Increase of geometrical and positional fatty acid isomers in dark meat from broilers fed heated oils

Formation of Zn-protoporphyrin during the elaboration process of non-nitrified serrano dry-cured hams and its relationship with lipolysis

This study assessed the ZnPP content, heme content, salt content, and instrumental color in the biceps femoris and semimembranosus muscles during the elaboration of Serrano dry-cured ham manufactured without the addition of nitrate and nitrite for 15 months. The effects of lipolysis and lipid oxidation on the content of Zn-protoporphyrin were also investigated in the biceps femoris. We found that the maximum formation of Zn-protoporphyrin occurred between end of resting and 6 months of processing, which coincides with temperature increase during processing and the end of salt equalization. Zn-protoporphyrin further increased in the biceps femoris until 9 months of processing but remained unchanged in the semimembranosus. Free fatty acid content increased till 6 months and then remained unchanged until the end of the process. These findings and those from an in vitro study reinforced the idea that the release of free fatty acids can promote the activity of the endogenous enzyme ferrochelatase and contribute to the formation of Zn-protoporphyrin from heme. However, the content of Zn-protoporphyrin decreased at the end of the processing, which may be due to the progression of lipid oxidation.

Use of tocopherol extract and different nitrite sources and starter cultures in the production of organic botifarra catalana, a cooked cured sausage

This research evaluates the effects of adding a tocopherol mix (0 or 200 mg/kg), two nitrite sources (sodium nitrite or a nitrate-rich vegetable concentrate) and the use of Staphylococcus carnosus together with fermentation types that varied in temperature (12 h at 4 ℃ or 16 ℃) on different quality parameters and acceptability of cooked cured sausages after vacuum packing and storage at 4 ℃ for 120 days. In the presence of S. carnosus, residual nitrate and nitrite levels were reduced. Sausages containing vegetable concentrates and without S. carnosus resulted in higher amounts of residual nitrate and lower curing efficiency. The lowest values in redness and acceptability were observed in those sausages without starter cultures. The addition of tocopherols had no effect on oxidative status and susceptibility to oxidation. However, the highest amount of hydroperoxides was related with nitrite decreased formation. Overall, vegetable concentrates can be used as curing agents if fermentation with a nitrate-reducing starter culture is allowed.

Effect of fermentation time and vegetable concentrate addition on quality parameters of organic Botifarra Catalana, a cured-cooked sausage

The effects of the addition of two different sources of nitrite (pure NaNO2 or a nitrate-rich vegetable concentrate) and three different fermentation times with nitrate-reducing cultures (6, 12, or 24 h at 16 °C) on microbial counts, pH, residual nitrate and nitrite amounts, and susceptibility to oxidation of botifarra catalana sausage were studied. Moreover, curing efficiency, color, tocopherol and tocotrienol contents, oxidative status, and consumer acceptability of these sausages were assessed after vacuum packaging and storage at 4 °C for up to 180 days. Residual nitrate and nitrite amounts were lower than the limits established by the European Union for organic meat products. Longer periods of fermentation produced higher meat curing efficiency ratios, whereas consumer acceptability scores were highest for sausages with added vegetable concentrate. Storage of the sausages caused small quality changes. Therefore, these results indicate that vegetable concentrate is a useful alternative for organic cured-cooked meat products.

Enrichment of eggs in n-3 polyunsaturated fatty acids by feeding hens with different amount of linseed oil in diet

The production of n-3 polyunsaturated fatty acid enriched eggs by addition of linseed oil to the laying hens' diet has been evaluated in terms of production parameters and n-6/n-3 ratio. A total of 150 18weeks old Lohmann Brown laying hens were housed in cages and fed with basal diet and four experimental diets containing 1%, 2%, 3% or 4% of linseed oil added to the basal diet. The effect of the altered level of linseed oil on hens laying performance, fatty acid content and composition and cholesterol content in egg yolk has been evaluated during 13weeks of experiment. Egg weight, yolk fat content, yolk weight, yolk percentage and shape index were not influenced by dietary treatment. The ratio between n-6 and n-3 polyunsaturated fatty acids in eggs decreased in first 5weeks and then remained stable until the end of the experiment for all experimental groups. Different contents of linseed oil in feed highly influenced the n-6/n-3 ratio (P<0.0001). Addition of linseed oil did not influence the cholesterol content in yolks (P=0.5200) while the only factor affecting the cholesterol content was the hens age (P<0.0001).

Dietary strategies to improve nutritional value, oxidative stability, and sensory properties of poultry products

Consumers demand both safer and more nutritious food products exempt of non-natural origin preservatives or other food additives. In this frame, products with lower fat content and/or a higher ratio in unsaturated fatty acids, especially n-3 fatty acids, are desired because these lipids can help prevent the development of cardiovascular and inflammatory pathologies. The intake of meat products is of interest because they are an excellent source of vitamins and minerals. In addition, the shelf-life of meat products can be extended by the presence of natural antioxidants coming from different sources such as plant extracts. Therefore, different strategies have been studied to improve the nutritional value, oxidative stability, and sensory characteristics of meat products and eggs through different mineral and natural dietary supplements. In comparison to other strategies, dietary supplements present the advantage that first the living animals may efficiently distribute the compounds throughout the tissues and second, the dietary supplementation is safer because the resulting enriched meat products and eggs ensure tolerable amounts in humans. Poultry meats and eggs are widely consumed and their fatty acid profile and tocopherol content can be easily modified through different dietary strategies thus being excellent models to improve their nutritional value and oxidative stability.

Effects of Various Fat Sources, α-Tocopheryl Acetate, and Ascorbic Acid Supplements on Fatty Acid Composition and α-Tocopherol Content in Raw and Vacuum-Packed, Cooked Dark Chicken Meat

A factorial design was used to study the effects of dietary fat sources (beef tallow, fresh and oxidized sunflower oils, and linseed oil), alpha-tocopheryl acetate (0 and 225 mg/kg), and ascorbic acid (0 and 110 mg/ kg) supplementation on fatty acid composition, as well as on fat and alpha-tocopherol content in vacuum-packed raw and cooked meat stored at -20 degrees C. Raw meat fatty acid composition was affected by dietary fat sources and tocopheryl acetate supplementation. After cooking, meat composition was only affected by dietary fat sources. Birds fed linseed oil yielded meat rich in n-3 fatty acids, especially linolenic acid, which provides about 20% of the adequate intake for this fatty acid. Birds fed sunflower or oxidized sunflower oil produced meat rich in n-6 fatty acids, whereas those fed beef tallow resulted in meat rich in saturated and monounsaturated fatty acids. Raw and cooked dark chicken meat alpha-tocopherol content was only affected by tocopherol supplementation. Supplementation with alpha-tocopheryl acetate led to alpha-tocopherol-enriched meat, which provides about 25% of the recommended dietary allowance. Moreover, this content in vacuum-packed samples was not modified even after 7 mo of storage at -20 degrees C.