Prevalence of boar taint in commercial pigs from Spanish farms.

The presence of boar taint can affect the sensory quality of pork because the "off" odours and flavours can be detected by consumers. The aim of this study was to determine the prevalence of boar taint in pig carcasses from 30 Spanish farms located in different regions of the country. Hot carcass weight and subcutaneous fat thickness means were 79.4±8.19 kg and 18.4±5.09 mm, respectively. Subcutaneous fat samples were classified into different levels according to androstenone and skatole concentrations in adipose tissue measured using GC-MS and HPLC. Androstenone results were: 87.4% of the carcasses below 0.50 µg/g, 7.1% from 0.50 to 1.00 µg/g (medium level), and 5.5% ≥1.00 µg/g (high level). Skatole results were: 88.9% of the carcasses below 0.10 µg/g, 4.5% from 0.10 to 0.20 µg/g (medium level), and 6.6% ≥0.20 µg/g (high level). Given these results, a future online method to classify carcasses according to boar taint is strongly recommended.

Effects of acerola fruit extract on sensory and shelf-life of salted beef patties from grinds differing in fatty acid composition.

The effects of added acerola fruit extract on sensory and shelf-life of beef patties were evaluated. Ground beef was obtained from young bulls fed one of four diets (CON: control, LIN: linseed, CLA: conjugated linoleic acid, LINCLA: LIN plus CLA). Pre-salted (1.8% w/w) beef patties (7.7% fat) with (0.15% w/w) or without acerola were packed in modified atmosphere (80%O2:20%CO2) and displayed in a retail case for 8days. There were no interactions between diet and antioxidant treatments. LIN and/or CLA had no effect on color and lipid stability during display. However, LIN increased n-3 fatty acids in beef and tended to increase intensity of rancid flavor. Addition of acerola extended shelf-life by at least 3 days by improving color and lipid stability and a decreased trend in intensity of rancid flavor of patties without affecting microbial counts. Thus, the use of acerola as a natural antioxidant can be considered an effective method to retard color and lipid oxidation in beef patties.

Effect of pH(24h), curing salts and muscle types on the oxidative stability, free amino acids profile and vitamin B2, B3 and B6 content of dry-cured ham.

The effects of a curing salt composition (with and without nitrifying salts), and the pH at 24h postmortem (pH24>6.0, 5.5

Characterization of Longissimus thoracis, Semitendinosus and Masseter muscles and relationships with technological quality in pigs. 2. Composition of muscles.

The composition of three porcine muscles (Longissimus thoracis: LT, Semitendinosus: ST, Masseter: MS) was characterized and its link with muscle quality was evaluated. The LT muscle had a higher content of tyrosine, tryptophan, and carbohydrates and a lower content of vitamin E and haem iron than the MS muscle, while the ST had similar composition to MS but a lower content of haem iron. Large differences between muscles were observed in relative amounts of most of the major fatty acids. The LT muscle had higher saturated fatty acids (SFA) and n-6:n-3 fatty acid ratio, and lower polyunsaturated fatty acids (PUFA), PUFA:SFA ratio, unsaturation index and average fatty acid chain length than the ST and MS muscles. Muscle pH, redness and chroma were positively correlated with vitamin E and unsaturated lipids and negatively correlated with tyrosine, tryptophan, carbohydrates and saturated lipids, whereas muscle lightness and expressible juice showed similar correlations but an opposite sign with these variables.

Effect of vaccination against gonadotrophin-releasing factor on growth performance, carcass, meat and fat quality of male Duroc pigs for dry-cured ham production.

The aim of this study was to compare production, carcass and meat quality parameters, boar taint compounds and fat composition of green and dry-cured hams, between immunocastrated (IM), surgically castrated (CM) and female (FE) Duroc purebred pigs (n=75, 138.7±8.27kg). Liveweight and fat and muscle thicknesses were measured and average daily gain was calculated during growth. Carcass, meat and fat quality parameters were measured. Immunocastrated grew faster than CM or FE after the second dose of vaccine. IM had the lowest dressing percentage but similar % of ham and carcass lean to FE and CM. The effect of the immunocastration on carcass fatness depended on the location, did not affect fat and meat quality and reduced skatole and androstenone levels. Both in green and dry-cured ham, immunocastration slightly altered FA composition. Thus, Duroc pigs vaccinated with Improvac are suitable for the production of high quality dry-cured ham.

Effect of high pressure processing on the level of some purines and pyrimidines nucleosides and bases in dry cured and cooked ham.

The effect of high pressure (at 600 and 900MPa) on the levels of purines and pyrimidines was evaluated in dry-cured and cooked ham. Pressurization of dry-cured ham did not modify purines and pyrimidines contents. On the contrary, treatment at 600 MPa and 900MPa caused a decrease in guanosine and an increase in adenosine respectively.

Effect of high pressure processing on cholesterol oxidation products in vacuum packaged sliced dry-cured ham.

The effect of high pressure processing (at 600 and 900 MPa) on cholesterol oxidation products has been studied in vacuum packaged sliced dry-cured ham. Pressurisation of dry-cured ham at 600 MPa did not show changes in the contents of cholesterol oxidation products. However, the effect of pressurisation at 900 MPa produced a significant increase in the contents of 7α-hydroxycholesterol, 7ß-hydroxycholesterol, ß-epoxycholesterol, α-epoxycholesterol, 25-hydroxycholesterol and 7-ketocholesterol. In view of the results, at the pressure of 900 MPa, a strong damage of membrane could be produced and the potential production of harmful compounds in dry-cured ham as it was observed for cholesterol oxidation products.

Inter-laboratory comparison of methods to measure androstenone in pork fat.

Today, different analytical methods are used by different laboratories to quantify androstenone in fat tissue. This study shows the comparison of methods used routinely in different laboratories for androstenone quantification: Time-resolved fluoroimmunoassay in Norwegian School of Veterinary Science (NSVS; Norway), gas chromatography coupled to mass spectrometry in Co-operative Central Laboratory (CCL; The Netherlands) and in Institut de Recerca i Tecnologia Agroalimentàries (IRTA; Spain), and high-pressure liquid chromatography in Agroscope Liebefeld-Posieux Research Station (ALP; Switzerland). In a first trial, a set of adipose tissue (AT) samples from 53 entire males was sent to CCL, IRTA and NSVS for determination of androstenone concentration. The average androstenone concentration (s.d.) was 2.47 (2.10) µg/g at NSVS, 1.31 (0.98) µg/g at CCL and 0.62 (0.52) µg/g at IRTA. Despite the large differences in absolute values, inter-laboratory correlations were high, ranging from 0.82 to 0.92. A closer look showed differences in the preparation step. Indeed, different matrices were used for the analysis: pure fat at NSVS, melted fat at CCL and AT at IRTA. A second trial was organised in order to circumvent the differences in sample preparation. Back fat samples from 10 entire males were lyophilised at the ALP labortary in Switzerland and were sent to the other laboratories for androstenone concentration measurement. The average concentration (s.d.) of androstenone in the freeze-dried AT samples was 0.87 (0.52), 1.03 (0.55), 0.84 (0.46) and 0.99 (0.67) µg/g at NSVS, CCL, IRTA and ALP, respectively, and the pairwise correlations between laboratories ranged from 0.92 to 0.97. Thus, this study shows the influence of the different sample preparation protocols, leading to major differences in the results, although still allowing high inter-laboratory correlations. The results further highlight the need for method standardisation and inter-laboratory ring tests for the determination of androstenone. This standardisation is especially relevant when deriving thresholds of consumer acceptance, whereas the ranking of animals for breeding purposes will be less affected due to the high correlations between methods.

Volatile profile and microbiological characterization of hollow defect in dry-cured ham.

This paper describes the physicochemical and microbiological parameters and volatile profile of the muscles surrounding the coxofemoral joint which are affected with hollow defect when compared to the part of muscles nearby which did not show this defect. Differences of the same parameters between both areas in dry-cured hams without this defect were also analyzed. Gram-positive catalase-positive cocci were the predominant flora in the muscles affected with hollow defect, with the main species being Staphyloccocus equorum, Staphylococcus nepalensis and Staphylococcus xylosus. Lactic acid bacteria, Listeria monocytogenes and Staphylococcus aureus were <2 log CFU g(-1) and Salmonella spp. was not detected. Volatile profile of samples affected with hollow defect had higher amounts of compounds such as esters, pyrazines, sulfurs and furans. There was a positive correlation between the amount of ester compounds and the hollow defect intensity. Moisture content was lower and pH values were higher in affected areas than in unaffected areas.

Analysis of seven purines and pyrimidines in pork meat products by ultra high performance liquid chromatography-tandem mass spectrometry.

An ultra high performance liquid chromatography-tandem mass spectrometry method (UPLC-MS/MS) is proposed for the simultaneous quantification of inosine, adenosine, guanosine, uridine, hypoxanthine, xanthine and uric acid in pork meat, dry-cured and cooked ham. Samples were added with (15)N(2)-xanthine (internal standard) and extracted with boiling water for 30 min. Supernatants were washed with hexane, added with formic acid 10% in water, methanol:acetone (1:1, v/v), evaporated to dryness under N(2), and finally re-dissolved in water prior to injection. Chromatographic separation was carried out with a HSS T3 column with a total time of analysis of 15 min. Two specific transitions for each compound were used for identification and quantification (with matrix matched calibration curves). Linearity, limit of detection, repeatability and accuracy were evaluated. The method was used to quantify the seven purines and pyrimidines in 15 commercial samples.

Processing of dry-cured ham in a reduced-oxygen atmosphere: effects on physicochemical and microbiological parameters and mite growth.

The effects of a reduced-oxygen atmosphere (ROA) ([O(2)]<4.5%) during part or the whole of dry-cured ham processing on microbiological and physico-chemical parameters and mite growth were investigated in two independent experiments. In Experiment 1, six hams were processed in ROA and six in air for 275 days; in Experiment 2, where lower RH was used, six hams were processed in ROA for 289 days, six for 214 days in air+75 days in ROA, and six in air for 289 days. Microbiological analyses during the process and physicochemical analyses in final products were carried out. The use of ROA during the whole process increased the L* colour parameter in the subcutaneous fat and proteolysis index and decreased b* in the external part of the subcutaneous fat and cholesterol oxide concentration. The use of ROA combined with low RH retarded microbial growth and prevented mite growth.

Detection of tetracycline and oxytetracycline residues in pig and calf hair by ultra-high-performance liquid chromatography tandem mass spectrometry.

An ultra-high-performance liquid chromatography tandem mass spectrometry method to detect residues of tetracycline (TC), epi-tetracycline (eTC) and oxytetracycline (OTC) in animal hair was developed. Hair samples were washed with water, extracted with NH(4)OH 0.1M, purified by SPE-C(18) cartridge and analyzed by tandem mass spectrometry (ESI(+), MRM mode) with satisfactory results. For the first time, accumulation of TC, eTC and OTC was confirmed in livestock hairs after a therapeutic treatment with TC and OTC, respectively. Administered drug residues were detectable in hair samples up to 2 months after the last treatment, providing a retrospective evidence of TC and OTC administration. Hair analysis seems to offer a wider window of detection than edible tissues.

Effects of tetracycline administration on the proteomic profile of pig muscle samples (L. dorsi).

Effect of tetracycline (TC) administration on the proteomic profile of pig muscle was evaluated by 2D electrophoresis and MALDI-TOF mass spectrometry. The TC content at slaughter was determined in L. dorsi samples by HPLC-DAD. Mean residual concentration of TC in the muscle of treated animals, calculated as the sum of TC and epi-TC was 126.3 microg/kg, indicating a rapid elimination of TC in this tissue. Several differential spots (n = 54, p < 0.05) were observed in protein profiles from control and treated animals. MALDI-TOF identification gave a positive match for 5 differential spots, that is, glycerol-3-phosphate dehydrogenase 1 (G3PD1), phosphoglycerate kinase 1, novelprotein (0610037L13Rik), leucine aminopeptidase 3 (LAP), and hypothetical protein isoform 2. Results show that proteomics could be a useful tool to reveal pharmacological treatments with TC, even if the possible uses of differential spots as biomarkers to detect illegal administration of TC require further studies. Different spot patterns as a consequence of TC treatments seem to be another interesting issue for the consequences on tissue metabolism and meat quality.

Consumers' sensory acceptability of pork from immunocastrated male pigs.

Boar taint is the off-odour or off flavour of cooked pork. Currently, the most common method of controlling boar taint is surgical castration. However, immunocastration has been used in some parts of the world as an alternative to surgical castration. The aim of this study was to evaluate the sensory acceptability of meat from immunocastrated pigs (IM) compared with meat from females (FE), surgically castrated (CM) and entire males (EM). Twenty animals of each type were evaluated by 201 consumers in 20 sessions. Longissimus thoracis muscle of the different animals was cooked in an oven at 180°C for 10min. Consumers scored the odour and the flavour of the meat in a 9-point category scale without an intermediate level. There were no significant differences in consumer's evaluation of meat from IM, CM, and FE. In contrast, EM meat presented a higher percentage of dissatisfied scores and was significantly (P<0.05) less accepted than meat from CM, IM and FE. Consumers' acceptability of EM meat was always lower, independently of its androstenone levels. However meat with low levels of androstenone was more accepted that meat with medium or high levels of this substance. It can be concluded that immunocastration produced pork that was accepted by the consumers, and was indistinguishable from pork from CM or FE.

Nutritional and sensory quality of porcine raw meat, cooked ham and dry-cured shoulder as affected by dietary enrichment with docosahexaenoic acid (DHA) and α-tocopheryl acetate.

The effects of dietary enrichment of pig diets with DHA from a marine source (Algatrium(®)) and α-tocopheryl acetate on the nutritional and sensory characteristics of pork and pork products were evaluated. Raw and cooked hams, and dry-cured shoulders from pigs fed with three diets (control, control supplemented with 0.3% DHA plus 50ppm α-tocopheryl acetate and control with 200ppm α-tocopheryl acetate) were used. The treatments did not cause any significant differences in proteolytic and antioxidant enzyme activities, except on catalase (CAT) which increased significantly in raw hams from pigs fed DHA supplemented diets. Vitamin E accumulated in samples with α-tocopheryl acetate supplementation. DHA added to the diet increased the DHA level by 87% compared with the control treatment in both raw and dry-cured shoulders, and exceeded 82% in cooked hams. In consequence, the incorporation of the n-3 source in the diet significantly reduced the n-6/n-3 ratio in all products. The ratio reduction ranged from 51% in dry-cured shoulders to 65% in cooked and raw hams. No significant differences were found among treatments in the sensory parameters evaluated in the cooked hams. Fishy odour and flavour were not detected in any sample by the trained panel. However, reduced cured and aged flavours and a stronger fishy flavour were found in dry-cured shoulders from pigs on the DHA enriched treatment; while, α-tocopheryl acetate supplementation had negligible influence on flavour.

Effects of alpha-tocopheryl acetate and beta-carotene dietary supplementation on the antioxidant enzymes, TBARS and sensory attributes of turkey meat.

1. The aim of the study was to evaluate the effects of alpha-tocopheryl acetate (50 mg/kg) and beta-carotene (15 mg/kg) dietary supplementation on the oxidative status of raw turkey breast and leg muscles assessed by thiobarbituric acid test values, the vitamin E levels and the antioxidant enzyme activities. In parallel, a quantitative descriptive sensory analysis was carried out on cooked, stored and reheated samples. 2. Vitamin E was present in sufficient quantity to reduce oxidation, since iron-induced reactive substances (TBARS) were significantly lower in antioxidant-supplemented treatments. The results suggested that the presence of beta-carotene in the diet limits the accumulation of alpha-tocopherol in turkey muscles. 3. In the present study, there was no conclusive relationship between dietary antioxidant supplementation and endogenous antioxidant enzyme activities. 4. Sensory evaluation showed that a longer supplementation time and dose may be necessary in turkeys to prevent meat from rancidity and warmed-over flavour (WOF). Leg pastiness and stringiness were modified by dietary antioxidant supplementation, indicating the possible synergism between antioxidants and cysteine proteinases in the perception of meat quality. 5. Given the modern trends that lead consumers to increase their consumption of poultry meat, it would be interesting to evaluate the commercial potential and cost effectiveness of routine dietary antioxidant supplementation.

The combined effects of alpha-tocopheryl acetate supplementation and enrofloxacin administration on oxidative stability of turkey meat.

1. The combined effects of dietary supplementation of vitamin E and enrofloxacin administration on the oxidative stability of turkey meat were assessed. 2. Enrofloxacin concentrations found in muscles and liver samples from turkeys receiving 200 g/kg of alpha-tocopheryl acetate plus 50 mg/kg of enrofloxacin without a withdrawal period were higher than those of samples administered with 50 mg/kg of enrofloxacin alone. Similarly, meat samples from turkeys receiving 50 mg/kg of enrofloxacin with withdrawal plus 200 mg/kg of alpha-tocopheryl acetate showed a significantly lower vitamin E accumulation than meat samples of the treatment with enrofloxacin without withdrawal plus vitamin E. 3. The results indicated an interaction between the antioxidant and the antibiotic in their effects on oxidation susceptibility and the abiotic safety of meat from turkeys fed on supplemented diets. A mutual stabilisation of both compounds by reducing the effects of free radicals or by affecting the absorption of the compounds is suggested.

Novel approach to control sulfamethazine misuse in food-producing animals by hair analysis.

The presence of sulfamethazine residues in pig and calf hair was compared with the residual levels encountered in the corresponding edible tissues (liver and muscle) as a consequence of drug administration. Sulfamethazine up to 84.7 mg kg-1 was found in calf hair samples after a pharmacological treatment, with a significant effect of hair pigmentation. High concentrations of the parent drug were detected in calf hair for 4 weeks after administration, when sulfamethazine residues were no longer detectable in the corresponding edible tissues. In a similar way, pig hair also accumulated sulfamethazine residues up to 40.5 mg kg-1, which was more than the amount detected in the corresponding muscle and liver samples at slaughter. Hair analysis seems a suitable tool to improve the efficacy of regulatory controls, and thus the safety of the food chain and to discourage the improper use of sulfamethazine in animal farming.

A simplified LC-DAD method with an RP-C12 column for routine monitoring of three sulfonamides in edible calf and pig tissue.

Use of an RP-C(12) analytical column with a mobile phase at pH 4.5 enabled excellent chromatographic separation and quantification of sulfadiazine (SDZ), sulfamerazine (SMR), and sulfamethazine (SMZ) in edible calf and pig tissue (muscle and liver). Tissue samples were extracted with acetonitrile, centrifuged without further clean-up, and analyzed by LC-DAD. The proposed conditions are useful for a rapid and reliable screening of the SDZ, SMR, and SMZ content of calf and pig tissue at concentrations lower than the maximum residue level (MRL) (LOQ between 27 and 55 ppb). Separation of some possible SMZ metabolites should be further investigated.

Hair analysis for veterinary drug monitoring in livestock production.

This review summarizes the basic information and applications concerning the use of hair analysis for the detection of misuse of therapeutic and anabolic agents in livestock animals. Hair biology, hair-shaft structure and the mechanisms of drug incorporation are described, considering the different factors which can affect the deposition. Sampling and extraction methods are reviewed with special attention to the particularities of this matrix, while the use of different analytical techniques is discussed, taking into account the concentration and the sensitivity required for drug detection. Advantages, drawbacks, promising prospects and possible applications of this technique in the future are also discussed.