Metabolomic analysis indicates that higher drip loss may be related to the production of methylglyoxal as a by-product of glycolysis.

The aim of the present study was to assess applicability of metabolomics analysis of exudate from chicken breast muscle to explanation of differences in drip loss. The research was carried out on the skinless breast fillets sourced from 60 broiler carcasses (7-wk-old male Ross broilers). In the meat samples the pH value, color parameters, drip loss, chemical composition, and sensory quality were evaluated. After measuring, the samples were divided into 2 groups taking into consideration the volume of drip loss (low ≤2% and high >2% drip loss). The muscle juice samples were collected during 24 h muscle storage and metabolomic analysis was performed. The results showed that chickens with higher drip loss were characterized by heavier carcasses. The meat with higher drip loss proved to be more acid, lighter, less red, and more yellow with higher level of glucose as well as glycolytic potential. That meat was also characterized by lower cooking loss, protein content and worse overall sensory quality as well as oxidation of lipids. The metabolomics analyses have shown that in the group with higher drip loss from muscle tissue the increase of metabolism of energy transformations taking place in muscle tissue after slaughter was observed and that differences between groups are related to 11 metabolic pathways, mainly carbohydrate metabolism (glycolysis, gluconeogenesis, pentose phosphate pathway) adenine and adenosine salvage, adenosine nucleotides degradation, arsenate detoxification, methylglyoxal degradation. Finally, the results indicate that in the group with higher drip loss and with deeper glycolysis, more methylglyoxal (as a by-product of carbohydrate metabolism) is produced which may lead to changes of muscle proteins properties and contribute to an increase in drip loss.

[Effect of semen diluters containing egg yolk contaminated with DDT on the survival of bull spermatozoa]. / Wplyw rozcienczalników nasienia zawierajacych zóltko jaj kurzych skazonych DDT na zywotnosc plemników buhaja in vitro

In two experiments, hens received 200 (group I) or 100 ppm of DDT per day and per kg of live weight (group II), for 17 or 10 days resp. The eggs of experimental hens were collected, and a 3 or 6 day collection of eggs was used for preparing a sample of pooled egg yolks; one part of this sample was used for preparation of a 25% egg yolk-citrate diluent, the other for DDT determination. The egg yolks of experimentally poisoned hens contained 12 to 957 ppm of DDT (egg yolks of controls 1-4 ppm) in consecutive collection samples. However, the survival time and survival indexes of bull semen (90 ejaculates) preserved at 3 degrees C and 46 degrees C in yolk citrate diluent containing DDT poluted egg yolk did not differ from those preserved in control diluter.