Chicken White Muscle Research Articles

Temperature Dependency of the Physical Properties of Chicken White Muscle in Relation to Proton Relaxation after Vacuum Cooking

Temperature Dependency of the Physical Properties of Chicken White Muscle in Relation to Proton Relaxation after Vacuum Cooking

Volatile flavour composition of cooked by-product blends of chicken, beef and pork: a quantitative GC–MS investigation

Volatile flavour composition of cooked chicken (CB), beef (BB) and pork (PB) by-product blends was investigated using gas chromatography–mass spectrometry (GC–MS) and the results were compared with those for cooked chicken white muscles (CM), beef shoulder muscles (BM) and pork shoulder muscles (PM), respectively. The total volatile flavour concentration of CB (4828 μg/kg sample) was three times higher than that observed for CM (1604 μg/kg sample). In BB and PB, the total volatile concentration was lower than that observed for their muscle counterparts. Aldehydes, alcohols and nitrogen- and/or sulphur-containing compounds dominated the volatile flavour profiles of CM, BM and PM while a marked dominance of alcohols was evident for CB and BB. The concentration of aldehydes in BB and PB was lower by about 66 and 70%, respectively, than that evident for the corresponding cooked muscles. The difference between the concentration of aldehydes in CM and CB was ∼7%. These differences between the volatile flavour profiles of cooked muscle samples and the corresponding by-product blends may be attributed to the compositional differences in aroma precursors in the samples. This study demonstrated that the volatile flavour compounds in cooked meat by-products are recoverable, but a careful blending of different by-products of a particular species in appropriate proportions may be necessary to generate an aroma similar to that of the respective cooked muscles.

Endogenous skeletal muscle antioxidants.

Skeletal muscle is susceptible to oxidative deterioration due to a combination of lipid oxidation catalysts and membrane lipid systems that are high in unsaturated fatty acids. To prevent or delay oxidation reactions, several endogenous antioxidant systems are found in muscle tissue. These include alpha-tocopherol, histidine-containing dipeptides, and antioxidant enzymes such as glutathione peroxidase, superoxide dismutase, and catalase. The contribution of alpha-tocopherol to the oxidative stability of skeletal muscle is largely influenced by diet. Dietary supplementation of tocopherol has been shown to increase muscle alpha-tocopherol concentrations and inhibit both lipid oxidation and color deterioration. Dietary selenium supplementation has also been shown to increase the oxidative stability of muscle presumably by increasing the activity of glutathione peroxidase. The oxidative stability of skeletal muscle is also influenced by the histidine-containing dipeptides, carnosine and anserine. Whereas carnosine and anserine are affected by diet less than alpha-tocopherol and glutathione peroxidase, their concentrations vary widely with species and muscle type. In pigs, beef, and turkey muscle, carnosine concentrations are greater than anserine, while the opposite is true in rabbit, salmon, and chicken muscle. Anserine and carnosine are found in greater concentrations in muscle high in white fibers, with chicken white muscle containing over fivefold more anserine and carnosine than red muscle. Anserine and carnosine are thought to inhibit lipid oxidation by a combination of free radical scavenging and metal chelation.

Properties of thiamin triphosphate-synthesizing activity of chicken cytosolic adenylate kinase and the effect of adenine nucleotides

Cytosolic adenylate kinase synthesizes thiamin triphosphate (TTP) from thiamin diphosphate (TDP) in vitro by a reversible reaction: TDP + ADP ⇌ Mg 2+ TTP + AMP . The backward (TTP → TDP) reaction rate was 3-times faster than the forward (TDP → TTP) reaction rate when all the substrate concentrations were 0.1 mM. This property of TTP-synthesizing activity of the enzyme did not explain the fat that the [TTP]/[TDP] molar ratio determined in chicken white skeletal muscle is 5.0 (Miyoshi, K., Egi, Y., Shioda, T. and Kawasaki, T. (1990) J. Biochem. 108, 267–270). To solve this problem, we have studied the properties of TTP-synthesizing activity of the purified recombinant chicken cytosolic adenylate kinase preparation and the effect of adenine nucleotides, especially of ATP. The backward reaction of the TTP synthesis did not proceed in the presence of 8.8 mM ATP, a physiological concentration in chicken white skeletal muscle, while the forward reaction proceeded at a reduced rate. The [TTP]/[TDP] ratio found after a long incubation period was 3.0 and 0.7, respectively, in the presence and absence of 8.8 mM ATP. These results indicate that the high [TTP]/[TDP] molar ratio found in chicken white muscle was demonstrated in vitro by the purified chicken cytosolic adenylate kinase and support in vivo TTP synthesis by this enzyme.

Evidence for In Vivo Synthesis of Thiamin Triphosphate by Cytosolic Adenylate Kinase in Chicken Skeletal Muscle

We showed previously that cytosolic adenylate kinase (AK1) purified from pig skeletal muscle catalyzes in vitro formation of thiamin triphosphate (TTP) from thiamin diphosphate (TDP) and ADP in addition to ATP formation from ADP [Shikata, H. et al. (1989) Biochem. Int. 18, 933-942]. To obtain evidence for in vivo synthesis of TTP by AK1, changes in TTP content and AK1 activity were determined in chicken skeletal muscle during development after hatching. Thiamin phosphate metabolism in chicken skeletal muscle was also studied. i) An extremely high TTP content, 81% of total thiamin (thiamin plus thiamin phosphates), was detected in the white (fast-twitch) muscle of adult normal chicken (5th to 9th month) compared with a relatively high TTP content of 31% in the red (slow-tonic) muscle. Since approximately equivalent amounts of total thiamin were present in the two types of muscle, the ratio of TTP to TDP was high (5.0) in the white muscle and low (0.41) in the red muscle. ii) Rabbit anti-chicken AK1 antiserum against the purified chicken cytosolic AK1 preparation was obtained. Both AK1 activity and TTP-synthesizing activity in crude cytosol fraction of adult chicken white muscle were inhibited in parallel by the antiserum. iii) In the white muscle of normal chicken, the TTP content and AK1 activity responsible for forming either ATP or TTP were increased in a parallel manner up to day 16 after hatching, after which both remained constant. In the red muscle, on the other hand, both the TTP content and the AK1 activity were low in comparison with those in the white muscle, and were almost constant after hatching.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracytoplasmic vacuoles in alpha W fibers of dystrophic chicken muscle--probable early pathologic event initiates massive fiber necrosis.

An electron-microscopic study on dystrophic chicken white muscle, posterior latissimus dorsi (PLD), was performed with histochemical identification of three fiber types of beta R (red), alpha R and alpha W (white) fibers to evaluate the pathophysiology in fiber necrosis. As seen in histochemically stained sections, vacuolar formation in the cytoplasm, an outstanding pathologic feature in chicken dystrophy, was recognized in the alpha W fibers by electron microscopy. The vacuole was membrane-bound and thought to originate from coalescence or dilatation of extensively proliferated sarcotubular system. There was evidence of a delay in fiber type transformation from alpha R to alpha W in dystrophic white muscle, while the initial pathologic event of sarcotubular system proliferation might be expressed only after muscle fibers had attained histochemical characteristics of alpha W fibers. Localized myofibrillar degeneration was encountered in the vicinity of the vacuole with focal membrane defect. An influx of extracellular fluid through the vacuolated sarcotubular system into the sarcoplasm may activate certain proteases, such as calcium-dependent protease because the extracellular fluid contains high concentration of calcium ion. The activated protease then degrades structural protein, especially Z-line protein, followed by fiber necrosis with phagocytosis.

INFLUENCE OF DIVALENT CATIONS ON POULTRY MEAT EMULSIONS AND SAUSAGES

ABSTRACTThe emulsifying capacity of a 3% NaCl extract of chicken white muscle was decreased by 10 mM CuCl2, slightly increased by FeCl2, and greatly increased by ZnCl2. Calcium and other cation chlorides had no effect. Zinc enhancement was optimum at pH 5.5. At pH values above 4.3,10 mM Cu would not form an emulsion but 1 mM Cu increased emulsifying capacity as pH increased. When 2.2 mM zinc or copper was included in the formulation, the force required to shear sausages prepared from red and white muscle was reduced by half and the water and fat losses on cooking were large. Addition of calcium or iron to the sausage emulsion was less detrimental.

CONTRACTIBILITY OF MUSCLE FIBRES AS A POSSIBLE AID TO JUDGING TEXTURAL CHANGES IN FROZEN MEATS AND FISH.

Following addition of ATP, the contractibility of muscle fibres in suspension (obtained by muscle homogenization) changes during frozen storage of the muscle. These changes were detected by turbidity measurements. In beef, there were no significant changes up to 6 months storage at- 8°C or lower. Considerable loss in contractibility occurred in chicken white muscle. Losses were rapid in cod and carp muscle, contractibility being completely lost in one month at- 3°C. The method is proposed as one criterion for judging textural changes in lean fish during frozen storage.