Physicochemical Characteristics, Fatty Acid Profile, Alpha-Tocopherol Content, and Lipid Oxidation of Meat from Ewes Fed Different Levels of Distilled Myrtle Residues

Effects of Drying Methods on Chemical Composition, Lipid Oxidation, and Fatty Acid Profile of a Traditional Dried Meat Kaddid

This work aimed to study the effect of three drying methods, namely sun-drying (SD) (T = 32 °C), continuous convective drying (CCD) (T = 35 ± 2 °C) and interval starting accessibility Drying (ISAD) (T = 35 ± 2 °C) with an active time of 30 s (ton) and a tempering time of 60 s (toff), on selected quality characteristics of a traditional dry-salted meat product known as "kaddid". The analyses of chemical composition, lipid oxidation and fatty acid profile of kaddid were carried out before and after 45 days of storage (t = 0 vs. t = 45) at ambient temperature. Chemical composition and lipid oxidation (TBARS) of kaddid were affected by the drying methods. The CCD samples showed the lowest level of lipid oxidation. Protein content was better preserved via the ISAD method (7.27 g/kg DM). The fatty acid profile revealed the lowest mono-unsaturated fatty acid content in the ISAD samples; however, no significant difference was observed between the drying processes for the total poly-unsaturated fatty acid content. The storage period led to a significant decrease in the SFA values of CCD and ISAD samples against an increase in the MUFA ones. ISAD appeared to be a promising drying mode with a lower effective drying time and a good product quality preservation.

Effect of myrtle leaves integration in sheep diet and its addition as powder on leg meat' oxidative stability, physicochemical, microbiological and sensory properties during storage

The synthetic antioxidant improved the shelf life of meat products; however, consumers start to reject them for health reason. For this, the natural antioxidants like Myrtle distillate leaves (MDL) could be an interesting alternative and potential natural antioxidant given their richness in bioactive compounds. This study aimed to test the effect of myrtle distillate leaves (MDL) as natural antioxidant in premortem phase as diet of cull ewes and in postmortem phase in form of powder added to deboned legs on meat' quality. All ewes received individually 500 g of hay and 750 g of concentrate for Control (C) group; for Myrt group, the concentrate was partially replaced (400 g) by pellets containing 30% MDL and 350 g concentrate. For each ewe, both legs were used for the experiment; one leg was treated with MDL powder and the other with Control. Meat from ewes' fed MDL presented better scores for red color, aftertaste and juiciness, than control group. Meat treated with MDL powder showed the highest values of total phenolic, α-tocopherol content and redness score with lower lipid oxidation (p < .05). The microbiological quality of meat was not affected by MDL. Myrtle distillate leaves could be used in different forms, in order to obtain higher meat product quality.

Flavor formation based on lipid in meat and meat products: A review

Meat product is popular throughout the world due to its unique taste. Flavor is one of the most important quality characteristics of meat products and also is a key influencing factor in the overall acceptability of meat products. The flavor of meat products is formed by precursors undergoing a series of complex reactions. During meat product processing, lipids are hydrolyzed by lipase to produce flavor precursors such as free fatty acid, then further oxidized to form volatile flavor compounds. This review summarizes lipolysis, lipid oxidation, and interaction of lipid with Maillard reaction and amino acid during meat products processing and storage as well as influencing factors on lipid degradation including raw meat (source of meat, feeding pattern, and castration), processing methods (thermal processing, nonthermal processing, salting, and fermentation) and additives. Meanwhile, the volatile compounds produced by lipids in meat products including aldehydes, alcohols, ketones, and hydrocarbons are summed up. Analytical methods of volatile compounds and the application of lipidomics analysis in mechanisms of flavor formation of meat products are also reviewed. PRACTICAL APPLICATIONS: Flavor is one of the most important quality characteristics of meat products, which influences the acceptability of meat products for consumption. Lipids play an important role in the flavor formation of meat products. Understanding the relationship between flavor compounds and changes in lipid compositions during the processing and storage of meat products will be helpful to control the quality of meat products.

Inhibitory effect of taurine on rotator cuff degeneration via mitochondrial protection

OBJECTIVES

Degenerative rotator cuff tears do not heal spontaneously, necessitating surgical intervention. This makes prevention crucial, but effective prophylactic measures are currently lacking. Oxidative stress has recently been implicated as a cause of degenerative rotator cuff tears, while mitochondrial injury has been reported in the development of age-related rotator cuff degeneration. Taurine, which has antioxidant properties, has been found to be effective in the treatment of various mitochondrial abnormalities. This prompted us to investigate the inhibitory effect of taurine and some other antioxidants against rotator cuff degeneration using tenocytes.

METHODS

Hydrogen peroxide (H₂O₂, 2 mM) was added to tenocytes in medium with 0.8 µM taurine (Group TAU), medium with 100 µM α-tocopherol (Group E), and medium with 150 µM ascorbic acid (Group C), then each medium was cultured for 24 h. Tenocytes supplemented with 2 mM H₂O₂ alone were similarly cultured for 24 h (Group H₂O₂). In each group, immunostaining was performed for the oxidative stress marker 8-hydroxy-2'-deoxyguanosine and advanced glycation end products (AGE), which contribute to the development of age-related rotator cuff degeneration. In addition, levels of reactive oxygen species were measured using a cell-based assay kit, and results were compared. Immunostaining was also performed for indices of apoptosis (caspase-9, cleaved caspase-3 and Bcl-2), and Western blotting was used to quantify activation of caspase-9 at an early stage in each group.

RESULTS

Oxidative stress and AGE levels were decreased in the E and C groups. Levels of all parameters were reduced in the TAU group.

CONCLUSIONS

Taurine showed preventative effects against rotator cuff degeneration. The simple method of administration and paucity of side effects make clinical application easy, and the clear potential as a novel prophylactic strategy against degenerative rotator cuff tear warrants further study.

Trans-10 18:1 in ruminant meats: A review

Trans (t) fatty acids (TFA) from partially hydrogenated vegetable oils (i.e., industrial trans) have been phased out of foods in many countries due to their promotion of cardiovascular disease. This leaves ruminant-derived foods as the main source of TFA. Unlike industrial TFA where catalytic hydrogenation yields a broad distribution of isomers, ruminant TFA are enzymatically derived and can result in enrichment of specific isomers. Comparisons between industrial and ruminant TFA have often exonerated ruminant TFA due to their lack or at times positive effects on health. At extremes, however, ruminant-sourced foods can have either high levels of t10- or t11-18:1, and when considering enriched sources, t10-18:1 has properties similar to industrial TFA, whereas t11-18:1 can be converted to an isomer of conjugated linoleic acid (cis(c)9,t11-conjugated linoleic acid), both of which have potential positive health effects. Increased t10-18:1 in meat-producing ruminants has not been associated with negative effects on live animal production or meat quality. As such, reducing t10-18:1 has not been of immediate concern to ruminant meat producers, as there have been no economic consequences for its enrichment; nevertheless at high levels, it can compromise the nutritional quality of beef and lamb. In anticipation that regulations regarding TFA may focus more on t10-18:1 in beef and lamb, the present review will cover its production, analysis, biological effects, strategies for manipulation, and regulatory policy.

Effects of Using Rosemary Residues as a Cereal Substitute in Concentrate on Vitamin E, Antioxidant Activity, Color, Lipid Oxidation, and Fatty Acid Profile of Barbarine Lamb Meat

Simple Summary

The aim of this study was to investigate the effects of the inclusion of rosemary residues (RR) and protein sources on lamb meat quality. Twenty-four male Barbarine lambs were divided into three homogeneous groups receiving individually: 600 g of oat hay as a roughage supplemented with 600 g of commercial concentrate for the control group (C), concentrate containing rosemary residues (RR) plus soybean meal for the RRS group, and RR plus faba bean for the RRF group. The inclusion of RR did not affect meat lipid oxidation, but improved meat nutritional properties by increasing its polyphenol and polyunsaturated FA content. The source of crude protein did not affect any parameter studied.

Abstract

The shortage of some ingredients and, consequently, the continuous increase in the price of feed encourage the search for other alternatives to maintain animal production and enhance its products. In this line, the use of aromatic plant by-products in animal diet has been recently and widely considered, given their richness in bioactive compounds. Therefore, the aim of this study was to investigate the effects of the inclusion of rosemary residues (RR) and protein sources on lamb meat quality. The experiment was carried out on 24 male Barbarine lambs (3 months old) with an average body weight (BW) of 17.8 ± 2.6 kg, which were divided into three homogeneous groups according to BW. The diet comprised 600 g of oat hay and 600 g of concentrate. Three types of concentrate were evaluated: commercial concentrate as the control group (C); rosemary residues (RR) plus soybean meal as the RRS group, and RR plus faba bean as the RRF group. After an experimental period of 65 days, lambs were slaughtered. The inclusion of RR in both concentrates increased the α-tocopherol and total polyphenol content in meat and protected meat against discoloration (high red index and chroma after 9 days of storage) but did not affect meat lipid oxidation, which was similar for all groups. The FA profile was affected by the inclusion of RR, with no effect from the source of protein (faba bean or soybean). The inclusion of RR in the concentrate increased the C18:2 n-6, C18:3 n-3, C20:4 n-6, C20:5 n-3, and C22:5 n-3 content (p < 0.05). Consequently, the inclusion of RR also increased the total polyunsaturated FA (p < 0.05) and the ratio of polyunsaturated FA to saturated FA (p < 0.05). The results of this study demonstrate that concentrate based on RR could be useful for lamb meat production by improving the nutritional quality of meat, especially the fatty acid profile. In addition, soybean meal can be replaced by faba bean in lamb concentrate without affecting meat quality.

Carcass Traits and Meat Quality of Fat-Tailed Lambs Fed Rosemary Residues as a Part of Concentrate

Simple Summary

This study aims to investigate the carcass and meat quality from lambs fed a dietary treatment including rosemary residues obtained after distillation as cereal substitute in concentrate knowing that cereals are the main component of concentrate. Twenty-four male lambs from local fat-tailed Barbarine breed were allocated into three groups. They received individually oat hay as roughage and as complementation standard concentrate for control group (C) and two concentrate types containing rosemary residues (RR) for the other groups. The protein source was soybean (S) for RRS group while faba bean (F, Vicia Faba) which is a legume was the protein source for RRF group. The results suggest a positive action of rosemary by-products in improving phenolic and tocopherol compounds given their richness in these components. In addition, growth, the non-carcass and carcass traits and the meat physical properties were not altered.

Abstract

Facing climate change implications on feeds unavailability, unconventional resources are being considered with a growing interest such as aromatic plant distillation residues with a two-fold object, enhancing meat quality by increasing the antioxidant properties and reducing feed prices which are often imported though expensive. Hence, this study aims to assess the effects of rosemary distillation residues (RR) incorporation in concentrate associated to two nitrogen sources as a substitute for standard concentrate on lamb’s growth, carcass traits and meat quality. For this, 24 Barbarine male lambs (3 months old, 17.83 ± 2.6 kg body weight) were divided into three groups. All lambs received individually 600 g of oat hay as roughage and 600 g of standard concentrate for control group, 600 g of concentrate based on RR and soybean meal for RRS group and 600 g of concentrate based on RR and faba bean for RRF group. After 65 days of experiment, all lambs were slaughtered. Phenolic and tocopherol intakes were significantly higher for both RR groups compared to control (p < 0.05). Growth, carcass weights, dressing percentages and non-carcass component weights were unaffected by the diet (p > 0.05). Moreover, regional and tissular compositions and meat physical properties were similar irrespective of the diet (p > 0.05). All color parameters were similar among groups (p > 0.05). However, meat produced by lambs receiving RR-based concentrate was richer on vitamin E and polyphenol contents than control lambs (p < 0.05). Rosemary by-products may substitute the standard concentrate resulting in similar lamb’s growth and carcass traits, while improving meat quality by increasing vitamin E content, which could improve its antioxidant power.