Omega-3 Fatty Acid Profile of Eggs from Laying Hens Fed Diets Supplemented with Chia, Fish Oil, and Flaxseed

Abstract

The aim of this study was to investigate the effect of diets supplemented with fish oil, flaxseed, and chia seed on the omega-3 fatty acid composition and sensory properties of hens’ eggs. No significant difference in yolk fat content was found between treatments. The fatty acid composition of egg yolk was significantly affected by the dietary treatments. Inclusion of chia at 300 g/kg into the diet produced eggs with the highest concentration of omega-3 fatty acid. Eicosapentaenoic acid and docosahexaenoic acid were only detected in eggs from laying hens fed the diet supplemented with fish oil. Diet had a significant effect on color, flavor and overall acceptability of eggs. Types and levels of omega-3 fatty acids in feed influence the level of yolk omega-3 fatty acids in egg yolk. Inclusion of chia into the hens’ diet significantly increased the concentration of yolk omega-3 fatty acid without significant change in sensory properties.Practical ApplicationChia seeds are considered as one of the highest sources of omega-3 fatty acids among plants. By feeding hens diets that are enriched in omega-3 fatty acids, it is possible to increase omega-3 fatty acid content of the eggs. Such eggs could be a good source of omega-3 for human consumption.

Full text

S: Sensory & Food
Quality
Omega-3 Fatty Acid Profile of Eggs from Laying
Hens Fed Diets Supplemented with Chia, Fish Oil,
and Flaxseed
Ranil Coorey, Agnes Novinda, Hannah Williams, and Vijay Jayasena
Abstract: The aim of this study was to investigate the effect of diets supplemented with fish oil, flaxseed, and chia
seed on the omega-3 fatty acid composition and sensory properties of hens’ eggs. No significant difference in yolk fat
content was found between treatments. The fatty acid composition of egg yolk was significantly affected by the dietary
treatments. Inclusion of chia at 300 g/kg into the diet produced eggs with the highest concentration of omega-3 fatty acid.
Eicosapentaenoic acid and docosahexaenoic acid were only detected in eggs from laying hens fed the diet supplemented
with fish oil. Diet had a significant effect on color, flavor and overall acceptability of eggs. Types and levels of omega-3
fatty acids in feed influence the level of yolk omega-3 fatty acids in egg yolk. Inclusion of chia into the hens’ diet
significantly increased the concentration of yolk omega-3 fatty acid without significant change in sensory properties.
Keywords: chia seed, eggs, flaxseed, omega-3 fatty acid, sensory properties
Practical Application: Chia seeds are considered as one of the highest sources of omega-3 fatty acids among plants. By
feeding hens diets that are enriched in omega-3 fatty acids, it is possible to increase omega-3 fatty acid content of the
eggs. Such eggs could be a good source of omega-3 for human consumption.
Introduction
Omega-3 (ω-3) fatty acids are essential nutrients contributing
to growth and development throughout human life and have been
reported to play a crucial role in the reduction of blood pres-
sure, inflammatory diseases, and the risk of sudden death from
cardiac arrest (Connor 2000; Juturu 2008). The nutritionally im-
portant ω-3 fatty acids are alpha-linolenic acid (ALA, C18:3n-
3), eicosapentaenoic acid (EPA, C20:5n-3), and docosahexaenoic
acid (DHA, C22:6n-3). Even though ALA must be derived from
the diet, both EPA and DHA can be synthesized from ALA de
novo but the synthesis process is relatively inefficient in humans
(Whelan and Rust 2006; Aydin and Dogan 2010). In addition,
ALA has been projected to be less bio-available for mediating
health benefits when compared to EPA and DHA (Cachaldora
and others 2008).
The consumption of foods high in EPA and DHA such as
fish and seafood is decreasing (Van Elswyk 1997a; Simopoulos
2000; Mazalli and others 2004; Aydin and Dogan 2010) and public
concerns have been raised over the safety of seafood due to possible
contamination with industrial pollutants (Whelan and Rust 2006).
Western diets are deficient in ω-3 fatty acids and high in omega-6
(ω-6) fatty acids due to the increase consumption of vegetable oils
such as sunflower, corn, and safflower that are high in ω-6 fatty
acids (Connor 2000; Simopoulos 2002; Aydin and Dogan 2010).
There are also limited sources of ω-3 fatty acids for those on
MS 20140863 Submitted 5/21/2014, Accepted 10/1/2014. Authors Coorey,
Novinda and Jayasena are with School of Public Health, Faculty of Health Sciences,
Curtin Univ., GPO Box U1987, Perth, Western Australia, 6845, Australia. Author
Williams is formally from the School of Public Health, Faculty of Health Sciences,
Curtin Univ., GPO Box U1987, Perth, Western Australia 6845, Australia. Direct
inquiries to author Coorey (E-mail: r.coorey@curtin.edu.au).
vegetarian diets since most of the ω-3–enriched food products are
manufactured using fish oil (Rubio-Rodriguez and others 2010).
As a means to increase ω-3 fatty acids in chicken egg, the fatty
acid composition of the feed can be modified through the inclusion
of marine sources (for example, fish oil/meal), flaxseed (Linum
usitatissimum) and/or chia seed (Salvia hispanica). Previous research
has shown that hens fed with marine products or flaxseed resulted
in tainted eggs with a “fishy” taste (Jiang and others 1992; Van
Elswyk and others 1992, 1995; Caston and others 1994; Schiedeler
and others 1997). Studies on feeding chia seed are limited and a
few studies have shown no detection of “fishy” oil flavors (Ayerza
and Coates 2000, 2001, 2002; Ayerza and others 2002). Studies on
the use of chia are limited to the study of its lipid, polysaccharide,
and protein fractions (Bushway and others 1981, 1984), snack
food like products manufactured for human consumption (Coorey
and others 2012; Radocaj and others 2014). Coorey and others
(2014) studied the chia gel for its functional properties and its
possibility for use as a food ingredient. Surai and Sparks (2001)
reviewed the literature on enhancing the nutritional quality of
eggs by increasing its anti-oxidant, ω-3 DHA, vitamin E, and
other nutrients. They concluded that it is possible and advantages
to develop such “designer eggs.” At the same time, Ali and others
(2012) reviewed the literature on clinical studies on safety of chia
and its active ingredients. They concluded that chia is a good
source of healthy oil. The effect of feeding hens ground chia seed
on ω-3 content and flavor of eggs has not been published.
This research project was undertaken to investigate the change in
the ω-3 fatty acid profiles and sensory characteristics of eggs when
hens’ diets were supplemented with fish oil, ground flaxseed, and
ground chia seed. The data can be used to determine the optimal
nonmarine diet treatment that would achieve maximum ω-3 fatty
acid deposition without any negative impact on the sensory prop-
erties of eggs. This would be beneficial for the community and egg
C2014 Institute of Food Technologists R
S180 Journal of Food Science rVol. 80, Nr. 1, 2015 doi: 10.1111/1750-3841.12735
Further reproduction without permission is prohibited

S: Sensory & Food
Quality
Omega-3 in eggs from chia fed hens . . .
Table 1–The nutritional composition of the base (control) feed.
Nutrient Composition
Protein (%) 15
Metabolisable energy (kcal/kg) 2500
Crudefiber(%) 8
Added salt (%) 0.2
Calcium (%) 3.5
Note The diets met standard nutrient requirements for layer poultry (Personal
Communication, Dr. Jenny Davis, Animal Nutritionist, Milne Agr iGroup, Perth,
Western Australia, Australia).
industry as it would encourage the production of ω-3–enriched
eggs. Once the potential to add ω-3 containing plant material to
chicken feed has been established without any negative impact
on the eggs sensory properties, the feed conversion and similar
efficiencies can be determined.
Materials and Methods
Materials
The base diet (control) used for this study was Vege Layer Crum-
ble, a commercial layer chicken feed manufactured by Milne Agri-
Group in Perth, Western Australia, Australia. The control diet
consisted of cereal grains, oilseed meal, cereal by products, lupins,
salt, amino acids, and a vitamin/mineral premix. The nutritional
composition of the base formulation is shown in Table 1. Melrose
Organic branded flaxseed was purchased from “Loose Produce,”
a local supplier within the Perth Metropolitan Area. Fish oil was
supplied by Ridley AgriProducts Narangba Queensland, Australia,
and chia seed was supplied by The Chia Company, Melbourne,
VIC, Australia.
Whole chia seeds and flaxseed were ground using a Retsch
Grindomix GM 2000 (Retsch, Haan, Germany) for 5 s at a speed
of 7000 rpm to produce a fine meal. The control feed and the
flaxseed, chia seed, and fish oil were derived from single batches.
All experiments were conducted in triplicate.
Animals and diets
The feeding trial was conducted at a commercial egg produc-
tion facility in Munster, Western Australia. Forty-eight Isa Brown
laying hens at 35 wk of age were housed 6 to a cage. All hens
were fed the control diet for 2 wk to allow them to acclimatize
to their diet and environmental conditions as well as to obtain
baseline data (Week 0). Hens were assigned at random to each of
the 8 diet treatments (6 hens per treatment). The 8 diet treatments
consisted of control, and control diet supplemented with fish oil,
flaxseed, and chia (Table 2). The animal nutritionist recommended
and checked treatment diets (diets with the supplemented sources
of ω-3) before commencement of the experiments to ensure all
diets were adequate for all nutrients essential to hen health and
egg quality. Animal ethics approval was obtained from the Curtin
Univ. Ethics Committee.
The experimental feeding period lasted for 5 wk with each
hen receiving 135 g/d of feed supplemented with 3 g/d of shell
grit (Karunajeewa 1978). Feed and water were supplied freely.
All diet treatments were mixed in a Hobart NCM 10-10 mixer
(Hobart, Southgate, London, UK) for 2 min, vacuumed packed,
and delivered to the egg facility on a weekly basis. Eggs were
collected daily and labeled with the collection date and placed in
refrigerated storage at the facility, in preparation for delivery and
analysis.
Fat analysis
Crude fat content was determined using the AOAC method
920.39 (AOAC 2005). A Buchi E-816 SOX Extraction Unit
(Buchi, Flawil, St Galen, Switzerland) was used to analyze the
fat content.
Fatty acid composition determination
Total fat from the diets and egg yolks were extracted using
the chloroform–methanol cold extraction method for total lipids
according to AOAC method 983.23 (AOAC 2005) as modified by
Phillips and others (1997) and similar to the methods by Coorey
and others (2012). Samples (5 g) were weighed into a 500 mL
centrifuge bottle and 0.5 mol sodium acetate (32 mL), methanol
(80 mL), and chloroform (40 mL) were added. Centrifuge bottles
were then placed in a Ratek SWB20 shaking water bath (Ratek
Instruments, Boronia, VIC, Australia) at 25 °C and shaken for
30 min. Chloroform (40 mL) was then added to the centrifuge
bottles and shaken again for a further 30 min. Deionized water
(40 mL) was added and samples were shaken for another 30 min.
Subsequently, samples were centrifuged at a speed of 2300 rpm for
10 min. The bottom organic layer containing the fat was carefully
siphoned off, placed in a beaker, and left overnight in a fume
hood to evaporate the chloroform. Eggs collected on the last day
of each week (week 1 to week 4) were used to determine fatty
acids composition. Yokes were separated using a hand held yoke
separator before lipids extraction using a gram of sample, thus, the
sample to solvents ratio adjusted accordingly.
Fat extracted from all samples were derivatized using boron
trichloride–methanol, 12% (w/w) according to the procedure
provided by Sigma-Aldrich (1997). Toluene (2 mL) was added
to 50 mg of sample in a screw top test tube. Subsequently, 2 mL
of boron trichloride–methanol solution was added and the mix-
ture was flushed with nitrogen gas for 10 s and heated in a water
bath at 60 °C for 10 min. Once cooled, water (2 mL) and hexane
(2 mL) were added into the test tube and shaken lightly to extract
the fatty acid methly esters (FAME). Anhydrous sodium sulfate
was added to the hexane extracts to remove moisture then the an-
hydrous hexane extracts were transferred into a 10 mL volumetric
flask and filled to volume with hexane. The moisture removal step
was carried out twice to ensure maximum extraction of FAMEs
from the oil.
FAMEs were then analyzed by gas chromatography. Sample
(1 mL) was pipetted into an auto-sampler vial and on the Perkin
Elmer AutoSystem XL gas chromatography (Perkin Elmer, Nor-
walk, Conn., U.S.A.) equipped with an auto-sampler, an SGE
Forte GC BPX70 capillary column (30 m ×0.32 mm; 0.25 μm;
SGE Analytical Science, Ringwood, VIC, Australia), a spit-splitless
injector and a flame ionization detector. Helium, flowing at a rate
of 20 mL/min, was used as the carrier gas. The temperature of the
injector and detector were held at 200 and 250 °C, respectively.
The oven temperature was initially set at 80 °Cforthe1st2min
and increased at a rate of 45 °C/min to 130 °C, where it remained
for 10 min. It was then increased at a rate of 2 °C/min to 172 °C
for the final 6 min. Supleco 37 component FAME mix (Supelco,
Bellefonte, Pa., U.S.A.) was used as the pure methyl ester standard.
Once calibrated using the standard, fatty acid peaks of each sample
were identified and fatty acid composition was calculated.
Sensory evaluation
Eggs collected on the last week (week 5) of the feeding trial
were used for sensory evaluation. Eggs were stored at 4 °C until
they were used for sensory evaluation.
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Omega-3 in eggs from chia fed hens . . .
Table 2–The list of treatments.
Fish oil (mL/100 g Flaxseed flour (g/100 Chia flour (g/100 g
of control feed) of control feed) of control feed)
Control/base 0 0 0
Treatment 1 1.5 0 0
Treatment 2 0 15 0
Treatment 3 0 20 0
Treatment 4 0 30 0
Treatment 5 0 0 20
Treatment 6 0 0 30
Treatment 7 0 0 40
Note The diet treatments met standard nutrient requirements for layer poultry (Personal Communication, Dr. Jenny Davis, Animal Nutritionist, Milne AgriGroup, Perth, Western
Australia, Australia).
Because of the limited number of eggs available, scrambled eggs
were used for the sensory evaluation. Randomly selected eggs from
each diet treatment were blended with whole milk for 30 s using
a hand whisk. The blended egg mixture was poured into a heated
(120 °C) equilibrated (30 s) Teflon-lined electric skillet lightly
coated with canola oil (Coles brand, Coles Supermarkets, Perth
Metropolitan Area, Western Australia). Samples were cooked for
2 min with gentle mixing. After cooking, the scrambled eggs
were placed in plastic cups labeled with 3 digit random codes.
Before being served to panelists, samples were reheated for 10
s in a 900 W microwave oven (Panasonic, Model NN-6455A,
Matsushita Microwave Oven Corp of America, Secaucus, N.J.,
U.S.A.). Panelists evaluated their degree of liking for color, odor,
flavor, and overall acceptability on a Labeled Hedonic Scale (Lim
and others 2009). Water and plain crackers were used as palate
cleansers between samples. A total of 93 panelists participated in
the sensory evaluation.
Statistical analysis
Data collected from chemical testing and sensory evaluations
were analyzed using SPSS ver. 18.0 for Windows statistical software
(SPSS Inc., Chicago, Ill., U.S.A.). Multiple means comparisons
for all chemical analysis were performed using two-way analysis
of variance (ANOVA) with the significance level defined at
Pࣘ0.05. The Bonferroni post hoc test was applied to determine
the significant differences between samples. All chemical analyses
were conducted in triplicate and were reported as the mean value
of triplicates.
Before the data analysis, the rating for Labeled Hedonic Scale
was measured from the bottom of the scale in millimeters and
translated into a range from 0 to 200. One-way ANOVA was
used to analyses the data followed by Bonferroni test for post hoc
examination of differences among means. To prevent carry over
effects or order bias, a randomized balanced incomplete block
design was used with each panelist tasting 4 samples (Plan 11.10
t=8, k=4, r=7, b=14, λ=3, E=0.86, Type I; Cochran
and Cox 1957).
Results and Discussion
Total fat and fatty acid compositions of the ingredients and
experimental diets are listed in Table 3. Results show that only the
diets with fish oil contained EPA and DHA.
Layers performance
It was visually observed that the diet supplemented with 30%
chia was the preferred treatment throughout the 5-wk feeding
trial. Observations throughout the feeding trial found that hens
fed diets supplemented with flaxseed (in particular the diet with
30% flaxseed) produced wetter manures compared to the other
treatments due to high-fiber diet and the presence of undesirable
compounds such as linoline.
Fat content and fatty acid composition of egg yolk
Diet treatments had no significant effect on the (P>0.05) fat
content of the yolks. The fat content gradually increased through-
out the experimental feeding trial period (Figure 1).
To t a l ω-3 content (calculated as the sum of ALA, EPA, and
DHA) and ALA concentration in eggs were significantly influ-
enced (P<0.05) by the diet. As the trial progressed, ALA and
total ω-3 content increased for most treatments. The total ω-3
concentration of eggs in week 4 ranged from 18 (control) to 321
(30% chia) mg/50 g yolk (Figure 2).
The highest ALA content was found in eggs produced by hens
fed with diets supplemented with 30% chia (Figure 2). Eggs from
hens fed with 30% chia diet had ALA (202, 266, 291, and 321
mg/50 g egg yolk) throughout the trial sampling period while
the control diet remained the same (week 1 to 4, respectively).
The control diet had 17, 17, 17, and 18 mg/50 g ALA content
during the same period. Incorporation of 40% chia resulted in
lower ALA content compared to the 30% chia diet. This finding
is inconsistent with Ayerza and Coates (2000), who found that
increased percentages of chia in the diet tend to increase the ALA
content in the yolks. In their study, the incor poration of chia
at 7% in the diet increase the ALA content to 4.0% and at an
incorporation level of 28% the ALA increased to 16% over a 90
d feeding period. In this study, the high amount of ALA found
in eggs from the 30% chia diet was probably due to the diet
being the most preferred treatment and thus being consumed more
compared to other treatments as visually observed throughout the
feeding trial.
Several earlier researchers have highlighted that the levels of total
ω-3 fatty acids in yolk increased linearly as the levels of flaxseed
increased in the diet (Caston and Leeson 1990; Scheideler and
Froning 1996; Van Elswyk 1997a). However, the result in this
study indicated that from week 2 onward ALA contents of eggs
from the 20% flaxseed supplemented diets (176, 206, and 225
mg/50 g, weeks 2, 3, and 4, respectively) were higher than the
30% flaxseed diets (154, 171, and 189 mg/50 g egg, weeks 2, 3,
and 4, respectively). This is most likely due to the laxative effect
of flaxseed as hypothesized by Scheideler and Froning (1996).
The high-fiber level (and possibly the presence of undesirable
compounds) results in wet manure. The high fiber in poultry
ration also causes decline in productivity. It was observed that
hens on the 30% flaxseed diet produced very wet manure. High
content of flaxseed in the diet could result in an increase rate
of passage in the gut reducing the nutrient uptake and resulting
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Omega-3 in eggs from chia fed hens . . .
Table 3–Total fat and fatty acid composition of the raw material and the experimental diets.
Source Composition (g/kg)
To t a l f a t A L A a(C18:3n-3) EPAb(C20:5n-3) DHAc(C22:6n-3)
Chia Seed 235.31 112.0 ND ND
Flaxseed 243.4 60.8 ND ND
Fish oil 1000 2.6 115.62 68.55
Control diet 31.87 1.1 ND ND
1.5% Fish oil 71.93 1.1 1.15 0.97
15% Flaxseed 71.93 9.7 ND ND
20% Flaxseed 80.11 11.9 ND ND
30% Flaxseed 97.98 17.6 ND ND
15% Chia seed 83.72 10.7 ND ND
30% Chia seed 100.17 27.2 ND ND
40% Chia seed 137.44 34.6 ND ND
ND, not detected.
aAlpha-linolenic acid.
bEicosapentaenoic acid.
cDocosahexaenoic acid.
in eggs with a lower ALA content. This finding also supports
Scheideler (2003) conclusion that inclusion of 20% flax seed is
the maximum acceptable amount that can be added to chicken
feed.
Studies using flaxseed and chia seed as a dietary source have
reported the detection of the ω-3 fatty acids, EPA, and DHA
in eggs (Ferrier and others 1995; Van Elswyk 1997b; Ayerza and
Coates 1999, 2000, 2001; Bean and Leeson 2003; Antruejo and
others 2011). However in our study, ω-3 fatty acids were only
detected in eggs from hens fed with the diet supplemented with
fish oil (Figure 3). This could be due to the type of ω–3 in the
plant sources used in the study and its concentration at the levels
of application.
Ideally, ω-3–enriched products should reflect the nutritional
profile of fish oil and contain EPA and DHA. However, EPA and
DHA were not detected in eggs from hens given diets supple-
mented with flaxseed and chia. This may be due to the several
limitations faced during the course of the trial such as the selective
eating of feed resulting in insufficient consumption of the ω-3 and
the short time period of the feeding tr ial. Factors such as the short
Figure 1–Effect of dietary treatments on total fat content of egg yolk (g/50 g egg yolk; ±SD).
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Omega-3 in eggs from chia fed hens . . .
feeding trial period may have contributed to the hens’ inability to
convert ALA into EPA and DHA. Nevertheless, earlier researches
have reported that eggs from hens given flaxseed and chia seed
supplemented diets contain ω-3 fatty acids (Antruejo and others
2011; Fraeye and others 2012). In the study of Antruejo and oth-
ers (2011), 22:6n were observed after 28 d (4 wk). Ayerza (2008)
reports that diets containing chia at 14% was able to increase the
ω-3 fatty acids content. The breed of the birds, the experimental
conditions such as environmental/seasonal temperature variations
may have affect conversion of ALA to EPA and DHA. Such ef-
fects can be determined in future studies by evaluating the feed
consumption patterns.
Figure 2–Effect of dietary treatments on total ω-3 and ALA contents of egg yolk (±SD).
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Omega-3 in eggs from chia fed hens . . .
The concentrations of ALA, EPA, DHA, and total ω-3 fatty
acids in the yolk in this study were lower compared to previously
reported findings (Aymond and Van Elswyk 1995; Ferrier and
others 1995; Van Elswyk and others 1995, 1997a, 1997b; Ayerza
and Coates 1999; Bean and Leeson 2003). The substantial differ-
ences could be due to several reasons. The fish oil used in this
study was commercial feed grade fish oil and not pure menhaden
fish oil, which may have a lower EPA and DHA levels. Second,
previous studies by Ayerza and Coates (2000), Ferrier and others
(1995), and Van Elswyk (1997b) used different breeds of hens and
this may have influenced the result. Furthermore, the feeding trial
by Ayerza and Coates (2000) was conducted over a longer period
(90 d period) of time and Bean and Leeson (2003) implemented
a “phase in period” in their study to gradually introduce the diet
treatments. In addition, the incorporation of ALA and DHA into
egg yolk is a gradual process and may take up to several weeks
depending on the feed source as reported by Van Elswyk (1997a).
Sensory evaluation
A total of 93 panelists over the age of 18 years in good health
and nonsmokers participated in the study. Data from the sensory
evaluation demonstrated significant differences (P<0.05) in the
degree of liking for flavor, color, and overall acceptability while
no significant difference (P>0.05) in odor among treatments
(Table 4). Variations in sensory scores existed among eggs from
the different diet treatments. However, preference scores for none
Table 4–The preference scores for the eggs from hens fed the
different diets.
Treatment Color Flavor Odor Overall acceptability
Control 151.5 a,b a143.9 a,b 137.2 a 149.1 a
Fish oil 141.1 a,b,c 137.0 a,b 127.9 a 139.5 a,b
Flaxseed 15% 130.8 c 126.1 a,b 119.5 a 129.3 a,c
Flaxseed 20% 125.7 c 131.0 a,b 124.3 a 133.9 a,c
Flaxseed 30% 122.5 c,d 116.8 b 125.0 a 127.4 b,c
Chia seed 15% 130.0 c 123.1 a,b 125.0 a 132.9 a,c
Chia seed 30% 133.6 a,c 124.1 a,b 117.1 a 129.8 a,c
Chia seed 40% 105.9 d 124.8 a,b 126.4 a 116.2 c
aValues sharing a same in line lower case letter in the same column are not significantly
different.
of the sensory attributes fell in the dislike range (0 to 100) of
the LHS scale (Figure 4). The color, flavor, odor, and overall
acceptability scores for the eggs from the hens fed with the 30%
chia diet showed no significant differences compared to those from
the control. It is an indication that the acceptability had not been
affected by the 30% chia diet.
There was a clear indication that the level of flaxseed and chia
supplementation affected the degree of liking of the eggs. The
score for flavor of the scrambled eggs from the 30% flaxseed diet
(116.8) and the 40% chia diet (124.8) were significantly lower
(P<0.05) than the control (143.9). This is in agreement with
earlier studies by Caston and others (1994) and Scheideler and
Figure 3–Effect of fish oil enriched dietary treatments on EPA and DHA content of egg yolk (mg/50 g egg assuming 15 g egg yolk; ±SD). None of the
other treatments had an impact.
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Omega-3 in eggs from chia fed hens . . .
others (1997) who reported that there was a significant difference
for preference of eggs from hens fed with high levels of flaxseed
as compared with control eggs. However, eggs from the fish oil
treatment scored higher for flavor when compared to flaxseed
diets (126.1, 131.0, and 116.8) and chia seed diets (123.1, 124.1,
and 124.8). This is most likely due to the low level of fish oil
used in the trial as earlier studies have reported a decrease in
organoleptic properties of eggs only when menhaden fish oil above
levels of 1.5% was used (Van Elswyk and others 1992, 1995). Van
Elswyk and others (1992) noted that the fishy-off flavors were more
prominent in scrambled eggs made with eggs from hens feed 3%
Menhaden oil in the diet. Jiang and others (1992) made similar
observation with boiled eggs made from hens on 15% flaxseed
diets. In this study, panelists made no comments on fishy odors or
off-flavors for the eggs from any of the diet treatment.
The perception of color of the scrambled eggs by the sensory
panel was influenced by the different diet treatments. There was
no significant difference in the color between the 1.5% fish oil,
30% chia seed, and the control diet. In addition, the preference
of color trended lower (130.8, 125.7, and 122.5), even though
not to significant levels, as the flaxseed supplementation increased
from 15%, 20% to 30%. This is in agreement with Scheideler and
others (1997), who reported a similar finding in scrambled eggs.
The overall acceptability indicated that only eggs from diets sup-
plemented with 30% flaxseed (127.4) and 40% chia seed (116.2)
differed significantly (P<0.05) from the control egg (149.1).
However, this is most likely due to the low preference scores
recorded for flavor (116.8) and color (122.5) for eggs from the
30% flaxseed diet and the low preference score obtained for color
(105.9) for eggs from the 40% chia seed supplemented diet. Fur-
thermore, comments made by the panelists indicated that color
of the egg samples played a significant part in determining the
overall acceptability and that panelists preferred yellower scram-
bled eggs. In addition, panelists’ comments on their perception
of color indicated that eggs from the control and fish oil supple-
mented diets had a yellower appearance compared to eggs from
other treatments.
Conclusions
Types and levels of ω-3 fatty acid sources (fish oil, flaxseed, and
chia seed) influence the ω-3 fatty acids content of egg yolk. Chia
at 30% can be incorporated into feed, resulting in higher ω-3 fatty
acids content without significantly influencing the sensory quality
of eggs. However, it must be confirmed the conversion of plant
ω-3 to EPA and DHA. It would be interesting to see a future study
that evaluate the relationship between the effects of adding chia
to chicken feed and the impact on flavor based on different egg
preparation methods. Although cost of flaxseed is less compared
to chia seeds and fish oil, incorporation of 30% flaxseed is not
recommended due to significant decrease in the sensory quality of
the eggs. Laxative effect of the flaxseed could result in insufficient
nutrients uptake by the hens causing other problems such as poor
100
110
120
130
140
150
160
Colour
Flavour
Odour
Overall
acceptability
Control
1.5% Fish oil
15% Flaxseed
20% Flaxseed
30% Flaxseed
15% Chia seed
30% Chia seed
40% Chia seed
Figure 4–Effect of dietary treatments on preference scores of color, flavor, odor, and overall acceptability.
S186 Journal of Food Science rVol. 80, Nr. 1, 2015

S: Sensory & Food
Quality
Omega-3 in eggs from chia fed hens . . .
health and productivity. Since this study has shown that chia can
be added up to 30% into chicken feed without negative impact
on egg flavor, it would be interesting for future studies to evalu-
ate layer performance such on productivity, egg quality, and feed
conversion. The use of flaxseed is not recommended due to the
negative impact on egg sensory quality and hen performance.
A better or more homogenized mix of the ω-3 sources with
the control diet perhaps in a pelletized or granular form is sug-
gested for feeding trials to prevent selective picking by the hens.
In addition, a phase in and longer period of feeding trial should
be conducted to allow hens to slowly adapt to the diet change
and reduce the likelihood of problems with palatability and de-
creased feed intake. More in depth research comparing these ω-3
sources on egg composition, production, quality parameters, and
sensory characteristics is worthy of investigation.
References
Ali NM, Yeap SK, Ho WY, Beh BK, Tan SW, Tan SG. 2012. The promising fu-
ture of chia, Salvia hispanica L. J Biomed and Biotech. DOI: http://dx.doi.org.
dbgw.lis.curtin.edu.au/10.1155/2012/171956.
[AOAC] A ssn . of Of fici al An aly tic al Ch emi st . 2005. Official methods of analysis. Available from:
http://www.eoma.aoac.org. Accessed 2011 March 16.
Antruejo A, Azcona JO, Garcia PT, Gallinger C, Rosmini M, Ayerza R, Coates W, Perez CD.
2011. Omega-3 enriched egg production: the effect of α-linolenic ω-3 fatty acid sources
on laying hen performance and yolk lipid content and fatty acid composition. Br Poult Sci.
52(6):750–60.
Aydin R, Dogan I. 2010. Fatty acid profile and cholesterol content of egg yolk from chickens
fed diets supplemented with purslane (Portulaca oleracea L.). J Sci Food Agric 90(10):1759–63.
Ayerza R. 2008. Chia as a new source of omega-3 fatty acids—nutritional compar ison with
other raw materials and its advantages when producing omega-3 enriched eggs in Wild-Type
Food. In: DeMeester BE, Watson RR, editors. Health promotion and disease prevention: the
columbus concept. Totowa, NJ: Humana Press Inc. p 179–94
Ayerza R, Coates W. 1999. An omega-3 fatty acid enriched chia diet: influence on egg fatty
acid composition, cholesterol and oil content. Can J Anim Sci 79(1):53–8.
Ayerza R, Coates W. 2000. Dietary levels of chia: influence on yolk cholesterol, lipid content
and fatty acid composition for two strains of hens. Poult Sci 79(5):724–39.
Ayerza R, Coates W. 2001. Omega -3 enriched eggs: The influence of dietary α-linolenic fatty
acid source on egg production and composition. Can J Anim Sci 81(3):355–62
Ayerza R, Coates W. 2002 Dietary levels of chia: influence on hen weight, egg production and
sensory quality for two strains of hens. Br Poult Sci 43(2):283–90.
Ayeraza R, Coates W, Lauria M. 2002. Chia seed (Salvia hispanica L.) as an ω-3 fatty acid source
for boilers: influence on fatty acid composition, cholesterol and fat content of white and dark
meats, growth performance and sensory characteristics. Poult Sci 81(6):826–37
Aymond WM, Van Elswyk M. 1995. Yolk thiobarbituric acid reactive substances and n-3 fatty
acids in response to whole and ground flaxseed. Poult Sci 74(8):1388–94.
Bean LD, Leeson S. 2003. Long-term effects of feeding flaxseed on performance and egg f atty
acid composition of brown and white hens. Poult Sci 82(3):388–94.
Bushway AA, Belyea PR, Bushway RJ. 1981. Chia seed as a source of oil, polysaccharide and
protein. J Food Sci 46(5): 1349–50
Bushway AA, Wilson AM, Houston L, Bushway RJ. 1984. Selected properties of the lipid and
protein fractions from chia seed. J Food Sci 49(2):555–57
Cachaldora P, Garcia-Rebollar P, Alvarez C, De Blas JC, Mendez J. 2008. Effect of type and
level of basal fat and level of fish oil supplementation on yolk fat composition and n-3 fatty
acids deposition efficiency in laying hens. Anim Feed Sci Tech 141(1–2):104–14.
Caston LJ, Leeson S. 1990. Research note: dietary flax and egg composition. Poult Sci
69(9):1617–20.
Caston LJ, Squires EJ, Leeson S. 1994. Hen performance, egg quality, and the sensory evaluation
of eggs from SCWL hens fed dietary flax. Can J Anim Sci 74(2):347–53.
Connor WE. 2000. Importance of n-3 fatty acids in health and disease. Am J Clin Nutr
71(suppl):171S–5S.
Coorey R, Grant A, Jayasena V. 2012. Effects of chia flour incorporation on the nutritive quality
and consumer acceptance of chips. J Food Res 1(4):85–95.
Coorey R, Tjoe A, Jayasena V. 2014. Gelling properties of chia seed and flour. J Food Sci
79(5):859–66.
Cochran WG, Cox GM. 1957. Experimental design. 2nd ed. New York: John Wiley and Sons.
Ferrier LK, Caston LJ, Leeson S, Squires J, Weaver BJ, Holub BJ. 1995. Alpha-linolenic acid
and docosahexaenoic acid–enriched eggs from hens fed flaxseed: influenced on blood lipids
and platelet phospholipid fatty acid in humans. Am J Clin Nut 62(1):81–6.
Fraeye I, Bruneel C, Lemahieu C, Buyse J, Muylaert K, Foubert I. 2012. Dietary enrichment
of eggs with omega-3 fatty acids: a review Food Res Inter 48(2):961–69.
Jiang Z, Ahn DU, Ladner L, Sim JS. 1992. Influence of feeding full-fat flax and sunflower seeds
on internal and sensory qualities of egg. Poult Sci 71(2):378–82.
Juturu V. 2008. Omega-3 fatty acids and the cardiometabolic syndrome. J Cardiometab Syndr
3(4):244–53.
Karunajeewa H. 1978. The effect of cockle-shell grit, dietary level of calcium and EDTA on
eggshell quality and laying performance of crossbred hens. Aust J Exp Agric Anim Hus 18(94):
667–74.
Lim J, Wood A, Green BG. 2009. Derivation and evaluation of a labelled hedonic scale. Chem.
Senses 34(9):739–51.
Mazalli MR, Faria DE, Salvador D, Ito DT. 2004. A comparison of the feeding value of Different
sources of fat for laying hens. 2. Lipid, cholesterol, and vitamin E profiles of egg yolk. J Appl
Poult Res 13(2):280–90.
PhillipsKM,Tarrago-TraniMT,GroveTM,GrunI,LugogoR,HarrisRF,StewartKK.
1997. Simplified gravimetric determination of total f at in food composites after chloroform-
methanol extraction. J Am Oil Chem Soc 74(2):137–42.
Radocaj O, Dimic E, Tsao R. 2014. Effects of hemp (Cannabis sativa L.) seed oil press-cake and
decaffeinated green tea leaves (Camellia sinensis) on functional characteristics of gluten-free
crackers. J Food Sci 79(3): 318–25.
Rubio-Rodriguez N, Beltran S, Jamie I, de Diego SM, Sanz MT, Carballido JR. 2010 Pro-
duction of omega-3 polyunsaturated fatty acid concentrates: a review. Innov Food Sci Emerg
Technol 11(1):1–12.
Scheideler SE. 2003. Flaxseed in poultry diets: meat and eggs. In Thompson LU, Cun-
nane SC, editors. Flaxseed in human nutrition, 2nd ed., chapter 23. Available from:
http://www.crcnetbase.com.dbgw.lis.curtin.edu.au/doi/pdf/10.1201/9781439831915.ch23.
Accessed 2011 April 6.
Scheideler SE, Froning GW. 1996. The combined influence of dietary flaxseed variety, level,
form and storage conditions on egg production and composition among vitamin E- supple-
mented hens. Poult Sci 75(10):1221–26.
Scheideler SE, Froning GW, Cuppett S. 1997. Studies of consumer acceptance of high omega-3
fatty acid enriched eggs. J Appl Poult Res 6(2):137–46.
Sigma-Aldrich Co. 1997. BCl3-Methanol, 12% w/w Product specification. Available from:
http://www.sigmaaldrich.com/etc/medialib/docs/Aldr ich/General_Information/bcl3_
methanol.Par.0001.File.tmp/bcl3_methanol.pdf. Accessed 2011 March 17.
Simopoulos AP. 2000. Symposium: role of poultry products in enriching the human diet with
N-3 PUFA. Human requirement for N-3 polyunsaturated fatty acids. Poult Sci 79(7): 961–70.
Simopoulos AP. 2002. The importance of the ratio of omega-6/omega-3 essential fatty acids.
Biomed Pharmacother 56(8):365–79.
Surai PF, Sparks NHC. 2001. Designer eggs: from improvement of egg composition to functional
food. Trends in Food Sci Tech 12(1):7–16.
Van Elswyk M. 1997a. Nutritional and physiological effects of flax seed in diets for laying fowl.
World Poultry Sci J 53(3):253–64.
Van Elswyk M. 1997b. Comparison of n-3 fatty acid sources in laying hen ration for improvement
of whole egg nutritional quality: a review. Br J Nut 78(suppl. 1): S61–69
Van Elswyk M, Sams AR, Hargis PS. 1992. Composition, functionality and sensory evaluation
of eggs from hens fed dietary menhaden oil. J Food Sci 57(2):342–44.
Van Elswyk M, Dawson PL, Sam AR. 1995. Dietary menhaden oil influences sensory charac-
teristic and headspace volatiles of shell eggs. J Food Sci 60(1):85–9.
Whelan J, Rust C. 2006. Innovative dietary sources of n-3 fatty acids. Annu Rev Nutr 26:75–103.
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