Changes in Cooking Losses and Sensory Attributes of Angus and Holstein Beef with Increasing Carcass Weight, Marbling Score or Longissimus Ether Extract

Cooking loss and sensory attribute changes were quantified for increases in carcass weight, marbling score and intramuscular fat in rib roasts from 74 small framed Angus and 71 Holstein steers slaughtered over a wide weight range. Cooking losses increased (P < 0.005) 2.6 percentage units for each 100 kg increase in carcass weight. Marbling score explained less than 1.2% of the variation in tenderness and was positively related (P < 0.01) to flavor of roasts from Angus but not Holsteins. Carcass weight, marbling score and intramuscular fat were more related to pan juice and total losses and explained little of the variation in sensory attributes. Therefore, alternatives to traditional indicators are needed to explain variation in sensory attributes of beef from young cattle.     

Comparative study of three legume starches

Starch content of chickpea ( Cicer arietinum ), pigeon pea ( Cajanus cajan ) and bonavist bean ( Dolichos lablab ) was 58,52 and 50% respectively with recovery of 57.9, 48.1 and 49.0%. The amylose content was 33.5, 27.0 and 31.0%; amylose chain length was 1420,550 and 830 glucose units and amylopectin chain length was 29, 27 and 28 glucose units for chickpea, pigeon pea and bonavist bean respectively. Chickpea starch granules ranged from large oval shaped (21 × 30 pm) to small spherical (13 pm in diameter); pigeon pea from (35 × 42 pm) to 15.2 pm and bonavist bean (35 × 42 pm) to 15.2 pm. The gelatin-ization temperature range was 67–76°C for chickpea, 71–78°C for pigeon pea and 78–80°C for bonavist bean starch. The swelling power for chickpea, pigeon pea and bonavist bean at 95°C were 17, 18.5 and 22.5% respectively. The legumes showed a single-stage and somewhat restricted swelling. Solubility curves for legume starches showed a similar pattern and indicated that they have higher solubility at elevated temperatures than wheat starch. The liquefaction characteristics showed that chickpea has the highest resistance to cooking and was the most sensitive to a-amylase. The three legume starches gave stabilized Brabender hot-paste viscosity; chickpea had a lower overall viscosity due to its exceptionally long amylose chains.     

The cellular microenvironment and cytoskeletal actin dynamics in liver fibrogenesis

Hepatic stellate cells (HSCs) are the primary effector cells in liver fibrosis. In the normal liver, HSCs serve as the primary vitamin A storage cells in the body and retain a “quiescent” phenotype. However, after liver injury, they transdifferentiate to an “activated” myofibroblast-like phenotype, which is associated with dramatic upregulation of smooth muscle specific actin and extracellular matrix proteins. The result is a fibrotic, stiff, and dysfunctional liver. Therefore, understanding the molecular mechanisms that govern HSC function is essential for the development of anti-fibrotic medications. The actin cytoskeleton has emerged as a key component of the fibrogenic response in wound healing. Recent data indicate that the cytoskeleton receives signals from the cellular microenvironment and translates them to cellular function—in particular, increased type I collagen expression. Dynamic in nature, the actin cytoskeleton continuously polymerizes and depolymerizes in response to changes in the cellular microenvironment. In this viewpoint, we discuss the recent developments underlying cytoskeletal actin dynamics in liver fibrosis, including how the cellular microenvironment affects HSC function and the molecular mechanisms that regulate the actininduced increase in collagen expression typical of activated HSCs.     

Molecular typing of methicillin and vancomycin-resistant <i>Staphylococcus aureus</i> isolated from clinical specimens by doublelocus sequence typing (DLST) method

Methicillin-resistant Staphylococcus aureus (MRSA) strains are the essential cause of infections in communities and hospitals. The present study was conducted to determine the molecular typing of MRSA, isolated from hospitalized patients, using the double-locus sequence typing (DLST). In total, 280 S. aureus isolated from clinical specimens by phenotypic (catalase, coagulase, DNase, oxacillin, vancomycin screening agar and antibiotic disk diffusion), and molecular methods (PCR for determining the mecA, vanA and nuc genes). The DLST and sequencing was performed for MRSA containing mecA. Out of 280 specimens, confirmed as Staphylococcus aureus (S. aureus), 123 (43.9%) strains were MRSA. The highest resistance toward the erythromycin (15 μg), followed by ciprofloxacin (5 μg), clindamycin (2 μg), tetracycline (30 μg), gentamicin (10 μg) and rifampicin (5 μg), was 98.3%, 97.5%, 94.3%, 90.2%, 83.7% and 41.4%, respectively. Also, the least resistance (0%) was observed in each of teicoplanin (30 μg), linzolide (30 μg), and vancomycin (30 μg). All (100%) of MRSA strains had the mecA, and none of them have had the vanA. The results of DLST showed that the most common sequence types were BPH 2003 and 0217. The DLST type 18-32 was a significant cluster of MRSA. By sequencing MRSA and comparing the dominant types via the DLST, it is possible to establish the etiology of the disease in a much shorter time, and prevent the complications of the disease. Therefore, the combination of partial sequences of clfB and spa can serve as useful genetic markers for MRSA typing. It concluded that the MRSA in our region was relatively high, but no vancomycin resistance was found. The majority of the MRSA DLST type was 18–32.     

Muscle Mineral Concentrations as Predictors of Taste Panel Sensory Attributes of Beef

M. longissimus concentrations of Zn, Co, Se, Cd, Mn, Na, Fe, Ca and Mg were used to predict taste panel sensory attributes of 144 beef rib roasts. The best equations included 4, 6, 2 and 5 predictors for flavor, juiciness, tenderness and chew test, respectively, and explained from 4.9 (tenderness) to 26% (flavor) of the variation. When all predictors were used, they explained 28.2, 25.6, 7.5 and 25.4% of the variation in flavor, juiciness, tenderness and chew test. Thus, muscle mineral concentration is as poor a predictor of sensory attributes as marbling score. If variation in taste panel sensory attributes of beef from young cattle is important, other predictors must be identified.