The relationship between muscle α-tocopherol concentration and meat oxidation in light lambs fed vitamin E supplements prior to slaughter.

BACKGROUND: The use of concentrates supplemented with α-tocopherol in animals is an effective method to reduce the oxidative processes that occur in meat products. The high cost of α-tocopherol requires accurate feeding, so it is necessary to define the minimum period of α-tocopherol concentrate supplementation that will ensure an acceptable meat quality. Indoor concentrate-fed light lambs (n = 35) were supplemented with 500 mg dl-α-tocopheryl acetate (VE) kg(-1) concentrate for a period of between 4 and 28 days before being slaughtered at 22-24 kg body weight. Control lambs (n = 12) were not supplemented with α-tocopherol. RESULTS: The α-tocopherol content in both plasma and muscle tissues increased significantly with the length of supplementation (P < 0.001). The thiobarbituric acid-reactive substance (TBARS) concentration in meat decreased exponentially when the muscle α-tocopherol concentration was increased to 0.61-0.90 mg kg(-1) fresh meat (P < 0.05). After 7 days of display, the formation of metmyoglobin (MMb) decreased significantly as the α-tocopherol content increased to 0.31-0.60 mg kg(-1) meat (P < 0.05). CONCLUSION: A range of 0.61-0.90 mg α-tocopherol kg(-1) fresh meat protected fresh lamb meat from lipid oxidation and MMb formation. This level can be achieved by supplementation with 500 mg VE kg(-1) concentrate for a period of 7-14 days before slaughter.

Quantification and classification of deoxynivalenol-contaminated oat samples by near-infrared hyperspectral imaging.

Deoxynivalenol (DON) is the most occurring mycotoxin in oat and oat-based products. Near-infrared hyperspectral imaging (NIR-HSI) has been proposed as a promising methodology for analysing DON contamination in the food industry. The present study aims to apply NIR-HSI for DON detection in oat kernels and to quantify and classify naturally DON-contaminated oat samples. Unground and ground oat samples were scanned by NIR-HSI before their DON content was determined by HPLC. The data were pre-treated and analysed by PLS regression and four classification methods. The most efficient DON prediction model was for unground samples (R2 = 0.75 and RMSEP = 403.18 µg/kg), using twelve characteristic wavelengths with a special interest in 1203 and 1388 nm. The random forest algorithm of unground samples according to the EU maximum limit for unprocessed oats (1750 µg/kg) achieved a classification accuracy of 77.8 %. These findings indicate that NIR-HSI is a promising tool for detecting DON in oats.

Forage preservation (grazing vs. hay) fed to ewes affects the fatty acid profile of milk and CPT1B gene expression in the sheep mammary gland.

BACKGROUND: Alterations in lipid metabolism occur when animals are exposed to different feeding systems. In the last few decades, the characterisation of genes involved in fat metabolism and technological advances have enabled the study of the effect of diet on the milk fatty acid (FA) profile in the mammary gland and aided in the elucidation of the mechanisms of the response to diet. The aim of this study was to evaluate the effect of different forage diets (grazing vs. hay) near the time of ewe parturition on the relationship between the fatty acid profile and gene expression in the mammary gland of the Churra Tensina sheep breed. RESULTS: In this study, the forage type affected the C18:2 cis-9 trans-11 (CLA) and long-chain saturated fatty acid (LCFA) content, with higher percentages during grazing than during hay feeding. This may suggest that these FAs act as regulatory factors for the transcriptional control of the carnitine palmitoyltransferase 1B (CPT1B) gene, which was more highly expressed in the grazing group (GRE). The most highly expressed gene in the mammary gland at the fifth week of lactation is CAAT/ enhancer- binding protein beta (CEBPB), possibly due to its role in milk fat synthesis in the mammary gland. More stable housekeeping genes in the ovine mammary gland that would be appropriate for use in gene expression studies were ribosomal protein L19 (RPL19) and glyceraldehyde- 3- phosphate dehydrogenase (GAPDH). CONCLUSIONS: Small changes in diet, such as the forage preservation (grazing vs. hay), can affect the milk fatty acid profile and the expression of the CPT1B gene, which is associated with the oxidation of fatty acids. When compared to hay fed indoors, grazing fresh low mountain pastures stimulates the milk content of CLA and LCFA via mammary uptake. In this sense, LCFA in milk may be acting as a regulatory factor for transcriptional control of the CPT1B gene, which was more highly expressed in the grazing group.

A novel surgical approach to marginal soft tissue recessions: two-year results of 11 case studies.

This article describes a surgical procedure used to achieve gingival coverage in denuded roots in mandibular canines. The first surgical stage involves an apically displaced partial-thickness flap in the area adjacent to the recession. A laterally displaced graft is then employed to cover the recession. Although the technique involves a two-stage surgery, a palatal graft is not required and the surgical procedure only affects one site. This article also presents the clinical results 24 months after the second-stage surgery in 11 deep and wide recessions affecting misaligned mandibular canines.

Evaluation of heavy metals and polycyclic aromatic hydrocarbons in honeys from different origins.

A survey of honey samples from different geographical and botanical origins, including some samples collected from a fire-affected area in Spain, was conducted to assess their content of heavy metals and polycyclic aromatic hydrocarbons (PAHs). The levels of the determined toxic elements (Pb, Cd, As, and Sn) were low and were in the range of those reported by other studies. In our work the total amount of heavy metals and Pb was higher in dark honeys than in pale honeys. In the collected samples, no detectable levels of the 15 PAHs studied were found. The obtained data served to assess the levels of heavy metals and PAHs in honey samples from different geographical and environmental origins and to contribute to the scarce data about pollutant content of this matrix. In light of these results, the analyzed samples do not pose any serious concern to human health, and the data obtained in this study could serve to contribute to the establishment of specific maximum limits for honey.

Multiresidue determination of carcinogenic polycyclic aromatic hydrocarbons in honey by solid-phase extraction and high-performance liquid chromatography.

An analytical procedure based on solid-phase extraction, using ethyl acetate as the elution solvent, and high-performance liquid chromatography with fluorescence and diode array detection was developed for the identification and quantification of polycyclic aromatic hydrocarbons (PAHs) in honey. The method has been optimized and validated in accordance with Commission Regulation 333/2007 and Commission Decision 2002/657/EC. This method allows the identification of the 15 PAHs that should be monitored in food matrices, as proposed in 2002 by the Scientific Committee on Food and later by the European Union in the Commission Recommendation 2005/108/EC, because of their genotoxic and carcinogenic properties. The results of the validation study were in agreement with quality criteria described in European legislation in terms of sensitivity, accuracy, and ruggedness, and the method was applied to the analysis of 42 honey samples (21 from Spain and 21 from other regions). The honey samples were not contaminated by PAHs at detectable levels and thus could be marketed without health risk.