Iberian Pork Research Articles

The antimycotic potential of Debaryomyces hansenii LRC2 on Iberian Pork Loins with low concentration preservatives

The use of preservatives such as nitrite and salt is a widespread practice in meat industry. For many years it has resulted in benefits like extending the shelf life of cured meat products. The EU has published new regulations to reduce the content of preservatives in foods as recent investigations have concluded that its excessive usage is related to health issues, so new alternatives are needed. Debaryomyces hansenii is a non-conventional yeast with known biocontrol possibilities. It can be found in many of environments and is the most frequent yeast isolated from sausages and dry meat products. The LRC2 strain used in this work is an isolate from Iberian Pork Loin, characterized biochemically and molecularly. The potential of D. hansenii LRC2 strain was evaluated following a volatile compounds inhibition assay. Then a scale-up trial was performed by inoculating a battery of Iberian Pork loins followed by a quality study of the final product. This was carried out through physical and microbial analysis as the identification of volatile compound profiles with GC-IMS. Finally, sensory tests were performed by a group of trained panellists and regular consumers. Results in our research show that the production of volatile compounds from LRC2 inhibited the activity of unwanted molds in all the conditions studied. The inhibition rates surpassed 75% in all cases, strengthening the hypothesis of its potential preservative effect in cured meat products. When testing the yeast inoculation effect and the reduction of preservatives in Iberian Pork Loins, a loss of sensory quality is observed when preservatives are drastically reduced reducing the panellists’ grades by more than 3 points on a 1–9 scale in overall quality. In all conditions, the LRC2 inoculated loins showed significant fewer mold populations than the non-inoculated ones, improving the safety food level of the final product. This study confirms that the application of natural yeast-based alternatives is a feasible option for the new meat industry needs.

Classification of raw cuts from Iberian and Celta pigs based on lipid analysis and chemometrics

This study explores the fatty acid (FA) profiles of four distinct raw cuts sourced from Iberian and Celta pigs, two prominent and commercially significant autochthonous breeds of the Iberian Peninsula. Significant variations in FA profiles were observed among cuts. Livers exhibited the highest lipid content and concentrations of linoleic and arachidonic acids. In contrast, cheek, presa, and loin were characterised by increased monounsaturated FA, primarily oleic acid. Differences were also found between breeds, albeit less pronounced. Palmitoleic acid was more prevalent in Iberian pigs, with the exception of livers, where no significant differences were found. Conversely, Celta pigs displayed higher levels of linoleic and arachidonic acids, except for livers, where arachidonic acid was higher in Iberian pork. A chemometric study successfully distinguishes between Iberian and Celta pig samples using a PLS-DA model. Variable Importance in Projection (VIP) analysis reveals that linoleic, arachidonic, α-linolenic, eicosenoic and palmitoleic acids, along with some minor FA, are key variables for accurate breed classification in each cut, highlighting the importance of comprehensive FA profile analyses that go beyond major fatty acids or unsaturation levels.

Effect of dietary fat on proximal composition, sensorial analysis and shelf life of a traditional Spanish cooked pork product "Lomo de Sajonia" from Iberian pork.

This study aims to evaluate the effect of different dietary fat sources on the quality of a Spanish-cooked meat product Lomo de Sajonia (LSA) and its shelf-life. Forty loins were selected from Iberian pigs fed four dietary treatments containing pork fat (G-1), Greedy-Grass Olive® (GGO) (enriched oleic-acid oil) (G-2), G-2 and high oleic sunflower (G-3), and G-3 plus a mixture of commercial organic acids (Bioll®) (G-4). Loins were manufactured to obtain LSA, and the quality and sensorial attributes were assessed. The shelf life was established according to microbial count and sensorial analysis, which was packed in a modified atmosphere and stored under retail conditions. All meat quality parameters of LSA remained stable in all groups, except fat content and overall liking, which showed the highest values for G-2 LSA. Regarding the shelf life, sensorial attributes remained acceptable in all groups during storage time, while a delay in microbial growth was recorded for the LSA of G-3. According to the results, including GGO in Iberian pig diets could enhance LSA traits, possibly linked to increased assimilation compared with conventional fat sources. However, adding organic acids to the diet did not have the expected effect on improving the shelf life of the LSA.

Free-range acorn feeding results in negative carbon footprint of Iberian pig production in the dehesa agro-forestry system

Iberian pig production has its own quality regulation, which defines different handling and feeding systems for this breed. These differences influence production costs, market price and environmental impact. The most extensive system of fattening Iberian pigs is based on foraging acorns in a silvopastoral system named dehesa, and consumers usually associate the Iberian pork with this system, although nowadays more intensive systems are dominant due to their productivity and management simplicity. The aim of this study is to assess the Carbon Footprint (CF) of the different Iberian pig production systems using the Life Cycle Assessment (LCA) methodology.This study is based on data collected from 19 Iberian pig farms producing nursery growers (≤25 kg, 2 farms), pre-finished pigs (100–110 kg, 3 farms) and 3 types of finished pigs (150–175 kg), including free-range fattened pigs (17 farms), outdoor intensively fattened pigs (2 farms) and indoor intensively fattened pigs (2 farms). The CF was calculated with a “cradle to farm gate” approach using the kg of live weight (kgLW) as functional unit, and including C sequestration in soils and biomass, which was calculated by field monitoring in a selection of measuring points. The average CFs of the final products were 9.2 ± 2.5 kg CO2eq kgLW−1 for nursery growers, 5.6 ± 2.42 kg CO2eq kgLW−1 for pre-finished pigs, −5.6 ± 6.5 kg CO2eq kgLW−1 for free-range fattened pigs, 3.1 ± 1.5 kg CO2eq kgLW−1 for outdoor intensively fattened pigs and 7.7 ± 0.3 kg CO2eq kgLW−1 for intensively fattened pigs. The main C sinks of the dehesa system (trees and soil) sequestered an average of 3.18 t CO2eq ha−1 year−1. This C sequestration, averaging −10.2 ± 6.7 kg CO2eq kgLW−1 in free-range pig production, offsets 223% of the GHG emissions in those systems, which resulted in a negative CF (net CO2 sequestration). There was a direct relationship between CF and pig stocking rate, leading to strongly negative CF values on those farms with the lowest pig stocking rates.

The Effect of Deep Frying French Fries and Two Types of Iberian Pork on the Characteristics of Extra Virgin Olive Oil and the Fried Products.

Although deep frying is widely used, little is known about the effect of frying different meats on the frying oil. The aims of this study were to investigate whether the pork type influences the characteristics of the frying oil, to compare any effects with those of French fries, and to research whether the use of thermally damaged oil differentially affects those products. French fries and pork from pigs reared outdoors on acorns and grass (outdoor) or indoors on a concentrated feed (indoor) were deep-fried in either raw or previously heated olive oil. The type of product affected most color parameters, K268 and the α-tocopherol content of the oil. The frying of outdoor pork hardly affected the α-tocopherol content, whereas the frying of indoor pork and especially French fries caused a significant decrease. This suggests that the meat type should be considered when setting the frying lifespan of olive oil. Regarding the fried products, L*, moisture (only French fries) and the malondialdehyde (MDA) content (only indoor pork) were the only parameters affected by the previous oil damage. The outdoor pork was less susceptible to oxidation than the indoor pork when the oil was severely damaged. Therefore, pig outdoor-based systems based on antioxidant-rich diets might be convenient to maintain oxidation at the lowest level after frying.

Consumers' Expectations about Meat from Surgical Castrated or Immunocastrated Male and Female Iberian Pigs.

Simple SummaryPig castration is a common practice in the Iberian breed (boar and gilts), known for the quality of its products. This work studies the effect of pig castration (surgically castrated females and males, immunocastrated females and males and entire females) on the sensory expectations and acceptability of the meat. Attitudes and beliefs towards castration and immunocastration were also evaluated. The study was carried out in Madrid and Barcelona, where consumers (n = 252) evaluated meat from the five sex types in blind and informed conditions. Results showed that consumers could be classified into three groups as “Indifferent”, “Against castration and immunocastration” and “Against immunocastration”. Meat from castrated males had higher overall liking scores than the other types of meat. Information provided to the consumers, together with their expectations, affects the overall liking scores. Thus, this needs to be considered to determine the best marketing strategy according to the type of pork produced.A common practice in Iberian pigs is the castration of both males and females, and it can be carried out surgically or by immunization against gonadotropin-releasing factor (GnRF). The aim of this work was to determine consumers’ overall liking and expectations towards Iberian pork from five different sex types (castrated females, entire females, GnRF-vaccinated females, castrated males and GnRF-vaccinated males), as well as to know the attitudes and beliefs of consumers towards castration and immunocastration. Loins from 83 Iberian pigs were collected and evaluated by 252 consumers in Barcelona and Madrid. Consumers evaluated the five types of meat in three situations: blind condition (tasting the product), expectations (without tasting) and informed condition. Finally, attitudes and beliefs towards castration and immunocastration were also determined. Results distinguished three segments of consumers labeled as “Indifferent”, “Against castration and immunocastration” and “Against immunocastration”. Meat from castrated males had higher overall liking scores in the blind condition. Expectations towards pork depending on its sex type affect consumer-informed acceptability; thus, it is important to consider marketing strategies to avoid or direct the effect of the information provided on the acceptability of the pork.

A biosecurity survey on Iberian pig farms in Spain: Farmers' attitudes towards the implementation of measures and investment

The Iberian pork industry has proven to be very important in South-Western Europe, not only due its contribution to the economy of the area, but also because of the peculiarities of the farms situated there. These farms raise Iberian pigs in systems ranging from fully outdoor rearing systems to intensive-rearing farms similar to the conventional pig production models. The implementation of biosecurity measures in Iberian pig farms can be complex and, at times, it can be perceived somewhat negatively by farmers, especially those who run more extensive pig production systems. This research attempts to understand the attitudes of Iberian pig farmers in the South-West of Spain towards the adoption of and investment in biosecurity measures. For that purpose, data obtained from 104 online surveys taken by Iberian pig farmers in 2019 was analysed. A correspondence and a cluster analysis were performed, whereby three farm groups were identified according to their features (land area, breeding conditions, availability of facilities, etc.), the existence/use of biosecurity facilities and the adoption of biosecurity measures. The results have shown that most of the analysed farms have the necessary infrastructure to comply with the biosecurity principles and farmers perform basic biosecurity practices. However, farms that are more extensive, mainly those finishing their pigs outdoors (acorn-feed), need to improve their biosecurity. It is necessary therefore to implement an improvement plan following the current regulations in collaboration with policy makers with the purpose of improving the levels of biosecurity and increase disease risk awareness.

Exploring Sustainable Food Choices Factors and Purchasing Behavior in the Sustainable Development Goals Era in Spain

The aim of the present study was (1) to investigate what consumers include within the concept of food sustainability and its link with sustainable consumption, by identifying meaningful consumer typologies from the concept of food sustainability and food choice factors framed by SDG 12, and (2) to know how different farm systems attributes affecting purchase behavior are associated with such typologies. Consumers from two Spanish regions (n = 403) answered a paper questionnaire to know their degree of knowledge of sustainability, and beliefs, behavior, attitudes and preferences towards food sustainability, and the importance given to product characteristics and shopping practices. A principal component analysis was conducted to identify groups with similar answers, to average some of the questions before the final analysis of variance, which includes demographic classes as fixed effects. A cluster analysis using the most representative questions identified two clusters. cluster 1 (68.4%) responded to more sustainability-related attributes, and cluster 2 (31.5%) presented a less-expanded concept of sustainability. The origin of the product and quality certification (local, organic) was important for food purchase practices. The place of residence and gender differences of the consumers were the most influential factors. In the conjoint study, regarding the purchase of Iberian pork, cluster 1 remained unwilling to sacrifice outdoor systems and local breed at the expense of the price, in the case of the Iberian pig production. The most important demographic differentiator was the region of residence of the consumer. In conclusion, consumers are not aware of the wider aspects included in the sustainability concept. Moreover, the concept of sustainability elicits different meanings to the segments of the consumers identified.

Consumption of fresh Iberian pork: Two-stage cluster for the identification of segments of consumers according to their habits and lifestyles

This study investigates the behaviour of consumers regarding four cuts of Iberian meat with greater presence in the market: tenderloin, secreto, presa and pluma. A sample of 1501 consumers responded to an online survey about their consumption habits for these four cuts, sociodemographic characteristics and lifestyle. From this information, three homogeneous segments of consumers were identified: “unmotivated and indifferent to Iberian meat”, “innovators and stakeholders” and “traditional with frequent consumption”. The Iberian tenderloin and the secreto were the most consumed cuts in all consumption segments, while the main reason for the lower consumption of presa and pluma was “I don't like it”, especially among “unmotivated” consumers.

Understanding consumers' perceptions towards Iberian pig production and animal welfare

The Spanish market offers a greater variety of Iberian pork products. The aim of this paper is to determine the perception of consumers of several aspects of Iberian pig production and animal welfare depending on the consumers' characteristics. Consumers from two Spanish regions (n = 403) answered a questionnaire about their beliefs and the importance of pig production, their purchase intentions and their willingness to pay. Consumers were segmented according to their level of knowledge about Iberian pig production. The results of this work indicate that consumers have poor knowledge about Iberian pig production. Even so, consumers show a remarkable preference for Iberian products, especially when the animals are reared freely and in natural conditions, giving great importance to animal welfare. Consumer preferences indicate the importance of emphasizing Iberian traditional pig product characteristics on the label to promote their purchase choices.

Introduction to the Special Issue

Introduction to the Special Issue

Automatic identification of the area covered by acorn trees in the dehesa (pastureland) Extremadura of Spain

The acorn is the fruit of oak trees and is an important crop in the Spanish dehesa extremeña because of the value it provides to feeding Iberian pigs to obtain the “acorn-fed” certification. For this reason, it is desirable to maximise production of Iberian pigs with the appropriate weight. Knowing the area covered by the acorn treetops to determine the Tree-Covered Area (TCA), a value required to estimate the number of Iberian pigs that can be released per hectare, as regulated by the Royal Decree 4/2014, issued by Spain in January of 2014. In this work, we propose a method to automatically estimate the TCA through digital aerial images (orthophotos) of the pastureland of Extremadura and, with this, to facilitate determining the number of Iberian pigs that can be released in a specific parcel of land. Requirements for automatic detection include the correct identification of acorn trees, correctly discerning their shadows, and discerning arbuscles (young acorn trees that are still unproductive, or shrubs that are not oaks). These requirements represent challenges that apply to both automatic and manual segmentations. The automated segmentation in this study is based on the modified version of the Gustafson-Kessel clustering algorithm presented by Babuska. The results of this work are promising when compared with the actual images and when compared with the results of manual segmentation. The entire set of 38 aerial images used in this work correspond to an approximate area of 15.56 hectares, and the results are of great interest to producers of Iberian pork with the “acorn-fed” certification.

Authentication of Iberian pork official quality categories using a portable near infrared spectroscopy (NIRS) instrument

A portable near infrared spectroscopy (NIRS) instrument was evaluated for the discrimination of individual Iberian pig carcasses into the four official quality categories (defined by a combination of genotype and feeding regime). Spectra were obtained scanning four anatomical locations (live animal skin, carcass surface, fresh meat and subcutaneous fat samples) at a commercial abattoir, using a handheld micro electro mechanical system instrument. The best assignments into official quality categories with the NIRS measurements in the carcass surface and subcutaneous fat were able to correctly classify 75.9% and 73.8% of the carcasses, respectively. Moreover, 93.2% and 93.4% of carcasses were correctly classified according to feeding regimes by using the spectra from fresh meat and subcutaneous fat samples. The results suggest that, using subcutaneous fat samples, a portable NIRS could be used in commercial abattoirs as a tool to support the control of official quality category assignment in Iberian pig carcasses.

Inoculation with a terroir selected Debaryomyces hansenii strain changes physico-chemical characteristics of Iberian cured pork loin

Debaryomyces hansenii Lr1, previously isolated from naturally fermented cured pork loin (“lomo embuchado”), was used to inoculate Iberian pork loin under four different conditions. In all cases, specifically inoculated D. hansenii yeasts grew on the surface of the product and affected its physico-chemical and sensory characteristics. Inoculated pork loin kept higher water activity and pH and possessed lower sodium content than control samples at the end of the 90 days ripening period. Moreover, inoculation with Lr1 yeast did not change the general profile of fatty acids but modified the levels of volatile and aroma compounds by decreasing aldehydes and increasing esters and alcohol compounds. Principal Component Analysis (PCA) of the different physico-chemical parameters that were determined showed a clear separation between the samples indicating that they were different. A tendency in consumers acceptance to prefer cured pork loin specifically inoculated with the higher amounts of yeasts used in this study was observed.

Fourier transform near-infrared spectroscopy coupled to a long fibre optic head for the quality control of IBERIAN pork loins: Intact versus minced

Conventional chemical analyses of meat products are time-consuming, expensive and destructive. The advantages of NIR spectroscopy are its speed, portability, suitability for both at-line and on-line analysis, low cost and the possibility of simultaneously measuring many different parameters in a large number of samples. The purpose of this study was to develop and validate calibrations for the prediction of moisture, protein and fat in Iberian pig pork loins using an FT-NIR instrument coupled to a 5-m fibre optic sensor head.The best equations obtained for intact loin in both modes of analysis (full and optimal spectral range) displayed Standard Error of Cross-Validation (RMSECV) of 1.06% and 1.09% and Determination Coefficient of Cross-Validation (RCV2) of 0.69 and 0.77 for fat: RMSECV of 0.87% and 0.77% and RCV2 of 0.67 and 0.73 for moisture; while for protein, the RMSECV values were 0.51% and 0.49% and the RCV2 values were 0.66 and 0.70.

Determining Mandatory Nutritional Parameters for Iberian Meat Products Using a New Method Based on Near Infra-Red Reflectance Spectroscopy and Data Mining

The new regulation about mandatory labelling on nutrition requires the declaration of specific parameters: protein, lipid, salt and carbohydrate contents. This study reports a fast, accurate method to determine the values of these mandatory nutritional parameters based on near infra-red reflectance spectroscopy (NIRs) technology and data mining techniques, used in an automatic way. For that, two batches of different Iberian pork meat products (dry-cured ham, dry-cured loin, dry-cured shoulder, dry-fermented Salchichon sausage, and dry-fermented Chorizo sausage were used. One batch of each product was used to train the method and the remaining batch was used for validation. To develop the method, prediction equations were obtained from the NIRs, while nutritional data for the training batches were obtained by applying data mining techniques, and the prediction equations were evaluated against the NIRs data from the validation batch. The prediction equations achieved from very good to excellent degrees of relationship (R > 0.75) and accurate results (MAE 0.75). This new method is rapid, as it takes around 10 minutes in comparison with traditional methods that take around 6 days.

Short Communication: The potential of portable near infrared spectroscopy for assuring quality and authenticity in the food chain, using Iberian hams as an example

This communication assesses the use of a portable near infrared (NIR) instrument to measure quantitative (fatty acid profile) properties and qualitative (‘Premium’ and ‘Non-premium’) categories of individual Iberian pork carcasses at the slaughterhouse. Acorn-fed Iberian pigs have more unsaturated fats than pigs fed conventional compound feed. Recent advances in miniaturisation have led to a number of handheld NIR devices being developed, allowing processing decisions to be made earlier, significantly reducing time and costs. The most common methods used for assessing quality and authenticity of Iberian hams are analysis of the fatty acid composition of subcutaneous fat using gas chromatography and DNA analysis. In this study, NIR calibrations for fatty acids and classification as premium or non-premium ham, based on carcass fat measured in situ, were developed using a portable NIR spectrometer. The accuracy of the quantitative equations was evaluated through the standard error of cross validation or standard error of prediction of 0.84 for palmitic acid (C16:0), 0.94 for stearic acid (C18:0), 1.47 for oleic acid (C18:1) and 0.58 for linoleic acid (C18:2). Qualitative calibrations provided acceptable results, with up to 98% of samples (n = 234) correctly classified with probabilities ⩾0.9. Results indicated a portable NIR instrument has the potential to be used to measure quality and authenticity of Iberian pork carcasses.

Evaluation of the microbiological contamination of food processing environments through implementing surface sensors in an iberian pork processing plant: An approach towards the control of Listeria monocytogenes

Food safety is one of the biggest concerns of food industrial development due to the risk of foodborne diseases, which are one of the most relevant health problems in the contemporary world and an important cause of reduced economic productivity. One of the main sources of microbial contamination in food products are industrial surfaces, which are colonized by pathogenic microorganisms capable of forming biofilms, making surfaces into reservoirs and potential sources of cross-contamination to food products. A study was conducted to determine the microbiological contamination from different microbial groups on different industrial surfaces in a meat processing plant through implementing a sensor-based sampling system, with a focus on detecting L. monocytogenes. The results obtained showed two main groups of areas with greater and lesser degrees of microbiological contamination, determined as the total aerobic counts of the microbial group with the highest contribution. The areas considered as major contributors to microbial contamination were three of the sampled floors and the storage cabinet for tools, demonstrating to be important sources of possible cross-contamination. A total of four L. monocytogenes presences were obtained during sampling. Moreover, a direct relation was observed between aerobic counts and detecting L. monocytogenes, and three possible hypotheses were formulated to explain the connection. Last, a safety zone marking the limits beyond which the surface can be considered as a safety risk was established, although more studies are needed to demonstrate if these limits can be used as an internal hygienic surface control. The use of SCH sensors as a surface sampling system for the food industry have been shown to work effectively and with relative ease.

The Iberian Pork Meat Industry in Jabugo (Huelva, Spain), 1997-2016.

The municipality of Jabugo is one of the most important in the transformation of the Iberian pork. In the last decades, the industry has undergone a transformation, with processes of concentration, relocation and positioning among the companies in the industry. As a result, large companies have been strengthened, and the Protected Designation of Origin “Jabugo emerges as an opportunity for the sector.

Effect of the Olive Leaf Extracts In Vitro and in Active Packaging of Sliced Iberian Pork Loin

The objective of this study was to investigate the antioxidative and antimicrobial in vitro effects of the olive leaf extract (OLE), and to test its effectiveness for meat preservation in an active packaging with OLE. With this purpose, microbial counts, physico‐chemical properties, lipid stability and sensory properties of packaged loin steaks from Iberian pigs were analyzed during refrigerated storage. In vitro assays confirmed the antioxidant and antibacterial activity of fresh OLE and freeze‐dried OLE (FDE). However, the effectiveness of the extract found in vitro was not confirmed in the in vivo assays. The application of the extracts into the packaging did not show antioxidant and antimicrobial effects on meat even applying high dose of the lyophilized extract. Copyright © 2016 John Wiley & Sons, Ltd.