Effect of Intramuscular Fat,Breed, and Age at Slaughter on Fatty Acid Composition in Green Hams

The evolution of fatty acid classes (ΣSFA, ΣMUFA, and ΣPUFA) in neutral lipids (NL) and phospholipids (PL) in pigs were studied. The M. biceps femoris in green hams from Norwegian breeds Landrace (LR), Duroc (DU), and Hampshire (HS) slaughtered at 6, 7.5, and 9 mo of age were examined. The parameters were analyzed for age and breed effects with and without adjustment for NL or PL content. The fatty acid class contents of NL were not significantly different between the age groups. However, when NL content was adjusted, deposition of ΣSFA and ΣMUFA in NL significantly increased and deposition of ΣPUFA in NL significantly decreased with age. Duroc had consistently higher fatty acid class contents, but after adjusting for NL content, only the deposition of ΣSFA proved to be genetically different. The nonlinear relationship between NL content and ΣMUFA and ΣPUFA, together with the genetic potential of HS to deposit less ΣSFA than LR, gave significantly different fatty acid class compositions between the breeds. The content and proportion of ΣMUFA in PL increased with age. Specific ratios were also determined. The fat firmness index, C18:0/C18:2n ? 6 in NL, increased with age and was lowest in HS due to genetics and highest in DU due to its high NL content. The sensory rancidity index C18:1n ? 9/Σn ? 6 increased in NL and decreased in PL between 7.5 and 9 mo. The C18:1n ? 9/Σn ? 6 in NL was highest in DU due to higher NL content. The Σn ? 6/Σn ? 3 in NL and PL increased between 7.5 and 9 mo.     

Fatty Acid Content,Flavor Compounds,and Sensory Quality of Pork Loin as Affected by Dietary Supplementation with l‐arginine and Glutamic Acid

To investigate the effect of functional amino acid on meat flavor and eating quality, 60 growing‐finishing pigs (Duroc × Large White × Landrace) were dietarily supplemented with or without 1.0% l ‐arginine, glutamic acid, or l ‐arginine plus glutamic acid for 2 months. After animals were slaughtered, the muscle fatty acid profile, flavor compounds, and meat sensory quality were comparatively investigated. The results showed that dietary supplementation with arginine, glutamic acid, or arginine plus glutamic acid had little effect on free amino acids, no effect on 5′‐nucleotides and meat sensory taste traits, but supplementation with arginine plus glutamic acid significantly increased (P < 0.05) fat accumulation and fatty acid content in muscle, increased (P < 0.05) the formation of multiple fatty acid oxidation‐derived volatile compounds, and improved the tenderness, juiciness, and overall eating quality of meat. This study revealed that dietary supplementation with 1.0% l ‐arginine and glutamic acid could be used to improve meat eating quality in pork production.     

Lipid degradation and sensory characteristics of M. biceps femoris in dry‐cured hams from Duroc using three different processing methods

Hams from Norwegian Duroc pigs, reared and fed identically, were dry‐cured using three different processing methods: Spanish Serrano (SS), Norwegian Parma‐style (PS) and deboning before curing (ND). The fatty acid compositions of the green and dry‐cured hams were analysed in terms of their neutral lipid, phospholipid and free fatty acid contents and correlated with sensory attributes. Although the three dry‐curing processes were quite different, the hams′ lipid profiles, lipid degradation patterns and lipid‐associated sensorial characteristics differed only slightly. The phospholipids were the most extensively degraded lipid class (88, 89% and 84% degradation in PS, SS and ND hams, respectively) for all processing methods. The SS and PS hams had slightly riper sensory profiles due to their extensive conversion of fatty acids into aroma components. The free fatty acid contents of PS, SS and ND hams were 6.3, 6.2 and 7.5 times greater than those of green hams, respectively.     

Effect of Iberian × Duroc genotype on composition and sensory properties of dry‐cured ham

BACKGROUND: Dry‐cured ham quality from three different Iberian × Duroc genotypes was studied: GEN1, Iberian × Duroc1; GEN2, Duroc1 × Iberian; GEN3, Duroc2 × Iberian. GEN1 and GEN2 are reciprocal crosses, while the difference between GEN2 and GEN3 is the Duroc sire line. The line Duroc1 (DU1) was selected for the manufacture of dry‐cured meat products, whereas the line Duroc2 (DU2) was selected for meat production with low carcass fat. RESULTS: Dry‐cured hams from all genotypes had similar chemical composition. However, intramuscular fat of dry‐cured hams from GEN3 was more unsaturated than that from GEN2, while GEN1 was intermediate. Lipid oxidation, measured as 2‐thiobarbituric acid‐reactive substances (TBARS) and hexanal content, was similar between genotypes. The colour of hams was affected by genotype; hams from GEN2 showed higher lightness (CIE L*), while those from GEN3 had a less intense colour (lower a* and C*). Texture measured instrumentally did not differ between genotypes; however, in the sensory analysis, panellists considered hams from GEN3 more fibrous, while those from GEN2 were considered juicier. Hams from GEN3 were also perceived as saltier and more acid. CONCLUSION: Genotype affected the quality of Iberian hams, with those from GEN3 being of lower quality, and this genotype was considered less suitable for the manufacture of Iberian dry‐cured ham. Copyright © 2007 Society of Chemical Industry     

Proteolysis,Texture, and Sensory Characteristics of Serrano Hams from Duroc and Large White Pigs during Dry‐Curing

Proteolysis, texture, physicochemical, and sensory characteristics of Serrano hams from Duroc and Large White pigs at 5, 7, 9, 12, and 15 m of curing (3 hams per breed per curing time) were investigated. Higher concentrations of some sarcoplasmic and myofibrillar proteins, peptides with molecular mass in the ranges 3700 to 12000 Da, 700 to 2000 Da, and below 450 Da, and total free amino acids were recorded for Large White hams, while hydrophobic peptides were at higher levels in Duroc hams. A 40 kDa peak in the low‐ionic‐strength soluble protein fraction and 2 peaks of 40 and 45 kDa in the high‐ionic‐strength soluble protein fraction found only in Duroc hams could be of use in discriminating products from different breeds. Physicochemical and textural characteristics of both types of hams evolved similarly during curing and differences in organoleptic traits between breeds were negligible. Flavor intensity and flavor quality of hams were strongly correlated to curing time, with r² values over 0.95 for flavor intensity and over 0.90 for flavor quality, and to the concentration of total free amino acids, with r² values over 0.90 for both flavor intensity and flavor quality. The sensory evaluation scores of Duroc hams, at least as high as those of Large White hams, make the production of high‐quality Serrano ham from pure breed Duroc pigs feasible. Practical Application: Duroc breed crosses are advantageous in the production of dry‐cured hams, resulting in higher marbling, enhanced flavor and lower processing losses, but the characteristics of pure breed Duroc hams have not been investigated. The similar evolution of the compositional, proteolytic, textural, and sensory characteristics of Serrano hams from Duroc and Large White pigs during dry‐curing recorded in the present work makes the production of high‐quality dry‐cured hams from pure breed Duroc pigs feasible. Three protein peaks found only in Duroc hams can be of use to discriminate products from different breeds.     

Fatty acids and triacylglycerols profiles from different types of Iberian dry-cured hams

Thirty hams were allotted into four groups according to fattening diet ("Montanera" - acorns and pasture; and "Pienso" - concentrated diet) and genotype of pigs (Iberian and Iberian×Duroc pigs). Total lipids, triacylglycerol composition and fatty acids from neutral lipids fraction were measured in biceps femoris muscle. Fattening diet largely affected lipid composition of hams. Total intramuscular lipids and triacylglycerols content were higher in Montanera hams than in Pienso hams. In Montanera hams, triacylglycerols contained more oleic acid (C18:1) and less stearic (C18:0) and palmitic (C16:0) acids (p<0.001) and accordingly less PSO, PPL, PPO, PPS, SSO (p<0.001) and more OLL, OOL, OOO triacylglycerols compared to Pienso hams (p<0.001). Genotype of pigs has an important effect in triacylglycerols composition but only a limited effect on their fatty acids composition. So, Iberian hams contained more of PLLn, PLL, POLn and POL+SLL compared to Iberian×Duroc hams (p<0.001) and POO and SOO were present in a higher quantity in Iberian×Duroc hams (p<0.01).     

Preference and juiciness of Iberian dry-cured loin as affected by intramuscular fat content, crossbreeding and rearing system

Preference ranking tests for juiciness and overall liking of dry cured loins from Iberian pigs with different genetic backgrounds (pure Iberian or crossbred Iberian×Duroc pigs), reared under different productive systems (outdoors on acorns and grass or indoors with mixed diets) and with different intramuscular fat (IMF) content, were conducted. IMF showed a positive influence on preference for juiciness and liking in subjects over 25 years of age, while younger consumers showed a similar trend for juiciness but not for preference. Loins from pure Iberian pigs showed significantly better ranking for juiciness and overall liking than those from crossbred pigs, even when the IMF content was similar. Dry cured loins from pigs reared outdoors and fed on acorns and pasture were ranked significantly better than those from animals fed indoors on concentrates, even though the mixed diets used were enriched in monounsaturated fatty acids and vitamin E in order to obtain meat with similar features to that of pigs reared outdoors, and despite very similar IMF contents. In conclusion, dry cured loins with high IMF content, from pure Iberian pigs and reared outdoors on acorns and grass attain the highest consumer preference.     

Comparison of Duroc and British landrace pigs for meat a and eating quality

Duroc and halothane negative British Landrace boars and gilts were performance tested from 30 to 80kg on ad-libitum or restricted feeding regimes, with like-sexed non-littermate groups of pigs penned together. Meat and eating quality was determined using objective laboratory measurements and by taste panel and consumer panel assessment on 160 pigs with 20 full-sib families for each breed, and two boars and two gilts per family. Duroc M. longissimus(?) was darker in colour, had a more intense, redder colour and contained more fat and less moisture than Landrace muscle. Duroc subcutaneous fat was less firm, had a higher water content and concentrations of linoleic acid and lower concentrations of stearic acid than Landrace fat. The taste and consumer panels scored Duroc meat as being more juicy, but less tender, having poorer flavour and being less acceptable than Landrace meat. The higher juiciness scores of Duroc meat were probably attributable to the higher intramuscular fat content compared to Landrace meat. Duroc boars had lower values for flavour liking and acceptability compared to other breed-sex combinations which may be due to the particular fatty acid composition of the subcutaneous fat in Duroc boars.     

The effects of breed,sex, intramuscular fat and ultimate pH on pork tenderness

A study was conducted to evaluate the influence of breed and sex of animals on tenderness of pork. For evaluation, carcasses of pure breed barrows and gilts of Large White, Czech pig meat, Landrace and Duroc were used. For laboratory investigations, the samples of musculus longissimus lumborum et thoracis (20 mm thick) were taken from the same place, at the first cruciate vertebra 48 h post mortem. Seven days post mortem, the texture of heat-processed meat was measured objectively by the shear method on Instron equipped with Warner–Bratzler shear device. Meat tenderness and juiciness were also evaluated sensorially. It was observed that the tenderness of cooked meat is influenced by breed (the tenderest meat was from Duroc breed). The sex of animals has significant effect on meat tenderness too. At the same time, the effects of pH 45 minutes (pH₄₅) and 24 hours (pH₂₄) post mortem and intramuscular fat content on meat tenderness were evaluated. Correlations were found between shear force (tenderness) and intramuscular fat content and also between shear force and pH value 45 min post mortem. The shear force decreased with increasing intramuscular fat content and with increasing pH₄₅ value. Sensory evaluation of tenderness confirmed the objectively measured data.     

INTRAMUSCULAR LIPIDS IN M. LONGISSIMUS DORSI FROM PORK, AS RELATED TO BREED AND SENSORY PROPERTIES

The content, composition and distribution of intramuscular lipids in M. longissimus dorsi (LD) of pure bred Hampshire, Swedish Landrace and Swedish Yorkshire pigs were investigated. The highest content of intramuscular lipids was found in Hampshire (2.0%). Swedish Yorkshire had on an average 1.8% intramuscular lipids and Swedish Landrace 1.4%. About 35% of the fatty acids are saturated, 51–56% are monounsaturated and 8–12% are polyunsaturated. The content, as well as the fatty acid composition of the intramuscular lipids, were influenced by breed and sex and most probably also by genetic factors. The intramuscular lipids were mainly found in fat depots containing 20 to 150 fat cells. The fat depots were situated in the perimysium and, to some extent, in the endomysium. The fat cells had mostly an elliptical shape. The diameter of the fat cells varied between 15 and 180 μm but a diameter of 30–60 μm was most frequently noted. An increase in fat depot size was related to an increase in fat cell diameter. For the Swedish Landrace breed a relationship between the sensory properties of LD and the content and the distribution of intramuscular lipids was noted. The sensory properties of Yorkshire were related to the content, composition and distribution of intramuscular lipids, whereas no relationship was noted for the Hampshire breed.     

Fatty acid composition of lipid in Longissimus dorsi muscle of Duroc and British Landrace pigs and its relationship with eating quality

The fatty acid composition of intramuscular fat from Duroc and halothane negative British Landrace pigs was determined and the relationships between fatty acid concentrations and aspects of eating quality were estimated from data on 160 pigs. Boars and gilts from each breed were performance tested on ad libitum or restricted feeding regimes with an average slaughter weight of 80 kg. Eating quality was assessed by ten experienced taste panelists.

Intramuscular fat of Duroc pigs had higher concentrations of saturated and mono-unsaturated fatty acids and lower concentrations of poly-unsaturated fatty acids than Landrace pigs. With increasing intramuscular fat content, concentrations of saturated and mono-unsaturated fatty acids increased and concentrations of poly-unsaturated fatty acids decreased and the rate of change in fatty acid concentrations was greater in Landrace pigs than in Duroc pigs.

Eating quality traits were generally improved as the concentration of mono-unsaturated fatty acids increased and poly-unsaturated fatty acids decreased.     

Effects of breed, diet and muscle on fat deposition and eating quality in pigs

A study in 192 entire male pigs examined the effects of breed, diet and muscle on growth, fatness, sensory traits and fatty acid composition. There were four breeds: two modern breeds, Duroc and Large White and two traditional breeds, Berkshire and Tamworth. The diets differed in energy:protein ratio, being conventional (C) and low protein (LP) diets, respectively. Muscles investigated were the ‘white' longissimus dorsi (LD) and the ‘red' psoas major (PS). Breed influenced growth rate and fatness, the modern breeds being faster-growing with leaner carcasses. However, the concentrations of neutral lipid fatty acids and marbling fat (neutral lipid + phosopholipid fatty acids) were higher in Berkshire and Duroc, in both LD and PS. Relationships between marbling fat and P2 fat thickness showed clear breed effects, with Duroc having high marbling fat at low P2 and Tamworth low marbling fat at high P2. Breed effects on sensory scores given by the trained taste panel to griddled LD and PS steaks were relatively small. Breed affected the fatty acid composition of intramuscular neutral lipid, with high % values for the saturated fatty acids, 14:0 and 16:0 in Berkshire and Tamworth (fat carcasses) and high values for polyunsaturated fatty acids in Duroc and Large White (lean carcasses). Duroc had particularly high concentrations of the long-chain polyunsaturated fatty acids, 20:5n−3 and 22:6n−3 in phospholipid of both muscles. Diet influenced growth rate and fatness, the LP diet slowing growth and producing fatter meat, more so in the two modern breeds, and particularly in intramuscular rather than subcutaneous fat. This diet produced more tender and juicy meat, although pork flavour and flavour liking were reduced. The PS muscle had higher tenderness, juiciness, pork flavour, flavour liking and overall liking scores than LD. The concentration of phospholipid fatty acids was higher in PS than LD but neutral lipid fatty acid content and marbling fat were higher in LD.     

Pig sire type and sex effects on carcass traits,meat quality and physicochemical and sensory characteristics of Serrano dry‐cured ham

This study demonstrates that improvements in animal line selection by breeding enterprises exert a strong effect on carcass traits, meat quality and sensory characteristics of Serrano dry‐cured ham. A total of 461 pigs from the offspring of a Duroc (DU) × Landrace (LD) sow mated with two DU boars and a DU × Large White (LW) boar from three breeding enterprises were evaluated. The two DU terminal sires were significantly different (P < 0.05) in carcass conformation, backfat thickness, ham and loin yields, raw ham traits, myoglobin concentration and total pigments formed during the curing process; in addition, the two lines provided different percentages of hams (54 vs 91%) with sufficient subcutaneous fat and weight to manufacture dry‐cured Serrano hams using a slow ripening process (11 months). The DU × LW sire had the best carcass and ham traits from an economic standpoint and obtained highest scores for sensory characteristics of Serrano ham evaluated by a trained panel test; furthermore, this line provided 84% of total hams suitable for manufacturing Serrano hams by a slow process. When the sex effect was analysed, carcass and ham traits of females were more favourable, but females presented a higher incidence of pale, soft and exudative (PSE) meat and a lower percentage of hams with sufficient subcutaneous fat and weight to produce Serrano hams using a slow ripening process (61% for females and 91% for castrates). On the other hand, castrates provided Serrano hams cured by a slow procedure with better organoleptic characteristics than females. Right and left hams were similar. Copyright © 2005 Society of Chemical Industry     

FRESH AND PROCESSED QUALITIES OF COUNTRY-STYLE CURED HAMS FROM PUREBRED DUROC AND GENETICALLY UNDEFINED MARKET HOGS

The objective of this study was to determine country-style processing differences between hams from purebred Duroc market hogs and market hogs of unknown genetic makeup. Genetically undefined hams purchased from commercial suppliers were sampled the same day as hams from Duroc market hogs. Processing and curing followed standard commercial procedures. After curing, hams were weighed and sliced using a band saw. Slices from the approximate center of the ham were utilized to evaluate cured objective color, moisture content, pH, and salt content. There were no significant differences in cured ham yield between Duroc and genetically undefined market hogs. Intramuscular fat content was greater (P< 0.05) in hams from Duroc market hogs when compared to the hams from genetically undefined pigs. Subjective color, marbling and firmness scores were higher (P< 0.05) in hams from Duroc pigs. Objective color evaluation of cured, center-slices favored the hams from Duroc market hogs.     

Enhancement Effects on Quality Characteristics of Pork Derived from Pigs of Various Commercial Genetic Backgrounds

ABSTRACT: We evaluated quality characteristics of enhanced pork derived from pigs from commercial genetic backgrounds (Duroc, Large White, Pietrain, Hampshire, Landrace, and 2 synthetic lines). Loins enhanced to contain 0.4% phosphate and 0.25% salt were evaluated by a 10-member sensory panel for visual appearance, flavor, and texture. Instrumental color, cook loss, and Warner-Bratzler shear force were also determined. Except for tenderness, genetic line had limited effects on sensory characteristics; it did affect visual pink color, lightness, and marbling. Enhancement positively affected flavor and juiciness. Pork from pigs of some of the genetic backgrounds responded positively to enhancement in terms of color, purge, cook loss, and instrumental color, whereas others responded very little.     

Sex and crossbreed effects on the characteristics of dry-cured ham

The right ham of 76 gilts and 82 barrows from five different crossbreeds, which included Duroc (DU), Landrace (LR), Large White (LW) and Belgian Landrace (BL) lines - DUx(LRxLW), LWx(DUxLW), LWx(LRxLW), BLx(DUxLW) and BLx(LRxLW) - were processed to produce dry cured hams. The external appearance of the hams, and the colour and thickness of the subcutaneous fat were determined. Chemical analyses, appearance, texture, flavour and odour were evaluated on biceps femoris (BF) muscle. The hams from the barrows showed a thicker and whiter layer of subcutaneous fat, higher marbling and lower processing loss than those from gilts. Hams from DU-sired pigs presented the highest marbling, but the worst texture characteristics. The texture characteristics of the hams from the LBx(LRxLW) cross were similar to those of the hams from DU-sired pigs. The hams from the LW-sired crosses showed the highest intensity of holes surrounding the coxo-femoral joint. The LBx(DUxLW) could be the most suitable among the five crosses studied for dry-cured ham production under the processing conditions used in this study.     

Effect of intensifying high‐temperature ripening on proteolysis,lipolysis and flavor of Jinhua ham

BACKGROUND: The flavor quality of dry‐cured ham comes from proteolysis, lipolysis and lipid oxidation, Maillard reaction and Strecker amino acid degradation. Intense proteolysis, lipolysis and lipid oxidation make major contributions to flavor development of dry‐cured ham. Increasing the temperature in fermenting and ripening could promote these reactions and accelerate flavor development in dry‐cured hams. The specific aroma flavor of Jinhua ham is developed only during long‐time high‐temperature ripening in July and August. Our objective was to effectively shorten the process time by intense high‐temperature ripening based on the flavor and quality features of traditional Jinhua ham. RESULTS: Muscle dehydration rate of 80‐day ripened hams (29.43 ± 1.16%) was higher than that of the traditional process (P < 0.05). The total free fatty acids in ripened hams of 45–80 days were all higher than that of traditional hams (P < 0.05) and the level of TBARS was significantly lower (P < 0.01). The flavor profile of modern‐processed hams was different from that of the traditional Jinhua ham. The contents of carboxylic acids and aldehydes were obviously higher than those of the traditional products (P < 0.05). The results of organoleptic evaluation for flavor and quality showed that 80‐day ripened hams reached the first‐grade level of traditional Jinhua ham. CONCLUSION: Long‐time (25–30 days) intensifying high‐temperature ripening (35–37 °C) could accelerate the proteolysis, lipolysis, lipids oxidation, flavor development and effectively shorten the process time based on the traditional flavor and quality features of dry‐cured ham. Copyright © 2009 Society of Chemical Industry     

SENSORY PROPERTIES OF PORK, AS INFLUENCED BY COOKING TEMPERATURE AND BREED

Samples of M. longissimus dorsi were taken from identically reared pure bred pigs of the Hampshire (n= 50), Swedish Landrace (n= 30) and Swedish Yorkshire (n= 51) breeds and sensory evaluated after being fried to 60, 68 and 80°C. A sensory profile comprising three juiciness attributes, i.e., visible juiciness, initial juiciness and dryness in mouth, four tenderness attributes, i.e., hardness, stringyness, chewing time and chewing residual, and the attribute elasticity was developed. The relationships between the different attributes were to some extent influenced by final frying temperature. A final frying temperature of 68°C — or even somewhat lower — seems to be the most suitable one from a sensory point of view. The meat is then juicy and tender, no longer having any “rawness” left, as at 60°C. There is a marked influence of breed on the eating quality. Hampshire is more tender and more juicy than Swedish Landrace, which in turn is more tender and more juicy than Swedish Yorkshire. A breed difference was also noted in the susceptibility to heating. A higher loss in eating quality was noted for Hampshire and Swedish Landrace than for Swedish Yorkshire when the final frying temperature was increased. Hampshire had a somewhat higher frying loss than the other two breeds, but it did not result in the least juicy product which indicates that the sensory property juiciness is not directly correlated to the cooking yield.     

Influence of intramuscular fat content on the quality of pig meat - 1. Composition of the lipid fraction and sensory characteristics of m. longissimus lumborum

The present study is part of a project which aimed to examine the influence of intramuscular fat (IMF) content on the sensory attributes and consumer acceptability of pork. Two experiments were conducted to evaluate the influence of IMF level on the composition of the lipid fraction and on the sensory qualities of muscle longissimus lumborum (LL). Each of these experiments used 32 castrated male pigs selected after slaughter either from 125 Duroc×Landrace (Experiment 1) or 102 Tia Meslan×Landrace (Experiment 2) crossbred animals, and showing large variability in LL IMF content: from <1.5 to >3.5% in Experiment 1 and from 1.25 to 3.25% in Experiment 2. Results from lipid analyses indicate that in both experiments, an increase in IMF content is almost entirely reflected by an increase in the triglycerides content of the muscle. In Experiment 2, higher IMF content was associated with higher free fatty acids. Marbling score was significantly affected by IMF level in Experiment 1 but not in Experiment 2. In Experiment 1, a trend towards a favourable effect of high IMF levels on flavour (p=0.09) and tenderness (p=0.055) was observed. In experiment 2, increased IMF level was associated with significantly higher juiciness and flavour scores. The results from the present study indicate that the variability in IMF level of LL muscle was almost entirely due to the variability in triglyceride contents. Favourable effects of increased IMF levels on the sensory attributes of pork were demonstrated in both experiments using different types of animals, but the nature and the magnitude of these effects depended on the experiment considered.