Content uploaded by Gema Nieto
Author content
All content in this area was uploaded by Gema Nieto on Jan 30, 2014
Content may be subject to copyright.
Chapter 12
© 2012 Nieto and Ros, licensee InTech. This is an open access chapter distributed under the terms of the
Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Modification of Fatty Acid Composition in Meat
Through Diet: Effect on Lipid Peroxidation and
Relationship to Nutritional Quality – A Review
Gema Nieto and Gaspar Ros
Additional information is available at the end of the chapter
http://dx.doi.org/10.5772/51114
1. Introduction
The use of nutritional strategies to improve quality of food products from livestock is a new
approach that emerges at the interface of food science and animal science. These strategies
have emphasized in the alteration of nutritional profile, for example increasing the content
of polyunsaturated fatty acid (PUFA), and in the improvement of the oxidative stability,
such as supplementation of animal with natural antioxidants to minimize pigment and lipid
oxidation in meat.
The interest in the modification of fatty acid of meat is due to that fatty acid composition
plays an important role in the definition of meat quality because it is related to differences in
sensory attributes and in the nutritional value for human consumption [1]. Meat is a major
source of fat in the diet, especially of saturated fatty acids (SFA), which have been
implicated in diseases, especially in developed countries, such as cardiovascular diseases
and some types of cancer.
One of the key goals of nutritional research focuses on establishing clear relationships
between components of diet and chronic diseases, considering that nutrients could provide
beneficial health results. The incidence of these diseases in humans is associated with the
amount and the type of fat consumed in the diet. Diets high in SFA contribute to increase
LDL-cholesterol level, which is positively related to the occurrence of heart diseases.
However, some monounsaturated fatty acids (MUFA) and PUFA, in particular long-chain n-
3 PUFA have favourable effects on human health.
In recent years, consumers′ pressure to reduce the composition and quality of fat in meat
has led to attempts to modify meat by dietary strategies. Where as in recent years consumers
Lipid Peroxidation
240
have been advised to limit their intake of saturated fats and to reach a ratio of PUFA:SFA
greater than 4 and the type of polyunsaturated fatty acid is now being emphasized and a
higher ratio of n-3: n-6 fatty acids is advocated [1]. There is also now concern about the
consumption of unsaturated fatty acids that are formed during high-temperature
hydrogenation of oils for use in food products: the trans-unsaturated fatty acids in which the
double bonds are in the trans-stereometric position.
Nutritional approaches to improve the oxidative stability of muscle foods are often more
effective than direct addition of food ingredients since the antioxidants are preferentially
deposited where it is most needed. In addition, diet often represents the only technology
available to alter the oxidative stability of intact muscle foods, where utilization of
exogenous antioxidants additives is difficult if not impossible. Since product composition is
altered biologically, nutritional alteration of muscle composition is more label-friendly since
no additive declarations are required.
Among the strategies used, meat and meat products can be modified by adding ingredients
considered beneficial for health where the ingredients are able to eliminate or reduce
components that are considered harmful. In this sense, several studies have shown that
animal diet can strongly influence the fatty acid composition of meat. Scerra et al. [2]
showed that feeding ewes with pasture increases the PUFA content of intramuscular fat of
the lamb infant compared with diets consisting of concentrate. Nieto et al. [3] showed that
feeding Segureña ewes with thyme increases the PUFA content of intramuscular fat of the
lamb meat compared with control diets. Similarly, Elmore et al. [4] showed that feeding
lambs with diets rich in fish oil can modify the fatty acid profile of meat (increasing the level
of PUFA). Moreover Bas et al. [5] used linseed diet and Ponnampalam et al. [6] used fish oil,
in order to increase the content of long-chain n-3 fatty acids in lamb meat.
The variation of fatty acid compositions has profound effects on meat quality, because fatty
acid composition determines the firmness/oiliness of adipose tissue and the oxidative
stability of muscle, which in turn affects flavour and muscle colour. It is well known that
high PUFA levels may produce alterations in meat flavour due to their susceptibility to
oxidation and the production of unpleasant volatile components during cooking [7].
Therefore, it′s important to study the implications of the modification of fatty acid in the
quality of the meat and the lipid stability, for that it would be interesting the use of
liposomes to study the lipid oxidation.
Since liposomes mimic cellular structures [8], the feasibility to protect lipid membranes in
the presence of natural antioxidants can be investigated in model systems prior to
administration trough feeding. Such previous experiments are particularly interesting for
meat industry as they furnish preliminary insights with respect to lipid oxidation at
relatively short timescales [9].
2. Lipid digestion in ruminants and non-ruminants
It is well known that lipid digestion is different in ruminant and non-ruminant and that the
nature of lipid digestion by the animal has an important effect on the transfer of fatty acids
Modification of Fatty Acid Composition in Meat Through Diet:
Effect on Lipid Peroxidation and Relationship to Nutritional Quality – A Review 241
from the diet into the animal product. In case of non-ruminant, the principal site of
digestion of dietary lipid is the small intestine, where the pancreatic lipase breaks the
triacylglycerols down to mainly 2-monoacylglycerols and free fatty acids and the formation
of micelles aids absorption, with lipid uptake mediated by the lipoprotein lipase enzyme,
which is widely distributed throughout the body. Therefore dietary fatty acids in the non-
ruminant are absorbed unchanged before incorporation into the tissue lipids. Dietary lipid
sources have a direct and generally predictable effect on the fatty acid composition of pig
and poultry products and the supply of unsaturated fatty acids (UFA) to tissues may be
simply increased by increasing their proportion in the diet [10].
However, digestion and metabolism of ingested lipids in the rumen results in the exit of
mainly long-chain, saturated fatty acids from the rumen. The rumen microorganisms in the
ruminant digestive system have a major impact on the composition of fatty acids leaving the
rumen for absorption in the small intestine. Microbial enzymes are responsible for the
isomerisation and hydrolysis of dietary lipid and the conversion of UFA to various partially
and fully saturated derivatives, including stearic acid (C18:0). Although linoleic (C18:2 n-6) and
linolenic (C18:3 n-3) acids are the main UFA in the diet of ruminants, the processes within the
rumen ensure that the major fatty acid leaving the rumen is C18:0. The intestinal absorption
coefficient of individual fatty acids is higher in ruminants than nonruminants, ranging from
80% for SFA to 92% for PUFA in conventional low fat diets. Therefore, the higher absorption
efficiency of SFA by ruminants has been attributed to the greater capacity of the bile salt and
lysophospholipid micellar system to solubilise fatty acids, as well as the acid conditions
within the duodenum and jejunum (pH 3.0–6.0).
3. Fatty acid in meat
Taking into accounts that fat is currently an unpopular constituent of meat and however
contributes to meat quality and is important to the nutritional value of meat. This section
considers the fatty acid composition in different species and the roles of the fat in meat quality.
Doing a brief introduction of the importance of fatty acids, firstly we will highlight the
essential unsaturated fatty acids, linoleic (C18:2), linolenic (C18:3) and arachidonic (C20:4). They
are necessary constituents of mitochondria and cell walls. These fatty acids are specials,
because contrary to the production from saturated sources, the body can not produce any of
the fatty acid mentioned above, unless one of them is available in the diet. Oleic, linoleic and
linolenic acids each belong to a different family of compounds in which unsaturation occurs
at the n–9, the n–6 and n–3 carbon atoms, respectively, in the hydrocarbon chain numbering
from the methyl carbon (n). They are thus referred to as the ω –9, ω –6 and ω –3 series.
Linoleic acid is abundant in vegetable oils and at about 20 times the concentration found in
meat; and linolenic acid is present in leafy plant tissues [11].
Doing a comparative data between the content of PUFA in the muscular tissue of the beef,
lamb and pork (Table 1), it is clear that linoleic acid (C18:2) is markedly greater in the lean
meat of pigs than in that of either the beef or lamb.
Lipid Peroxidation
242
C18:2 C18:3 C20:4 C22:5 C22:6
Beef 2.0 1.3 1.0 Tr. -
Lamb 2.5 2.5 - Tr. -
Pork 7.4 0.9 Tr. Tr. 1.0
Table 1. Polyunsaturated fatty acids and cholesterol in lean meat (as % total fatty acids)
In addition, the Table 2 shows the study of Enser at al. [12], who obtained 50 samples of beef
sirloin steaks, pork chops, and lamb chops and determined the fatty acid profile of the
muscle portions of these retail meat cuts. In the same way that Table 1, the most notable
difference among the ruminant species and pork was the fivefold greater concentration of
linoleic in pork and significantly greater proportions of C20:3, C20:4, and C22:6, and C14:0. For
example, pork have a proportions of linoleic acid (C18:2 n-6): 302 mg/100g of loin muscle,
while beef and lamb contains 89 and 25 mg/100g, respectively. The reason of this is because
linoleic acid is derived entirely from the diet. It passes through the pig′s stomach unchanged
and is then absorbed into the blood stream in the small intestine and incorporated from
there into tissues. When linoleic acid is ingested, they are metabolized by animal liver to
produce two families of long chain polyunsaturated fatty acids which are specific to
animals, respectively, the n-6 and n-3 series.
Fatty acid Pork Beef Lamb
C 12:0 (lauric) 2.6 2.9 13.8
C 14:0 (myristic) 30 103 155
C 16:0 (palmitic) 526 962 1101
C 18:0 (stearic) 278 507 898
C 18:1 (trans) - 104 231
C 18:1 (oleic) 759 1395 1625
C 18:2 n-6 (linoleic) 302 89 125
C 18:3 n-3 (-linolenic) 21 26 66
C 20:3 n-6 (lauric) 7 7 2
C 20:4 n-6 (arachidonic) 46 22 29
C 20:5 n-3 (eicosopentaenoic) 6 10 21
C 22:5 n-3 (docosopentaenoic) 13 16 24
C 22:6 n-3 (docosohexaenoic) 8 2 7
Total 2255 3835 4934
P:S 0.58 0.11 0.15
n-6:n-3 7.22 2.11 1.32
Source: Enser et al. [12]
Table 2. Fatty acid Content (mg/100g) of loin muscle in steaks or chops.
Modification of Fatty Acid Composition in Meat Through Diet:
Effect on Lipid Peroxidation and Relationship to Nutritional Quality – A Review 243
However, in ruminants, linoleic acid (C18:2 n–6) and -linolenic acid (C18:3 n-3) which are
at present in many concentrate feed ingredients, are degraded into monounsaturated
(MUFA) and saturated fatty acids (SFA) in the rumen by microbial biohydrogenation
(70–95% and 85-100%, respectively) and only a small proportion, around 10% of dietary
consumption, is available for incorporation into tissue lipids. By that reason, beef and
lamb contain lower content of linoleic acid, compared with pork meat. Muscle also
contains significant proportions of long chain (C20-22) PUFAS which are formed from
C18:2 n–6 and C18:3 n–3 by the action of Δ5 and Δ 6 desaturase and elongase enzymes.
Important products are arachidonic acid (C20:4 n-6) and eicosapentaenoic acid (EPA, C20:5
n-3).
Taking into accounts that in ruminants, rumen microorganisms hydrogenate a substantial
proportion of PUFA diet, resulting in high levels of SFA for deposition in muscle tissue,
lamb or beef meat contain a low relationship between fatty acids PUFA and SFA (ratio P/S),
which increases the risk of cardiovascular problems and other diseases.
The consequences of a greater incorporation of C18:2 n-6 into pig muscle fatty acids compared
with ruminants produces higher levels of C20:4 n-6 by synthesis and the net result is a higher
ratio of n-6:n-3 PUFA compared with the ruminants. If the nutritional advice is for ratios
<4.0, the present value of 7 on pig muscle is unbalanced relative to that of the ruminants
(1.32 in lamb and 2.11 in beef). In addition, another ratio is the ratio of all PUFA to SFA (P:S).
The ratio P/S in a normal diet is 0.4 [13] and in lamb meat is 0.15 and in beef 0.11, while in
pork is 0.58.
For all these reasons, there is an increase interesting in research intended to modify the fatty
acid composition in meat, especially reducing the concentration of SFA and increasing
PUFA.
4. Dietary modification of fatty acid in meat
Doing the comparison between ruminants and non-ruminants, the fatty acid composition of
stored lipids of the ruminant is relatively unwilling to changes in the fatty acid profile of
ingested lipids. This logic has been the basis for expression of the concept that ruminant fats
are more saturated than those of non-ruminants. Although effects of ruminal
biohydrogenation on ruminant tissue fatty acid profiles are generalized, numerous
researchers have demonstrated that ruminant lipids can be manipulated by dietary means to
contain a higher proportion of unsaturated fatty acids. The next paragraphs will show the
different strategies to modify the fatty acids of ruminants and nonruminants.
4.1. Altering quality of muscle from monogastric
Monogastric farm animals are worldwide a main source of high-quality products with a
high content of highly available protein, minerals, and vitamins. Pigs and chickens are the
main monogastric farm animals [1].
Lipid Peroxidation
244
To altering the quality of muscle of monogastric, it′s necessary to know the digestion of
nutrients in these animals. Anaerobic microorganisms are able to hydrogenate unsaturated
fatty acids (UFA) preferably polyunsaturated fatty acids (PUFA). During these processes
they build trans-fatty acid as well as conjugated fatty. While in ruminants these fatty acids
are absorbed to a great extent, monogastric animals excrete most of them with the feces as
they are produced in the lower parts of the digestive tract.
4.2. Altering quality of muscle from ruminants
Meat from ruminants is a major source of essential nutrients (amino acids, iron, zinc and
vitamins from the B group). Meat from ruminants (huge diversity of breeding systems
and pieces) is characterised by great variations in fats, quantitatively and qualitatively.
Some saturated (C14:0 and C16:0) and monounsaturated trans fatty acids are not
recommended for human consumption and it is possible to reduce their concentrations in
meats by increasing the proportions of polyunsaturated fatty acids absorbed by the
animals from their diets. To achieve this goal, fatty acids must be protected against
hydrogenation in the rumen. Dietary intake of PUFA from the n-3 series and especially
from the n-6 series by the animals favour the production of conjugated linoleic acid by the
rumen bacteria. Some of these fats, such as CLA (conjugated linoleic acid), could be
beneficial to human health. CLA is important in the prevention of specific cancers and in
the treatment of obesity that has been demonstrated in animal models and, at least partly,
in humans.
Alteration of quality in food products from ruminants requires knowledge of the nutritional
and metabolic principles that influence product composition. Ruminants are unique among
mammals due to their pregastric fermentation. Microflora and microfauna present in the
ruminant forestomach dramatically modify the ingested nutrients and consequently have a
large impact on the metabolism and composition of the muscle and milk [1].
5. Fatty acid sources
It's important to take into accounts several factors to choice the ingredient and the form by
which it is included in the feed: (a) the cost and availability; (b) the impact of the ingredients
and its fatty acid composition on feed digestibility; (3) the influence of consumers and
retailers regarding the introduction of ingredients into the food chain and (4) animal feed
regulations regarding permitted supplements.
Recognizing that fatty acids are readily absorbed from the diet and incorporated into tissue
fat, producers have attempted to improve the nutritional quality of meat by incorporating
various sources of n-3-PUFA [7, 14]. The main dietary sources of n-3 fatty acids fed to pig
are vegetable oils [15-20], fish oil/fish meal [21,22] and forage [23]. Novel oil sources such as
chia seed, marine algae, lupin and camelina have been investigated as lipid sources in
animal feeds.
Modification of Fatty Acid Composition in Meat Through Diet:
Effect on Lipid Peroxidation and Relationship to Nutritional Quality – A Review 245
5.1. Lipid sources for ruminants
5.1.1. Forages
Several studies have shown that ruminants consuming fresh pasture have higher content of
UFA in their meat that those receiving a cereal-based concentrate diet.
Grass is a good source of n−3 PUFA although there can be variation due to maturity and
variety. Grass lipids contain high proportions of the unsaturated linolenic acid (C18:3 n−3).
Other studies have suggested that the (n−6)/(n−3) ratio in phospolipids may be useful to
discriminate grass-fed from grain-fed lambs [1, 24].
Therefore, pasture-raised animals have higher proportions of linolenic acid in their fat than
stallfed animals [25].
French et al. [15] compared the effect of offering grazed grass, grass silage and concentrates
on the fatty acid composition of intramuscular fat in steers. Similar low intramuscular fat
contents (<4.5 g/100 g muscle) were determined in meat from all diets offered, hence a
possible confounding effect due to differences in the amount of fat deposited was avoided.
Decreasing the proportion of concentrate in the ration effectively increased the proportion of
grass intake and resulted in a linear increase in PUFA:SFA ratio (P<0.01) and a linear
decrease in the concentration of SFA (P<0.001). The highest concentration of PUFA in the
intramuscular fat was found in those animals that had consumed grass only (22 kg grazed
grass). Grass and grass silage had a much greater proportion of -linolenic acid than the
concentrates, although levels of linoleic acid were similar. The content of linoleic acid in the
intramuscular fat was not significantly different between treatments but concentrations of -
linolenic acid and total conjugated linoleic acid were significantly higher for grass-fed steers
than for steers offered grass silage and/or concentrates.
Moreover, Nuernberg et al. [26] showed that the concentration of lauric acid was higher in
subcutaneous fat and muscle of lambs fed on pasture compared to lambs fed concentrate.
Similar results were found by Demirel et al. [27], who studied the fatty acids of lamb meat
from two breeds fed different forage: concentrate ratio. And Scerra et al. [2], who showed
that lamb meat derived from pasture-fed ewes had a lower levels of lauric and palmitic acid
(compared with diets with concentrate) that are though to be a public health risk
Sañudo et al. [28] studied British lambs compared with lambs fed grass fed grain, the result
showed that a higher percentage of linolenic acid in the meat of grass-fed lambs, as result of
the introduction of this natural antioxidant.
Realinia et al. [29] studied thirty Hereford steers that were finished either on pasture or
concentrate to determine dietary and antioxidant treatment effects on fatty acid
composition and quality of beef. These authors reported that the percentages of C14:0, C16:0,
and C18:1 fatty acids were higher (P<0.01) in the intramuscular fat of concentrate-fed steers,
whereas pasture-fed cattle showed greater (P<0.01) proportions of C18:0, C18:2, C18:3, C20:4,
C20:5, and C22:5. Total conjugated linoleic acid (CLA) was higher (P<0.01) for pasture- than
concentrate-fed cattle. Therefore, these authors reported that finishing cattle on pasture
Lipid Peroxidation
246
enhanced the unsaturated fatty acid profile of intramuscular fat in beef including CLA
and omega-3 fatty acids. Results from this study suggest that the negative image of beef
attributed to its highly saturated nature may be overcome by enhancing the fatty acid
profile of intramuscular fat in beef through pasture feeding from a human health
perspective.
5.1.2. Oilseeds
Many studies to manipulate the fatty acid composition of meat using whole oilseeds have
been conducted. For example, the effect of the physical form of linseed offered on the fatty
acid composition of meat has been reported by several workers: Raes et al. [30] reported that
the replacement of whole soyabean with extruded linseed or crushed linseed in the finishing
diet of Belgian Blue young bulls increased -linolenic acid. Mach et al. [31] reported that
whole canola seed (-linolenic acid content 10.6 g/100 g total FA) or whole linseed (-
linolenic acid content 54.2 g/100 g total FA), at three lipid levels (50, 80 and 110 g/kg DM) to
54 Holstein bulls increased linearly with lipid level the concentration of n−3 PUFA in the
longissimus dorsi muscle.
Elmore et al. [4] reported that the feeding of lamb with diets rich in fat and oils (fish oils,
kelp and flax seed) increased the level of polyunsaturated fatty acids. Similarly, Nute et al.
(2007) studied the oxidative stability and quality of fresh meat from lambs fed different
levels of n-3 PUFA from linseed oil, fish oil, a supplement produced from flax seed (PLS),
seed sunflower and soybean meal, seaweed, and combinations of these different oils. They
reported that the fatty acid composition of semimembranosus muscle phospholipids was
affected by diet.
The rabbit meat was also used in several studies with the objective of fatty acid
modification. As the study of Kouba et al. [32], who studied rabbits fed with a diet
containing 30 g of extruded linseed/kg. Feeding the linseed diet increased (P < 0.005) the
content of 18:2n-3 in muscles, perirenal fat, and raw and cooked meat. The long chain n-3
polyunsaturated fatty acid (PUFA) contents were also increased (P < 0.01) in the meat. The
linseed diet produced a decrease in the n-6/n-3 ratio. These authors highlights that the
inclusion of linseed in rabbit diets is a valid method of improving the nutritional value of
rabbit meat.
5.1.3. Marine algae
Marine algae are an alternative to fish oil as a dietary source of n−3 long chain PUFA
(LCPUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
In the study of Cooper [33], the marine algae were included in the sheep diet not only as a
source of DHA (fish oil/algae diet supplied 15 g/100 g total FA as DHA) but also because
it had been previously shown to undergo a lower level of biohydrogenation than fish oil
[33]. In another study of the same author [34] studied the manipulation of the n-3 PUFA
Modification of Fatty Acid Composition in Meat Through Diet:
Effect on Lipid Peroxidation and Relationship to Nutritional Quality – A Review 247
fatty acid content of muscle and adipose tissue lamb was studied. For that fifty lambs,
with an initial live weight of 29 ± 2.1 kg, were allocated to one of five concentrate-based
diets formulated to have a similar fatty acid content (60 g/kg DM), but containing either
linseed oil (high in 18:3n3); fish oil (high in 20:5n3 and 22:6n3); protected linseed and
soybean (PLS; high in 18:2n6 and 18:3n3); fish oil and marine algae (fish/algae; high in
20:5n3 and 22:6n3); or PLS and algae (PLS/algae; high in 18:3n3 and 22:6n3). Lambs
fed either diet containing marine algae contained the highest (P < 0.05) percentage of
22:6n3 in the phospholipid (mean of 5.2%), 2.8-fold higher than in sheep fed the fish oil
diet.
A more limited number of studies have looked into the effects of dietary supplementation
with DHA-rich marine algae on the fatty acid composition of muscle tissue of rabbits [35],
lambs [4] and pigs [36, 37].
5.2. Lipid sources for non-ruminants
The cereal-based diet commonly offered to poultry and pigs supplies mainly n−6 PUFA and
a small amount of n−3 PUFA. This is reflected in the fatty acid composition of the animal
product. Dietary modification of poultry meat, eggs or pork to increase the n−3 PUFA
content requires a supply of n−3 PUFA from the diet.
The actual strategies to non-ruminants are focused on assessing the effect of offering
terrestrial versus marine sources of n−3 PUFA and the subsequent implications for product
quality.
5.2.1. Vegetable oils
Enrichment of poultry diets with plant oils has been shown to have different impacts on
abdominal fat and the site of fatty acid deposition depending on the SFA, MUFA and PUFA
content of the oil [38].
Crespo & Esteve-García [38] studied broiler chickens fed with a basal diet supplemented for
20 days before slaughter with 10% inclusion of linseed oil, sunflower oil and olive oil. As
expected with non-ruminant, the fatty acid profile of the deposited fat in the broiler carcase
reflected the dietary fat source. The supplementation with olive oil resulting in the highest
proportion of C18:1, sunflower oil supplementation resulting in the highest proportion of
linoleic acid (51.1 g/100 g total body FA), while linseed oil contributed the highest amount of
n−3 PUFA and most favourable n−6:n−3 ratio in the carcase fat.
In addition, Lu et al. [39] investigated the effects of soybean oil and linseed oil on the fatty
acid compositions of pork. The three dietary treatments were: (a) no oil supplement; (b) 3%
soybean oil supplement; (c) 3% linseed oil supplement. Dietary linseed oil and soybean oil
significantly increased the contents of C18:3 and C18:2 in the neutral lipids and phospholipids
in both longissimus muscle and biceps brachii muscle, respectively.
Lipid Peroxidation
248
5.2.2. Linseed and fish oil
The n−3 long chain polyunsaturated fatty acids can be incorporated into non-ruminant
products from dietary fish oil. The transfer of these fatty acids was found to be influenced
by time and duration of feeding and the presence of other oil supplements. Haak et al. [40]
offered to pigs a basal diet composed of barley, wheat and soyabean meal ad libitum alone
or supplemented with 1.2% linseed or fish oil during: the whole fattening period; the first
fattening phase (weeks 1–8) only; or the second fattening phase (6 weeks or 9 weeks, until
slaughter at 100 kg). Haak et al. [40] reported that incorporation of -linolenic acid into the
longissimus thoracis muscle was similar (1.24 g/100 g total FA) when linseed was offered
throughout the fattening period or only during the second phase. When fish oil was offered
during either of the fattening phases, only the proportion of DHA incorporated was
affected, being greater when fish oil was offered during the second fattening phase (P<0.05).
Incorporation of EPA (Eicosapentaenoic acid) and DHA (Docosahexaenoic acid ) following
fish oil supplementation for the whole fattening period was 1.37 and 1.02 g/100 g total FA in
the longissimus thoracis muscle, representing a six-fold increase compared to the basal diet
and a three- and five-fold increase respectively, compared to the linseed diet. In agreement
with other animal work [34], Haak et al. [40] concluded that a direct dietary source of DHA
was required to increase DHA in animal muscle and that levels in pork could not be
substantially influenced by dietary supply of precursors.
5.2.3. Marine algae
It′s well known that microalgae are the original source of DHA in the marine food chain [41],
dried marine algae have also been included in animal feeds to improve the DHA level of foods
of animal origin. Studies has mainly focused on the quality of eggs [42, 43] and chicken meat
[44]. A more limited number of studies have looked into the effects of dietary supplementation
with DHA-rich marine algae on the fatty acid composition of muscle tissue of pigs [36, 37].
6. Effects of fatty acid modification on the nutritional value of meat
There is a growing consumers resistance to the incorporation of additives into foods,
especially where the additives are of synthetic origin, even when they have a nutritional or
health advantage. Dietary supplementation of the growing animal provides a unique
method of manipulating the content of some micronutrients and other nonnutrient bioactive
compounds in meat, with a view to improving the nutrient intake of consumers or
improving their overall health.
Research on heart disease in humans has tended to implicate high intakes of saturated fat
and cholesterol as contributory factors with a possible protective effect of polyunsaturated
fat and a neutral effect of monounsaturated fat [45]. Overall, the advice to consumers has
been to control the level of energy consumed as fat to under 35% and in particular, to limit
saturated fats to 10%of energy intake [13]. It is also recommended that the proportion of
short- and medium-chain saturated fatty acids be reduced and that intake of n-6 fatty acids
be reduced relative to n-3 [45].
Modification of Fatty Acid Composition in Meat Through Diet:
Effect on Lipid Peroxidation and Relationship to Nutritional Quality – A Review 249
The nutritional properties of meat are largely related to its fat content and its fatty acid
composition. In this sense, long-chain n-3 fatty acids, such as C20:5 n-3 and C22:6 n-3 have
beneficial health effects, such as reduction in the thrombotic tendency of blood, associated
with lower coronary heart disease in humans [46]. In addition, the role of dietary fat in
human health is further complicated by the differing biological activity of some fatty acids
when present at different stereospecific positions in triacylglycerols [47].
To avoid possible health dangers from the consumption of the meat of ruminants, a greater
degree of unsaturation could be introduced into their fats. One example of the modification of
fatty acid in meat resulting in an improvement of human health is the study of Diaz et al. [48].
These authors studied the fatty acid content and sensory characteristics of meat from light
lambs fed three diets supplemented with different sources of n-3 fatty acids (fish oil, linseed
and linseed plus microalgae) and a control diet during refrigerated storage. The meat from
lambs fed linseed diets had the highest levels of C18:3 n-3,while animals fed fish oil, had the
highest long-chain n-3 polyunsaturated fatty acids (PUFA). Thus, 100 g of meat from lamb fed
the fish oil diet provided 183 mg of long-chain n-3 PUFA, representing 40% of the daily
recommended intake. The levels of n-3, n-6 and long-chain n-3 PUFA decreased during a 7-
day storage period. These authors reported that consumption of 100 g of lamb muscle from
lambs fed control diet would provide about 5% of the daily recommended intake for long
chain n-3 fatty acids (500 mg per day, according to EFSA [49]. In case of linseed plus
microalgae and linseed diets, would provide nearly 10% of the daily recommended intake for
long-chain n-3 fatty acids. The greatest supply of n-3 PUFA and long-chain n-3 fatty acids
would come from lambs fed fish oil diet, which would provide about 34% of the daily
recommended intake for long-chain n-3 fatty acids. Moreover, the highest PUFA/SFA ratio was
found in lambs fed linseed and fish oil diets, which was close to the recommended value
(0.35). The lowest value was observed in lambs fed control diet. During storage, the total
content of PUFA, including n-3 PUFA, n-6 PUFA and the long-chain n-3 PUFA, decreased.
Thus, meat from lambs fed fish oil could supply close to 40% of the daily recommended intake
for long-chain n-3 fatty acids on day 0. On day 7 this meat supplies almost 31% and, therefore,
this could be considered a reduction in the nutritional value of the meat. This decrease could
be a consequence of oxidation changes, since PUFA are more prone to oxidation than MUFA
or SFA; the meat from the supplemented groups and especially from animals fed fish diet, are
more prone to oxidation than the control diet (with lower content in PUFA and long-chain n-3
PUFA). Therefore, the importance of the influence of the modification of fatty acid profile on
the lipid peroxidation should be studied.
7. Quality of PUFA enriched animal products and relation with lipid
peroxidation
One of the main factors limiting the quality of meat and meat products is lipid oxidation.
Lipid oxidation results in rancid odour and flavour, sometimes referred to as warmed-over
flavour. Fatty acids are oxidised into aldehydes, alkanes, alcohols and ketones by chemical
(auto-oxidation) or enzymatic (β-oxidation) reactions. In this sense, rancid aroma is
Lipid Peroxidation
250
apparently due to the dominance of alkanal (hexanal, nonanal) or certain alcohols (1-penten-
3-ol, 1-octen-3-ol). The reason is due to the first step of lipid oxidation, which involves the
removal of hydrogen from a methylene carbon in the fatty acid. This becomes easier as the
number of double bonds in the fatty acid increases, which is why polyunsaturated fatty
acids are particularly susceptible to oxidation. Therefore, increasing the degree of
unsaturation of muscle membranes reduces the oxidative stability of the muscle. In addition,
the relative oxidation rates of fatty acids containing 1, 2, 3, 4, 5 or 6 double bonds are 0.025,
1, 2, 4, 6 and 8, respectively [50].
It is very interesting to correlate the fatty acid profile of the meat with the development of off-
odour and off-flavour in order to understand the susceptibility of oxidative damage in the meat.
For example, If the ratio of PUFA to SFA is higher in the meat, this softer fat is more susceptible
to oxidative damage, and this may cause difficulties for the retailers who are increasingly
turning toward centralized butchery and modified atmosphere packaging, both of which lead
to meats being exposed to higher levels of oxygen for a longer period of time prior to retail.
There are few studies that examine the effect of an enrichment of the diet in n-3 PUFA and
the oxidation potential of muscle. Some of these studies are made in rabbit meat [51-52, 32]
and lamb meat [53]. While Kouba et al. [32], reported that the enriched Longissimus dorsi
did not exhibit a lower oxidative stability, Castellini et al. [51] and Dal Bosco et al. [52] found
that feeding a n-3 PUFA enriched diet lowered significantly TBARS level in, raw meat and
Longissimus dorsi. One plausible explanation could be that these authors only
supplemented the experimental diet with a high amount of vitamin E, which led to an
increase of vitamin E level in tissues of rabbits fed this diet, as already described by Oriani et
al. [54], and it is well known that the susceptibility of lipids to oxidation can be reduced by
vitamin E, as described by Lin et al. [55] in poultry and Monahan et al. [56] in pigs.
The oxidative processes in living animals are dependent on the endocrine and enzymatic
activities in the tissues. There is some evidence that differences between species and breeds
of animals exists. However, a high individual variation has also to be assumed. Oxidative
processes can occur at many different stages in animal nutrition. During digestion the
nutrients are soluble and therefore can be easily oxidized. Extrinsic influences on the
oxidative processes mainly derive from the composition of the feedstuffs and feed additives.
Therefore, feed should be protected against oxidative damage already during storage.
With increased content of polyunsaturated fatty acids (PUFA) a higher oxidation rate in the
feed, in the digest as well as in the intermediate metabolism, occurs. But feedstuffs can also
contain antioxidants like vitamins, carotenoids, or phenols, or prooxidative compounds like
some trace elements. To improve the oxidative stability of the feed, antioxidative additives
are often used as supplements to the diets.
Notwithstanding the beneficial attributes of polyunsaturated fatty acids, it should be noted
that lipid oxidation products are believed to adversely affect the health of cells. Fortunately
muscular tissue contains several enzymes that protect cells against such change, the most
important of which is glutathione peroxidase [57].
Modification of Fatty Acid Composition in Meat Through Diet:
Effect on Lipid Peroxidation and Relationship to Nutritional Quality – A Review 251
To avoid the lipid oxidation tendency shown in meat rich-PUFA, Díaz et al. [48], recommended
the inclusion of antioxidants in the diet of lambs, in order to avoid the negative impact on the
flavour and to prevent fatty acids from oxidation of these on lamb meat enriched in n-3 fatty
acids. Therefore, the inclusion of antioxidants with the incorporation of the ingredients
responsible of the fatty acid modification through the feed could be an interesting strategy to
prevent oxidation of the meat. Similarly, it has been shown that some fatty acids (such as
conjugated linoleic acid) can exert antioxidant activity in meat by reducing lipid oxidation [58].
In a previous study made by our group, the effectiveness of thyme leaves diet (during
pregnancy and lactation of ewes) to improving the lamb meat lipid stability was attributed to
the antioxidant effect of the phenolic compounds present in the thyme leaf. These bioactive
compounds in the leaves may interfere with the propagation reaction of lipid oxidation, besides
inhibiting the enzymatic systems involved in initiation reactions [59]. It has been shown that
diet with natural antioxidants interferes with the metabolism of fatty acids in ruminants [60].
Taking into accounts another studies using plants of the family Labiatae in the diet, Youdim
and Deans [61] showed that a dietary supply of thyme oil or thymol to ageing rats showed a
beneficial effect on the antioxidative enzymes superoxide dismutase and glutathione
peroxidase, as well as on the polyunsaturated fatty acid composition in various tissues. Animals
receiving these supplements had higher concentrations of polyunsaturated fatty acids in
phospholipids of the brain compared to the untreated controls. Similarly, Lee et al. [62] showed
that the pattern of fatty acids of the abdominal fat of chicken was also altered by oregano oil and
dietary carvacrol lowered plasma triglycerides. In animals for food productions, such effects are
of importance for product quality: these supplement may improve the dietary value and lead to
a better oxidative stability and longer shelf-life of fat, and meat [63].
7.1. Liposomes
Oxidative stress leads to oxidation of low-density lipoproteins (LDL), which plays a key role
in the pathogenesis of atherosclerosis, which is the primary cause of coronary heart disease
[64]. The nutritional manipulations of the fatty acid composition of meats increase the
susceptibility of their lipids to peroxidation; because as have been explained in the previous
sections, PUFA are known to act as substrates initiating the oxidative process in meat. In this
sense, much attention has been paid to the use of the natural antioxidants, since potentially
these components may reduce the level of oxidative stress in the feed.
Several methods have been described in the literature for assessing antioxidant activity.
These include radical scavenging assays, ferric reducing assay, or inhibition of the oxidation
of oils, emulsions, low-density lipoproteins (LDL), or liposomes. The use of LDL is an
interesting method of assessing antioxidant properties relevant to human nutrition, since
these systems allow investigation of the protection of a substrate by an antioxidant in a
model biological membrane or a lipoprotein. Assessment of the activity of mixtures of lipid-
soluble and water-soluble antioxidants in liposomes has clear advantages over other
commonly used methods. The liposome system allows the lipid-soluble components to be
present in the lipid phase without the presence of a cosolvent, while the water soluble
antioxidants can be added to the aqueous phase of the liposome [8].
Lipid Peroxidation
252
The liposome system also allows study the synergy between different antioxidants
ingredients used in the manufacture of feed, as tocopherols or other water-soluble
antioxidants to be demonstrated [65- 66], whereas synergy is not normally observed if these
components are present in homogeneous solution.
Therefore, the use of a liposome system is an interesting strategy for a preliminary
assessment of the antioxidant activity of ingredients used in the manufacture of feedstuffs.
This was the objective of a previous study [9] where the use of liposomes as biological
membrane models to evaluate the potential of natural antioxidants as inhibitors of lipid
peroxidation was described. For that, the antioxidative effects of by-products from
manufacturing of essential oils, i.e., distilled rosemary leaf residues (DRL), distilled thyme
leaf residues (DTL), and the combined antioxidative effects of DRL or DTL with -
tocopherol (TOH), ascorbic acid (AA), and quercetin (QC) on peroxidation of L--
phosphatidylcholine liposomes as initiated by hydrophilic azo-initiators, were investigated.
The results showed that the extracts from DRL and DTL all had an obvious antioxidative
effect as evidenced by a lag phase for the formation of phosphatidylcholine-derived
conjugated dienes. Combination of TOH or QC with DRL and DTL, respectively, showed
synergism in prolonging of the lag phase. Distilled leaves of rosemary and thyme were
found to be a rich source of antioxidants as shown by the inhibition of the formation of
conjugated dienes in a liposome system. Based on this study, it can be concluded that
rosemary and thyme residues, as by-products from distillation of essential oils, are a readily
accessible source of natural antioxidants, which possibly provides a good alternative to
using synthetic antioxidants in the protection of foods and meat products in particular.
After this study, it was reported that both distilled leaves (rosemary and thyme) were
readily accessible source of natural antioxidants in animal feedstuffs, these by-products
were added to the feed of pregnant ewes [67- 71]. As shown previously with the liposomes
model system study, the meat of lambs from ewes fed with distilled rosemary and thyme
leaf had lower levels of lipid oxidation and these additives were considered a good
alternative to using synthetic antioxidant in animal diets.
8. Conclusions
This review suggest that the negative image of meat attributed to its highly saturated nature
may be overcome by enhancing the fatty acid profile of intramuscular fat through feeding
from a human health perspective. Increasing the n-3 PUFA content of animal feedstuffs can
be a promising and sustainable way to improve the nutritional value of meat, without
forcing consumers to change their eating habits.
It’s well known that although dietary PUFA improves meat nutritional qualities, such meats
are more susceptible to lipid oxidation during processing. Therefore, there is a need to study
the differences in oxidative stability of the muscles in order to understand the effect of
dietary on lipid peroxidation. For that the use of liposomes is an interesting strategy to
study the lipid peroxidation in model system as preliminary studies (prior the
administration of fatty acid sources through feeding).
Modification of Fatty Acid Composition in Meat Through Diet:
Effect on Lipid Peroxidation and Relationship to Nutritional Quality – A Review 253
When all of these considerations are taken into account, the possibility of preserving the
nutritional qualities of processed meat rich in PUFA by an original dietary antioxidant
strategy is recommended, in order to prevent the lipid peroxidation and the decrease of
overall liking of meat.
Author details
Gema Nieto and Gaspar Ros
Department of Food Technology, Nutrition and Food Science,
Faculty of Veterinary Sciences, University of Murcia, Murcia, Spain
Acknowledgement
We thank the University of Murcia for the postdoctoral contract of Gema Nieto.
9. References
[1] Wood JD, Richardson RI, Nute GR, Fisher AV, Campo MM, Kasapidou E, Sheard
PR, Enser, M.(2003). Effects of fatty acids on meat quality: A review. Meat Sci.66:
21–32.
[2] Scerra M, Caparra P, Foti F, GalofaroV, Sinatra MC, & Scerra V (2007) Influence of ewe
feeding systems on fatty acid composition of suckling lambs. Meat Sci. 76: 390-394.
[3] Nieto G, Bañon S, Garrido MD (2012a) Incorporation of thyme leaves in the diet of
pregnant and lactating ewes: Effect on the fatty acid profile of lamb. Small Ruminant
Res. 105: 140-147.
[4] Elmore JS, Cooper SL, Enser M, Mottram DS, Sinclair LA, Wilkinson, RG, Wood JD
(2005) Dietary manipulation of fatty acid composition in lamb meat and its effect on the
volatile aroma compounds of grilled lamb. Meat Sci. 69: 233-242.
[5] Bas, P.; Berthelot, E.; Pottier, E. Normand, J. (2007) Effect of level of linseed on fatty acid
composition of muscles and adipose tissues of lambs with emphasis on trans fatty acids.
Meat Sci. 77: 678-688.
[6] Ponnampalam EN, Trout GR, Sinclair AJ, Egan AR, Leury BJ (2001) Comparison of the
color stability and lipid oxidative stability of fresh and vacuum packaged lamb muscle
containing elevated omega-3 and omega-6 fatty acid levels from dietary manipulation.
Meat Sci. 58: 151–161.
[7] Wood JD, Enser M, Fisher AV, Nute GR, Richardson RI, Sheard PR. (1999)
Manipulating meat quality and composition. Proceedings of the Nutrition Society. 58:
363– 370.
[8] Roberts WG, Gordon MH (2003) Determination of the total antioxidant activity of fruits
and vegetables by a liposome assay. J. Agr. Food Chem. 51 (5): 1486–1493
[9] Nieto G, Huvaere K, Skibsted LH (2011a) Antioxidant activity of rosemary and thyme
by-products and synergism with added antioxidant in a liposome system. Eur. Food
Res.Technol. 233: 11-18.
Lipid Peroxidation
254
[10] Woods VB, Fearon AM (2009) Dietary sources of unsaturated fatty acids for animals
and their transfer into meat, milk and eggs: A review. Livest. Sci. 126:1– 20.
[11] Decker EA, Faustman C, Lope-Bote C.J (2000) Antioxidants in muscle foods. Nutritional
strategies to improve quality. Wiley-Interscience. 465 p.
[12] Enser MS, Hallet K, Hewitt B, Fursey GAJ, Wood JD (1996) Fatty acid content and
composition of English beef, lamb and pork retail. Meat Sci. 42: 443-456.
[13] Department of Health (1994) Nutritional aspects of cardiovascular disease (Report on
health and social subjects no. 46). H.M. Stationery Office, London.
[14] Raes K, Haak L, Balcaen A, Claeys E, Demeyer D, De Smet S (2004) Effect of linseed
feeding at similar linoleic acid levels on the fatty acid composition of double-muscled
Belgian Blue young bulls. Meat Sci. 66 (2): 307–315.
[15] French P, Stanton C, Lawless F, O'Riordan EG, Monahan FJ, Caffrey PJ, Moloney AP
(2000) Fatty acid composition, including conjugated linoleic acid, of intramuscular fat
from steers offered grazed grass, grass silage or concentrate-based diets. J. Anim. Sci.78:
(11): 2849–2855.
[16] Loor JJ, Hoover WH, Miller-Webster TK, Herbein JH, Polan CE (2003)
Biohydrogenation of unsaturated fatty acids in continuous culture fermenters during
digestion of orchard grass or red clover with three levels of ground corn
supplementation. J. Anim. Sci. 81: 1611–1627.
[17] Romans JR, Johnson RC, Wulf DM, Libal GW, Costello WJ (1995) Effects of ground
flaxseed in swine diets on pig performance and on physical and sensory characteristics
and omega-3 fatty acids content of pork: I. Dietary level of flaxseed. J. Anim. Sci. 73:
1982– 1986.
[18] Leskanich CO, Matthews KR, Warkup CC, Noble RC, Hazzledine M (1997) The effect of
dietary oil containing (n-3) fatty acids on the fatty acid, physicochemical and
organoleptic characteristics of pig meat and fat. J. Anim. Sci. 75: 673– 683.
[19] Enser M, Richardson RI, Wood JD, Gill BP, Shaeard PR (2000) Feeding linseed to
increase the n-3 PUFA of pork: fatty acid composition of muscle, adipose tissue, liver
and sausage. Meat Sci. 55: 201–212.
[20] Kouba M, Enser M, Whittington FM, Nue GR, Wood JD (2003) Effect of a high &
linolenic acid diet on lipogenic enzyme activities, fatty acid composition, and meat
quality in the growing pig. J. Anim. Sci. 81: 1967– 1979.
[21] Øverland M, Taugbl O, Haug A, Sundstl E (1996) Effect of fish oil on growth
performance, carcass characteristics, sensory parameters, and fatty acid composition in
pigs. Acta Agric. Scand., A. Anim. Sci. 46: 11 –17.
[22] Kjos NP, Skrede A, Øverland M (1999) Effect of dietary fish silage and fish fat on
growth performance and sensory quality of growing-finishing pigs. Can. J. Anim. Sci.
79: 139–147.
[23] Nilzen V, Babol J, Dutta PC, Lundeheim N, Enfalt AC, Lundstrom K (2001) Free-range
rearing of pigs with access to pasture grazing-effect on fatty acid composition and lipid
oxidation products. Meat Sci. 58: 267–275.
Modification of Fatty Acid Composition in Meat Through Diet:
Effect on Lipid Peroxidation and Relationship to Nutritional Quality – A Review 255
[24] Aurousseau B, Bauchart D, Calichon E, Micol D, Priolo A (2004) Effect of grass or
concentrate feeding systems and rate of growth on triglyceride and phospholipid and
their fatty acids in the M. Longissimus thoracis of lambs. Meat Sci. 66: 531–541.
[25] Wood JD, Enser M (1997) Factors influencing fatty acids in meat and the role of
antioxidants in improving meat quality. British J. Nutrition. 78: S49–S60.
[26] Nuernberg K, Fischer A, Nuernberg G., Ender, K., & Dannenberger, D. (2008). Meat
quality and fatty acid composition of lipids in muscle and fatty tissue of Skudde lambs
fed grass versus concentrate. Small Ruminant Res. 74: 279-283.
[27] Demirel G, Ozpinar H, Nazli B, Keser O (2006) Fatty acids of lamb meat from two
breeds fed different forage: concentrate ratio. Meat Sci. 72: 229–235.
[28] Sañudo C, Enser M, Campo MM, Nute GR, Maria G, Sierra I, Wood J D (2000) Fatty
acid composition and sensory characteristics of lamb carcasses from Britain and Spain.
Meat Sci. 54: 339–346.
[29] Realinia CE, Ducketta SK, Britob GW, Dalla Rizzab M, De Mattos D (2004) Effect of
pasture vs. concentrate feeding with or without antioxidants on carcass characteristics,
fatty acid composition, and quality of Uruguayan beef. Meat Sci. 66: 567–577.
[30] Raes, K., De Smet, S., & Demeyer, D. (2004). Effect of dietary fatty acids on
incorporation of long chain polyunsaturated fatty acids and conjugated linoleic acid in
lamb, beef and pork meat: a review. Anim. Feed Sci. Tech. 113: 199–221.
[31] Mach N, Devant M, Díaz I, Font-Furnols M, Oliver MA, García JA, Bach A (2006)
Increasing the amount of n−3 fatty acids in meat from young Holstein bulls through
nutrition. J. Anim. Sci. 84: 3039–3048.
[32] Kouba M, Benatmane F, Blochet JE, Mourot J (2008) Effect of a linseed diet on lipid
oxidation, fatty acid composition of muscle, perirenal fat, and raw and cooked rabbit
meat. Meat Sci. 77 (80): 829-834.
[33] Cooper SL (2002). Dietary manipulation of the fatty acid Composition of sheep Meat.
Ph.D. Diss. Open University, Milton Keynes, UK.
[34] Cooper SL, Sinclair LA, Wilkinson RG, Hallett KG, Enser M, Wood, JD (2004)
Manipulation of the n−3 polyunsaturated fatty acid content of muscle and adipose
tissue in lambs. J. Anim. Sci. 82: 1461–1470.
[35] Tassinari M, Mordenti AL, Testi S, Zotti A (2002) Esperienze sulla possibilita` di
arricchire con la dieta la carne di coniglio di LCPUFA n-3. Prog. Nutr. 4: 119– 124.
[36] Marriott NG, Garret JE, Sims MD, Abrul JR (2002) Composition of pigs fed a diet with
docosahexaenoic acid. J. Muscle Foods. 13: 265– 277.
[37] Sardi L, Martelli G, Lambertini L, Parisini P, Mordenti A (2006) Effects of a dietary
supplement of DHA-rich marine algae on Italian heavy pig production parameters.
Livest. Sci. 103: 95–103.
[38] Crespo N, Esteve-García E (2002) Nutrient and fatty acid deposition in broilers fed
different dietary fatty acid profiles. Poultry Sci. 81: 1533–1542.
[39] Lu P, Zhang LY, D Yin JD, Everts AKR, Li DF (2008) Effects of soybean oil and linseed
oil on fatty acid compositions of muscle lipids and cooked pork flavour. Meat Sci. 80:
910–918.
Lipid Peroxidation
256
[40] Haak L, De Smeet A, Fremaut D, Van Walleghem K, Raes K (2008) Fatty acid profile
and oxidative stability of pork influence by duration and time of dietary linseed or fish
oil supplementation. J. Anim. Sci. 86:1418–1425.
[41] Abril R, Garret J, Zeller SG, Sande WJ, Mast RW (2003) Safety assessment of DHA-rich
microalgae from Schizochytrium sp.: Part V. Target animal safety/toxicity in growing
swine. Regulatory Toxicology and Pharmacology. 37:73– 82.
[42] Van Elswyk, M.E., (1997). Comparison of n−3 fatty acid sources in laying hen rations for
improvement of whole egg nutritional quality. A review. British Journal and Nutrition,
Vol. 78 (Suppl. 1), 61–69.
[43] Meluzzi A, Sirri F, Tallarico N, Franchini A (2001) Effect of different vegetable lipid
sources on the fatty acid composition of egg yolk and on hen performance. Arch.
Geflugelkd. 65: 207– 213.
[44] Sirri F, Minelli G, Iaffaldano N, Tallarico N, Franchini A (2003) Oxidative stability and
quality traits of n-3 PUFA enriched chicken meat. Italian J. Anim. Sci. 2 (1): 450–452.
[45] Gibney MJ (1993) Fat in animal products: Facts and perceptions. In Safety and Quality
of Food from Animals, J.D. Wood and T.L.J. Lawrence (eds.), p.p.57-61. British Society
of Animal Production Occasional Publication No. 17, BSAP, Edinburgh.
[46] EFSA (European Food Safety Authority) (2010a). Scientific opinion on dietary reference
values for fats, including saturated fatty acids, polyunsaturated fatty acids,
monounsaturated fatty acids, trans fatty acids, and cholesterol. EFSA Journal, 8(1461),
1–107.
[47] Decker EA (1996) The role of stereospecific saturated fatty acid positions on lipid
nutrition. Nutrition Review. 54: 108–110.
[48] Díaz MT, Cañeque V, Sánchez S, Lauzurica C, Pérez C, Fernández C, Àlvarez I, De la
Fuente J (2011) Nutritional and sensory aspects of light lamb meat enriched in n-3 fatty
acids during refrigerated storage. Food Chem.124: 147–155.
[49] EFSA (European Food Safety Authority) (2010b). Outcome of the public consultation on
the draft opinion of the scientific panel on dietetic products, nutrition, and allergies
(NDA) on dietary reference values for fats, including saturated fatty acids,
polyunsaturated fatty acids, monounsaturated fatty acids, trans fatty acids, and
cholesterol. EFSA ON–1507, pp. 1–23.
[50] Horwitt MK (1986) Interpretations of requirements of thiamine, riboflavin, niacin-
tryptophan and vitamin E plus comments on balance studies and vitamin B-6. The
American Journal of Clinical Nutrition, 44: 5–973.
[51] Castellini C, Dal Bosco A, Bernardini M, Cyril HW (1998) Effect of dietary vitamin E on
the oxidative stability of raw and cooked rabbit meat. Meat Sci. 50: 153–161.
[52] Dal Bosco A, Castellini C, Bianchi L, Mugnai C (2004) Effect of dietary alinolenic acid
and vitamin E on the fatty acid composition, storage stability and sensory traits of
rabbit meat. Meat Sci. 66: 407–413.
[53] Berthelot, V., Bas, P., Pottier, E., & Normand, J. (2012). The effect of maternal linseed
supplementation and/or lamb linseed supplementation on muscle and subcutaneous
adipose tissue fatty acid composition of indoor lambs. Meat Science, 90, 548–557.
Modification of Fatty Acid Composition in Meat Through Diet:
Effect on Lipid Peroxidation and Relationship to Nutritional Quality – A Review 257
[54] Oriani G, Salvatori G, Pastorelli G, Pantaelo L, Ritieni A, Corino C (2001) Oxidative
status of plasma and muscle in rabbits supplemented with dietary vitamin E. J.
Nutritional Biochem. 12: 138–143.
[55] Lin, C. F., Asghar, A., Gray, J. I., Buckley, D. J., Booren, A. M., Crackel, R. L., et al.
(1989). Effects of oxidised dietary oil and antioxidant supplementation on broiler
growth and meat stability. British Poultry Science, Vol. 30, p.p. 855–864.
[56] Monahan FJ, Buckley DJ, Morrissey PA, Lynch PB, Gray JI (1992) Influence of dietary
fat and a-tocopherol supplementation on lipid oxidation in pork. Meat Sci. 31: 229–241.
[57] Halliwell B, Aeschbach R, Loeliger J, Auroma OI (1995) The characterization of
antioxidants. Food Chem. Toxicol. 33: 601–617.
[58] Joo ST, Lee JI, Ha YL, Park GB (2002) Effects of dietary conjugated linoleic acid on fatty
acid composition, lipid oxidation, color, and water-holding capacity of pork loin. J.
Anim. Sci. 80: 108–112.
[59] You KM, Jong HG, Kim HP (1999) Inhibition of cyclooxygenase/ lipoxygenase from
human platelets by polyhydroxylated/ methoxylated flavonoids isolated from
medicinal plants. Arch. Pharm. Res. 22 (1): 18–24.
[60] Vasta V, Pennisi M, Lanza D, Barbagallo M, Bella A, Priolo A (2007) Intramuscular fatty
acid composition of lambs given a tanniniferous diet with or without polyethylene
glycol supplementation. Meat Sci. 76: 739–745.
[61] Youdim KA, Deans SG (2000) Effect of thyme oil and thymol dietary supplementation
on the antioxidant status and fatty acid composition of the ageing rat brain. British J.
Nutrition. 83: 878.
[62] Lee, K.W., Everts, H., Kappert, H.J., Frehner, M., Losa, R., & Beynen, A.C. (2003). Effects
of dietary essential oil components on growth performance, digestive enzymes and
lipid metabolism in female broiler chickens. British Poultry Science, Vol. 44, p.p. 450.
[63] Govaris A, Botsoglou E, Florou-Paneri P, Moulas A, Papageorgiou G (2005) Dietary
supplementation of oregano essential oil and -tocopheryl acetate on microbial growth
and lipid oxidation of turkey breast fillets during storage. Int. J. Poultry Sci. 4: 969.
[64] Reaven PD, Witztum JL (1996) Oxidized low-density lipoproteins in atherogenesis: Role
of dietary modification. Annu. Rev. Nutr. 16: 51-71.
[65] Niki, E., Noguchi, N., Tsuchihashi, H., & Gotoh, N. (1995). Interaction among vitamin
C, vitamin E, and beta-carotene. Am. J. Clin. Nutr. 62: S1322-S1326.
[66] Livrea MA, Tesoriere L, D’Arpa D, Morreale M (1997) Reaction of melatonin with
lipoperoxyl radicals in phospholipid bilayers. Free Radic. Biol. Med. 23: 706-711.
[67] Nieto G, Bañon S, Garrido MD (2010a) Effect on lamb meat quality of including thyme
(Thymus zygis ssp. gracilis) leaves in ewes’ diet. Meat Sci. 85: 82-88.
[68] Nieto G, Díaz P, Bañon S, Garrido MD (2010b) Dietary administration of ewes diets
with a distillate from rosemary leaves (Rosmarinus officinalis): influence on lamb meat
quality. Meat Sci. 84: 23-29.
[69] Nieto G, Bañon S, Garrido MD (2011b) Effect of supplementing ewes’ diet with thyme
(Thymus zygis ssp. gracilis) leaves on the lipid oxidation of cooked lamb meat. Food
Chem. 125(4): 1147-1152.
Lipid Peroxidation
258
[70] Nieto G, Estrada M, Jordán MJ, Garrido MD, Bañon S (2011c) Effects in ewe diet of
rosemary by-product on lipid oxidation and the eating quality of cooked lamb under
retail display. Food Chem. 124(4): 1423-1429.
[71] Nieto G, Bañon S, Garrido MD (2012b) Administration of distillate thyme leaves into
the diet of Segureña ewes: effect on lamb meat quality. Animal, In press.
