Food Programme End of Project Reports
http://hdl.handle.net/11019/966
Food research end-of-project reports2024-03-29T01:43:14ZEnhancement of the Nutritional Value and Eating Quality of Beef
http://hdl.handle.net/11019/1347
Enhancement of the Nutritional Value and Eating Quality of Beef
Moloney, Aidan P; Monahan, Frank J; Noci, F.; Murray, Brendan; Troy, Declan J.
Consumer interest in the nutritional aspects of health has increased
interest in developing methods to manipulate the fatty acid composition
of ruminant products. Ruminant meats such as beef and lamb
are often criticised by nutritionists for having high amounts of saturated
fatty acids (S) and low polyunsaturated fatty acids (P).The P:S
ratio in beef is approximately 0.1, the ideal being about 0.4.
This project is part of a larger EU-supported project entitled
Healthy Beef (Enhancing the content of beneficial fatty acids in beef
and improving meat quality for the consumer: QLRT-CT-2000-31423).
The Teagasc contribution, which was a collaboration between
Grange Research Centre and The National Food Centre, focussed
on nutritional manipulation of beef cattle. In particular, on exploiting
grazing and fishoil as tools to enhance the concentration of
“healthy” fatty acids in beef.
The conclusions were:
• The beneficial effect of a grazed grass-based diet on the fatty
acid composition of beef was confirmed
• The scale of this beneficial effect is strongly dependent on the
duration of grazing
• The optimum concentration of beneficial fatty acids was not
achieved suggesting that feeding management prior to grazing
is important
• Grazing influenced beef colour and drip-loss in a durationdependent
manner
• Animals finished off grass for 40 or 98 days produced meat
that was tougher than that from animals finished on silage and
concentrates or fed grass for the last 158 days.
• Fish oil supplementation enhanced the concentration in beef,
of fatty acids that are beneficial to human health
• The linear response to increasing level of fish oil consumption
indicates scope to further enhance the concentrations of
beneficial fatty acids in beef Wilting of grass prior to ensiling did not impact negatively on
the overall content of n-3P in muscle, but it increased the
concentration of conjugated linoleic acid
• Dietary inclusion of fish oil or wilting of grass prior to ensiling
did not affect muscle appearance
• Fish oil seemed to increase tenderness but only at the high
level of inclusion. This merits further study
• There was some evidence that wilting of grass prior to ensiling
enhanced meat tenderness. This needs to be confirmed.
End of Project Report; This project was supported by the European Commission (Healthy Beef, QLRT-CT-2000-31423).
2004-01-01T00:00:00ZVariation in the quality of meat from Irish steers at the time of slaughter.
http://hdl.handle.net/11019/1346
Variation in the quality of meat from Irish steers at the time of slaughter.
Moloney, Aidan P; Mullen, Anne Maria; Maher, S.C.; Buckley, D.J.; Kerry, Joseph P.
There is no information on the variation in quality, in particular
tenderness, that exists in Irish Beef nor is there information on the
variation that would remain if optimum practices were imposed at
all stages of the beef production chain. Evaluation of the success of
measures to improve beef consistency requires information on
existing variation and the minimum variation achievable.The objectives
of this project were (i) to establish the variation that exists in
the quality of meat from Irish cattle, (ii) to quantify the minimum
variation in meat quality that can be achieved in a practical beef production
system, (iii) to determine the effects and mechanisms of
additional sources of variation.
The conclusions from this project are:
• The M. longissimus dorsi (loin) was found to be more variable
than the M. semimembranosus (topside) for most quality
attributes examined (tenderness, sarcomere length and pH).
The scale of variation within the loin was similar to that
reported by the other research groups within the EU and US.
Heifers were more variable than steers for most attributes,
while there was no consistent classification effect on the
variability of meat quality attributes.
• Tenderness was equally variable in meat from genetically similar
steers, managed similarly, compared to commercial steers
randomly selected from a factory lairage but matched for
weight and grade.This was likely a result of both groups being
crossbred beef cattle of similar age, fat score, carcass weight
and managed identically post-mortem. However, variation in
tenderness of both groups was less than that observed in
a survey of commercial throughput (experiment 1). This
decrease is attributed to better pre-and-post-slaughter handling
practices.
• The data suggest that selection of sires (within a breed) with
better than average conformation has no deleterious effect on the eating quality of beef of their progeny.A more comprehensive
comparison of sires within a breed and between
breeds is required to confirm the generality of this conclusion.
• In a comparison of genotypes, gender and slaughter weights,
there was no evidence that variation around the mean value
for tenderness differed between breeds or liveweights after
14 days ageing. Bulls were more variable than steers for some
quality traits but the variation in tenderness was similar for
bulls and steers after 14 days ageing.
• While optimising the management of animals during the pre
and post-slaughter period reduced variation in tenderness,
some residual variation remained. A large percentage of the
residual variation in tenderness (Warner Bratzler shear force)
after 2 and 7 days post-mortem was explained by proteolysis
(breakdown of myofibrillar proteins).Variation in tenderness
(Warner Bratzler shear force) after 2 days post-mortem was
largely explained by phosphates (energy) and proteolysis,
while sensory tenderness was largely explained by phosphates
and glycolytic potential.
• Further work is required to reduce residual variation in Irish
beef and to determine the causes of this variation.
End of Project Report
0001-01-01T00:00:00ZSignificance of Lactobacilli in Cheddar Cheese
http://hdl.handle.net/11019/1317
Significance of Lactobacilli in Cheddar Cheese
Cogan, Tim; Beresford, Tom; Drinan, Finbarr; Palles, Tony; Fitzsimons, Nora
The objectives of this project were to isolate and identify the non-starter lactobacilli in mature Cheddar cheese, identify strains which impart mature flavours to cheese and determine their role in developing cheese flavour.
The main conclusions were as follows:
Based on an analysis of 18 mature Cheddar cheeses, selected from 7 commercial manufacturers, non-starter lactic acid bacteria typically numbered, as expected, 106-108 per gram and were dominated (97 percent) by Lactobacillus paracasei.
Although a small number of strains (typically 1 to 4) was found in each cheese there was considerable strain diversity in cheeses within as well as between manufacturing plants.
When selected strains were investigated for survival and flavour enhancement when added (as starter adjuncts) with the normal starter cultures in Cheddar cheese manufacture, it was found that they remained dominant for up to 3 months of ripening. Commercial grading of these cheeses at 3 and 6 months confirmed that the added strains did modify flavour development and one (DPC 4103), in particular, had a beneficial effect.
It was confirmed that two selected strains of non-starter lactobacilli were capable of metabolising citrate under the conditions of Cheddar cheese ripening and, consequently, if present in sufficient numbers, would influence flavour development.
The work was greatly facilitated by the successful and novel adaptation of a modern rapid molecular technique (RAPD) for species and strain classification.
In summary these studies found that one species of lactobacilli (Lb. paracasei) was the dominant non-starter lactic acid bacteria in mature Cheddar cheese. Although a wide variety of strains were identified, only a few were found in any particular cheese, suggesting their likely role in cheese flavour diversity even within the same manufacturing plant. This suggests the potential for flavour control or enhancement through the selective and controlled use of non-starter lactic acid bacteria.
Preliminary investigations of the metabolism of those organisms supports this view and a follow-up study now in progress should provide greater clarity on this matter.
End of Project Report
1998-09-01T00:00:00ZCoffee-Stability of Agglomerated Whole Milk Powder and other Dairy Creamer Emulsions
http://hdl.handle.net/11019/1316
Coffee-Stability of Agglomerated Whole Milk Powder and other Dairy Creamer Emulsions
Kelly, Philip; Oldfield, D.J.; Teehan, C.M.
The objectives of this project were: (a) to investigate the circumstances that cause
milk powders and creamers to fail when added to coffee based beverages; (b) to evaluate
the role of processing variables in relation to their thermostabilising effects on milk during
drying of coffee whiteners; and (c) to determine the role of emulsion formation on the
stability of imitation creamers.
End of Project Report
1999-02-01T00:00:00Z