Effect of protein level in commercial diets on pork meat quality

This study assessed the effect of protein level on meat quality, intramuscular and subcutaneous fat, instrumental texture and sensory attributes on Longissimus dorsi in pork. Animals were fed two experimental diets that produced two animal groups with different percentages of intramuscular fat (IMF) (1.76 vs. 2.63). There were no significant differences in meat quality or texture profile analysis parameters between IMF groups. The percentage of saturated fatty acids was also similar, but the percentage of monounsaturated was significantly higher in the group with higher IMF and the percentage of polyunsaturated fatty acids was higher in the group with lower IMF. IMF groups had little effect on the fatty acid composition of subcutaneous fat. Warner-Bratzler shear force (WBSF) values were significantly higher in the group with lower IMF, whereas tenderness was higher in the group with higher IMF. Finally, WBSF appeared to be a good predictor of the tenderness for grill-cooked pork.     

Sensory and consumer evaluation of pork loins from crossbreeds between Danish Landrace,Yorkshire, Duroc,Iberian and Mangalitza

Iberian (I) and Mangalitza (M) boars were crossed with Duroc (D) and Landrace/Yorkshire (LY) sows and compared with the traditional crossbreed DLY. The sensory attributes were analysed, and consumers evaluated the fried loins. Gas chromatography (GC) aroma analysis was performed on the fried meat, and fatty acid composition was determined on the loin and the subcutaneous fat, respectively. No marked differences were found in odour, appearance or flavour/taste between the alternative crossbreeds and DLY; however, the alternative crossbreeds had improved textural properties. Consumer evaluation revealed that the alternative crossbreeds obtained positive associations compared with DLY, and MD was ranked best or second best by almost 60% of the consumers. No pronounced differences were found in the aroma compounds between the different crossbreeds. Correlations were found between the fatty acid composition and sensory attributes. In conclusion, by crossing the alternative breeds Iberian and Mangalitza with traditional Danish pig breeds it is possible to produce pork with attractive sensory attributes.     

不同部位牦牛肉氨基酸、脂肪酸含量分析与营养价值评价

为明确不同部位牦牛肉氨基酸、脂肪酸等营养物质含量,采集西藏那曲牦牛的上脑、里脊、外脊、米龙、臀肉、腱子肉、腹肉、肩肉及胸肉9 个部位分割肉,测定其蛋白质、脂肪、灰分、氨基酸和脂肪酸组成。结果表明：不同部位牦牛肉的蛋白质含量为19.30%～24.20%,其中腹肉中蛋白质含量最低,外脊中最高;脂肪含量为1.03%～22.47%,腹肉中脂肪含量显著高于其他各部位,米龙、外脊、臀肉和肩肉中脂肪含量较低,不足1.5%。在测定的18 种氨基酸中,谷氨酸含量最高,其次是赖氨酸、天冬氨酸、亮氨酸和精氨酸;腹肉中氨基酸含量显著低于其他部位（P＜0.05）,9 个不同部位牦牛肉中必需氨基酸占总氨基酸的比例为39.03%～40.00%,与联合国粮农组织/世界卫生组织的推荐值接近;里脊和外脊能够满足所有膳食氨基酸需要,上脑、米龙、臀肉、腱子肉、腹肉、肩肉及胸肉中,缬氨酸是限制性氨基酸。脂肪酸总量由大到小为腹肉＞上脑＞里脊＞臀肉＞外脊＞胸肉＞肩肉＞腱子肉＞米龙,油酸、棕榈酸和硬脂酸是牦牛肉中主要的脂肪酸,二十二碳六烯酸、二十碳五烯酸等n-3脂肪酸含量较少,n-6/n-3比值高于膳食推荐值。以常规营养组分、氨基酸组成和脂肪酸组成分别进行聚类分析,总体可分为腹肉、上脑与其他部位肉三大类。综上所述,不同部位牦牛肉中蛋白质、脂肪、氨基酸及脂肪酸等营养物质含量存在差异。     

中国地方猪种与国外猪种猪肉脂肪酸组成的对比分析

为深入了解猪肉脂肪酸组成,提高猪肉营养品质、促进优良猪种资源的保护和开发提供科学依据。采用气相色谱法测定猪肉脂肪酸组成,比较了10个猪种肌肉内15项脂肪酸、饱和与不饱和脂肪酸、必需脂肪酸的相对含量,并对脂肪酸组成指标进行因子分析和系统聚类分析。饱和脂肪酸中,南阳黑猪肌肉中棕榈酸相对含量最高(31.45%),滇南小耳猪肌肉的硬脂酸相对含量最高(17.79%),单不饱和脂肪酸和多不饱和脂肪酸相对含量最高的猪种分别为撒坝猪(49.02%)和南阳黑猪(25.55%)。主成分分析获得的前5个主成分可以解释全部变异的92.709%,基于主成分值的UPGMA聚类图将10个猪种归为六大类。动物脂肪酸组成受不同品种影响,中国地方猪种与国外猪种猪肉脂肪酸构成和相对含量呈现不同程度的差异。仅以猪肉脂肪酸的构成及营养价值的角度来衡量,中国地方猪种南阳黑猪猪肉在10个猪种中品质更优。     

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.     

Two by-products of the olive oil extraction industry as oleic acid supplement source for Iberian pigs: effect on the meat's chemical composition and induced lipoperoxidation

BACKGROUND: The objective of the present study was to evaluate the effect of two by‐products of the olive oil extraction industry—olive soapstocks and olive‐pomace oil—as added fat sources into feed concentrates, in two different rearing systems (free‐range complemented with concentrates and intensive rearing with concentrates) on the chemical composition and oxidative stability of Iberian pig meat. RESULTS: No differences in the chemical composition, colour and fatty acid composition of gluteobiceps m. were found due to added fat source. However, the feeding system had a significant effect on protein (P < 0.05), γ‐tocopherol (P < 0.05), colour (P < 0.01) and fatty acid composition of gluteobiceps m. Neither added fat source nor the feeding system had an effect on the malondialdehyde content. CONCLUSION: The addition of olive soapstock or olive‐pomace oil as fat sources into concentrates did not influence meat composition or fatty acid profile. However, there are differences in the fatty acid composition of meat from Iberian pigs as a result of the production system used. Copyright © 2012 Society of Chemical Industry     

Fatty acid content and composition of english beef, lamb and pork at retail

We have determined the fatty acid content and composition of retail samples of meat and assessed them with respect to UK dietary recommendations. Fifty beef sirloin steaks, pork chops and lamb chops were purchased from four supermarkets on separate occasions. The percentage of muscle (boneless basis) in the samples was 84.4 ± 4.3, 69.8 ± 7.7 and 78.9 ± 7.1 for beef, lamb and pork, respectively, with fatty acid contents of 3.84 ± 1.3, 4.73 ± 1.66 and 2.26 ± 0.7 g per 100 g muscle, respectively. Adipose tissue fatty acid contents were 70.0 ± 8.2, 70.6 ± 8.6 and 65.3 ± 9.4 g per 100 g tissue. A range of C20 and C22 polyunsaturated fatty acids (PUFA) was present in the muscle of all three species and pork adipose tissue but their concentrations in lamb and beef adipose tissue were too low to measure. The mean P:S ratios for beef, lamb and pork muscle were (adipose tissue values in parentheses): 0.11 (0.05); 0.15 (0.09) and 0.58 (0.61), and the n−6:n−3 ratios were 2.1 (2.3), 1.3 (1.4) and 7.2 (7.6). We conclude that the muscles of red meat species are a valuable source of PUFA, particularly the C20 and C22 n−3 fatty acids, in the human diet and that, considered as part of a varied diet, the low P:S ratio of the ruminant muscle, the high n−6:n−3 ratio of pork and the total fatty acid contents do not detract significantly from the nutritional value of lean meat.     

Quality characteristics of low fat ostrich meat patties formulated with either pork lard or modified corn starch, soya isolate and water

A trained taste panel could not distinguish (P>0.05) between ostrich meat patties containing either 10% pork lard or 10% of a modified starch/protein isolate (fat replacer) mixture. The panel could distinguish between the types of ostrich muscle/meat cuts used with a significant (P<0.05) number preferring ostrich patties made from meat containing a higher collagen content (±3% vs <1%). The chemical analysis of the patties showed that within the meat classes (Class fillet-de-membraned, Class A-very lean off-cuts and Class B-off-cuts containing visual connective tissue and some fat), the patties containing the pork fat had a +6% higher total fat content than those containing the fat replacer. The fatty acid profiles of the various products were in accordance with the meat type and fat or fat replacer used. The mineral profile was as expected for lean ostrich meat that had spices added. It is concluded that fat replacers can be used successfully for the production of low fat ostrich patties without any negative quality attributes being perceived.     

Effect of crossbreeding and gender on meat quality and fatty acid composition in pork

This study considers the effect of crossbreeding and gender (barrows; gilts) on meat quality and intramuscular and subcutaneous fatty acid composition in pork. The sire lines included Large White (LW), Duroc (D) and Pietrain (P) and the dam line was Landrace (LR)×LW, producing LW×(LR×LW), D×(LR×LW) and P×(LR×LW). Pork samples were removed from Longissimus dorsi (LD) and Semimembranosus (SM) muscles and subcutaneous fat (SCF). There were no important differences in meat quality parameters but D×(LR×LW) had the highest percentage of intramuscular fat. Castrated males had more intramuscular fat and more intense meat colour than female pigs. The Large White and Duroc sire line had saturated fatty acids (SFA) in SM, whereas the Pietrain sire line was significantly higher than Duroc sire line in the concentration of polyunsaturated fatty acids (PUFA), PUFA/SFA (P/S) and the n-6/n-3 ratio. The concentrations of SFA and monounsaturated fatty acids (MUFA) in SCF were significantly higher in LW×(LR×LW) and P×(LR×LW), respectively. No differences were found in the percentage of PUFA, P/S and n-6/n-3 ratio between D×(LR×LW) and P×(LR×LW). Female pigs had the most polyunsaturated intramuscular and subcutaneous fat. The results demonstrate small differences in fatty acid compositions among sires.     

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.     

Influence of a severe reduction of the feeding level during the period immediately prior to free‐range fattening on performance and fat quality in Iberian pigs

BACKGROUND: Restricted feeding before fattening is a common procedure in the production of Iberian pigs, but little scientific information about its consequences on productive traits and characteristics of fat is available. This work studied the effect of a severe feeding restriction previous to the free‐range fattening on carcass and fat quality traits in Iberian pigs, considering two different feeding levels (high restriction: HR; versus maintenance level: M) before free‐range fattening. RESULTS: Animals from the M group showed longer and higher‐perimeter hams and tended (P < 0.10) to show higher slaughter and carcass weights, carcass inner length and loin and sirloin weights than HR ones. Animals from the HR group showed lower proportions of total saturated fatty acids (SFA) and higher total monounsaturated fatty acids in the backfat inner layer than those from the M group. Total polyunsaturated fatty acids in intramuscular neutral lipids were higher in HR pigs than in M ones, while stearic acid (C18:0) was lower. The average daily gain, fatty acid profile of the outer backfat layer and that of the hepatic polar and neutral lipids and the rheological features of backfat inner layer remained unaffected. CONCLUSION: A severe reduction of the feeding level previous to free‐range fattening does not produce compensatory growth, tends to diminish carcass quality and to slightly increase IMF content and improves the fatty acid profile of the inner backfat layer. Copyright © 2007 Society of Chemical Industry     

不同部位双峰驼肉的食用品质及营养成分分析

为了探究双峰驼不同部位肉的品质特性差异及加工适宜性,为双峰驼肉的精细化加工提供理论依据,选取8岁龄阿拉善双峰驼的里脊、外脊、胸肉、腹肉、臀肉、骆驼霖、腱子肉7个部位肉样,检测不同部位双峰驼肉的食用品质,并对其营养成分和质构特性进行分析。结果表明,里脊的色差最小,颜色较鲜艳,保水性适中;外脊的脂肪（质量分数6.50%）较高,嫩度较好,但水分含量（质量分数66.11%）低导致其保水性较差;胸肉的硬度最低,具有良好的弹性和嫩度且所含氨基酸和脂肪酸最丰富、种类最齐全;腹肉具有较高的脂肪（质量分数9.03%）、良好的保水性;臀肉的硬度、熟肉率和内聚性最差;骆驼霖的蛋白质（质量分数21.27%）较高且脂肪（质量分数0.33%）较低;腱子肉的水分含量（质量分数75.27%）较高且系水率（0.89%）最大,但脂肪酸种类较少。结果表明,阿拉善双峰驼不同部位肉的品质特性存在差异,各部位肉有其适宜的加工方式。     

猪肉脂肪概念及其测定方法研究

脂肪是肉品风味的重要前体物质之一,猪肉脂肪、脂肪酸含量和组成与猪肉品质和风味之间的关系是当今肉品科学的热点研究问题之一。然而目前许多研究报道对肌内脂肪、肌间脂肪、总脂肪和粗脂肪4个基本概念仍然十分模糊,表述和使用的测定方法不正确。综述了猪肉肌内脂肪、肌间脂肪、总脂肪和粗脂肪的经典定义和规范标准测定方法。     

A feasibility study on the use of near-infrared spectroscopy for prediction of the fatty acid profile in live Iberian pigs and carcasses

This work reports on the development and optimisation of NIRS technology for fat characterization both in live pigs and in carcasses in the slaughterhouse; use of this technology would enable implementation of a real-time traceability and control system based on non-destructive sensors. A total of 52 Iberian pig fat samples were analysed using a LabSpec^®Pro A108310 spectrophotometer (Analytical Spectral Device Inc.), with a high-intensity fiber-optic contact probe. Spectra were collected in five analysis modes: from the live animal, from the carcass in the slaughterhouse, from a subcutaneous fat sample with skin, from a skin-free subcutaneous fat sample and from a transverse section. Calibrations were developed for the prediction of the four main fatty acids in Iberian pig fat, obtaining for palmitic acid SECV values of 1.24% for in vivo analysis and 0.82% for carcass analysis, for stearic acid 0.67% and 0.94%, for oleic acid 1.42% and 1.48% and for linoleic 0.36% and 0.55%, respectively. The calibrations accounted for between 60% and 74% of the variation recorded in live animals, and between 31% and 87% of variation in carcasses. These results confirm the feasibility of NIRS technology for the on-site inspection and control of Iberian pig, both in the field and in the slaughterhouse.     

猪肉丸主要原料对其凝胶性质和感官品质的影响

研究主要原料玉米淀粉、大豆分离蛋白、肥肉、水,在不同添加量时,对猪肉丸凝胶性质中硬度、弹性、黏聚性、咀爵性、蒸煮损失率和感官品质的影响.通过质构分析和感官评价,结果表明:玉米淀粉的不同添加量对猪肉丸的硬度、弹性、黏聚性、咀嚼性、蒸煮损失率有显著差异,在添加量22％时感官评分最高;大豆分离蛋白的不同添加量对猪肉丸的硬度、弹性、咀嚼性、蒸煮损失率有显著差异,在添加量为2.0％时感官评分最高;肥肉的不同添加量对猪肉丸的硬度、咀嚼性、蒸煮损失率有显著差异,在添加量30％时感官评分最高;在水的不同添加量对猪肉丸硬度、黏聚性、咀嚼性、蒸煮损失率有显著差异,在添加量35％时感官评分最高.     

云南两个地方猪和杜洛克猪的营养成分比较

对火毛撒坝猪、高黎贡山猪、杜洛克猪的生长性状、胴体性能、肉质性状进行比较,为云南两个优质地方猪种的保护与开发利用提供理论依据。试验饲养火毛撒坝猪、高黎贡山猪、杜洛克猪各10头(5♂,5♀),至260日龄随机屠宰各猪种6头(3♂,3♀),测定其生长性状、胴体性能、肉质性状、肌肉组织学特性、脂肪酸、氨基酸和胆固醇,并进行显著性比较分析。结果说明:高黎贡山猪猪肉风味、口感更好,营养价值更高;火毛撒坝猪胆固醇含量低,保健性能更佳,但沉脂率强,在饲养方式上有待改进;杜洛克猪仍保持外来猪种的特性,但鲜味氨基酸和总氨基酸含量比火毛撒坝猪高,还需进一步研究。     

Effect of organic pig production systems on performance and meat quality

The present study was carried out to establish knowledge of consequence for setting up guidelines of importance for production of competitive organic pork of high quality. Performance and meat quality characteristics were compared between three organic pig production systems based on indoor housing with access to an outdoor area and a Danish conventional indoor system including 100% concentrate during the finishing feeding stage.

The three organic systems used the following three feeding regimes: 100% organic concentrate according to Danish recommendations, 70% organic concentrate (restricted) plus ad libitum organic barley/pea silage and 70% organic concentrate (restricted) plus ad libitum organic clover grass silage, respectively.

With exception of a slightly lower daily gain in organic pigs fed 100% concentrate, no significant difference was found in performance and meat quality characteristics compared with results obtained in the conventional system. In contrast and independent of roughage used, organic pigs raised on 70% concentrate had a significant reduction in daily gain (P < 0.001) compared with pigs raised on 100% concentrate, despite the fact that no difference in feed conversion rate was seen between the tested production systems. However, the percentage of leanness increased significantly in meat from organic pigs raised on 70% concentrate plus roughage compared with meat from pigs given 100% concentrate. This was reflected in higher yield (weight) of lean cuts and lower yield of cuts with high fat content from pigs fed 70% concentrate plus roughage. In general, organic feeding resulted in a significantly higher content of polyunsaturated fatty acids in the back fat (1.8%), which increased further when restricted feeding plus roughage (4%) was used. Restricted concentrate feeding gave rise to a decrease in tenderness compared with pork from pigs fed 100% concentrate.     

The use of video image analysis for quantitative measurement of visible fat and lean in meat: Part 1-boneless fresh and cured meats

The most accurate method of measuring fat content in meat is undoubtedly chemical analysis, but this can be both costly and time-comsuming. A system using a video camera and an image analyser has been used for rapid, non-destructive measurement of visible fat and lean in fresh boneless meats and meat products. Modifications to optics and illumination have improved the contrast, enhancing the separation between fat and lean areas in beef, lamb, pork and processed meats such as ham and bacon, resulting in improved fat and lean estimations compared with the system as originally supplied. Video image analysis (VIA) has been compared with fat area measurement by planimetry, weight of fat by dissection and with chemical analysis of fat in retail size cuts of meat such as chops and steaks. Comparison of VIA data with dissection and planimetry showed good correlation. There was also good agreement with chemical fat analysis.     

驴肉主要营养成分及与其它畜禽肉的分析比较

本文测定了驴肉的水分、灰分、蛋白质、粗脂肪、脂肪酸、矿物元素、氨基酸的含量,并将驴肉与其他畜禽肉的营养成分作对比分析。结果表明:驴肉蛋白质含量比羊肉、牛肉、猪肉高,而脂肪含量比羊肉、牛肉、猪肉低。驴肉的氨基酸和脂肪酸组成是比较理想的,矿物元素中Fe含量明显高于其它畜禽肉。从营养学角度看,驴肉是比较理想的动物性食品原料。