The impact of homogenizer type and speed on the determination of myofibrillar fragmentation

Hopkins, David L.; Martin, Laurent; Gilmour, A.

doi:10.1016/j.meatsci.2004.01.011

Cited by 58 publications

(33 citation statements)

References 11 publications

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“…MFI values MFI values were determined in liquid nitrogen frozen samples as described by Hopkins et al (2004). Five hundred milligrams of the frozen muscles taken from liquid nitrogen were homogenized in 30 ml pre-chilled buffer.…”

Section: Shear Force Measurementmentioning

confidence: 99%

The effect of calcium chloride injection on shear force and caspase activities in bovine longissimus muscles during postmortem conditioning

Cao

Khan

et al. 2012

Animal

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Tenderness is considered as the most important quality determinant of meat. Calcium chloride application has been shown to improve tenderness by regulating endogenous proteinases. This study was designed to determine the effect of 300 mM calcium chloride injection on myofibrillar structures, caspase activities and shear force in longissimus muscles of bulls duringpostmortemstorage of 7 days. Myofibrillar fragmentation index was determined as an index of proteolysis occurring in muscle fibers and associated proteins. Maximum tenderness was observed at days 4 and 7 in both treated and control samples. The injection of calcium chloride significantly increased myofibrillar proteolysis and improved tenderness atpostmortemdays 4 and 7. The treatment reduced caspase-9 activity at 4 h and day 4, whereas those of caspase-8 and -3 activities at days 1 and 4 with respect to control. The improved tenderness and increased myofibril fragmentation with decreased caspase activities suggested that the proteolytic systems activated with calcium chloride injection possibly behave independent of the caspase system.

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Section: Shear Force Measurementmentioning

confidence: 99%

The effect of calcium chloride injection on shear force and caspase activities in bovine longissimus muscles during postmortem conditioning

Cao

Khan

et al. 2012

Animal

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“…Determination of sarcomere length on 1 day post-mortem samples was performed as described by Hopkins and Thompson (2001a). A thin slice of frozen muscle from each portion of the LL was used for determination of myofibrillar fragmentation index (MFI) as described by Hopkins et al (2004) and Martin et al (2004).…”

Section: Measurement Of Shear Force Sarcomere Length and Myofibrillamentioning

confidence: 99%

Effects of stimulation on tenderness of lamb with a focus on protein degradation

Martin

Hopkins

Gardner

et al. 2006

Aust. J. Exp. Agric.

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Abstract. Past studies have identified that electrical stimulation systems not only affect the pH-temperature decline of lamb carcasses, but also affect the tenderness of the product. It is unknown whether these differences are due to the effects of an optimal pH-temperature decline path by which the occurrence of shortening is decreased and proteolytic enzyme activity is increased, or by another mechanism, such as disruption of the muscle myofibres. This study attempted to elucidate this by placing control and mid-voltage electrically stimulated samples of the M. longissimus thoracis et lumborum in a water bath to prevent shortening by imposing an even pH-temperature decline on all samples. In order to obtain a complete understanding of the effects of stimulation on the muscle, samples were taken for indicators of tenderness, myofibre degradation and protein breakdown. No effect of stimulation was seen on tenderness and structural degradation measures aside from the expected rapid lowering of muscle pH. Interesting relationships were observed, however, between the different methods of meat tenderness assessment, with muscle structural protein degradation, shear force and muscle fibre and myofibre breakdown comparisons. These results suggest that the effects of electrical stimulation seen in mid-voltage systems as applied in this study are due only to the prevention of shortening conditions.

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“…Earlier studies indicated that the homogenization conditions result in different free amino acids level as a consequence of various disruption impacts. The shaft homogenizer-rotor stators is one of the most widely used tools for animal tissues (Burden, 2008), which generated the smallest fragments than CryoGrinder and Omni mixer (Hopkins et al, 2004). In addition, the speed and duration of homogenization may greatly interact with homogenizer types (Hopkins et al, 2004), otherwise the speed and efficiency of homogenization were greatly eroded when a smaller homogenizer was adopted (Burden, 2008).…”

Section: Introductionmentioning

confidence: 99%

“…For consistency results of free amino acid levels in beef over ageing period, it is very important to choose a right generator and dispersers for fibrous tissue samples which matches your sample volume and (Halpine, 2004). However most cases the type of homogenizer, speed and dispersing elements has not been specified in the published papers (Hopkins et al, 2004). These together can result in large variations in free amino acids content between laboratories and experiments and thus consequently generating controversial data.…”

Section: Introductionmentioning

confidence: 99%

Effect of Extraction Methods on the Types and Levels of Free Amino Acid of Beef Longissimus Muscle

Dashdorj¹,

Hwang²

2012

Korean Journal for Food Science of Animal Resources

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The current study was carried out to investigate the impact of extraction conditions on the free amino acid level and type in beef longissimus muscle. The sample blocks were chiller aged for 1 d and 7 d at 4 o C. There are three homogenization speeds (11,000, 19,000 and 24,000 rpm) for bigger and two speeds (11,000 and 13,000 rpm) for smaller homogenizer's dispersing tools were used for evaluation. Results showed that chiller ageing greatly (p<0.05) increased extractable free amino acids, except cystine. Homogenization with the bigger dispersing tool at 24,000 rpm resulted in the highest free amino acid levels for both 1 and 7 d samples. Significant differences (p<0.05) in the mean values of most amino acids due to the effect of speed and interactions between ageing times. However, the speed effect and interaction between ageing with homogenization speed were not significant (p>0.05) for most of the amino acids except valine and isoleucine when using the smaller dispensing tools. The current data indicated that a standardized method for free amino acid types and levels of aged beef samples. In addition, the results also suggested that utilization of a big dispensing tool at high homogenization speed is a better condition for releasing free amino acid contents in beef samples.

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The impact of homogenizer type and speed on the determination of myofibrillar fragmentation

Cited by 58 publications

References 11 publications

The effect of calcium chloride injection on shear force and caspase activities in bovine longissimus muscles during postmortem conditioning

The effect of calcium chloride injection on shear force and caspase activities in bovine longissimus muscles during postmortem conditioning

Effects of stimulation on tenderness of lamb with a focus on protein degradation

Effect of Extraction Methods on the Types and Levels of Free Amino Acid of Beef Longissimus Muscle

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