Can samples be powdered to determine sarcomere length?

Abstract Text:

The objective of this study was to assess the effectiveness of using powdered meat samples in determining sarcomere length. The relationship between sarcomere length and tenderness has been well-established. Average sarcomere length of the muscle fibers varies considerably from animal to animal, from muscle to muscle and it is affected during rigor mortis. Different meat species have different sarcomere length ranges for Longissimus dorsi muscle fibers. Diffraction techniques have been used very extensively to study not only different muscles but also the physiology of the muscle in different states, such as resting, contracting and rigor. However the preparation method prior the readings under the laser light have differed within published researches. Ten Longissimus dorsi samples from beef, pork and lamb were prepared using three different preparation methods:  fresh, frozen conventionally (frozen), and frozen in liquid nitrogen and powdered (powdered).   Samples were then homogenized in a 0.25M sucrose, 0.002M potassium chloride, and 0.005M sodium iodoacetate solution at pH 7.0.  Light diffraction using a Helium-Neon laser was used to measure and sarcomeres lengths. Data was analyzed using PROC MIXED procedure from SAS 9.3 (2011) program. Sarcomere lengths (Table 1) differed (P < 0.05) by species, as expected. No differences between preparation methods (P > 0.05) were found for pork and lamb. The frozen preparation method resulted in shorter sarcomeres (P < 0.05) for beef samples. These results indicate that any of the methods used for sample preparation can be used as far as results are concerned, but laboratory work, time and expenses can be shortened by using the powdering method to prepare muscle samples for sarcomere length measurement.ble 1:  Sarcomere lengths for livestock species using three different sample preparation methods (n = 10 samples/species and preparation method).

Least Square Mean Estimates
Species	Preparation Method
	Fresh	Frozen	Powder
Beef	1.46a	1.41b	1.44a
Lamb	1.32c	1.33c	1.31c
Pork	1.48d	1.49d	1.46d
LSD within column= 0.045 (P < 0.05)
LSD within row= 0.042 (P < 0.05)
Means lacking a common superscript with row and column differ (P < 0.05)

Keywords: Sarcomere, research method, beef, pork, lamb