RAPID DETERMINATION OF COLLAGEN IN BEEF BY WARING BLENDOR AND CENTRIFUGE TECHNIQUE^1,2

Abstract

Bell, Morgan, and Dorman (1941) have demonstrated that the Mitchrll, Hamilton, and Haines (1028) method for determination of collagen in meat may fail to account for as much as one-half of the collagen. While the method of Bell et al. (hereafter called the Bell method) demonstrated a gyeatly improved reliability, it unfortuiiately added a greater burden to the already tedious and time-consnniing method of Rlitchell et al. (hereafter called the Mitchell method).Cover, ?tIackey, Murphey, Miller, Bass, Bell, arid IIanialainrn (1913) have compared collagen analyses obtained by nsing modifid metliods of Rogue (1923) and of Spencer, Morgnlus, and Wilder (1937). They have found distinctly higher results by the former method, due to its inclusion of other soluble nitrogen compounds. The Spencer method (a gelatintannate procedure), while apparently reliable, is likewise bnrdened with an excessively time-c~onsuming procednrc.The senior author and co-workers (1941) haye observed that nonturbid aqueous extracts of raw meat could be obtained b y centrifiigation of aqueous dispersions of beef miiscle tissue adjusted to the isoelectric point ( p H 5.07). Therefore, it seemed it should be possible to substitute a rapid centrifugation operation in place of the sieve and linen filter procedure of the Bell method.Furthermore, it seemed that the 90-miiiute ball-milliiig step used iir both the Bell and Illitchell methods might be substituted f o r by use of the Waring Rlendor. I'reliminarg experiments had shown that the Waring Blendor dispersed beef muscle tissne so finely that it nearly all passed quite easily through a 100-mrsh sieve. Such a procedure for dispersion wonld, therefore, be impractical for the sieve and linen filter separations employed by the Bell method. Ilowerer, such fine dispersion should offer no difficulty in centrifugation, and, in fact, should aid in more effective extraction than that attained by ball-milling.Since Hall P t nl. (1944) and many other workers have observed a relation betwc3en tenderiiess of meat and collagen coiltent, it is evident that a method for collagen determillation employing simple, expeditions technique of the kind proposed wonld be highly useful in meat research. Contriliution K O . 379, I k p a r t m e n t of Chemistry, Kansas Agricultural ExpPriment Statio I. ' From thesis submitted hp L o i s Meisner T I a r t l c~ in partial fulfillment of the requirrments for the degree of

Connective tissue of meat: I.—separation and determination

“…They depend essentially upon trituration with water, or with acid, alkali or salt solutions, to remove the bulk of the muscle tissue, followed by autoclaving with water to hydrolyse the collagen. In some cases trypsin treatment to remove remaining muscle protein preceded the separation of elastin (Schepilewsky, 1899 ;Mitchell, Zimmerman & Hamilton, 1926 ;Mitchell, Hamilton & Haines, I929 ;Bell, Morgan & Dorman, 1941 ;Hartley & Hall, 1949 ;Bate-Smith, 1934, 1935, 1939Spencer, Morgulis & Wilder, 1937 ;Lowry, Gilligan & Katersky, 1941).…”

A Comparison of Two Methods for Determining the Collagen Content of Cooked Meat

“…During a study of the effect of various methods of cooking beef round on the collagen content of the meat, the method of Hartley and Hall ( 4 ) was used for the first 31 cooked samples. Since collagen is hydrolyzed to gelatin during cooking, losses in collagen were expected for all the cooking methods.…”