Genetic parameters for meat and fat quality and carcass composition traits in Iberian pigs

Carcass composition and quality traits were measured in heavy Iberian pigs after extensive handling. The weights of trimmed hams, forelegs and loins were recorded on 2170–2553 pigs, intramuscular fat content in M. longissimus (IMF) on 1489 and percentages of palmitic, stearic, oleic and linoleic acids in the subcutaneous fat on 1495 pigs, slaughtered at about 160 kg live weight. For carcass traits the heritability estimates ranged from 0.28 to 0.41. Heritability estimate for IMF was 0.25 and estimates of heritability for the measured fatty acids ranged from 0.29 to 0.41. The estimated genetic correlations (rg) suggest antagonism between IMF and weights of hams (rg=−0.30) and loins (rg=−0.33) and an unfavourable positive association of premium cuts with linoleic acid content (rg: 0.31–0.57). The incorporation of meat and fat quality traits to the selection aims of the breeding scheme for Iberian pigs seems advisable.     

GC-MS法测定宣威火腿中脂肪酸组成

以宣威火腿为对象,通过提取成熟宣威火腿的肌间脂肪和皮下脂肪,采用气相色谱-质谱联用法(GC-MS)对宣威火腿肌间脂肪与皮下脂肪中脂肪酸的组分进行探讨。结果表明:宣威火腿肌间脂肪中含11种饱和脂肪酸,占总脂肪酸的34.75%,15种不饱和脂肪酸,占总脂肪酸含量的64.78%,主要的脂肪酸为油酸(C18∶1)、棕榈酸(C16∶0)、硬脂酸(C18∶0)、亚油酸(C18∶2),含量分别为33.44%、23.37%、8.44%、20.55%;皮下脂肪中含11种饱和脂肪酸,占总脂肪酸的36.23%,15种不饱和脂肪酸,占总脂肪酸含量的63.47%,主要的脂肪酸为油酸(C18∶1)、棕榈酸(C16∶0)、硬脂酸(Cl8∶0)、亚油酸(C18∶2),含量分别为31.47%、21.90%、11.13%、22.39%。     

The influences of carcass weight and depot on the fatty acid composition of fats of suckling Manchego lambs

The effects of carcass weight (<5.5 kg, 5.5–6.5 kg, ⩾6.5 kg) of Manchego suckling lambs, type of fat depot of the leg (subcutaneous, intermuscular and intramuscular) and muscle (m. longissimus dorsi (LD) or m. quadriceps femoris (QF)) on the fatty acid composition were studied. Carcass fatness increased with increasing carcass weight. However, few differences in fatty acid proportion were observed between the three carcass weight groups. The lightest carcasses had lower proportions of myristic (C14:0) and palmitoleic (C16:1) acid and higher proportions of stearic (C18:0) acid, desirable fatty acids (DFA) (C18:0 + total unsaturated fatty acid (TUFA)) and a greater nutritive value ((C18:0 + C18:1)/C16:0). The fatty acid composition of subcutaneous and intermuscular fat depots of the leg were similar, whereas the intramuscular fat depot was different from both of these, since it had a lower proportion of saturated fatty acids (SFA), a greater proportion of TUFA, higher PUFA/SFA and n − 6/n − 3 ratios, and greater DFA and nutritive values. The intramuscular fat of the LD was more saturated than QF, higher SFA, and had lower value of PUFA/SFA ratio and DFA. These results indicated that the intramuscular fat quality of the leg was better than subcutaneous and intermuscular fat depots and also that intramuscular fat displayed better attributes of quality (lower SFA, higher TUFA, and greater PUFA/SFA ratio and DFA as well) than intramuscular fat of the LD from the consumer health standpoint. Despite carcass weight affected carcass fatness, it did not seem to influence the proportions of saturated or polyunsaturated fatty acids. For this reason, carcass weight probably had little effect on the organoleptic characteristics of the meat.     

The effects of differences in inherent muscle quality and frozen storage on the flavor and texture profiles of pork loin roasts

Complete flavor and texture profiles on pork loins from 118 carcasses revealed the following findings: (1) freezing, storing and thawing pork loins produced a slight tenderizing effect by making them less cohesive and easier to chew; permitted greater moisture release during chewing, thereby, slightly increasing the juiciness; resulted in a breakdown to more appropriate residual particles which resulted in a more appropriate, well balanced and blended texture; but resulted in a less appropriate and well balanced flavor; (2) pork with normal muscle quality had a firmer, more elastic, and cohesive texture which was stringier, more fibrous, and harder to compress, resulting in a slower breakdown to particles which tended to be fibrous, grainy and mealy; (3) the PSE condition appeared to result in a drier texture with less moisture and fat being released during mastication and a greater amount of moisture being absorbed from the mouth; (4) the DFD condition appeared to result in a juicier texture with greater amounts of fat and moisture being released into the mouth during mastication and a softer texture which was less cohesive, fibrous, and stringy and easier to chew, but as the DFD condition became extreme the texture became excessively soft, crumbly and mushy resulting in a relatively large proportion of small mealy and/or mushy particles which detracted from the texture amplitude; (5) the PSE condition resulted in a predominance of sour notes which detracted from the flavor amplitude, and possibly resulted from more extensive accumulation of lactic acid during postmortem glycolysis; and (6) the DFD condition resulted in a predominance of porky, sweet, and fatty character notes which enhanced the flavor amplitude but as the DFD condition became extreme, more character notes contributing to off-flavors were detected, a portion of which were apparently due to sex taint.

Present findings clearly document the influence of differences in inherent muscle quality on palatability properties of pork loins and aid in resolving the controversy that presently exists within the literature regarding the effects of freezing, frozen storage, and thawing on pork palatability. However, further research will be required to document the impact of such influences on consumer acceptance.     

A survey of pre-slaughter conditions, halothane gene frequency, and carcass and meat quality in five Spanish pig commercial abattoirs

A total of 116 deliveries, comprising 15,695 commercial pigs delivered to five abattoirs, were surveyed during winter and summer. Information about on-farm fasting, transport duration and stocking density, and lairage time was collected. Cortisol, creatine phospho-kinase (CPK), and lactate, and DNA for halothane genotype were analysed in a subsample of pigs at exsanguination in every journey. Electrical conductivity (PQM) in semimembranosus muscle (SM) and carcass characteristics (Fat-o-Meater and skin damage) were measured in each carcass. pHu of SM was analysed in the laboratory in a subsample in every journey. Carcasses were identified as PSE or DFD based on PQM and pHu, respectively. The n gene frequency ranged among abattoirs from 54 to 8%. Mean lean content was 58.9% for nn, 57.3% for Nn, and 55.8% for NN pigs, though a difference of 2.5% lean was observed between two abattoirs with the same n gene frequency. A straight relationship of the incidence of serious PSE carcasses and n gene frequency was found. The overall incidence of serious PSE and DFD carcasses was 6.5 and 12.5%, respectively. A higher incidence of PSE carcasses was found in summer; in deliveries with <12 h on-farm fasting; with transport stocking densities >0.40 m(2)/100 kg pig; and in transports of <2 h duration. A higher incidence of DFD carcasses was found in winter; with transport stocking densities <0.40 m(2)/100 kg pig; transports of >2 h duration; and lairage times >9 h. Cortisol level in blood increased in winter and decreased after 12-18 h fasting time. A rise in the lactate concentration was observed in pigs transported in high stocking density (<0.40 m(2)/100 kg pig) and for a longer time (>2 h). All blood stress indices increase as increasing lairage time. Carcasses with more skin damage had higher levels of cortisol, CPK and lactate, and higher incidence of DFD meat, compared with non and low skin damage carcasses.     

EFFECTS OF INJECTION OF A DILUTE PHOSPHATE-SALT SOLUTION ON PORK CHARACTERISTICS FROM PSE, NORMAL AND DFD CARCASSES

Phosphate-salt pump effects were evaluated on sensory characteristics of pale, soft, exudative (PSE) pork, normal and dark, firm and dry (DFD) pork. Water-holding capacity, instrumental color (L*, a*, b*), pH, and muscle color scores were determined at 24 h postmortem on pork loin pairs (n=21 pairs). Based on color score, paired loins were assigned to PSE, normal or dark, firm, dry groups. PSE muscles were lighter, redder and more yellow than normal or DFD muscles; hue angle indicated that DFD muscles were actually closer to the true red axis of the CIE Lab Color Space. Drip and purge losses were higher (p<0.05) in PSE muscles. Paired loins were pumped with water (controls) or 0.3% tripolyphosphate solution (0.25% salt) to 110% of original weight, vacuum packaged, frozen, cut into chops, and cooked to 70 or 80C. Phosphate-salt pumped loins were juicier and more tender (p<0.05) than water-pumped loins regardless of muscle condition. Loins cooked to 70C were juicier, were more tender (sensory) but required more force to shear than those cooked to 80C.     

Fatty acid composition of muscle and fat tissues of Omani Jebel Akhdar goats of different sexes and weights

This paper describes the fatty acid (FA) composition of muscle and fat tissue in Omani Jebel Akhdar buck, wether and does slaughtered at 11, 18 or 28 kg body weight (BW). The fat percentage in dry matter (DM) of the subcutaneous and kidney fats ranged between 85 and 98% and that of muscle ranged between 17 and 21%. Subcutaneous fat tended to have lower DM than kidney fat. Palmitic (C16:0), stearic (C18:0) and oleic (C18:1) acids comprised the largest proportions of FA in the muscle tissue (approximately 80%) with oleic acid being the most abundant. Ninety-one percent of the total FA were contributed by the C16 and C18 fatty acids being 31.6 and 58.5%, respectively. C19 and C20 were not detected in the muscle tissue. The essential FA, C20:2, C20:3 and C20:4 contributing about 1%. Muscle tissue of the Jebel Akhdar goat contained an average 51.3% and 48.7% of saturated (SFA) and unsaturated fatty acids (UFA), respectively. Polyunsaturated FA (PUFA) constituted about 5% and monounsaturated (MFA) 43.5% of the total FA. Subcutaneous fat contained more total FA (68.08%) than kidney fat (48.14%) in the whole tissue. Kidney fat contained higher percentages of C16 and C18 but less C:18:1 than subcutaneous fat. The proportions of SFA to UFA was high in both fat depots with the SFA being much higher in the kidney than subcutaneous fats. C16, C18 and C:18:1c acids comprised 64.2 and 78% and C16s and C18s made up 81 and 85% of total FA in subcutaneous and kidney fats, respectively. In both subcutaneous and kidney fats, there was a trend of increasing values of DM and fat percentage with intact males having the lowest and females the highest values. Males had higher levels of C15, C18:2 and C18:3 but lower levels of C17, C18 and total C16, C18 and C18:1 in muscle tissue. Intact males had higher levels of C10, 12, 15 FA but lower C16:1 and C16+18+18:1 than others in subcutaneous fat. Intact males had a similar trend for C12 and 14 but lower SFA and higher UFA in kidney fat. There was a trend of increasing DM and fat% in dry matter with increasing body weight. C10, 12 and 14 of the kidney fat decreased with increasing slaughter weight. There was a trend of the two C16 FA decreasing and the four C18 increasing with BW in the kidney fat. This resulted in proportions of the total C16 and C18 FA increasing from 81.8 to 86.8%. These findings confirm those of other studies on goat meat quality that, as judged by fatty acid composition it is not inferior to that of meats from other farm animals.     

Composition and estimation of intramuscular and subcutaneous fatty acid composition in Spanish young bulls

Sixty Pirenaica yearling intact bulls were raised and slaughtered at 519±50kg live weight and 371±18 days of age. Fatty acid composition of intramuscular lipids in longissimus dorsi muscle and subcutaneous fat were determined by capillary gas chromatography. Carcass conformation and fatness, carcass weight, ether extractable intramuscular fat percentage, marbling, dorsal fat thickness, and ultrasonic parameters were recorded to study the relationship between these traits and fatty acid profile. Lipids of subcutaneous adipose tissue had higher monounsaturated fatty acids (MUFA) percentage (49% vs. 33%) but lower saturated fatty acids (SFA) (51% vs. 46%) and polyunsaturated fatty acids (PUFA) (16% vs. 5%) percentages than intramuscular fat depots (p<0.001). Fatter carcasses had higher MUFA percentage and lower PUFA percentage (p<0.01) in intramuscular fat. Carcass weight and conformation would contribute to explain the fatty acid profile of subcutaneous fat (p<0.05). Ultrasound readings reflected the effect of fatness on fat composition.     

毛叶山桐子果实化学成分及脂肪酸动态分析与评价

对不同生长期的重庆1号、重庆2号品种的毛叶山桐子果实的整果、果肉和种子中的基本化学成分含量进行比较,并运用气相色谱法对油脂中脂肪酸组成及相对含量进行分析.结果表明,2个品种果实在不同生长期和不同部位中粗脂肪、蛋白质、总糖、灰分、总酚、总黄酮等成分含量差异显著(P＜0.05);2个品种毛叶山桐子作为油脂原料的最佳采收期分...     

宣威火腿与金华火腿中游离脂肪酸组成比较分析

以两年宣威火腿和金华火腿为对象,采用气相色谱-质谱联用法(GC-MS)分别对宣威火腿和金华火腿的皮下和肌内脂肪中游离脂肪酸的组成进行分析。结果表明:宣威火腿和金华火腿的肌内脂肪和皮下脂肪中均检测出22种游离脂肪酸,含量较高的脂肪酸为棕榈酸(C16:0)、硬脂酸(C18:0)、油酸(C18:1n9c)与亚油酸(C18:2n6c),且不同火腿及不同部位间的脂肪酸组成含量存在明显差异;金华火腿肌内及皮下脂肪中总游离脂肪酸含量分别为29.24、102.68 μg/mg,分别比宣威火腿高34.58%(p<0.05)、29.09%(p>0.05);宣威火腿和金华火腿肌内脂肪中饱和脂肪酸含量高于不饱和脂肪酸含量,皮下脂肪中不饱和脂肪酸含量高于饱和脂肪酸含量。金华火腿肌内、皮下游离脂肪酸含量均高于宣威火腿相应部位游离脂肪酸含量。     

Fatty acid and triglyceride profiles of intramuscular and subcutaneous fat from fresh and dry-cured hams from Hairless Mexican Pigs

The study was designed to compare the fatty acid profiles and triglyceride composition of subcutaneous and intramuscular fat of raw and cured hams from Hairless Mexican Pigs. Curing (180 days) was developed throughout several ordered steps: salting, stabilization, drying and ripening. For the salting step, hams were rubbed with nitrate salt, and kept on salt 1 day per kilogram at 0-4?°C and at relative humidity of 80-85%. The rest of the process consisted of small increments of temperature (from 0-24?°C) and small decrements of relative humidity (from 82-68%). The curing process decreased (P<0.05) significantly the proportion of unsaturated fatty acids (raw: 59.2±0.3% and cured: 55.3±0.4%) and increased the saturated ones (raw: 34.4±0.3% and cured: 39.4±0.5%). Subcutaneous and intramuscular fat had similar (P>0.05) percentages of unsaturated (57.60±0.3 and 56.88±0.4%, respectively) and saturated fatty acids (37.5±0.33 and 38.3±0.4%, respectively). With the exception of the monopalmitate, the curing process decreased (P<0.05) the levels of all acylglycerols studied.     

Prevention of pre-harvest aflatoxin production and the effect of different harvest times on peanut (Arachis hypogaea L.) fatty acids

The aim of this study was to investigate the relationship between aflatoxin and fatty acids and to determine the optimum harvest time to avoid pre-harvest aflatoxin formation. It was established that harvest time had statistically significant effects on the levels of saturated fatty acids: myristic acid (C14:0), palmitic acid (C16:0), heptadecanoic acid (C17:0), stearic acid (C18:0), arachidic acid (C20:0), behenic acid (C22:0), lignoceric acid (C24:0), monounsaturated fatty acids; palmitoleic acid (C16:1), heptadecenoic acid (C17:1), oleic acid (C18:1) and gadoleic acid (C20:1); and on polyunsaturated fatty acids: linoleic acid (C18:2) and linolenic acid (C18:3). By delaying the harvest time, the ratio of saturated fatty acids decreased and unsaturated fatty acids increased. It was shown that the longer harvesting was delayed, the greater the quantity of oleic acid that was produced. Before harvest time, if the soil moisture was 5% or higher, aflatoxin was produced by fungi. It was found that the weather conditions of the region were suitable for aflatoxin production. Soil moisture appears to be more important than soil temperature for aflatoxin formation. The production of aflatoxin was not observed in the first and second harvests, both of which are at early harvest times. It was found that aflatoxin B1 during harvest time was the most significant of the four toxins. The third harvest time, which is the most widely used, was observed to have significant problems due to aflatoxin formation. Therefore, it is suggested as a result of this study that the harvest of peanuts must be done considering seed yield before the middle of September to avoid aflatoxin formation at harvest time.     

Milling fractions fatty acid composition of common (Fagopyrum esculentum Moench) and tartary (Fagopyrum tataricum (L.) Gaertn) buckwheat

The objective of the present study was to determine the composition of fatty acids in the whole grain, hulls, bran and the light flour of common (Fagopyrum esculentum Moench) and Tartary (Fagopyrum tataricum (L.) Gaertn) buckwheat harvested in two consecutive years. Fatty acid composition for different milling fractions was determined as methyl esters using gas chromatography. Nine fatty acids were determined: lauric (12:0), myristic (14:0), palmitic (16:0), palmitoleic (16:1), stearic (18:0), oleic (C18:1; n-9), linoleic (C18:2; n-6), α-linolenic (C18:3; n-3) and arachidic (20:0) acid. The highest relative content was determined for linoleic acid (from 35.54 to 47.57%), followed by oleic acid (from 20.96 to 40.76%) and palmitic acid (from 13.86 to 26.42%). The total fatty acid content was the highest in bran (up to 62.64 g/kg), followed by whole grains (up to 22.93 g/kg), light flour (up to 9.69 g/kg) and hulls (up to 5.87 g/kg). Saturated fatty acid content was the highest in the hulls and the lowest in the bran. Polyunsaturated fatty acid content was the highest in light flour. High positive correlations were found between saturated fatty acids with 18 carbon atoms or less.     

Influence of long term feeding of palm oil on the lipid composition of perirenal adipose tissue in rats

The composition of perirenal adipose tissue in Wistar strain of rats fed palm oil (PO) fat at 5% and 20% in diet for a period of 18 weeks was studied. Peanut oil (PNO) at 5% and 20% were used as controls. Under the experimental conditions, the saturation index was higher in animals fed diet containing PO compared to those fed PNO. There was no significant difference with reference to 12:0, 14:0 and 18:1 fatty acid levels, whereas linoleic acid (18:2) showed a proportional relationship between the intake and perirenal adipose tissue levels. There was a significant correlation of dietary intake of linoleic acid and the U/S ratio in the adipose tissue. Linoleic acid (18:2, n6) levels were increased in 20% PNO groups as compared to those fed PO. However, palmitoleic acid (16:1) did not show a proportional relationship between the intake and adipose tissue levels. Thus, our studies show that more saturated fatty acids are incorporated in the PO group than in the PNO groups at the end of 18 weeks feeding.     

硬脂酰辅酶A去饱和酶1基因表达对草原安格斯牛血液脂肪酸组成的影响

研究硬脂酰辅酶A去饱和酶1(stearoyl-coenzyme A desaturase 1,SCD1)基因表达对草原安格斯牛血液脂肪酸组成的影响,采集38头平均体质量(698±34)?kg、48月龄草原安格斯牛血液样品,测定其脂肪酸组成与含量,采用实时荧光定量聚合酶链式反应测定SCD1基因表达量,一代测序技术检测SC...     

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.     

陇西腊肉传统制作过程中细菌群落演替对脂肪水解及氧化的影响

为探究陇西腊肉传统制作过程中细菌群落演替对脂肪水解及氧化的影响,采用Illumina MiSeq测序技术解析陇西腊肉制作过程中微生物群落结构及演替规律,并结合气相色谱-质谱联用技术检测制作过程中脂肪酸组成及含量变化,以及肉样中酸价、过氧化值的变化。结果表明：测序深度有效地覆盖了样品中绝大部分细菌种类,测序结果进行整理、过滤后共得到186 866 条有效序列,聚类后有580 个可操作分类单元,注释到15 个门,414 个属。整个制作过程中,Proteobacteria和Firmicutes为优势细菌门,而Brochothrix、Carnobacterium、Lactobacillus、Pseudoalteromonas、Psychrobacter和Cupriavidus为优势细菌属。通过PICRUSt软件分析,菌群中与脂肪酸代谢相关基因的丰度较高;脂肪酸组成分析揭示棕榈酸（C16:0）、硬脂酸（C18:0）、棕榈油酸（C16:1）、油酸（C18:1）、亚油酸（C18:2n6c）是主要的成分,占比达到83.84%～92.43%。通过相关分析得到：Streptococcus、Staphylococcus、Lactobacillus、Cupriavidus、Carnobacterium、Brochothrix是陇西腊肉制作过程中参与脂肪代谢的相关菌群,其中,Streptococcus、Lactobacillus与饱和脂肪酸、多不饱和脂肪酸变化相关;而Carnobacterium、Staphylococcus、Brochothrix、Cupriavidus主要参与不饱和脂肪酸代谢,并与棕榈油酸、油酸、亚油酸含量的变化密切相关。     

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).     

Differences in quality characteristics of normal, PSE and DFD pork

Differences in water-holding capacity, colour and tenderness/toughness were studied in 21 pork loins belonging to three quality categories, i.e. dark firm dry (DFD), normal and pale soft exudative (PSE). The division into the three groups was based upon the ultimate pH-values of the loins (< pH 5·5, pH 5·5-6·0, pH > 6·4). The PSE loins were characterized by a poor waterholding capacity, higher cooking loss and paler colour in contrast to the DFD category. The normal loins took an intermediate position. Neither sarcomere length, determined on fresh muscle tissue, nor Armour tenderometer values showed significant differences between the various quality categories. This was in contrast to the Warner-Bratzler (W-B) shear force values, determined on cooked loins, which had the lowest values in the DFD category. A strong relationship between the W-B values and the cooking losses was found. It was concluded that neither sarcomere length nor Armour tenderometer measurements were able to predict the shear force values of cooked pork loins.