LPT 321: Meat Science (1+1)

ESTIMATION OF R VALUE 

Principle

• R value is the ratio of ATP (Adenosine tri phosphate) to IMP (Ionosine mono phosphate).
• ATP is progressively converted into IMP with progress in rigor mortis. Thus, R value in an index of the progress of rigor mortis.

Equipment

• Waring Laboratory Tissue Homogeniser.
• UV-vis - Spectrophotometer

Reagents

• 1 M Perchloric acid and
• 0.1 M Phoshphate buffer.

Procedure

• About 2 g of muscle is homogenized along with 10 ml of 1 M perchloric acid. The homogenate is filtered.
• Exactly 0.1 ml of the filtrate is taken, and diluted with 4.9 ml of 0.1 M Phoshphate buffer (pH 7.0) .
• This solution is used to measure the absorbance of IMP ( 250 nm wavelength) and ATP as well (260 nm), and the phospahate buffer serves as the blank in both the cases.
• The R value is calculated as the ratio of the absorbance of IMP : ATP.

Assesment

• As, the R value in an index of the progress of rigor mortis, the greater the R value, the more has rigor progressed.