Effect of Two Organic Production Strategies and Ageing Time on Textural Characteristics of Beef from the Retinta Breed

Effect of different electrical stimulation systems on beef quality and palatability: Constant current compared to constant voltage

This study examined the effects of constant current electrical stimulation (CCES) compared to constant voltage electrical stimulation (CVES), when applied within the same beef carcass (n = 79), on longissimus thoracis et lumborum (LTL) quality and palatability. There was a stimulation method × time interaction for pH, with CCES reducing the 3 h post-mortem pH, but increasing the 72 h post-mortem pH compared to CVES (P < 0.001). The CCES decreased the meat subjective Japanese Meat Grading Agency (JMGA) colour scores (P < 0.05) and increased the objective L⁎ (P < 0.01), a⁎ (P < 0.05) and b⁎ (P < 0.05) colour values at 3 d post-mortem and L⁎ and b⁎ values (P < 0.05) during retail display compared to CVES, although the objective values from both stimulation methods were above established consumer acceptability thresholds. Additionally, CCES reduced the purge (P < 0.05) and drip (P < 0.01) losses, and tended to reduce shear force values (P = 0.089) compared to CVES, although these did not translate into differences in juiciness or tenderness evaluated by trained panelists (P > 0.1). Regarding flavour, the CCES meat had greater bloody/serumy flavour (P < 0.05) and corn aroma (P < 0.05), less unidentified aroma (P < 0.05), and tended to have greater corn flavour (P = 0.077) and less barnyard aroma (P = 0.079) than CVES meat. There were also increased concentrations of flavour-related volatile compounds including 2-methyl-butanal, 3-methyl-butanal and 2-5-dimethyl pyrazine levels (P < 0.05) with CCES. Overall, the CCES system slightly improved meat quality and flavour compared to CVES when applied to the same beef carcasses. Further consumer studies would be warranted to determine whether these differences translate into more acceptable meat.

Meat Quality Traits in Beef from Heifers: Effect of including Distiller Grains in Finishing Pasture-Based Diets

Distiller grains (DG), which are the by-product from the bioethanol industry, represent an interesting alternative as animal feedstock. To our knowledge, little information is available on the inclusion of DG on the quality of meat from pasture-fed heifers. Thus, the aim of the present study was to evaluate the effect of DG inclusion in pasture-based systems on the main meat quality attributes of Charolais x Aberdeen Angus heifers. For this purpose, meat from heifers fed with a pasture-based diet without supplementation (P) or with 0.75% of live weight DG supplementation (PDG; DG plus dry-rolled corn, 50:50) or with 0.75% of live weight dry-rolled corn supplementation (PRC) was evaluated. Physical (pH, WHC, color, texture), sensory and nutritional (fat content, fatty acid, and amino acid profile) attributes were evaluated in beef samples. No effect of supplementation was observed on meat pH or color (p > 0.05). Meat from PDG heifers showed higher values of WBSF than meat from P heifers (p = 0.039). However, the overall tenderness evaluated by trained panelists showed no differences due to supplementation (p > 0.05). Our results indicate that the inclusion of DG as a partial corn-replacement supplementation for heifers under grazing represents a strategic tool not only related to meat quality, but also as an alternative to reduce food–feed competition.

Characterization of Four Rearing Managements and Their Influence on Carcass and Meat Qualities in Charolais Heifers

The study aim was to identify the effects of the rearing management applied throughout the heifers’ life on the carcass (e.g., conformation, marbling, fat) and meat (color, texture, and sensory profiles) properties. From the individual data of 171 heifers from 25 commercial farms, a typology of four rearing managements was established from 50 rearing factors. The managements had an effect on the conformation, the color (fat and muscle), and the rhomboideus grain meat, for the carcass, and the lightness, the atypical flavor, and the overall acceptability for the longissimus (LM) meat. The carcass traits compared to the meat were more sensitive to a change of rearing management. Our results confirmed that it was possible to target the same carcass or meat quality from different managements. Moreover, according to the aims of the targeted carcass and LM meat quality, management 3 could be an interesting trade-off to jointly manage the quality of both products. For example, the carcasses that were produced had a high conformation, smooth meat grain and the LM meat was more liked. This management was intermediate compared to the other rearing managements and had a long fattening period with a diet mainly based on conserved grass and a high concentrate quantity.

The effect of aging on beef taste, aroma and texture, and the role of microorganisms: a review

The present review summarizes the advantages and disadvantages of three different aging methods (traditional dry aging, wet aging in vacuum shrink pack and dry aging in a highly moisture-permeable bag), discusses the effects of aging on beef which focus on the formation of taste-active compounds and aroma-active compounds and texture changes, and speculates the role of microbes. All these three aging methods can improve the aroma, flavor and texture of beef to varying degrees. It is concluded that the improvement in the taste during aging may be attributed to the following three aspects: First, the release of reducing sugars from the transition of glycogen and ATP; Second, the formation of free amino acids (FAAs) and peptides through proteolysis; Third, IMP, GMP, inosine and hypoxanthine which are produced by the degradation of nucleotides. The improvement of aroma is related to the volatile aroma-active components, which are produced by the thermal oxidation/degradation of fatty acids and the Maillard reaction between amino acids and reducing sugars during aging. And the change of texture is mainly owing to the degradation of cytoskeletal myofibrin and collagen with intramural connective tissue in meat by the endogenous proteolysis system. The role of microorganism in aging will be the main direction of further research.

The Effect of Grazing Level and Ageing Time on the Physicochemical and Sensory Characteristics of Beef Meat in Organic and Conventional Production

This study investigated the influence of the production system (conventional vs. organic), the grass consumption level and the ageing period (7 and 14 days) on beef quality. Three groups of samples from Limousin × Avileña calves were analysed: F100, formed by animals fed 100% on forage; F74, formed by animals fed on an average amount of forage of 74%; and F35, formed by animals fed on straw fodder (35%) and concentrate (65%). The results showed that the higher the grass content, the lower the fat oxidation and the higher the n-3 content, but also the higher the SFA level, the initial Warner-Bratzler shear force (WBSF), and the more residue it leaves on chewing. As for the effect of production system, organic samples showed higher intramuscular fat content and lower moisture and MUFA content. These samples were darker and showed lower values for flavour quality. Among the organic samples, F100 had higher n-3 and CLA content and higher values for colour, hardness, odour and flavour quality. Increased ageing time may improve the sensory characteristics of the meat, especially in the case of the F100 samples. The results pointed out that F100 samples aged at least 14 days showed the best physico-chemical, nutritional and sensory characteristics.