Effects of growth rate, sex and slaughter weight on fat characteristics of pork bellies

A total of 119 Duroc × (Landrace × Yorkshire) commercial pigs were used to investigate the effect of growth rate (fast vs slow), sex (barrows vs gilts) and slaughter liveweight (107, 115 and 125 kg) on the fat characteristics of bellies. Backfat thickness increased with weight (P < 0.01). Fat firmness score was only affected by sex (P < 0.05), with gilts showing softer bellies than barrows. Fat from gilts and slow growing pigs showed a lower proportion of saturated fatty acids (SFA; P < 0.001 and P < 0.01, respectively), a higher proportion of linoleic fatty acid (C18:2 n-6; P < 0.01), a higher proportion of total polyunsaturated fatty acids (PUFA; P < 0.001 and P < 0.01, respectively), and an increased iodine value (P < 0.001). Consequently, the fat from these bellies had higher PUFA:SFA ratios (P < 0.001) and n-6:n-3 ratios (P < 0.01 and P < 0.001, respectively) than that from the bellies of barrows and fast growing pigs. The belly fat from barrows and fast growing pigs had higher stearic fatty acid (C18:0; P < 0.01) and SFA proportions (P < 0.001 and P < 0.01, respectively) than that from gilts and slow growing pigs. The belly fat from gilts and slow growing pigs would better meet the health requirements of consumers, but it is more prone to rancidity during storage leading to a potentially reduced bacon shelf-life.     

Intramuscular lipid and fatty acid profile of sheep comprising four sex-types and seven slaughter weights produced following commercial procedure

The intramuscular lipid and fatty acid profiles of the m. longissimus dorsi from 84 sheep comprising four sex-types (enire ram, vasectomised ram, wether and ewe) and seven slaughter weights (32, 36, 40, 44, 48 and 52kg) were measured. Animals were reared following the commercial practice. Specifically, they were fed pasture and a concentrate diet, and age at slaughter ranged from 180 to 390 days. Differences between entire and vasectomised rams, and between wethers and ewes in intramuscular lipid content were not significant (P>0.05). However, entire and vasectomised rams were significantly lower (P<0.05) in intramuscular lipid content than ewes and wethers. Sex related differences in 14:0 (myristic acid), t18:1, c18:1, t18:2 and c18:2 proportions were not significant (P>0.05). Ewes and wethers were similar in 16:0 (palmitic acid) and 18:0 (stearic acid) proportions, but ewes contained significantly higher 16:0 and lower 18:0 proportions than entire and vasectomised rams (P<0.01). Entire and vasectomised rams recorded the highest c18:3 proportions, wethers were intermediate whilst ewes contained the lowest proportion (P<0.01). Although neither saturated fatty acid (SFA) nor monounsaturated fatty acid (MUFA) proportions varied with sex-type, vasectomised rams contained significantly higher polyunsaturated fatty acid (PUFA) proportion that the other sex-types (P<0.05). Whilst intramuscular lipid content, and 18:0 and c18:1 proportions were linearly correlated with slaughter weight (P<0.001), 14:0 and c18:3 proportions decreased quadratically with increasing slaughter weight (P<0.001). The vasectomised ram and the entire ram were similar in fatty acid profile, except the significantly higher PUFA proportion recorded by the vasectomised ram.     

The influence of diets containing either conventional corn, conventional corn with choice white grease, high oil corn, or high oil high oleic corn on belly/bacon quality

The objectives of this study were to evaluate diets possessing different fatty acid profiles (as influenced by corn type) with regard to fatty acid profile and firmness of pork bellies. Crossbred barrows (n=196) were fed one of four corn-based diets consisting of conventional corn (CONV), CONV with choice white grease (CWG), high oil corn (HOC), or high oleic, high oil corn (HOHOC). Following 98 days on test, two animals representing the average pen weight (118 kg) were selected for harvest (n=56). A 50-g fat sample was removed from each belly for fatty acid profile analysis. Lateral and vertical flex tests were performed to determine belly firmness. Bellies were pumped and cooked according to a commercial protocol. Total saturated fatty acids increased (P<0.001) and total unsaturated fatty acids decreased (P<0.05) when CWG was added to the CONV diet or when HOC or HOHOC were substituted for CONV corn. Pigs fed CONV corn had firmer bellies, while those fed HOC were softer. No differences were observed across treatment for percentage pump retention, smokehouse yield, or slicing yield (P>0.05). Based on the results of this study, corn type influences fatty acid profile, and belly firmness, but does not affect pump retention, or slicing yields.     

Effect of dietary energy and protein levels on fatty acid composition of intramuscular fat in double-muscled Belgian Blue bulls

Seventy six Belgian Blue (BB) bulls, with double-muscled conformation, were randomly allocated to six dietary treatments in a 2 × 3 factorial experiment. The treatments included low (N(L)=127 g CP/kg DM), medium (N(M)=153 g CP/kg DM) and high (N(H)=172 g CP/kg DM) levels of dietary protein in combination with low (E(L)=7.38 MJ ME/kg DM) and high (E(H)=8.03 MJ ME/kg DM) levels of dietary energy. Fatty acid composition was determined on total lipid samples of the M. longissimus thoracis of all animals and on the separated triacylglycerol and polar lipid fatty acid fractions of the medium-protein group. Dietary energy and protein levels influenced the carcass characteristics of BB bulls but the effects were small. Carcass fat cover score, carcass fat content and intramuscular fat content were slightly but significantly higher in the animals on the high versus the low energy diets. The overall intramuscular fat content was very low (<1%) and the overall polyunsaturated:saturated fatty acid ratio (0.39) high compared to normal figures for beef. The high versus the low dietary energy level increased the monounsaturated (P<0.001) and decreased the polyunsaturated (P<0.001) fatty acid proportion with no change in the saturated fatty acid proportion. This may have been due in part to the addition of beef tallow to increase the energy level of the diet. Concomitant shifts in the individual fatty acids included increased proportions of C14:0 (P<0.001), C16:0 (P<0.03), C16:1 (P<0.01), C18:1 (P<0.001) and decreased proportions of C18:2 (P<0.001) and C20:4 (P<0.001). Increasing dietary protein levels had inconsistent effects on the fatty acid profiles. The proportion of polar lipid fatty acids in the total fatty acids was 0.34 and 0.25 for the E(L) and E(H) group, respectively, in the Nm treatment group. Changes in fatty acid proportions of the triacylglycerol fatty acid fraction were similar to those seen in the total lipid fatty acids when related to dietary energy level, but no significant changes in the polar lipid fatty acid proportions were observed. Significant linear relationships were found between measures of carcass and muscle fatness and fatty acid proportions. With increasing muscle total fatty acid content, saturated and monounsaturated fatty acid proportions increased (r=0.38 and r=0.55, respectively, P<0.01) and the polyunsaturated fatty acid proportion decreased (r=-0.73, P<0.01). The diet had some effects but the relatively unsaturated intramuscular fatty acid composition was mainly related to the low total fat content of the BB animals.     

Effect of restricted feeding and realimentation periods on pork quality and fatty acid profile of M. longissimus thoracis

An experiment with 94 fattening pigs (48 gilts and 46 barrows) was conducted to determine the effect of feeding 25% restricted diets at different body weights on meat quality and fatty acid profile of M. longissimus thoracis (LT). During the 84 days of the experiment (4 periods, 21 days each), animals with an initial weight of about 31 kg were fed in different periods of observation ad libitum (A) or restricted diets (R) in groups AAAA, AARA, RAAA and RARA. After 21 days of the experiment, the restricted-fed pigs, compared to those fed ad libitum, had a lower total fat content of M. longissimus thoracis (P<0.05), higher shear force (P=0.068), and lower proportions of SFA (C14:0, C18:0 P<0.05) and MUFA and higher proportions of PUFA (C20:4, C22:4 P<0.05) in the fatty acid profile. Three weeks after the restricted feed supply was lifted, the total fat content in LT muscle was higher than in animals fed ad libitum throughout (2.34 vs. 2.02), very close after the next 3 weeks of realimentation (3.16 vs. 3.15) and lower after another 3 weeks (3.19 vs. 3.49). Regardless of the time at which restricted feeding was started and the number of restricted feeding periods, the total fat content in the LT muscle at the end of the experiment was similar or lower in groups RAAA, AARA and RARA, compared to group AAAA. The coefficient of correlation between the total fat content in LT and the shear force was -0.36 (P<0.01). Colour, pH and drip loss did not depend on the level of nutrition. After 84 days of observation, animals from groups RARA and AARA, compared to pigs from groups AAAA and RAAA, were characterized by a slightly higher shear force of LT, lower SFA and MUFA (P<0.001), and higher n-6 PUFA (P<0.01) and n-3 PUFA (P<0.01) proportions in the fatty acid profile. The fatty acid profiles of AAAA pigs and pigs undergoing a 63-day realimentation period (RAAA) were similar. Regardless of the feeding scheme, the n-6:n-3 ratio exceeded 10 in all the groups.     

Influence of inclusion of chestnut in the finishing diet on fatty acid profile of dry-cured ham from Celta pig breed

The effect of the inclusion of chestnut in the finishing diet on fatty acid profile of dry-cured Celta ham was studied. Twelve hams of each type (from three different diets: concentrate, mixed and chestnut) were used. Significant differences between treatments (P<0.001) were found regarding total saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Ham samples from the mixed and chestnut groups had less SFA (35.57% and 35.63%, respectively) with respect to ham samples from the concentrate group (40.33%), while hams from the mixed and chestnut batches showed higher values of MUFA than hams from the concentrate group (50.70 vs. 49.79 vs. 43.85, P<0.001, respectively). From a nutritional point of view, Celta hams from chestnut diets could be considered as healthier regarding their fatty acid profiles (low n-6/n-3 ratio and high hypocholesterolemic/Hypercholesterolemic ratio). Discriminant analysis selected five variables (C(16:0), C(16:1cis-9), C(20:2), C(20:3n-6) and C(20:4n-6)) and calculated two discriminating functions which verifies the presence of chestnut in the finishing diet.     

Beef lipids in relation to animal breed and nutrition in Argentina

Fatty acid (FA) composition of intramuscular fat (IMF) in M. Longissimus dorsi (LD) was measured in 72 steers from Angus (A), Charolais×Angus (CHA×A) and Holstein Argentine (HA) breeds. The steers were allotted to four dietary treatments of six animals each: T1, steers grazed on pasture; T2, steers supplemented with cracked corn grain (0.7% of live-weight) daily and free access to pasture; T3, steers supplemented with cracked corn grain (1% of live-weight) daily and free access to pasture; and T4, feedlot (concentrate based on corn, alfalfa hay and soybean meal without access to pasture). At slaughter weight, samples of LD at the 11th rib were used for intramuscular lipid analysis. The diet was shown to be more important than breed in determining FA composition. Pasture beef had higher percentages of saturated fatty acids (SFA), n-3 polyunsaturated fatty acids (PUFA) and conjugated linoleic acid (CLA) and lower percentages of IMF, monounsaturated fatty acids (MUFA), n-6 PUFA and n-6/n-3 ratios than feedlot beef. HA beef presented lower percentages of SFA and more MUFA with a higher n-6/n-3 ratio than A and CHA×A. Comparing grass and feedlot beef the amounts of FA in muscle (mg/100g) were, respectively 18:3 n-3 (44 vs. 11mg), CLA (20 vs. 12mg), 20:5 n-3 (20 vs. 11mg), 22:5 n-5 (20 vs. 11mg), 22:6 n-3 (12 vs. 6mg) and n-3 PUFA (84 vs. 32mg). Feedlot beef has more SFA (1372 vs. 1081mg), MUFA (1574 vs. 1078mg), PUFA (350 vs. 227mg) and n-6 PUFA (318 vs.143mg).     

Variability of Fresh Pork Belly Quality Evaluation Results Depends on Measurement Locations

The increase in pork demand has led to an especially high increase in demand for precisely quality-defined bellies. The aim of the study was to determine the influence of quality measurement location on the pork belly on the results of qualitative evaluation and then to recommend the main measurement locations required to determine the precise quality evaluation of the whole cut. The research material consisted of 92 fresh pork belly samples, each divided on 12 testing locations. The highest pH values were noted for M2 (5.74), M1 (5.70), and D3 (5.69) locations, as well as A4 (5.53; P?≤?0.05) generating the most outliers. Location D2 was distinguished by generally obtaining the highest values for parameters L*, b*, C*, and H* and the lowest for a*; this was independent of the measurement side. The highest water holding capacity values were reported for D4 and D3 locations, and the lowest (about 7% lower than the maximal values) were obtained for A4 and A2 locations. The highest values for the cooking loss parameter were noted for D4, D1, and M4 (about 33%) locations, and the lowest values were observed for location M2 (only 22%). In the case of sensory evaluation between the analyzed locations, differences (P?≤?0.05) were recorded for all parameters. It is recommended to evaluate belly quality using one location: A1 and M3 are most accurate. The highest position in the ranking for processing quality parameters was occupied by the middle locations: M4, M1, and M3. However, when consumers ranked important quality parameters, the highest positions were given to location A1 and then D3 and M2. From a practical point of view, it is highly recommended to take quality parameters from location A1, which is much easier to obtain, and obtaining samples from this location leads to the least damage to the structure of the whole commercial cut.     

LIPID AND LIPID SOLUBLE COMPONENTS OF GONADS OF GREEN SEA URCHIN (STRONGYLOCENTROTUS DROEBACHIENSIS)

Seasonal changes in the lipid and lipid soluble components of gonads of green sea urchin (Strongylocentrotus droebachiensis) were investigated. The lipid content was highest in the spring while it was lowest in the winter. The composition of nonpolar and polar lipid classes of sea urchin gonads were not affected qualitatively, but there were significant (P<0.05) quantitative variations. Major nonpolar lipid classes were triacylglycerols (TAG), free fatty acids (FFA) and sterols (ST) while dominant polar lipid components were phosphatidylcholine (PC) and phosphatidylethanolamine (PE). The fatty acids 16:0 and 14:0 were the major saturated fatty acids (SFA) consistently present in total, nonpolar and polar lipids of sea urchin gonads. The 5-olefinic acid 20:1 n-15 was the dominant monounsaturated fatty acid (MUFA) while 20:4 n-6 and 20:5 n-3 were the major polyunsaturated fatty acids (PUFA) present. The content of PUFA increased during cold climatic conditions with a simultaneous decrease in the content of SFA. These changes were reversed during warm seasons. Total carotenoid content was highest in the spring. Echininone was the major carotenoid present and its relative content varied significantly (P<0.05) with the season; being highest in the spring and lowest in the summer. In addition, β-carotene was present in each season. Thus, the importance of seasonal variations on the lipid and lipid soluble components of sea urchin gonads is evident.     

Carcass fatty acid mapping

We hypothesized that subcutaneous (s.c.) adipose tissue would differ in monounsaturated (MUFA) and saturated fatty acid (SFA) composition among different depots throughout a beef carcass. To test this, 50 carcasses from a variety of breed types and backgrounds were sampled. External fat samples were collected from eight different carcass locations: round, sirloin, loin, rib, chuck, brisket, plate and flank. The brisket was significantly lower (P = 0.001) in palmitic (16:0) and stearic (18:0) acid than the other seven sampling sites. The brisket contained the highest concentration of MUFA (P = 0.001) and the lowest concentration of trans-vaccenic acid (P = 0.002) and SFA (P  0.002). There was a high, negative correlation between palmitoleic and stearic acid (R² = 0.76). The flank had the highest slip point (39 °C; a measure of melting point), whereas the brisket had the lowest slip point (25 °C) (P  0.001). We conclude that substantial differences exist in fatty acid composition across fat depots, which may be useful in formulating value-added processed beef products.     

高效液相色谱法检测熟制猪肉中呈味核苷酸

以市场上2 款黑猪（HZ1、 HZ2）和2 款白猪（BZ1、BZ2）通脊肉和五花肉为研究对象,对比分析其熟制后肉和汤中5’-肌苷酸、5’-腺苷酸、5’-鸟苷酸、肌苷和次黄嘌呤的含量差异。结果表明：猪肉中5’-肌苷酸含量明显高于其他核苷酸,且五花肉中呈味核苷酸含量远低于通脊肉;白猪肉和汤中5’-肌苷酸含量均显著高于黑猪肉（P＜0.05）,肌苷与次黄嘌呤含量总体上低于黑猪肉,白猪BZ1通脊肉和BZ2五花肉汤中5’-腺苷酸含量最高,白猪BZ2通脊肉5’-鸟苷酸含量最高,黑猪HZ1五花肉5’-鸟苷酸含量最低。综上,白猪肉在鲜味呈现上比黑猪肉更具优势,白猪BZ1最佳,黑猪HZ1最差。     

Influence of ewe feeding systems on fatty acid composition of suckling lambs

The main objective of this study was to evaluate the effects of ewe dietary treatments on the intramuscular fatty acid composition of suckling lambs. Twenty-four pregnant Italian Merino ewes were divided into two equal groups. One group (pasture-fed group) was allowed to graze a natural pasture and the other group (stall-fed group) was penned indoors and fed with hay and concentrate. After lambing, all ewes stayed with their respective lambs for the whole experimental period. Lambs were slaughtered at 100 days of age with an average live weight of 20kg. Fatty acid profiles of milk and lamb meat (longissimus lumborum muscle) were analysed. Intramuscular fat from pasture-fed lambs showed higher (P<0.001) proportions of polyunsaturated fatty acids. The percentage of lauric (C12:0; P<0.05), palmitic (C16.0; P<0.001) and oleic (C18.1; P<0.001) fatty acids were higher in the intramuscular fat from stall-fed lambs, whereas pasture-fed lambs showed greater proportions of linolenic (C18:3; P<0.001), eicosapentaenoic (C20:5; P<0.001) and docosapentaenoic (C22:5; P<0.05) fatty acids. Moreover, the intramuscular fat from pasture-fed lambs displayed a higher (P<0.001) PUFA/SFA ratio, and a lower (p<0.001) n-6/n-3 ratio. The conjugated linoleic acid (CLA) tended to be higher (P=0.07) in the intramuscular fat from pasture-fed lambs. This study confirmed that pasture enhanced the unsaturated fatty acid profile of intramuscular fat in lambs including n-3 fatty acids.     

Benchmarking value in the pork supply chain: Processing characteristics and consumer evaluations of pork bellies of different thicknesses when manufactured into bacon

Impact of belly thickness on processing yields and consumer evaluations of finished bacon products was measured. Before processing through a commercial facility, pork bellies (n=96 per group) were sorted into three target thickness groups: "thin" (approximately 2.0cm); "average" (approximately 2.5cm); "thick" (approximately 3.0cm). Processing yields at various production points were recorded and samples from each thickness group were evaluated by consumers for palatability characteristics and visual appearance. Bacon manufactured using "thick" bellies had the highest processing yields through the smoking and cooking phase. "Thin" bellies had the lowest slicing yields and generated the highest percentage of less valuable "#2 slices" (slice profile less than 1.9cm at any point) and "ends and pieces." Consumers found that bacon manufactured from "average" thickness bellies did not have deficiencies in palatability characteristics, but bacon manufactured from "thin" bellies lacked crispiness and bacon manufactured from "thick" bellies lacked flavor. Consumers found the lean-to-fat ratio and the visual appearance of bacon from "thick" bellies was less appealing than bacon from "thin" and "thick" bellies. Moreover, consumers showed much stronger purchase intent for bacon from "thin" and "average" bellies. Belly thickness impacted processing yield and consumer palatability evaluations of bacon. Producers need to minimize production of "thin" bellies because of reduced processing yields and "thick" bellies because of reduced consumer appeal.     

Carcass composition and meat quality of three different Iberian×Duroc genotype pigs

Carcass composition and meat quality of Longissimus dorsi (LD) and Biceps femoris (BF) muscles from three different Iberian×Duroc genotype pigs were studied: GEN1: ♂ Iberian×♀ Duroc1; GEN2: ♂ Duroc1×♀ Iberian; GEN3: ♂ Duroc2×♀ Iberian. Duroc1 (DU1) were selected for the manufacture of dry-cured meat products while Duroc2 (DU2) were pigs selected for meat production, with high percentages of meat cuts and low carcass fat. Genotype had a significant effect on the differences found while sex had not. GEN2 showed the highest weights at days 180 and 238 of weaning and the highest slaughter weights (day 316) followed by GEN3, while the lowest weights were found in GEN1. GEN3 had well conformed carcasses in comparison with GEN1 and GEN2, since GEN3 showed the highest percentages of ham and loin and the highest weight of loin as well as the lowest back and ham fat thickness. However, the use of DU2 pigs in the cross with Iberian had negative effects on meat quality, as GEN3 gave the worst meat quality in both muscles, postmortem pH, cook and drip loss, and colour and the lowest percentages of intramuscular fat (IMF). In subcutaneous fat (SCF), GEN3 had higher percentages of polyunsaturated fatty acids (PUFA) than GEN2, while GEN2 had higher saturated fatty acids (SFA) levels. In LD, IMF from GEN3 showed the highest percentage of MUFA and PUFA; while the fatty acid profile of GEN2 was more saturated. BF muscle showed similar trends, but not significantly so. On the other hand, few differences were found between reciprocal crosses (GEN1 vs. GEN2). GEN2 showed higher IMF in LD than GEN1, agreeing with their carcass weight. As a result, GEN1 had a fatty acid profile of IMF in the LD that was more unsaturated.     

风干金鲳鱼制品加工过程中脂质氧化和挥发性成分的变化

以金鲳鱼为原料,采用腌制2 d、风干3d的加工方式对金鲳鱼鱼背、鱼腹进行处理,探究金鲳鱼鱼背和鱼腹的脂质氧化规律和挥发性成分的变化.通过顶空固相微萃取-气质联用仪分析风干金鲳鱼制品加工过程中挥发性成分的变化.结果表明,鱼背的脂质氧化程度整体上稍高于鱼腹.鱼背和鱼腹脂肪酸组成变化规律大致相同,表现为饱和脂肪酸(satur...     

Fatty acid composition of subcutaneous and intramuscular adipose tissues and M. longissimus dorsi of Wagyu cattle

Three experiments were conducted to document the fatty acid composition of tissues from purebred Wagyu cattle from Japan and North American crossbred Wagyu. In experiment 1, subcutaneous (s.c.) adipose tissues (n = 23) were obtained from Japanese cattle representing the five Japanese fat quality grades. The monounsaturated:saturated fatty acid ratio (MUFA:SFA) was greatest in fat quality grade 5 samples (2·57) and least in the fat quality grade 3 samples (2·08; P < 0·05). In experiment 2, M. longissimus dorsi and the associated intramuscular (i.m.) and s.c. adipose tissues were obtained from carcasses of Wagyu crossbred steers (1/2–7/8) raised in the USA. Fatty acid composition varied among depots, but the MUFA:SFA ratio in s.c. adipose tissue (1·46) was not different from values reported for other breeds of cattle. In experiment 3, samples of M. longissimus dorsi ribsteaks were obtained from three regions in Japan. Samples from the Gunma region had the greatest (P < 0·05) MUFA:SFA ratio (2·10), relative to samples from the Kagoshima (1·82) and Miyazaki (1·65) regions. The data indicate that beef from purebred Wagyu cattle raised in Japan is enriched in monounsaturated fatty acids, and that the degree of enrichment depends upon the region of Japan from which the samples were obtained.     

Effect of feeding on fatty acid composition of muscles and adipose tissues in young goats raised in the Argan tree forest of Morocco

The characteristics of meat from goats raised in the Argan tree forest in the south-western part of Morocco were studied in two experiments. Each experiment was carried out on three groups of six male goats. They were reared either indoors (IC) and fed concentrate or outdoors where they grazed in the Argan tree forest and were offered concentrate (OC) or only Argan fruit pulp (OS). Outdoor-raised goats had a very low growth rate in the first experiment (34 g/d), whereas it was relatively high in the second experiment (64 g/d) in which herbaceous vegetation availability was higher. In each experiment, omental (OM) and perirenal (PR) weights were the lowest in the two groups of goats raised outdoors. Lipid and cholesterol contents in muscles were lower in goats raised in the Argan tree forest than in those raised indoors. Outdoor-raised goats had particularly high proportions of odd-chain fatty acids (FA), branched-chain (FA) of the iso and anteiso series in adipose tissues and muscles and higher n-6 and n-3 polyunsaturated FA (PUFA) proportions and a lower n-6:n-3 PUFA ratio than indoor-raised goats. Indoor-raised goats had a higher proportion of palmitic acid and a lower proportion of archidic acid than outdoor-raised goats. In indoor-raised goats, the proportions of Δ9 straight-chain mono-unsaturated fatty acids (MUFA) (C(16:1n-7) and cis C(18:1n-9)) were relatively higher than those of total MUFA, because of lower percentages of some MUFA, such as C(16:1n-9) and other isomers of oleic acid. The low fat content and FA profile of the meat from the goats reared in the Argan tree forest conveyed beneficial characteristics to this meat in regards to human health. The relatively high contents of branched-chain FA of iso and anteiso series and PUFA in the meat from goats raised in the Argan tree forest could be considered as a sign of typicity.     

Effect of a linseed diet on lipid oxidation, fatty acid composition of muscle, perirenal fat, and raw and cooked rabbit meat

Forty Californian×New Zealand rabbits (1kg initial body weight) were fed a control or a linseed isoenergetic diet containing 30g of extruded linseed/kg. Twenty rabbits for each dietary treatment were slaughtered at 11 weeks of age, at 35 days after the start of the experiment. Feeding the linseed diet increased (P<0.005) the content of 18:2n-3 in muscles, perirenal fat, and raw and cooked meat. The long chain n-3 polyunsaturated fatty acid (PUFA) contents were also increased (P<0.01) in the meat. The linseed diet produced a robust decrease in the n-6/n-3 ratio. Cooking did not alter n-3 PUFA more than saturated fatty acids (SFA) or monounsaturated fatty acids (MUFA). However, n-6 PUFA were altered by cooking. The oxidative stability of Longissimus dorsi was not affected by the linseed diet, even after 300min of forced-oxidation. Inclusion of linseed in rabbit diets is a valid method of improving the nutritional value of rabbit meat.     

Quality changes and shelf life of imported vacuum-packaged beef chuck during storage at 0°C

The objective of this study was to investigate differences in adipose tissue fatty acid composition among stress genotypes as well as to determine relationships of those fatty acids with performance, carcass and meat quality traits. Haplotypic analysis of parents and offspring was employed to assign 48 pigs to three stress genotypes of swine. Individual fatty acid profiles were determined on subcutaneous backfat. Stress genotype had a significant effect on the proportions of C14:0 (P<0.05), C16:0 (P<0.10), C16:1 (P<0.05) and C18:0 (P<0.05) fatty acids. After adjusting for stress and gender, there was a negative correlation between backfat thickness and essential fatty acids (linoleic and linolenic) (P<0.001). In contrast, the correlation of loin muscle area with C18:2 (P<0.01) and C18:3 (P<0.001) was positive. The degree of fat firmness was negatively correlated to the proportion of total unsaturated fatty acids (P<0.01). No significant correlations were observed between fatty acid contents and lean meat quality traits.