Montanera System Research Articles

Inclusion of olive by-products in growing diets causes minor effects on meat quality of Iberian pigs fattened in a traditional system

Aim of study: To evaluate two experimental diets based on olive cake supplied during the growth period as an alternative to the restricted feeding applied in the production of Iberian pigs fattened with acorn (Montanera system). Area of study: Southwest of Badajoz, Spain Material and methods: 44 Iberian pigs were divided in three diet groups: 1) control (C) group (n=15), 2) dry olive pulp (DOP) group, fed a compound feed elaborated with olive pulp (n=14), and 3) wet crude olive cake (WCOC) group, fed a compound feed and olive cake silage supplied ad libitum (n=15). Subcutaneous fat biopsies were taken and backfat thickness and longissimus thoracis et lumborum (LTL) area were measured. In addition, quality traits (intramuscular fat percentage, color, pigment content, water holding capacity and shear force) were measured in LTL. Backfat fatty acid profile and intramuscular fat were also analysed. Main results: Significant differences were observed between groups for most of the fatty acids in backfat at 95 kg but differences were of lower magnitude at 160 kg and affected only to C16:1, C18:0, C18:1, C20:0, C20:1 and ΣSFA. Otherwise, lower values for red color and myoglobin content and higher for thawing water losses were observed for DOP pigs. The WCOC did not affect the analysed quality traits. Research highlights: Experimental diets did not have an important impact on growth, carcass composition or meat quality. Therefore, WCOC dietary treatment could be an interesting alternative that could reduce the undesirable effects of feed restriction.

Effect of High-Hydrostatic-Pressure Processing and Storage Temperature on Sliced Iberian Dry-Cured Sausage ("Salchichón") from Pigs Reared in Montanera System.

The top-quality “salchichón” (a fermented dry-cured sausage) is manufactured from Iberian pigs reared outdoors. This work aims to evaluate the effect of hydrostatic high pressure (HHP) and storage temperature on sliced vacuum-packaged top-quality Iberian “salchichón”. Two types of “salchichón” (S1 and S2, manufactured at different companies) were processed at 600 MPa for 8 min and stored at 4 and 20 °C for 180 days. Microbiological, physicochemical, and sensory changes were evaluated. Microbiological counts were reduced by HHP treatment and also generally decreased during storage at both temperatures. Lightness and redness of slices decreased during storage at 20 °C, while yellowness values increased. Changes in color were also observed in sensory analysis of the dry-cured sausages. HHP increased lipid and protein oxidation values in S1, whereas protein oxidation increased at 20 °C in S2. S1 was more affected by HHP while S2 was more affected by the temperature of storage. Therefore, despite both products belonging to the same commercial category, slight differences in the composition of both products and/or differences in packaging determined a different behavior after HHP treatment and during storage at different temperatures.

Near-Infrared Spectroscopy (NIRS) as a Tool for Classification of Pre-Sliced Iberian Salchichón, Modified Atmosphere Packaged (MAP) According to the Official Commercial Categories of Raw Meat.

This study evaluates near-infrared spectroscopy (NIRS) feasibility in combination with various pre-treatments and chemometric approaches for pre-sliced Iberian salchichón under modified atmosphere (MAP) classification according to the official commercial category (defined by the combination of genotype and feeding regime) of the raw material used for its manufacturing (Black and Red purebred Iberian and Iberian × Duroc crossed (50%) pigs, respectively, reared outdoors in a Montanera system and White Iberian × Duroc crossed (50%) pigs with feed based on commercial fodder) without opening the package. In parallel, NIRS feasibility in combination with partial least squares regression (PLSR) to predict main quality traits was assessed. The best-fitting models developed by means of partial least squares discriminant analysis (PLS-DA) and linear discriminant analysis (LDA) yielded high discriminant ability and thus offered a tool to support the assignment of pre-sliced MAP Iberian salchichón according to the commercial category of the raw material. In addition, good predictive ability for C18:3 n-3 was obtained, which may help to support quality control.

Effect of Animal Age at Slaughter on the Muscle Fibres of Longissimus thoracis and Meat Quality of Fresh Loin from Iberian × Duroc Crossbred Pig under Two Production Systems.

Simple SummaryThis paper is in attempt to assess the impact of the production system Montanera and intensive, and the age at slaughter in each of them, on the muscle fibres of Longissimus thoracis (LT) and meat quality of fresh loins from Iberian pigs. The age at slaughter affected the fibre size of Montanera LT muscles, while the production system influenced the fibre type I population and type IIB fibre size. The age at slaughter affected the fresh loin quality trait depending on the production system; Montanera and intensive fresh loins from older animals yielded higher myoglobin and redness values. Additionally, intensive fresh loins derived from older animals yielded the lowest intramuscular fat and the highest cook loss and shear force in the Warner-Braztler shear force test. These above-mentioned parameters differed due to production systems, Montanera fresh loins less fat-infiltrated and tough but with higher redness values. The results of the present study contribute to shedding light regarding how the production-related factor animal slaughter age may influence the muscle fibre population, size and quality traits of fresh meat.Two production systems and several ages at slaughter were used: 12, 14 and 16 months for outdoor rearing (with the final finishing phase in the Montanera system, in which fed was based on natural resources, mainly acorns and grass) and 8, 10 and 12 months for animals reared indoors (intensive system: with feed based on commercial fodder) to evaluate their effect on the muscle fibre population and size of the Longissimus thoracis, (LT) muscle, as well as fresh loin quality traits. Animals that were older at slaughter revealed increased fibre sizes of the LT muscles in the pigs reared in the Montanera system. The LT muscles of the animals reared in intensive systems had a lower percentage of type I fibres and higher size of type IIB than those reared in the Montanera system. The approximate composition and instrumental colour of Montanera fresh loins were affected by the animal slaughter age. In the case of the intensive system, the effect of animal slaughter age had an impact on the approximate composition, instrumental colour, water loss and textural properties. Therefore, different ages at slaughter of Iberian pigs showed variations in some quality parameters in the fresh loins in both the Montanera and Intensive systems, thus proving to be a factor of variability and homogeneity of the Iberian products. The meat from Iberian pigs reared in an intensive system and slaughtered at a younger age proved to be more tender. The production system affected all the above quality traits, with the exception of water loss.

Effect of Breed Purity and Rearing Systems on the Stability of Sliced Iberian Dry-Cured Ham Stored in Modified Atmosphere and Vacuum Packaging.

The long-term storage stability of three quality categories of sliced Iberian dry-cured ham defined by the Spanish Iberian Quality Standard (Black, purebred Iberian reared outdoors in Montanera system; Red, Iberian × Duroc crossed (50%) pigs reared outdoors in Montanera system; and White, Iberian × Duroc crossed (50%) pigs commercially fed) and packaged under vacuum and modified atmosphere packaging (MAP) was studied. Commercial category affected the shelf life, being Black and Red presented the highest lipid oxidation during storage, whereas the effect of packaging was not as clear as the effect of commercial category. MAP preserved more the colour and the antioxidants content than vacuum packaging, while this latter reduced lipid oxidation development and maintained better the brightness and flavour of slices than MAP.

Quality Traits of Dry-Cured Loins from Iberian Pigs Reared in Montanera System as Affected by Pre-Freezing Cure.

Iberian dry-cured loins from pigs fattened in Montanera are usually subjected to seasonal production, which could be overcome through freezing the loin before the curing process. Hence, three homogeneous batches (n = 15 per batch) were established to evaluate the effect of different pre-freezing cure (−20 ± 2 °C) times (three and six months) of raw material on main quality characteristics of dry-cured loins in comparison to those elaborated from unfrozen meat. All samples were subjected to similar seasoning and same curing length to obtain dry-cured loins. Results showed a decrease in lightness, redness, chrome and hue values, polyunsaturated fatty acids (PUFA), higher oxidative phenomena, and changes in rheological properties in fresh loins on account on freezing (p ≤ 0.05). Some quality parameters of dry-cured loins were affected by freezing, weight loss, and hardness being higher as well as salt content being lower. PUFA and Warner–Braztler Shear Force (p ≤ 0.05) also showed higher values in dry-cured loins from frozen meat than those elaborated from unfrozen counterparts.

Antioxidants and fatty acid deposition and instrumental colour as affected by subcutaneous backfat layers and slaughtering age of Iberian x Duroc crossed pigs under Montanera

The effect of various slaughtering age options on the quality characteristics of subcutaneous backfat layers from Iberian x Duroc crossbred pigs under Montanera system was assessed. Three batches (IBxD16, IBxD14 and IBxD12) were established to start the Montanera with 14, 12 and 10 months of age and similar weight. After slaughter at 16, 14 and 12 months respectively, a piece of backfat was taken from each animal, and subsequently separated into outer, inner and subinner layers, and quality traits were performed in each one separately. Higher C18:1 n-9, MUFA, α- and γ-tocopherol were found in animals slaughtered with 16 months in the subinner backfat, which might be suitable to Iberian slaughtering age traceability. Lightness and redness varied with the age of the animal, for which showed an inverse pattern, and backfat layer, while yellowness only according to the latter.

Quality traits of fresh and dry-cured loin from Iberian x Duroc crossbred pig in the Montanera system according to slaughtering age

Iberian x Duroc cross grower pigs of similar weight, but 12, 10 and 8 months of age, were finished using the Montanera system to study effects on fresh and dry cured loin quality.Pigs were slaughtered simultaneously at 16, 14 and 12 months of age (IBxD16, IBxD14 and IBxD12) and longissimus thoracis et lumborum were removed and processed into dry-cured loin. Fresh and dry cured loins from the oldest animals (IBxD16) had higher tocopherols, C18:2 n-6 and PUFA as well as higher insoluble collagen, which led to greater hardness. Fresh loin from the youngest animals (IBxD12) had the lowest myoglobin content, redness (a*), chroma and hue angle. No differences in proximate composition or instrumental colour were found in dry-cured loins.

Effect of production system on physical–chemical, antioxidant and fatty acids composition of Longissimus dorsi and Serratus ventralis muscles from Iberian pig

The effect of three production systems of Iberian pigs namely Montanera (free-range system and feeding based on acorns and grass), Recebo (free-range system and nutrition based in combination of acorns, grass and mixed feeds) and Intensive (confinement with mixed feeds) on some quality traits of Longissimus dorsi (LD) and Serratus ventralis (SV) muscles were studied. Muscles from pigs raised in the Montanera system showed significantly higher CIE L∗, a∗ and b∗ values and higher haem pigment content than those from Intensive system. Similarly, muscles from pigs raised in the Montanera system had significantly higher contents of α and γ-tocopherol and phenolic compounds contents and higher lipophilic and hydrophilic activity antioxidant than those from pigs raised in the Intensive system. Fatty acids profiles from Montanera pigs had significantly higher monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids and lower saturated fatty acids (SFA) than those from pigs raised in the Intensive system. In relation to muscle effect, LD showed lower intramuscular fat (IMF), α-tocopherol, phenolic compounds, lipid oxidation and PUFA, but higher MUFA than SV.

Innate immune response of blood neutrophils in Iberian pigs under different production systems

Ninety Iberian pigs were grouped into three production systems commonly used in southwest Europe: Montanera (free-range and feeding on natural resources, mainly acorns and grass), Intensive (in confinement and fed commercial feed), and Recebo (similar to the Montanera system, but fed commercial feed in the final fattening stage). The aim of the present work was to determine and compare the phagocytic function of blood neutrophils from Iberian pigs in these production systems. We measured the phagocytic function of neutrophils (as measured by chemotaxis, phagocytosis and microbicidal capacity) from pigs at the beginning and end of fattening, in the different experimental groups. Neutrophils from Montanera animals were more active than those from the other production systems, especially those from the Intensive production group.

Changes in SPME-extracted volatile compounds from Iberian ham during ripening

A headspace SPME procedure was tested to study the evolution of volatile compounds during the ripening of Iberian hams from pigs reared in a Montanera system (outdoorbased, with acorn and pasture available) and a HO-Pienso system (indoor-based, with a high oleic acid concentrate). The effect of the ripening time on volatile compounds was more marked than the effect of feeding system. Most volatile compounds affected by the ripening time were compounds that come from Strecker and Maillard reactions, which increased significantly ( p < 0.05). Some of them (butanoic acid, 2,6- dimethylpirazyne and 1-octen-3-ol) were more abundant in Montanera than in Pienso hams. These small differences could be important because they involve compounds that have been identified as Iberian ham odorants.

Effect of ripening time and rearing system on amino acid-related flavour compounds of Iberian ham

The evolution of free amino acids and amino acid-derived volatile compounds during the ripening of Iberian ham from pigs reared in a Montanera system (outdoor-based, with acorn and pasture available) and a Pienso system (indoor-based, with a high oleic acid concentrate) was studied. Ripening time influenced significantly all the free amino acids detected ( p < 0.05) except for threonine and tyrosine. The total free amino acid content increased significantly from day 120 to day 230 (drying stage) and then the concentration remained almost steady. This marked increase in the free amino acid content matched an increase in the amino acid-derived volatile compounds. The volatile compounds also increased after day 230. Conversely, rearing system had a weak effect on the free amino acid content and on the amino acid-derived volatile compounds. Only glutamic acid was significantly influenced ( p = 0.027), and a slight effect on proline and aspartic acid was found ( p = 0.051 and p = 0.084, respectively), concentrations being larger in Montanera hams than in Pienso ones. With regard to the amino acid derived volatile compounds, only a significant influence of rearing system on acetaldehyde and on the coelution of 2,6-dimethylpyrazine+dihidro-2(3H)furanone was found. The small differences caused by rearing system confirm the great importance of concentrate formulation.

Note: Effect of Crossbreeding and Rearing System on Iberian Ham Volatile Compounds

Several volatile compounds from Iberian ham trapped from the headspace were analysed to research the effect of crossbreeding (Iberian vs. Iberian Duroc 50% pigs) and rearing system (Montanera system vs. Pienso system) on them. Thirty-four Iberian hams grouped following a factorial treatment structure were analysed. A two-way analysis of variance with interaction was applied to the data from 46 volatile compounds identified. The effect of crossbreeding was negligible on the studied volatile compounds, which was in agreement with the effect on fatty acid percentages of subcutaneous fat. On the contrary, the effect of rearing system was significant in most of the fatty acid percentages used to classify the hams into the current commercial grades of Iberian ham (16:0, 18:0 and 18:1, p&lt;0.001). However, a slight effect on the volatile compounds was found, and only a limited number of compounds were significantly affected. Results for the effect of crossbreeding and rearing system on headspace volatile compounds agreed with the sensory data for odour of hams.