Volatile compounds of dry hams from Iberian pigs

Effect of Muscle Fibre Type on the Fatty Acids Profile and Lipid Oxidation of Dry-Cured Venison SM (semimembranosus) Muscle

The aim of the study was to describe the effect of fibre type on the fatty acid profile and lipid oxidation observed in dry-cured ham produced from individual semimembranosus venison (roe-deer, fallow deer, deer and wild boar) muscles. The results indicated that wild boar meat was characterised by the highest percentage of IA fibres and it contained the higher percentage of MUFA, but a low of PUFA and SFA, and was characterised by a(n-6)/(n-3) ratio lower than in the case of deer meat and greater susceptibility to oxidative changes. The highest percentage of SFA, and the lowest of MUFA and PUFA, was recorded in fallow deer meat, which was also characterised by the highest percentage of white fibres. The curing and drying processes increased the percentage share of SFA and the susceptibility of muscle lipids to oxidation, decreased the percentage of PUFA, and caused insignificant changes in the (n-6)/(n-3) ratio of fatty acids. The products were also characterised by a low amount of fat.

Describing backfat and Semimembranosus muscle fatty acid variability in heavy pigs: Analysis of non-genetic factors

This study aimed to describe the multivariate structure of Semimembranosus muscle and backfat fatty acid (FA) composition in 798 Italian Large White heavy pigs and to investigate the effects of environmental factors and carcass characteristics on FA variations. The total FA variability in muscle and backfat was characterized by a negative correlation between saturated and polyunsaturated FAs, which strongly depended on the carcass adiposity. Slaughtering season was also relevant, with pigs slaughtered in autumn having more n-6 FAs and eicosadienoic acid in backfat, while pigs slaughtered in winter displayed more saturated FAs. Regarding Semimembranosus muscle, pigs with heavier belly cuts and slaughtered in autumn had higher proportions of cis-vaccenic and palmitoleic acids, while those slaughtered in summer had more saturated FAs. Slaughtering season emerged as a relevant factor shaping both backfat and muscle FA composition, indicating that more studies and attention should be paid to environmental factors, which may have effects on FA metabolism and deposition in finishing pigs.

Contents and composition of individual phospholipid classes from biceps femoris related to the rearing system in Iberian pig

During dry-cured ham processing, phospholipids (PL) are the main substrates of lipolysis and oxidation. However, the published data on individual PL classes in the pig muscle are inconsistent. This study determined the PL class contents and composition in biceps femoris of Iberian pigs according to the rearing system (Montanera vs Pienso). Phosphatidylcholine (PC), phosphatidylethanolamine (PE), cardiolipin (CL) and sphingomyelin contents were higher in the Montanera pigs than in the Pienso pigs. Total PL and PC, PE, phosphatidylinositol + phosphatidylserine and CL contained higher levels of oleic acid and slightly higher levels of n-3 polyunsaturated fatty acids (PUFA) but lower levels of n-6 PUFA in the Montanera pigs than in the Pienso pigs. The rearing system had no effect on the plasmalogen content but influenced aldehyde composition, mainly in PE and in total PL. These results can partially explain the differences in sensory properties of dry-cured ham between the Montanera and Pienso systems.

Determination of volatile marker compounds in raw ham using headspace-trap gas chromatography

A simple, reliable and automated method was developed and optimized for qualification and quantification of aroma-relevant volatile marker compounds of North European raw ham using a headspace (HS)-Trap gas chromatography-mass spectrometry (GC-MS) and GC-flame ionization detector (FID) analysis. A total of 38 volatile compounds were detected with this HS-Trap GC-MS method amongst which the largest groups were ketones (12), alcohols (8), hydrocarbons (7), aldehydes (6) and esters (3). The HS-Trap GC-FID method was optimized for the parameters: thermostatting time and temperature, vial and desorption pressure, number of extraction cycles and salt addition. A validation for 13 volatile marker compounds with limits of detection in ng/g was carried out. The optimized method can serve as alternative to conventional headspace and solid phase micro extraction methods and allows users to determine volatile compounds in raw hams making it of interest to industrial and academic meat scientists.

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<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.

Improvement of Dry-cured Iberian Ham Quality Characteristics Through Modifications of Dietary Fat Composition and Supplementation with Vitamin E

The effects of dietary fat composition and vitamin E supplementation on the quality characteristics of dry-cured Iberian hams ripened for two years were studied. Thirty Iberian Duroc pigs were fed diets containing three levels of poly and monounsaturated fatty acids. Within each dietary fat treatment, one group was fed a basal level of vitamin E (20mg α-tocopheryl acetate/kg diet) and the other group received a supplemented level (200mg α-tocopheryl acetate/kg diet). Dietary fat composition significantly affected total saturated fatty acids content of neutral and polar lipids from dry-cured Iberian ham ( p 0.012 and p 0.003, respectively). However, diet fatty acids composition did not influence either total monounsaturated or total polyunsaturated fatty acids of neutral and polar lipids. Vitamin E supplementation significantly enhanced dry-cured Iberian ham α-tocopherol content ( p 0.001). This, in turn, led to significantly lower levels of TBARS on days 6 and 9 of storage in slices from dry-cured Iberian hams made of vitamin E supplemented pigs and also lower oxidation levels in an induced lipid oxidation test in samples from those pigs. Dietary fatty acid composition did not significantly affect either TBARS during slices storage or malonaldehyde content in the induced oxidation test. No effect of vitamin E supplementation was observed in ham volatile aldehyde profile, but dietary fat significantly affected hexanal ( p 0.02), heptanal ( p 0.05) and total aldehyde content ( p 0.02), with those pigs fed a diet rich in PUFA showing higher values. Using diets supplemented in α-tocopherol and rich in monounsaturated fatty acids seemed adequate dietary strategies for feeding Iberian hams reared indoors.

Efecto de la dieta de cerdos ibéricos sobre la composición en ácidos grasos del tejido adiposo y muscular / Effect of diet on the fatty acid composition of adipose and muscular tissue in Iberian pigs

The fatty acid composition of total, apolar and polar lipid fractions from adipose and muscular tissues of Iberian pigs was determined. Animals were fed on diets of pasture and acorns ( montanera), acorns and cereals ( recebo) or cereals ( cebo ). The principal fatty acids in the total and apolar lipid fractions from muscular tissue were C18.1 (39-51%), C16.0 (21-27%), C18.0 (11-21%), C18.2 (3-7%) and C18.3 (1.7-5.4%). Significant differences were observed only in some cases. In the total lipid fraction from the muscular tissue significant differences ( p ≤ 0.05) were found between all three batches for the C161 fatty acid and between the cebo batch and the others for both C181 and C18:0. In total lipids from the adipose tissue, significant differences were found for both C161 and C18:3 between all three batches, and for C16:1 and C18:1 differences were observed only between the montanera batch and the others. The differences between batches in the apolar and polar frac tions were smaller than those for total lipids. A 100% partition among the three different diets studied was not obtained when a stepwise discriminant analysis was applied.

Unsaponifiable fraction and n-alkane profile of subcutaneous fat from Iberian ham / Fracción insaponificable y perfil de los n-alcanos de la grasa subcutánea del jamón Ibérico

The unsaponifiable fraction of subcutaneous fat of dry-cured Iberian hams from pigs fed on different systems during the finishing-fattening period and its feasibility as a method for classifying the hams according to the pigs' feeding background are studied. Unsaponifiable fraction and n-alkane content of subcutaneous fat from ten dry cured hams from Iberian x Duroc pigs raised on two different man agement systems ( Montanera, fed extensively on acorns and pasture, and Pienso, fed on a concentrate diet) are analyzed. The proportion of unsaponifiable material and n-alkanes [pentadecane (n-C15), heptadecane (n-C17), octadecane (n-C18), nonadecane (n-C19), eicosane (n-C20) and pentacosane (n-C25)] were higher ( P < 0.05) in hams from pigs raised under extensive conditions than in those from pigs receiving concentrate feeds. The unsaponifiable fraction assay of the fat from dry-cured Iberian hams is a promising technique for classifying hams based on the pigs' feeding background.

Effect of α—tocopheryl acetate supplementation and the extensive feeding of pigs on the volatile aldehydes during the maturation of Iberian ham / Efecto del suplemento con acetato de α—tocoferol y de la alimentación en extensive del cerdo en los aldehídos volátiles durante la maduración del jamón Ibérico

The effect of feeding regime—free—range reared on acorn and pasture, or in confinement with and without the incorporation of 100 mg/kg α-tocopheryl acetate to pig mixed feeds—on volatile alde hyde content in Biceps femoris muscle throughout the ripening of Iberian ham was studied. Saturated aldehydes from 4 to 10 carbon chain and two diunsaturated aldehydes, 2,4-nonadienal and 2,4- decadienal, were found in ham samples. Volatile aldehyde evolution was not affected by feeding regime throughout ripening of hams. Volatile aldehyde content and individual aldehydes rose mark edly from Day 0 to Day 210 ( p < 0.05), and afterwards decreased to Day 700 ( p < 0.05). Both α- tocopheryl acetate supplementation and feeding on acorn and pasture significantly decreased the total and individual aldehydes in Biceps femoris samples at Days 0, 210 and 700 ( p < 0.05) in compari son with muscle samples from pigs fed the non-supplemented diet.

Determination of volatile compounds and quality parameters of traditional Istrian dry-cured ham

The aim of this work was to determine the characteristics of Istrian dry-cured ham by instrumental methods and sensory analysis. The aroma-active compounds of Istrian dry-cured ham from 2010 and 2012 were investigated by using headspace-solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Samples of biceps femoris were also evaluated by measuring physical and chemical characteristics. 92 volatile aroma compounds of Istrian dry-cured ham were found. Volatile compounds belonged to several chemical groups: aldehydes (51.4; 51.3%), terpenes (16.5; 16.4%), alcohols (15.5; 13.2%), ketones (8.6; 7.4%), alkanes (3.8; 5.7%), esters (1.3; 1.6%), aromatic hydrocarbons (0.8; 3.9%) and acids (0.6; 0.9%). Principal component analysis (PCA) showed that fat content, tenderness and melting texture were positively correlated. Terpenes were strongly correlated with flavour of added spices. Sweet taste and the presence of esters were positively correlated as well as negative odour, raw meat flavour and water content.

Study of the volatile compounds and odor-active compounds of dry-cured Iberian ham extracted by SPME

The volatile compounds and the most odor-active compounds of dry-cured Iberian ham were investigated by extracting them using a solid phase microextraction technique with a 2 cm Carboxen/PDMS/DVB fiber. The detection frequency method was applied to estimate the potential contribution of each compound to the odor of hams. Twenty-one volatile compounds were tentatively identified for the first time in dry-cured ham by gas chromatography-mass spectrometry, and eight in dry-cured Iberian ham. Gas chromatography-olfactometry allowed the identification for the first time of six compounds not previously reported as odorants of Iberian ham, and also two odorants were newly identified in dry-cured ham. According to the detection frequency method, the most odor active compounds found were 3-methylbutanoic acid (dirty sock-like smelling), hexanal (cut grass-like odor), 3-methylbutanal (sweaty and bitter almond-like odor), 2-methyl-3-furanthiol (toasted nuts-like odor) and 1-octen-3-one (mushroom-like odor).

Volatile and amino acid profiling of dry cured hams from different swine breeds and processing methods

The flavor of dry cured ham explains the high appreciation of this product and it determines consumer acceptance. Volatile compounds provide valuable information about the odor and sensory quality of dry cured hams. Since amino acids are the origin of some volatile compounds of dry cured ham, the volatile and amino acid compositions of forty-one dry cured hams from Spain and France were determined to establish associations between them. The samples included different pig breeds (non Iberian vs. Iberian), which were additionally affected by different maturation times and feeding types (acorn vs. fodder). Results showed that 20 volatile compounds were able to distinguish Iberian and non Iberian hams, and 16 of those had relevant sensory impact according to their odor activity values. 3-Methylbutanol, 2-heptanol and hexanal were among the most concentrated volatile compounds. In the case of non-volatile compounds, the concentrations of amino acids were generally higher in Iberian hams, and all the amino acids were able to distinguish Iberian from non Iberian hams with the exception of tryptophan and asparagine. A strong correlation of some amino acids with volatile compounds was found in the particular case of alcohols and aldehydes when only Iberian hams were considered. The high correlation values found in some cases proved that proteolysis plays an important role in aroma generation.

Use of isotope analysis to characterize meat fromIberian-breed swine

We describe a method based on isotope analysis (δ(13)C) for characterization and differentiation of Iberian pork meat as a function of the diet of the animal. Using adipose tissue, it is possible to classify unknown samples in group of animals designated "acorn-fed", "recebo=mixed-fed" and "feed raised" according the δ(13)C value obtained, from the calibration straight line of y=-22.12-0.35x, with a correlation coefficient r=0.982 and s=0.1‰; where y=δ(13)C and x=arrobas of acorn and range forage received by the animals during the fattening period. Stress should be placed on the economic and industrial importance of Iberian-breed swine because the market prices of Iberian swine products depends on the classification of the animals according to the type of feeding regimen which they are subjected to.

Volatile compounds in Iberian dry-cured loin

The volatile profile of Iberian dry-cured loin from four different Iberian pig lines (Entrepelado, Lampiño, Retinto and Torbiscal) and two feeding systems (OUT - fed on acorn and grass-vs.-IND - fed on high oleic acid concentrate) was studied using solid phase microextraction (SPME). 133 volatile compounds were identified and assigned to 16 chemical families. Alcohols were the major group, ethanol being the main compound. The high number of esters detected and the levels of ethanol and acetic acid found, points to an important role of microorganism activity in the formation of volatile compounds in Iberian dry-cured loin. Sulphur compounds, coming mostly from garlic, constituted an important group, with 14 compounds. Significant differences were found among loins from pigs reared in different feeding systems but not among Iberian pig lines. Dry-cured loins from OUT pigs showed higher levels of many compounds derived from lipid oxidation, such as octanoic acid (P=0.000), decanoic acid (P=0.018) or hexanal (P=0.014).

Effect of long-term betaine supplementation on chemical and physical characteristics of three muscles from the Alentejano pig

BACKGROUND

The use of betaine as a dietary supplement to reduce fat deposition and increase lean muscle mass in pigs is increasing. However, there is no available information on its effect on the physical and chemical (i.e. fatty acid (FA) profile) characteristics of pork.

RESULTS

The effects of long-term betaine intake (1 g betaine kg(-1) diet for 20 weeks) on the chemical and physical characteristics of Musculus longissimus dorsi, M. biceps femoris and M. semimembranosus from the Alentejano pig were investigated. The contents of total protein, intramuscular lipids (neutral and polar), myoglobin and total collagen as well as the water-holding capacity, physical colour characteristics and FA profile of the three muscles were determined. With the exception of a significant increase in the intramuscular lipid content of M. longissimus dorsi and M. biceps femoris, betaine supplementation did not influence muscle chemical and colour characteristics or body fat deposition.

CONCLUSION

These data suggest that long-term betaine supplementation selectively increases intramuscular lipid deposition (a trait related to meat quality) while not affecting other chemical (including the atheroprotective FA profile) and physical characteristics of the Alentejano pig muscles studied.

Factors in pig production that impact the quality of dry-cured ham: a review

This study reviews the factors of pig production that impact the quality of dry-cured ham. When processing is standardized, the quality of the final dry-cured product is primarily determined by the quality of the meat before curing (green ham). This has been defined as the aptitude for seasoning and is determined by the green ham weight, adipose tissue quantity and quality, meat physico-chemical properties and the absence of visual defects. Various ante-mortem factors including pig age and weight, genetic type, diet, feeding strategy and slaughter conditions determine green ham properties such as the dynamics of water loss, salt intake and, as a consequence, proteolysis and lipolysis. Muscle conditions (pH, salt concentration, water content and availability, temperature) influence enzymatic activity and development of characteristic texture and flavor. Generally, hams of older and heavier pigs present better seasoning aptitude because of higher adiposity. Adiposity is also positively correlated with fat saturation, which is desired to avoid rancidity and oiliness. The fatty acid profile of tissue lipids can be manipulated by diet composition. Feeding strategy affects tissue accretion and protein turnover, thus directly impacting proteolysis. With respect to the impact of pig genotype on dry-cured ham quality, local breeds are generally considered more suitable for producing quality dry hams; however, the majority of dry-cured hams on the market today are from modern pig breeds raised in conventional systems, providing lean hams. The importance of all these factors of pig production is discussed and synthesized, with an emphasis on the main difficulties encountered in dry-cured ham production.

Development of volatile compounds during the manufacture of dry-cured "lacón," a Spanish traditional meat product

Volatile compounds were determined throughout the manufacture of dry-cured "lacón," a traditional dry-salted, and ripened meat product made in the north-west of Spain from the foreleg of the pig following a similar process to that of dry-cured ham. Volatiles were extracted by a purge-and-trap method and analyzed by gas chromatographic/mass spectrometry. One hundred and two volatile compounds were identified. In raw material, only 34 volatile compounds were found and at very low levels. The number of volatile compounds increased during processing. The substances identified belonged to several chemical classes: aldehydes (23), alcohols (9), ketones (15), hydrocarbons (37), esters (4), acids (3), furans (4), sulphur compounds (1), chloride compounds (1), and other compounds (4). Results indicated that the most abundant chemical family in flavor at the end of the manufacturing process was aldehydes, followed by hydrocarbons and ketones. Lipids were the most important precursor of flavor compounds of dry-cured "lacón."

The evolution of volatile compounds profile of "Toscano" dry-cured ham during ripening as revealed by SPME-GC-MS approach

The volatile compounds profile is an important feature for the characterization of dry-cured hams. Some minor typical Italian products, such as 'Toscano' ham, have been poorly studied in regards to their composition of volatile compounds. In this article, we studied the evolution of the aromatic profile of 'Toscano' dry-cured ham by solid-phase microextraction-gas chromatographic-mass spectrometry (SPME-GC-MS) with ripening. Ten right thighs were cured according to the 'Toscano' PDO protocol, sampled at 0, 1, 3, 6 and 12 months and submitted to volatile compounds analysis by SPME with a Divinylbenzene (DVB)/Carboxen/Polydimethylsiloxane (PDMS) 75-µ Stable Flex fibre. An Agilent 5975C mass selective detector (MSD) spectrometer with electron ionization (EI) source operating in scan mode within the m/z 29-350 range was used for data collection. Seven internal standards, either deuterium labeled or absent in the specimens and chosen to represent low or high boiling esters, alcohols, acids or phenols, were added to the homogenized samples and used to normalize the SPME fibre response to account for response changes upon wearing. Linear calibrations were obtained in this way for selected representative compounds. Over 60 compounds belonging to esters, aldehydes, organic acids, ketones and alcohols were identified by comparison with spectral libraries and Kovats indices. Aldehydes were the most represented chemical family, followed by organic acids, alcohols, ketones and esters. The aldehydes and ketones increased during the first 3 months, when the larger formation of volatiles occurred. For other families, the evolution over time was less evident. The principal component and discriminant analyses of the aromatic profile were effective in classifying the hams at 0, 6 or 12 months of ripening while for 1 and 3 months' samples a partial overlapping was shown. These results represent the first characterization of 'Toscano' ham and may constitute the basis to identify the best ripening time and define an analytical quality standard for this typical ham.

Volatile profile and microbiological characterization of hollow defect in dry-cured ham

This paper describes the physicochemical and microbiological parameters and volatile profile of the muscles surrounding the coxofemoral joint which are affected with hollow defect when compared to the part of muscles nearby which did not show this defect. Differences of the same parameters between both areas in dry-cured hams without this defect were also analyzed. Gram-positive catalase-positive cocci were the predominant flora in the muscles affected with hollow defect, with the main species being Staphyloccocus equorum, Staphylococcus nepalensis and Staphylococcus xylosus. Lactic acid bacteria, Listeria monocytogenes and Staphylococcus aureus were <2 log CFU g(-1) and Salmonella spp. was not detected. Volatile profile of samples affected with hollow defect had higher amounts of compounds such as esters, pyrazines, sulfurs and furans. There was a positive correlation between the amount of ester compounds and the hollow defect intensity. Moisture content was lower and pH values were higher in affected areas than in unaffected areas.

Influence of pre-cure freezing on the profile of volatile compounds during the processing of Iberian hams

BACKGROUND

This work was designed to study the effect of pre-cure freezing of raw thighs from Iberian pigs on the profile of volatile compounds during the processing of hams.

RESULTS

Generation of volatile compounds during Iberian ham processing was similar in both pre-cure frozen and refrigerated hams, the main differences being at the final stage. The levels of 2-methylbutanal, 2-methyl-1-butanol, 2,3-butanediol and 2-heptanol were significantly higher in dry-cured hams that were pre-cure frozen than in refrigerated ones, whereas the content of most detected esters was statistically lower in pre-cure frozen than in refrigerated hams.

CONCLUSION

The effect of pre-cure freezing of Iberian ham on the profile of volatile compounds during ripening was not remarkable. Few differences were found in the final product, which would not greatly modify the aroma and flavour features of the dry-cured hams.

Vacuum-packed ripened sausages: evolution of oxidative and hydrolytic degradation of lipid fraction during long-term storage and influence on the sensory properties

An experimental investigation was carried out with the aim to understand the oxidative and hydrolytic phenomena involving the lipid fraction of vacuum-packed sausages during long-term storage (5 months) and to verify their influence on the sensory characteristics. The data obtained pointed out that the oxidation was more pronounced in the initial stages of storage than in the further period, while the hydrolysis of lipid fraction significantly advanced during the whole storage time, supported by the high moisture level of the product. Both these phenomena resulted to be correlated with the sensory decay of the product. In particular, in the first stage of vacuum storage overall acceptability was found to be negatively correlated (p<0.05) with rancid taste, acid value, and oxidized triacylglycerols. In the further stage the oxidative processes slowed down and affected in a lesser extent the sensory properties, which were more distinctly characterized by the onset of pungent perception attributed to compounds arising from multiple origins such as carbohydrate fermentation. This investigation confirmed the unreliability of thiobarbituric acid reactive substances test and the usefulness of high performance size exclusion chromatography analysis of the polar compounds of the lipid fraction to correctly determine the levels of the oxidative and hydrolytic degradation of the lipid fraction of vacuum-packed ripened sausages during long-term storage.

Changes in the fatty acid and triacylglycerol profiles in the subcutaneous fat of Iberian ham during the dry-curing process

In this study, we have evaluated the changes that occur in the profiles of total fatty acids and triacylglycerols during the dry-curing process (730 days) of Iberian ham. The subcutaneous adipose tissues of six hams obtained from three Iberian pigs fed on acorns were analyzed periodically during the processing time (from the raw to the dry-cured samples), including postsalting, drying, and ripening stages. The environmental conditions were also registered. The curing process significantly decreased (p < 0.01) the relative percentages of total polyunsaturated fatty acids, including C18:2n-6 and C18:3n-3 and, therefore, significantly increased (p < 0.05) the level of monounsaturated fatty acids. The triglycerides containing 0-2 double bonds showed an increase during the curing process. On the contrary, the more unsaturated ones (3-5 double bonds) suffered a significant decrease. We have postulated that these changes could also be due to polymerization and oxidation reactions that affect the triacylglycerols and besides the fatty acids. In general, most fatty acids and triacylglycerols reversed the trend by about 500-600 days of processing.

Changes in the concentrations of free fatty acid, monoacylglycerol, and diacylglycerol in the subcutaneous fat of Iberian ham during the dry-curing process

Changes in diacylglycerols, monoacylglycerols, and free fatty acid composition of subcutaneous fat of six Iberian hams during the dry-cured process were investigated. In addition, an analytical method for simultaneous quantification of diacylglycerols, monoacylglycerols, and free fatty acid by solid-phase extraction-gas chromatography was developed. The different molecular species of free fatty acids, monoacylglycerols, and diacylglycerols and 1,2- and 1,3-isomers of diacylglycerols have been described for the first time in this type of sample. A logarithmic increase of the 1,3-diacylglycerol profile throughout the processing time has been found, reaching a balance value of 62% around 500 days. The formation of diacylglycerol isomers takes place, although the 1,3-/1,2-diacylglycerol ratio increases during the process to 1.65 due to isomerization of the 1,2-form toward the 1,3-form. The profiles of monoacyl- and diacylglycerols and free fatty acids follow the same trend. The experimental values of free fatty acid are greater than theoretical prediction, probably due to phospholipid and monoacylglycerol hydrolysis.

Impact of feeding and rearing systems of Iberian pigs on volatile profile and sensory characteristics of dry-cured loin

The effect of growing pigs on free-range (FR) or in confinement with three different diets [acorn (A), acorn and grass (A-G) and formulated diet (FD)] on composition, volatile profile and sensory characteristics of dry-cured loin was studied. The FR, A and A-G diets, in comparison with FD, induce a higher α- and γ-tocopherol concentration, which limits the TBARs values at 24h of air exposure. Sixty volatile compounds were identified in the headspace, including 14 aldehydes, 10 hydrocarbons, eight alcohols, five ketones, four furans, four pyrazines, four sulphur compounds, three acids, three esters, three phenols, one pyridine and one pyrrole. Volatiles from amino acid catabolism stressed the difference among batches FR being the batch with the highest level of these compounds. Products from FD showed the lowest fat content and L(∗) value. FR loins obtained the highest scores for appearance, odour and flavour in the rank order test sensory analysis.

Effect of different Duroc line sires on carcass composition, meat quality and dry-cured ham acceptability

Carcasses of 399 malignant hyperthermia gene free pigs from crosses sired by three types of Duroc (Virgen de la Fuente, DU1; Diputación de Teruel, DU2; DanBred, DU3) were analyzed for carcass and meat quality. Carcass leanness and fat parameters were measured at the last rib and at the space between the 3rd and 4th last ribs counting from the last one. Weights, pH, electrical conductivity, colour and intramuscular fat were also measured. A sample of 133 legs per cross were processed by dry-curing. The ham portion including Biceps femoris, Semimembranosus and Semitendinosus muscles was evaluated for instrumental texture and colour, biochemical and sensory analyses and acceptability (trained panel and consumers). DU3 carcasses were well conformed but lean. DU1 carcasses had a lower conformation but higher marbling. DU2 carcasses were intermediate. Dry-cured hams from DU1-sired pigs had a higher overall acceptability, although fat content influenced a consumers group negatively. Leaner DU3 hams had the lowest acceptability.