“Marbling, is there more to the Story” Research out of Germany

Website PostingRussel Horvey

RetiredBeef/Forage Specialist

Delburne, AB.(403)749-2780

horvey@telusplanet.netWebsite: bigdealgalloways.com

FaceBook: Horvey’s Big Deal Galloways

Acknowledgment

• I would like to acknowledge:• Judy Decker• Editor - American Galloway Breeders Association,

AGBA, Galloway Dispatch • Many of the slides in this presentation are from an

article Judy had in the AGBA Galloway Dispatch newsletter

• Thank you Judy

Is there more to the marbling story? Absolutely

• First, the distinction between marbling & intramuscular fat.• Marbling is a scoring system

– employed by Canada & the US as part of their grading systems. • Graders visually assess the apparent fat in the rib eye muscle

– and quantifies it on a predetermined scoring system.• Marbling is an evaluation of the visible fat dispersed amongst the

bundles of muscle fibers.

Is there more to the marbling story? Absolutely

• Intramuscular fat: • evaluates the quantity of fat dispersed among muscle fiber

bundles• based on an objective chemical evaluation • eliminates the subjectivity of the human eye

Is there more to the marbling story? Absolutely

• Correlation between: • Visual Marbling & Chemical Intramuscular evaluation• The correlation ranges from .70 to .90• Therefore the two variables are linked

– as one increases, so does the other• however, not for all parameters

Is there more to the marbling story? Absolutely

• Knowing, intramuscular fat contributes to meat quality,• it is important to know • fat cells are distributed differently within the muscle tissue

– which impacts meat quality • fat cells are distributed in groupings • grouping ranging from 1 to 1000 fat cells/group. • Visible Fat Deposits: (criterion used by graders)• are fat accumulations of more than 100 fat cells/group. • Microscopic Fat Deposits: • are fat accumulations of less than 100 cells/group• small accumulations, not counted in visually-based grading systems. • Question, what becomes of the beef carcass whose fat is distributed

more discretely, in accumulations that are below what the human eye can detect?

Is there more to the marbling story? Absolutely

• Computer Image Analysis (CIA)• Is technology evolving to evaluate intramuscular fat• CIA is video imaging and computer technology combined • Combined to digitize & analyze images of ultra-thin slices of beef• This technology unveils the hidden landscape of fat deposits• Fat deposits of specific shapes and distributions• including those below that 100 fat cell threshold limitation of the

human eye. • Following are Parameters utilized in a CIA Study by Dr. T. Hoshino -

Analyzing Fat Distribution of Different Cattle Breeds

Microscopic image of a group of intramuscular fat cells, orange-muscle fibres

blue-connective tissue, white-fat cells,

(approx. 200x magnification)

Is there more to the marbling story? Absolutely

• In 1990, Dr. T. Hoshino used CIA of intramuscular fat and described two distinct types of fat deposits:

• Punctiform Deposits: • smaller point-like fat deposits • located within the bundles of muscle fibers (the most desirable

form), • Reticular Deposites: • larger net-like streak of fat deposits • located between the bundles of muscle fibers(less desirable).

Is there more to the marbling story? Absolutely

• In 1996 researchers in Germany used CIA to evaluate intramuscular fat deposits in different breeds of cattle.– Belgian Blue– German Angus – Friesian– Galloway

• The research used 12- month old bulls

Is there more to the marbling story? Absolutely

• Using the longissimus dorsi muscle in one study, and the semitendinosus muscle in another,

• Dr. Jochen Wegner used CIA • to determine the values for a number of parameters,• several parameters of which are presented as ratio’s • to compare the distribution of intramuscular fat • in the various beef breeds sampled.

Table 2: Results of fat content and distribution in muscle samples taken from the M. longissimus dorsi muscle (mld).

Table 3: The researchers noted a coarser, less even distribution of fat in the M. semitendinosis muscle, (mst), as compared to the mld muscle, in table 2.

Does Fat Distribution Really Impact Eating Quality?

• The correlation between visible marbling and beef palatability exists• but is weak • A far better predictor is actual intramuscular fat and its distribution

pattern

References• J. Anim. Sci. 2006. 84: 1067-1075

Growth and breed-related changes of marbling characteristics in cattle E. Albrecht, F. Teuscher, K. Ender and J. Wegner2 Research Institute for the Biology of Farm Animals, D-18196 Dummerstorf, Germany

• Fleischwirtschaft 76 (11), 1145-1148 (1996) • http://jas.fass.org/cgi/reprint/84/5/1067?ck=nck•

http://www.jochen-wegner.de/Marbling%20and%20image%20analysis%20ASAS%2097.htm

Does Fat Distribution Really Impact Eating Quality?

Visible fat during growth based on Video Image Analysis VIA

• 89th Annual Mtg of the American Society of Animal Science, July 29-Aug 1, 1997, Nashville Tenn.

• Elke Albrecht, Jochen Wegner & Klaus Ender• Research Institute for Biology for Farm Animals– D-18196 Dummerstorf, Germany

• www.fbn-dummerstorf.de/fb6/wegner/wegner.htm

Visible fat during growth based on VIAVideo Image Analysis

• Marbling of beef is the visible intramuscular fat• Intramuscular fat influencing taste, juiciness and

tenderness of the meat.• The aim of this study was to: • objectively assess the quality, structure &

distribution of intramuscular fat • to study the development of fat deposits• in the longissimus muscle • of different breeds of cattle • during growth.

Visible fat during growth based on VIAVideo Image Analysis

• Breeds in Study: – German Angus, Galloway, Black Peids, White Belgian Blue

• Differences between the breeds appear in:– Quantity of fat– Structure of fat– Distribution of fat areas.

• Fat deposition in the White Belgian Blue remains essentially lower up to 24 months of age.

• The German Angus is particularly marked by bigger fat areas. • The Galloway had a very regular distribution of fat and the highest

number of fat areas. • The Black Piedmonts exhibit a fine marbling with less big fat cords.

Visible fat during growth based on VIAVideo Image Analysis

• The proportion of fat areas increases during growth in all breeds mainly due to the increase in the number of fat areas.

• The structure of fat deposits is determined through 2 different trends• One trend is that the bigger the fat areas leads to coarser structure• The other trend is that new small fat areas arrive continuously • New small fat areas is against the coarser structure

– As small fat areas increase the proportion of the 3 biggest fat areas decreases– It also results in a less enlargement of the size of fat areas

• The distribution in the muscle cross section becomes more regular with new developing fat areas

Visible fat during growth based on VIAVideo Image Analysis

• A positive influence on the tenderness and the sensory score of meat can be found:

• with a higher number of fat areas • & with a more regular distribution of fat areas

This chart is the result of a German study that compared the nature of the marbling and taste panel opinions.

[Albrecht 8/97]

Is there more to the marbling story? Absolutely

• Dr. Jochen Wegner used CIA to determined:• Galloway had the “largest (most desirable) value for:

– the number of areas of fat per cm2, • Galloways had the smallest (most desirable) values for:

– the size of the areas of fat, – the proportion (as a %) of the three largest areas of fat, – the proportion of long areas of fat and for the distribution of areas of

fat.• The results indicate:

– a finer and more regular deposition of fat for the Galloway.”

Charts to follow Show

• Check marks indicate where Galloways did well

Is there more to the marbling story? Summary

• Marbling traits measured by CIA: – reveal a more accurate evaluation of fat content & distribution – more accurate than subjectively (human) graded marbling in beef

• It is now well known and accepted: – that it is not just the overall quantity of intramuscular fat that improves meat

quality• but more importantly the type of fat deposits:

– with punctiform being superior to reticular – Punctiform is more small areas of fat within the bundles of muscle fibre– Verse reticular which is larger fat areas outside the bundles muscle fibres– and the distribution of the fat within the muscle tissue

• the distribution pattern of intramuscular fat is important because: – as distribution increases more evenly within the muscle – connective tissue is broken up to a greater degree

Thank you

Questions