolysis phenomena. The potential influence of the volatiles profile on the aroma of the products is also addressed in the present paper.

Evolution of nitrate and nitrite during the processing of dry-cured ham with partial replacement of NaCl by other chloride salts

Nitrate and nitrite are commonly added to dry-cured ham to provide protection against pathogen microorganisms, especially Clostridium botulinum. Both nitrate and nitrite were monitored with ion chromatography in dry-cured hams salted with different NaCl formulations (NaCl partially replaced by KCl and/or CaCl(2), and MgCl(2)). Nitrate, that is more stable than nitrite, diffuses into the ham and acts as a reservoir for nitrite generation. A correct nitrate and nitrite penetration was detected from the surface to the inner zones of the hams throughout its processing, independently of the salt formulation. Nitrate and nitrite achieved similar concentrations, around 37 and 2.2 ppm, respectively in the inner zones of the ham for the three assayed salt formulations at the end of the process, which are in compliance with European regulations.

Biochemical and sensory changes in dry-cured ham salted with partial replacements of NaCl by other chloride salts

The reduction of the content of sodium chloride in dry-cured ham was studied in to prevent the problems related to high sodium intake (i.e. the hypertension). One of the possibilities to reduce the sodium content is the partial replacement of sodium chloride by mixtures of potassium, magnesium and calcium chloride salts. The effect of two salting formulations (formulation II: 50% NaCl-50% KCl and formulation III: 55% NaCl, 25% KCl, 15 CaCl(2) and 5 MgCl(2)) on the protease activity through the dry-curing process and on the sensory characteristics of the final product was evaluated and compared to those of control hams (formulation I, 100% NaCl). Sensory attributes were all affected in the hams containing CaCl(2) and MgCl(2) while hams containing 50% KCl and NaCl (formulation II) were better valued, except for the attribute taste probably due to the potassium contribution to bitter taste.

Biochemical and sensory properties of dry-cured loins as affected by partial replacement of sodium by potassium, calcium, and magnesium

An attempt to decrease the NaCl content in dry-cured products through the use of three different salting treatments (II: 55% NaCl, 25% KCl, 15% CaCl(2), 5% MgCl(2); III: 45% NaCl, 25% KCl, 20% CaCl(2), 10% MgCl(2); and IV: 30% NaCl, 50% KCl, 15% CaCl(2), 5% MgCl(2)) in comparison to a control (I: 100% NaCl) was assayed to evaluate the biochemical and sensory characteristics in the final product. Most proteolytic enzyme activities from the loins submitted to the experimental salting treatments, especially treatments II and IV, remained higher than those salted traditionally (control). The higher aminopeptidase activity was also reflected in a larger release of free amino acids. Finally, a sensory paired comparison test revealed that those loins salted with the treatment II were not significantly different from the loins salted traditionally (100% NaCl), so that this treatment could be successfully used for sodium reduction.

Spatial and temporal variations of meiofaunal communities from the western sector of the Gulf of Batabanó, Cuba: III. Vertical distribution

The vertical distribution of meiofauna within subtidal sediments was studied in four stations pertaining to mangrove or muddy flats habitats. In 2003, replicated samples were taken in dry (February) and wet (July) seasons at the Bacunagua Inlet, southwestern coast of Cuba. The abundance and number of meiofaunal taxa exhibited a vertical gradient possibly due to changes in the concentrations of oxygen and hydrogen sulphide, rather than food availability along this gradient. Nematodes are capable of distributing themselves throughout the whole sediment column due to their ability to tolerate reducing conditions; however depletion of communities along depth was evident. Their presence in deeper sediments (6 - 10 cm) suggests that certain species are adequately adapted to spend their entire life cycle in these harsh environments (where soluble tannins and decomposing organic matter predominate). Copepods showed a strong limitation to vertical distribution (concentrating in the top 2 cm), possibly in response to a sharp vertical decline in oxygenation within these organically enriched sediments.

Proteomic identification of actin-derived oligopeptides in dry-cured ham

An intense proteolysis of muscle proteins, mainly due to the action of endogenous proteolytic enzymes, has been reported to occur during the processing of dry-cured ham. This gives rise to an important generation of free amino acids and peptides of small size that contribute directly or indirectly to flavor characteristics of the final product. The nature and properties of the free amino acids generated during postmortem proteolysis have been well established. However, little is known about the identity of peptides generated during the processing of dry-cured ham. In the present paper, we describe the isolation (by ethanol precipitation followed by size exclusion and reverse phase chromatographies) and identification (by matrix-assisted laser desorption/ionization time-of-flight MS and collision-induced dissociation MS/MS) in a Spanish dry-cured ham of the following four oligopeptides: (A) TKQEYDEAGPSIVHR, (B) ITKQEYDEAGPSIVHRK, (C) DSGDGVTHNVPIYE, and (D) DSGDGVTHNVPIYEG. This is the first time that these peptide fragments have been reported in dry-cured ham at the end of processing. Sequence homology analysis revealed that the four peptides originated from muscle actin, indicating an extensive hydrolysis of this protein during dry-curing. Some of the cleavage sites corresponding to these fragments in actin were reproduced by other authors through the incubation of this myofibrillar protein in the presence of cathepsin D (EC 3.4.23.5), thus supporting a relevant action of this enzyme during the processing of dry-cured ham.

Antibacterial activity of Rhizophora mangle bark

The aqueous extract of Rhizophora mangle bark, also formulated to ensure physical and chemical stability, was found to inhibit the growth of seven bacteria frequent in infected wounds.