Influence of gas mixture on quality and shelf life of veal calf meat

The paper investigates the effect of two different gas mixtures on chemical, physical and microbiological quality of veal meat packed in modified atmosphere during chill storage. Experimental gas atmospheres tested were O246 (46% O2, 31% N2 and 23% CO2) and O270 (70% O2, 8% N2 and 22% CO2). Samples were stored at 4°C for 14 days and tested at 0, 2, 4, 6, 8, 10, 12 and 14 days after packaging. The different O2 concentration influenced many parameters. Lower O2 concentration showed a greater increase of a* values (P<0.01) from the 2nd to the 8th packaging day, and a lower increase in drip loss values, thiobarbituric acid reactive substances and protein oxidation (P<0.001). Total aerobic mesophilic and psychrophilic count showed a gradual increase in bacterial load over storage time in both the experimental treatments. Results obtained showed that O246 is better than O270 in calf meat packaging because of a belated decline of meat quality, particularly about oxidative parameters

Influence of seasonality on the comfort supplied by different materials used as cubicle flooring for dairy cows

The comfort provided by four different cubicle floorings was evaluated with a preference test in relation to winter and summer seasons. The test showed that polyethylene vinyl acetate and polypropylene vinyl acetate mats were preferred during winter, while solid manure and wood shavings assured more comfort than inorganic floorings during summer period. Results obtained suggest that the resting comfort of cubicle floorings may be evaluated also in relation to environmental microclimatic patterns

ATP Sensitive Potassium Channels in the Skeletal Muscle Function: Involvement of the KCNJ11(Kir6.2) Gene in the Determination of Mechanical Warner Bratzer Shear Force

The ATP-sensitive K-channels (KATP) are distributed in the tissues coupling metabolism with K ions efflux. KATP subunits are encoded by KCNJ8 (Kir6.1), KCNJ11 (Kir6.2), ABCC8 (SUR1), and ABCC9 (SUR2) genes, alternative RNA splicing give rise to SUR variants that confer distinct physiological properties on the channel. An high expression/activity of the sarco-KATP channel is observed in various rat fast-twitch muscles, characterized by elevated muscle strength, while a low expression/activity is observed in the slow twitch muscles characterized by reduced strength and frailty. Down-regulation of the KATP subunits of fast-twitch fibers is found in conditions characterized by weakness and frailty. KCNJ11 gene knockout mice have reduced glycogen, lean phenotype, lower body fat, and weakness. KATP channel is also a sensor of muscle atrophy. The KCNJ11 gene is located on BTA15, close to a QTL for meat tenderness, it has also a role in glycogen storage, a key mechanism of the postmortem transformation of muscle into meat. The role of KCNJ11 gene in muscle function may underlie an effect of KCNJ11 genotypes on meat tenderness, as recently reported. The fiber phenotype and genotype are important in livestock production science. Quantitative traits including meat production and quality are influenced both by environment and genes. Molecular markers can play an important role in the genetic improvement of animals through breeding strategies. Many factors influence the muscle Warner-Bratzler shear force including breed, age, feeding, the biochemical, and functional parameters. The role of KCNJ11gene and related genes on muscle tenderness will be discussed in the present review

How Volatile Compounds, Oxidative Profile and Sensory Evaluation Can Change with Vacuum Aging in Donkey Meat

This study aims to improve knowledge on donkey meat and the vacuum aging effect on the Volatile Organic Compounds (VOCs), oxidative profile and status and the sensory characteristics. Ten 18-month old Martina Franca donkeys’ male foals were involved in the trial. Longissimus thoracis (LT) muscle was extracted from each left half carcass, between the fourth and the ninth rib. Each muscle was divided into five sections, vacuum packaged, stored at 2 C, and randomly assigned to one of the dierent aging time (1, 3, 6, 9, and 14 days of aging). Volatile compounds, oxidation parameters, and antioxidant enzymes were analysed, and a sensory test was performed. A nested one-way analysis of variance (ANOVA) was performed for aging time as an independent variable. Significance was set at p &lt; 0.05. Aldehydes are the most produced VOCs, but no changes were observed during vacuum aging (p &gt; 0.05). Nitrogen compounds increased during aging (p &lt; 0.01). TBARs and hydroperoxides did not change during the storage, whereas the protein carbonyls increased (p &lt; 0.05). Vacuum aging slowed down lipid oxidation and put in evidence the presence of protein oxidation and degradation, influencing the VOCs productions and sensory evaluation