The use of bioactive properties of sage preparations to improve the storage stability of low-pressure mechanically separated meat from chickens2.

The aim of this study was to determine the effect of Salvia officinalis L. (sage) preparations on the storage stability of vacuum-packed low-pressure mechanically separated meat (MSM) from chickens stored at -18°C for 9 mo. Chilled low-pressure MSM coming from 4 production batches was obtained from the plant located in north-eastern Poland. All sage preparations-a water extract, ethanol extracts, and an essential oil-were prepared and added to the MSM under laboratory conditions. Five samples of low-pressure MSM were prepared that differed in terms of the type of sage preparation added: control-without addition of sage, WE-2.0% addition of water extract from sage, E40-2.0% addition of 40% (vol/vol) ethanol extract from sage, E70-2.0% addition of 70% (vol/vol) ethanol extract from sage, and EOS-0.1% addition of essential oil from sage. The MSM samples were assessed immediately after arrival into the laboratory and after 1, 2, 3, 4, 6, and 9 mo of storage. The quality changes of MSM samples were determined on the basis of the thiobarbituric acid reactive substances (TBARS) index and microbial analyses. On the basis of the TBARS index it was proved that addition of essential oil and (40% and 70% (vol/vol)) as well as water extracts of sage significantly (P < 0.05) slowed down fat oxidation processes in low-pressure MSM from chickens. The growth of mesophilic aerobic bacteria and psychrotrophic bacteria, coliforms, and Enterobacteriaceae was significantly (P < 0.05) restricted by all sage preparations tested. The most effective inhibitory effect for groups of bacteria analyzed in this study was demonstrated by sage essential oil, despite insignificant (P > 0.05) differences between the preparations. In conclusion, it was found that sage preparations are rich in bioactive compounds. Due to their antioxidant and antibacterial properties, especially sage oil and ethanol extracts may be recommended as an auxiliary factor to prolong the storage stability of frozen, vacuum-packed low-pressure MSM from chickens.

Transcriptional background of beef marbling - novel genes implicated in intramuscular fat deposition.

The purpose of this study was to identify novel marbling-related genes by comparison of the global gene expression in semitendinosus muscle of 15-month-old Limousin (LIM), Holstein-Friesian (HF) and Hereford (HER) bulls. Muscle of LIM was lean with low intramuscular fat (IMF) content (0.53%) unlike the marbled muscles of HER and HF characterized by higher amounts of IMF (1.10 and 0.81%, respectively). The comparison of muscle transcriptional profile between marbled and lean beef revealed significant differences in expression of 144 genes, presumably involved in consecutive stages of adipose tissue development, such as preadipocyte proliferation and differentiation, adipocyte maturation, lipid filling and lipid metabolism leading to increased IMF deposition and marbling development. Correlation coefficients and regression analysis for nine of them (gadd45a, pias3, ccrn4l, diras3, pou5f1, hoxa9, atp2a2 and pim1) validated by real-time qPCR confirmed their moderate-high correlation with IMF% and explained up to 70.5% of the total variability in IMF deposition in the bulls.

Application of a computer vision system to classify beef as normal or dark, firm, and dry.

The purpose of this research was to evaluate the possibility of using computer vision systems (CVS) to detect DFD beef. The experimental material consisted of beef obtained from 60 carcasses (M. semimembranosus) that were 48 h postmortem. The beef was classified into 2 quality groups according to pH: normal (pH < 5.8) or DFD (pH ≥ 5.8). L*, a*, and b* color components were determined in the experimental materials using both CIELab and a CVS using 3 color models: RGB (red, green, blue), HSV (hue, saturation, value), and HSL (hue, saturation, lightness). The total heme pigment content also was determined. As determined by both CIELab and CVS, DFD meat was characterized by a darker color than normal beef. Color lightness, as determined using both CIELab and CVS, can also be used to detect DFD beef. A significant relationship was found between V (r = -0.79) and L (r = -0.77) using CVS and pH, which is an indicator of DFD beef. This finding indicates the possibility of using these color components to assess the pH level of beef.