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Jeff Wood talks with
ScienceWatch.com and answers a few questions about
this month's Fast Breaking Paper in the field of
Agricultural Sciences. The author has also sent along
an image of his work.
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Article Title: Fat deposition, fatty acid
composition and meat quality: A
review
Authors:
Wood,
JD;Enser, M;Fisher, AV;Nute, GR;Sheard,
PR;Richardson, RI;Hughes, SI;Whittington, FM
Journal: MEAT SCI
Volume: 78
Issue: 4
Page: 343-358
Year: APR 2008
* Univ Bristol, Dept Vet Clin Sci, Div Farm Anim Sci,
Bristol BS40 5DU, Avon, England.
* Univ Bristol, Dept Vet Clin Sci, Div Farm Anim Sci,
Bristol BS40 5DU, Avon, England.
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Why do you think your paper is highly
cited?
It is a review paper and gives an overview of published work on fatty acid
composition. The fatty acid composition of meat is a major factor in
nutritional value as well as in the quality (taste and keeping quality) of
meat. Ways to change fatty acid composition, improving nutritional value,
while maintaining or improving quality, are needed. Review papers are a
quick way for people to get into a topic.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
It is a synthesis of knowledge on the factors affecting fatty acid
composition and the implications for meat quality. It shows that a major
underlying factor explaining variations in the fatty acid composition of
tissues (muscle and adipose tissue) is the total amount of fat in the
animal. At low levels, the polyunsaturated fatty acids predominate, but as
growth proceeds, these are gradually diluted by fatty acids formed from
diets, which are mainly saturated and monounsaturated. From birth to
maturity, all the fatty acids change in characteristic ways, with
interesting differences between species. These interrelations have not
always been as well described before.
Would you summarize the significance of your paper in
layman's terms?
The paper shows that the nutritionally beneficial polyunsaturated fatty
acids in muscle are located in the cell structures and are at high
concentrations when the amount of visible white fat is low. As the animal
grows, it deposits more and more saturated and monounsaturated fatty acids
and nutritional value declines. The use of diets containing high levels of
polyunsaturated fatty acids in pigs and poultry can override this effect
because these are incorporated direct into body tissues after digestion.
This is more difficult in ruminants because polyunsaturated fatty acids in
the diet are changed to saturated fatty acids in the rumen. Nevertheless,
some fatty acids escape this process and are incorporated into body tissues
as in pigs. This is why meat from grass-fed cattle and sheep has high
concentrations of omega-3 fatty acids. The precursor fatty acid is a
constituent of grass.
How did you become involved in this research, and were
there any particular problems encountered along the way?
Much of the research reviewed was conducted at the University of Bristol
over several years. It is very satisfying to be able to assemble the
findings from all this work into a comprehensive picture. The subject is of
importance to the agricultural industry and so it has been well funded up
until recently. I have always been interested in the growth processes of
farm animals and this paper continues that interest.
Where do you see your research leading in the
future?
This paper sets a baseline from which research to fundamentally change the
fatty acid composition of meat can proceed. More understanding of the
genetic control of fatty acid composition will be needed to produce less
saturated fat in ruminant meats. Polyunsaturated fatty acids are more prone
to oxidation, which causes color changes and reduces shelf life in lean
meat. This problem requires a greater understanding of the use of
antioxidants and packaging systems.
Do you foresee any social or political implications for
your research?
Eating more healthily is very important and to be able to deliver healthier
meat is a challenge. Meat is criticized on several fronts (e.g., a high
carbon footprint). Meat is imported from countries with lower production
costs and possibly lower standards. There are several implications!
Jeff Wood
Professor of Food Animal Science, Farm Animal Science
School of Clinical Veterinary Science
University of Bristol
Bristol, UK
Web
Figure 1:
Figure 1:
Pork loin steak.
KEYWORDS: CONJUGATED LINOLEIC-ACID; DIETARY VITAMIN-E;
ADIPOSE-TISSUE; EATING QUALITY; N-3 PUFA; OXIDATIVE STABILITY;
PRODUCTION SYSTEMS; FRIESIAN STEERS; PROTEIN-LEVEL; PORK QUALITY.
