Prediction of lamb meat fatty acid composition using near-infrared reflectance spectroscopy (NIRS)

The aim of this study was to assess the feasibility of near-infrared reflectance spectroscopy (NIRS) for predicting lamb meat fatty acid composition. We compared ground vs. intact non-ground meat samples to determine whether grinding and homogenisation of meat samples improved the performance of the predictions. We used 76 male lambs, of which 32 were pasture-fed and 44 stall-fed with concentrate and hay. The reflectance spectrum of Longissimus lumborum muscle was measured at wavelengths between 400 and 2500 nm. Predictions were better with ground than with intact muscle samples. NIRS accurately predicts several individual fatty acids (FA) (16:0, 18:0, 16:1 Δ9 cis, 17:1 Δ9 cis, 18:1 Δ9 cis, 18:1 Δ11 cis and 16:1 Δ9 trans) and several FA groups (total linear saturated FA, total branched saturated FA, total saturated FA, total cis monounsaturated FA (MUFA), total trans MUFA, total MUFA and total polyunsaturated PUFA). These results show the potential of NIRS as a rapid, and convenient tool to predict the major FA in lamb meat.     

On-line determination of fatty acid composition in intramuscular fat of Iberian pork loin by NIRs with a remote reflectance fibre optic probe

A near infrared spectrometer equipped with a standard 210/210 bundle remote reflectance fibre-optic probe, with a 5×5 cm quartz window type, was used for the determination of fatty acids in the Longissimus dorsi muscle of Iberian breed swine. The fatty acids C14:0, C16:0, C16:1, C17:0, C17:1, C18:0, C18:1, C18:2, C18:3, Σpolyunsaturated, Σmonounsaturated and Σsaturated were determined in samples of intramuscular fat from Iberian breed swine by direct application of the fibre-optic probe onto the loin sample, with no treatment or manipulation of the sample. The regression method employed was modified partial least squares. The calibration results using the fibre-optic probe for 74 loin samples had multiple correlation coefficients (RSQ) for C14:0, C16:0, C16:1, C17:0, C17:1, C18:0, C18:1, C18:2, C18:3, Σpolyunsaturated, Σmonounsaturated and Σsaturated acid of 0.785, 0.798, 0.788, 0.825, 0.762, 0.765, 0.696, 0.859, 0.878, 0.807, 0.943, 0.858, respectively, and standard errors of prediction corrected for the same fatty acids (%) of 0.08, 0.63, 0.26, 0.02, 0.02, 0.51, 0,77, 0.64, 0.05, 1.06, 0.34, 0.70, respectively. The robustness of the method was checked by applying the fibre-optic probe to unknown samples of Iberian breed pork loin in a slaughterhouse, using 15 samples for the external validation.     

Influence of dietary fat, on fatty acid composition and sensory properties of dry-cured Parma ham

A feeding trial with 27 pigs was performed in order to estimate the effect of different dietary fats on the fatty acid composition, flavour and sensory properties of dry-cured Parma hams, ripened for 16 months. The animals received a pelleted diet supplemented with different fat sources: tallow (TA), corn oil (CO), and rapeseed oil (RO). The sensory quality of the hams was evaluated by means of sensory analyses and by instrumental procedures such as gas chromatography-mass spectrometry of the volatile aroma compounds. A treatment effect was detected for linolenic acid in RO vs. CO and TA hams (P<0.01) and for MUFA content (P<0.01) that was higher in RO and TA compared with CO. The results of panel test showed a significant difference (P<0.05) between TA vs. CO and RO hams. Volatile compounds showed limited differences even if in CO group the amount of singular compound is higher than TA and RO.     

Determination of fatty acids in the subcutaneous fat of Iberian breed swine by near infrared spectroscopy (NIRS) with a fibre-optic probe

A near infrared spectrometer equipped with a standard 1210/210 bundle remote reflectance fibre-optic probe, with a 5×5 cm quartz window, was used for the determination of fatty acids in the subcutaneous fat of Iberian pigs. A comparative study was made of the determination of fatty acids (C14:0, C16:0, C18:0, C18:1, C18:2, C18:3, C20: 1, Σpolyunsaturated, Σmonounsaturated and Σsaturated) in samples of subcutaneous fat from Iberian pigs by direct application of the fibre-optic probe on samples of whole subcutaneous fat and with cam-lock cups, assessing extracts of total lipids with diethyl ether. The regression method employed was modified partial least squares (MPLS). Calibration of 157 samples, using the fibre optic probe, allowed determination of fatty acids in the following ranges: C14:0 (0.78-1.77), C16:0 (15.87-29.74), C18:0 (4.61-15.90), C18:1 (43.50-61.27), C18:2 (2.03-13.94), C18:3 (0.13-1.14), C20:1 (0.45-2.32), Σpolyunsaturated (2.31-14.82), Σmonounsaturated (47.37-65.62), Σsaturated (22.09-47.31), with corrected standard errors of prediction SEP(C) of 0.093, 0.56, 0.67, 0.94, 0.42, 0.10, 0.20, 0.46, 0.94, 0.83, respectively. The robustness of the method using the fibre-optic probe was tested in a slaughterhouse using 23 samples for external validation, giving multiple correlation coefficients (RSQ) for C14:0, C16:0, C18:0, C18:1, C18:2, C18:3 C20:1, Σpolyunsaturated, Σmonounsaturated, Σsaturated acids of 0.72, 0.94, 0.72, 0.79, 0.88, 0.55, 0.17, 0.88, 0.74, and 0.90, respectively, and a corrected standard error of prediction [SEP(C)] for these acids (%) of 0.11, 0.60, 0.84, 1.20, 0.77, 0.11, 0.30, 0.76, 1.21, and 1.18, respectively.     

Texture and appearance of dry cured ham as affected by fat content and fatty acid composition

The relationship between texture and appearance characteristics and the moisture, intramuscular fat (IMF) content and fatty acid composition of dry cured Iberian ham was studied using principal component analysis. Intramuscular fat content positively influenced the proportion of oleic acid (R=0.5578), and exhibited a negative relationship with linoleic and arachidonic acids (R=−0.5215 and −0.5770 respectively). IMF content also had a positive influence on some texture and appearance traits of ham, such as oiliness, brightness, juiciness and marbling. However, it was negatively related to dryness, fibrousness and hardness. Moisture displayed no relationship with juiciness, dryness or any other textural or appearance trait. Therefore, within the ranges of fat content and moisture found in the present study, IMF content has a stronger influence on the texture of ham than the degree of dehydration.     

Age-related changes in intramuscular and subcutaneous fat content and fatty acid composition in growing pigs using longitudinal data

The evolution of intramuscular fat (IMF) and subcutaneous backfat (SB) content and fatty acid composition with age was investigated. A repeated sampling scheme (n=517) for longissimus dorsi (LM) and SB specimens was performed from 160 to 220 days on 216 purebred Duroc barrows. IMF content increased linearly with age at a rate of 0.05%/day, with major compositional changes occurring in C18:1 and C18.2, which increased and decreased by around 4%, respectively. Backfat thickness increase rate declined with age, showing similar compositional changes to IMF but halved in magnitude. Fat content itself also influenced fat composition. At a fixed age, both saturated (SFA) (C16:0) and monounsaturated (MUFA) (C18:1) increased with IMF but only SFA (C16:0 and C18:0) with SB. Aging mostly affected MUFA while fatness SFA. A delay in age at slaughter will enhance IMF and C18:1 in relation to overall fatness but at expense of decreasing body and loin growth rate.     

Fatty acid composition of subcutaneous fat of sheep grazed on eight different pastures

The levels of eight long chain fatty acids (14:0, 16:0, 16:1 17:0, 17:1, 18:0, 18:1, 18:2) were measured in the subcutaneous fat of S.A. Mutton Merino wethers (5 months old, 20-25 kg live mass, 8 per treatment) and, including 18:3, in eight pastures grazed for 84 days (maize stubble, Z. mays; Triticale; L. multiflorum; L. perenne; D. glomerata; D. eriantha; C. dactylon; M. sativa). Respectively, percentage fatty acid contents of subcutaneous fat and pastures were 14:0 5·04 ± 0·86 and 0·67 ± 0·37, 16:0 22·85 ± 0·81 and 17·83 ± 3·00, 16:1 2·07 ± 0·22 and 2·42 ± 1·17, 17:0, 1·68 ± 0·04 and 0·42 ± 0·16, 17:1 0·75 ± 0·06 and 0·17 ± 0·19, 18:0 25·94 ± 2·02 and 4·95 ± 1·68, 18:1 32·27 ± 0·93 and 8·12 ± 11·70, 18:2 1·59 ± 0·36 and 15·89 ± 5·16, 18:3 measured in pastures only 34·51 ± 15·91. The palmitoleic acid (16:1) content of pastures increased (P < 0·05) as the ether extractable lipid content of the pastures increased. Pasture treatments influenced the levels of 14:0, 17:1 and 18:2 highly significantly (P < 0·01) and of 18:0 significantly (P < 0·05). Increasing levels of fatness of ribcut samples were associated with a decrease in 14:0 and an increase in 17:1 (P < 0·01) and an increase in 18:2 (P < 0·05).     

Prediction of the feeding background of Iberian pigs using the fatty acid profile of subcutaneous, muscle and hepatic fat

Thirty Iberian pigs weighing 95 kg were randomly distributed into three groups of 10 animals each and fattened in three traditional management systems ['montanera' (MO), fed extensively on acorns, 'cebo' (CE) fed on a commercial diet and 'recebo' (RE), fed on acorns and a commercial diet]. Fatty acids from the Masseter muscle, lard and liver were analysed. In the lard, fatty acid profiles from MO and RE pigs presented minor differences; however, in the liver, RE pigs showed differences to MO pigs in most of the fatty acids studied. This suggests that the muscle and especially the liver fatty acid profile reflects the feeding regime during the last phase of feeding, while the lard reflects longer term differences.     

肃南牦牛不同部位脂肪中脂肪酸组成分析

目的 为建立科学的牦牛脂肪中脂肪酸评价方法,利用主成分分析法对牦牛不同部位脂肪品质进行综合评价,以期为指导高品质牦牛产品加工和品质评价提供依据。方法 本试验采集肃南牦牛肋条表面、臀肌、肾周、肠周及皮下5个不同部位的脂肪,测定牦牛不同部位脂肪AV、POV,并采用GC-MS技术对5个不同部位脂肪中脂肪酸组成及含量进行测定,采用面积归一化法进行定量,探究肃南牦牛不同部位脂肪组成成分的差异性,并结合多元统计分析讨论脂肪酸成分含量对不同部位脂肪品质的影响。结果 以脂肪酸种类及含量为评定指标,在5个不同部位中均检出36种脂肪酸,以硬脂酸为主,含量都在70~160 g/100g之间;其次是油酸、棕榈酸和亚油酸含量较高。对不同部位的SFA、MUFA、PUFA含量分析表明,皮下脂肪UFA/SFA比值较大,风味较佳、适口性更好。PCA分析表明前三个主成分的累积贡献率高达99.41%,很好的实现了牦牛5个不同部位脂肪的区分。结论 牦牛脂肪中脂肪酸种类丰富,富含多不饱和脂肪酸。不同部位脂肪酸含量有着显著性差异,PCA分析对牦牛不同部位脂肪品质进行综合评价是客观、可行的,为牦牛不同部位脂肪鉴别提供了快速、准确的新方法。     

Dietary CLA alters intramuscular fat and fatty acid composition of pig skeletal muscle and subcutaneous adipose tissue

The present study was conducted to determinate the responsiveness of different levels of dietary conjugated linoleic acid (CLA) on intramuscular fat (IMF) and fatty acid composition of skeletal muscle and fat in pigs fed from 59.5 to 133.5 kg. Forty female Large White × (Large White × Landrace) pigs were used. Four levels (0%, 0.5%, 1% and 2%) of a commercial enriched CLA oil supplementation (60% of CLA isomers, 30% cis-9, trans-11 and 30% trans-10, cis-12) were fed to pigs. Carcass, ham, foreleg and loin weights were recorded. Dietary CLA enrichment increased the loin weight (P < 0.01) and the combined weights of hams + forelegs + loins (P < 0.02). IMF content in Longissimus dorsi was also increased by dietary CLA treatment (P < 0.001) and a linear response was observed. Dietary CLA increased saturated fatty acids (SFA) and decreased monounsaturated fatty acids (MUFA) in muscle and adipose tissue (P < 0.001). Feeding 1% CLA to finishing swine increases IMF in heavy pigs slaughtered at an average weight of 133.5 kg.     

不同产地元宝枫种仁油脂含量及脂肪酸成分研究

元宝枫是我国特有的木本油料作物,种仁油脂含量丰富。为了探明元宝枫种仁油脂及脂肪酸含量在不同生长环境间的变化,促进元宝枫油用资源的开发,实验采用了索氏提取法及GC-MS分析法测定了9个产地天然元宝枫的种仁含油量、脂肪酸组分及含量,并分析成分间的差异性及相关性。结果表明9个产地元宝枫种仁平均含油量达到了43.30%,含量范围为18.87%～52. 23%。种仁油共鉴定出13种脂肪酸组分,其中亚油酸含量为最高,达到32. 28%,其次为油酸,平均含量为25. 36%,功能性成分神经酸的平均含量为5.25%,油脂中不饱和脂肪酸比例在87.05%～90. 16%。油脂和脂肪酸相关性分析显示,油酸与不饱和脂肪酸显著性正相关,与油脂含量极显著性正相关,相关系数分别为0.78,0. 82,神经酸分别与不饱和脂肪酸、油脂含量弱正相关,亚油酸与油脂含量呈极显著性负相关关系。实验为元宝枫种仁油营养价值评价提供一定的指导,为元宝枫种子食用及药用价值开发提供了基础。     

Influence of genetic type, live weight at slaughter and carcass fatness on fatty acid composition of subcutaneous adipose tissue of raw ham in the heavy pig

The study aimed to assess some quality traits of the subcutaneous adipose tissue of raw ham for Parma production, obtained from 56 “traditional” Landrace × Large White (L × LW) and 56 Cotswold commercial hybrid (CH) pigs reared in the same conditions and slaughtered at an average live weight (l.w.) of about 165 kg. Further, the relationships between lipid composition, l.w. and carcass fatness were studied. Compared to the CH, the fatty tissue of L × LW pigs showed a lower water (6.33% vs. 7.35%, P < 0.01) and a higher lipid (91.18% vs. 90.18%, P < 0.01) content. CH lipids had higher polyunsaturated fatty acids (16.53% vs. 13.75%, P < 0.01), and smaller saturated fatty acids (38.20% vs. 40.26%, P < 0.01) content and a higher iodine value (69.69 vs. 65.22, P < 0.01). An increased slaughter weight was associated with a lower degree of lipid unsaturation, but only the lowest weight class (<160 kg) showed a significant difference compared to the other two classes (⩾160 < 170 and ⩾170 kg). Regardless of genetic type or l.w. class, an increase in backfat thickness is associated with an increase in saturated and monounsaturated fatty acids and a remarkable reduction in polyunsaturated content.     

金华火腿中肌内脂肪的提取和脂肪酸分析研究

通过正交实验,确定金华火腿中肌内脂肪的最佳提取条件是:氯仿和甲醇(2:1,v/v)的用量为样品重量的14倍,振荡1.5h,取滤液加其1/2体积的1%NaCl溶液.处理60d的金华火腿中肌内脂肪的含量为12.4%,甘油酯、磷脂、游离脂肪酸分别占76.5%、18.8%、4.7%.甘油酯中单不饱和脂肪酸的含量最高,为47.89%;而磷脂中多不饱和脂肪酸的含量最高,为50.94%;游离脂肪酸中则含有较多的饱和脂肪酸(41.56%).甘油酯、磷脂和游离脂肪酸中都是以C16.0、C18:1、C18:2为主要成分.     

Protein,fat and fatty acid composition of Celosia species

The seeds of 13 lines of Celosia referable to four species were analysed for protein, fat and fatty acid composition. The protein contents varied from 101 to 170 g kg^?1 and fat contents from 56 to 109 g kg^?1. The fatty acid composition was of the simple palmitic-oleic-linoleic type.     

坚果中脂肪含量及脂肪酸组成分析

目的分析16种市售坚果中脂肪含量及脂肪酸组成,比较不同品种坚果间脂肪含量、饱和脂肪酸和不饱和脂肪酸组成的差异。方法采用气相色谱分析法测定坚果中37种脂肪酸的含量,用最小显著性差异法(least-significant difference,LSD)法进行多重比较。结果坚果的平均脂肪含量为(55.6±0.86)g/100 g,变化范围为40.2~71.3 g/100 g,碧根果脂肪含量显著高于其他品种坚果脂肪含量(P0.05);坚果中的不饱和脂肪酸含量为72.77~95.47 g/100 g脂肪,平均值为(86.68±0.12)g/100 g脂肪,显著高于饱和脂肪酸4.53~22.19 g/100 g脂肪,平均值为(11.31±0.16)g/100 g脂肪(P0.05),东北榛子中单不饱和脂肪酸总含量最高,为84.34 g/100 g脂肪,而纸皮核桃中的多不饱和脂肪酸总含量最高,为74.17 g/100 g;坚果中不含短链脂肪酸和中链脂肪酸。结论坚果中不饱和脂肪酸含量较多,富含ω-6和ω-3脂肪酸,营养价值较高。     

Comparative lipid composition of porcine muscles at different anatomical locations

The influence of anatomical location on the intramuscular lipids was studied in Large White pigs. The amount of total, neutral and polar lipids and the composition of fatty acids of the above three fractions were determined for Longissimus dorsi (LD) at two points and Transversus abdominis (TA) and Biceps femoris (BF) taken from the two half carcasses of an animal. The symmetrical samples from the same animal had identical intramuscular lipid characteristics. The three muscles did not show significant differences in their total (2·8 to 2·4g/100g) and neutral (2·1 to 1·4g/100g) lipid contents. The amount of polar lipids was characteristic of every muscle (0·65 g, 0·84 g and 0·97 g per 100 g, respectively, in LD, BF and TA). The fatty acid composition of neutral lipids was influenced by the type of muscle. Polar lipid had similar fatty acid composition in the three muscles. The intramuscular lipids contained appreciable amounts of essential fatty acids of the family n-6; interestingly, a part of which (25% of EFA) was the long chain fatty acid (C20 and C22) located in the polar lipids.     

Prediction of lean and fat composition in swine carcasses from ham area measurements with image analysis

Video images of ham cross-sections were recorded from 71 pork carcasses (ranging in weight from 72 to 119 kg). Three sets of prediction equations were developed to estimate pork carcass lean and fat composition from video image analysis (VIA) of ham cross-sectional area measurements, 10th rib back fat depth (TENFAT) and hot carcass weight (HCKg). Carcass data of dissected lean and fat in the four primal cuts (ham, loin, Boston button and picnic shoulder) were used as dependent variables in establishing regression equations. The first set of equations combined VIA ham measurements and total ham weight (HTKg). Regression models containing the single variable HTKg times ham percentage lean area (Vol. 1) or HTKg times ham percentage fat area (Vol. 2) accounted for 88% and 68% of the variation in total carcass lean weight (CLKg) and total carcass fat weight (CFKg) from the right side of each carcass, respectively. The second set of equations combined VIA ham measurements and TENFAT (cm). Multiple regression models involving TENFAT, Vol. 1, and Vol. 2 accounted for 91% and 90% of the variation in CLKg and CFKg. The third set of equations used VIA ham measurements, TENFAT and HCKg. Carcass lean weight was best predicted by HCKg, TENFAT, and ham lean area (HLA) (R² = .92). Carcass fat weight was best predicted by HCKg, TENFAT, and Vol. 2 (R² = .91). Overall correlations showed a high association between Vol. 1 and CLKg (r = .94, P < .0001) and Vol. 2 and CFKg (r = .83, P < .0001). Ham lean area was related to CLKg (r = .74, P < .0001) and ham fat area to CFKg (r = .81, P < .0001). The results of this study indicated video image analysis of ham cross-section slices combined with backfat depth at the 10th rib can be used for accurate estimation of total carcass lean or fat composition.     

Fatty acid composition of meat and perirenal fat in rabbits from two different rearing systems

To evaluate the effect of different rearing systems and sex on the fatty acid composition of rabbit meat and perirenal fat, the fat content and fatty acid composition of Longissimus lumborum and perirenal fat were determined by gas chromatography on 40 rabbits (20 males and 20 females) of the Carmagnola Grey breed reared from 9 to 16 weeks of age in individual California type cages (0.12 m²) or in group ground pens (0.25 m²/head). Ether extract percentage of muscle was significantly influenced by the housing system while, both sex and rearing method affected the fatty acid composition with a decrease in monounsaturated fatty acid (MUFA) and an increase in polyunsaturated ones (PUFA) in penned and male rabbits. The same trends were observed in the fatty acid composition of the perirenal fat, gender only had a significant affect on the saturated fatty acid (SFA) content in the perirenal fat. Indices relating to human health showed the PUFA/SFA ratio to be over the minimum recommendation for rabbits reared in pens and for males, while only the n6/n3 ratio was above the maximum recommendation for caged rabbits. Atherogenic index (AI) of perirenal fat was affected by gender, but no differences were observed in trombogenic index (TI) in either muscle or perirenal fat.     

Authentication analysis of cod liver oil from beef fat using fatty acid composition and FTIR spectra

This study aimed to authenticate cod liver oil (CLO) from beef fat (BF) by determining the level of BF as a fat adulterant in CLO. Two instrumental techniques, namely GC-FID for fatty acid analysis and Fourier transform infrared (FTIR) spectroscopy, were exploited for such authentication. The decreased level of some fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), could be used as an indicative means to detect the adulteration of CLO with BF. In addition, FTIR spectroscopy combined with partial least-squares (PLS) at frequency regions of 1200-1000 cm(-1) was successfully developed for the quantification of BF in CLO. Using the PLS model, the errors obtained in calibration and prediction samples were 0.55% and 0.82% v/v, respectively.