Vol.1, No.2, 17-23 (2011) Open Journal of Animal Sciences
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/OJAS/
Comparison of free fatty acid composition between
low-fat and full-fat goat milk cheeses stored for 3
months under refrigeration
W ass im No uira1, Young W. Park1*, Zehra Guler2, Thomas Terrill1
1Georgia Small Ruminant Research & Extension Center, Fort Valley State University, Fort Valley, USA;
2Department of Food Engineering, Mustafa Kemal University, Antakya, Turkey; parky@fvsu.edu
Received 17 May 2011, revised 12 June 2011, accepted 20 June 2011.
Differences i n free fatty acid (FFA) co mpositions
between low-fat (LF) a nd ful l-fa t ( FF: whol e m ilk)
goat chees es were ev aluated d uring 3 mon ths at
4˚C refriger ation. T he t wo types of che eses were
manufactured using a bulk milk from the mixed
herd of Saanen, Alpine, and Nubian goat bree ds.
LF cheeses were made using LF milk after
cream separation. FFAs of all cheeses were ex-
tracted in diisoprophyl ether using polypropyl-
ene chromatography column, and FFA concen-
trations were quantified using a gas chromato-
graph equipped with a fused silica capillary
column. Moisture, fat, protein contents (%) and
pH of fresh LF and FF cheeses were: 55.1, 52.3;
1.30, 25.6; 35.7, 22.5; 5.40, 5.42, respectively.
The FFA contents (mg/g cheese) of fresh FF and
LF cheeses prior to storage treatments for C4:0,
C6:0, C8:0, C10:0, C12:0, C14:0, C16:0, C18:0,
C18:1, and C18:2 were: 0. 020, 0.0 72; 0. 070, 0. 035;
0.061, 0.055; 0.181, 0.167; 0.073, 0.047; 0.174,
0.112; 0.579, 0.152; 0.308, 0.202; 0.521, 0.174;
and 0.057, 0.026, respectively. The respective
FFA to total fatty acid ratios for 0, 1 and 3
months aged FF and LF cheeses were 8.44, 12.4;
6.31, 16.91; 12.03, 14.19. The LF cheeses gener-
ated more FFA than FF cheeses, while actual
FFA content in FF cheese was significantly
higher than in LF cheese. The FFA contents of
LF cheese at 0, 1 and 3 months storage were
48.0, 96.8 and 36.4% of those of FF cheese, re-
spectively. It was concluded LF cheese gener-
ated higher amount of FFA than FF cheese, al-
though total FFA content was significantly
(P<0.05) lower in LF cheese than in FF chees e.
Keywords: Low Fat; Full Fat; Goat Milk Cheese;
Storage, Free Fatty Acid, Lipolysis
Dietary fat has been implicated with coronary heart
diseases, atherosclerosis, diabetes and other health pro-
blems. Consumption of reduced or low fat dairy prod-
ucts has been increasingly popular among health-con-
scientious consumers in recent years [1].
Fat reduction, however, presents a challenging prob-
lem because fat is important for texture and flavor of
dairy products such as cheeses [2,3]. Fat reduction in
hard and semi-hard cheeses results in undesirable rub-
bery texture, lack of flavor, and/or presence of
off-flavors [3,4]. Reduced-fat (RF) and low-fat (LF)
cheeses which possess the characteristics of traditional
full-fat (FF) cheeses have been in demand [5]. Many
manufacturing procedures, therefore, have been sug-
gested and investigated to maximize sensory quality of
RF cheeses [6-8].
A myriad of biochemical and physical changes can
occur in goat milk cheeses after manufacture due to rip-
ening and degradation of nutrients in the products [9-11].
Positive correlations have been found between lipolyzed
flavor, fat acidity and short chain free fatty acid contents
[6,8,12]. The flavor intensity of Kasar cheese, a hard
cheese, was closely related to C4 - C10 free fatty acids
[13]. The presence of large amounts of free fatty acids
(FFA) can facilitate the rate of lipid oxidation, and free
fatty acids oxidize slightly greater rate than esterified to
glycerol. Even-numbered fatty acids from butyric to
lauric accounted for the major contribution to rancid
flavor [11,14]. Flavor deterioration from lipid oxidation
(reaction of milk lipids with oxygen) and/or lipolysis in
dairy products creates serious problems in storage stabil-
ity of the products [8,11,15,16].
The amount of FFA accumulated during ripening may
be an overall measure of lipolysis, and is quite variable
W. Nouira et al. / Open Journal of Animal Sciences 1 (2011) 17-23
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/OJAS/
depending on the type of cheese, lactic and secondary
starters, rennet type used, ripening time, and manufac-
turing methods and other factors [10,12,17]. The in-
digenous milk lipase, rennet preparation and microbes
entered intentionally or unintentionally during cheese
processing and ripening are primarily responsible for the
extent of lipolysis [12,17].
Although the effect of storage on levels of free fatty
acids in low-fat and reduced-fat dairy cow products have
been studied extensively, there is little information on
such dairy goat products with respect to effect of storage,
free fatty acid concentration and extent of lipolysis.
Therefore, the objectives of this study were to: 1) deter-
mine free fatty acid (FFA) concentrations of low-fat (LF)
and full-fat (FF) goat milk cheeses stored for three
months under refrigeration, and 2) compare FFA con-
tents between the two types of goat milk cheeses as well
as between different storage periods in relation to lipoly-
sis of the products.
2.1. Preparation of Goat Milk
Goat milk used in this study was the bulk tank milk
collected from the milking goat herd consisted of Saanen,
Alpine and Nubian breeds at the Georgia Small Rumi-
nant Research and Extension Center, Fort Valley State
University, Fort valley, GA, USA. All goats were ma-
chine milked, and the experimental milks were pasteur-
ized at 63˚C (145˚F) for 30 minutes before manufacture
of the FF and LF experimental goat milk cheeses.
2.2. Manufacture of Low-Fat (LF) and Full-Fat
(FF) Goat Milk Cheeses
Three batches of LF and 3 batches of FF semi-soft
Cheddar-type caprine cheeses were manufactured at the
University dairy plant, according to the modified proce-
dures of Kosikowski [18] and Le Jaouen [19]. After pas-
teurization, the whole (FF) milk was cooled to 32˚C in a
227 L cheese vat. Lyophilized mesophilic direct vat set
starter culture (R704, 50 units, Chr. Hansen, Inc., Mil-
waukee, WI) and single strength rennet (10.6 mL of
rennet per 100 L milk; Chymax; Chr. Hansen, Inc., Mil-
waukee, WI) were added to the milk and then allowed to
coagulate for 30 minutes. The curd was cut using 1.6 cm
wire knives and allowed to heal for 10 minutes. The
temperature was gradually raised to 39˚C over 30 min-
utes and the curd was cooked for 45 minutes, assuring
for a firm curd. After draining whey, curds were salted at
a rate of 2.5% of original milk weight and placed
into150 × 150 mm cylindrical plastic molds and pressed
at 40 psi overnight at room temperature in a vertical
cheese press (Pneumatic Press, Kusel Equip. Co., Wa-
tertown, WI). Cheeses were removed from the molds
and vacuum packed in plastic pouches (FreshPak 500
vacuum pouches, Koch Supply, Kansas City, MO) using
a vacuum packager (Koch Ultravac 250, Koch Supply,
Kansas City, MO).
For LF cheese manufacture, cream was separated
from the pasteurized whole goat milk by a cream sepa-
rator (Model 17584, Clair Co., Althofen, Austria), and
then the LF cheese was made from the low-fat milk ac-
cording to the same procedure used for FF cheese.
2.3. Experimental Design
The experiment was conducted in a 2 × 3 × 3 factorial
arrangement. Two types (LF and FF) of goat milk
cheeses were manufactured in three batches, and the
experimental caprine cheeses were stored for 3 different
storage (aging) periods (0, 1 and 3 months).
All treated cheese samples were analyzed for basic
chemical compositions, pH, acid degree value (ADV)
and free fatty acid and total fatty acid concentrations to
determine the differences in the parameters between the
two types of caprine milk cheeses.
2.4. Chemical Analysis
2.4.1. Analyses of Basic Nutrient Composition
Percents of fat, protein, ash and total solids contents
were analyzed according to the procedures of A. O. A. C.
[20] and Richardson [21].
2.4.2. pH Analysi s
A 10 g cheese sample and 20 ml deionized water were
homogenized in a Waring blender (Waring Products, Inc.,
New Hartford, CT). The pH of the cheeses were deter-
mined using an Accumet model pH meter (No. 910;
Fisher Scientific, Pittsburgh, PA).
2.4.3. Acid Degr ee Value (ADV)
The ADV refers to measure of the amount of free fatty
acids present in a fat sample, which is a quantitative in-
dex of hydrolytic lipolysis in dairy products. ADV was
determined by the Standard Methods for the Examina-
tion of Dairy Products [21]. Approximately 10 g of sam-
ple were grated, homogenized, and placed into a Bab-
cock cheese bottle for fat extraction; 1 ml of the final
extracted fat was titrated against the standard alcoholic
0.02N KOH solution. Calculation of ADV was per-
formed using the following formula:
ml KOH for sampleml KOH for blank N100
ADV= Weight of fatg
where N = normality of KOH solution in methanol.
W. Nouira et al. / Open Journal of Animal Sciences 1 (2011) 17-23
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/OJAS/
2.4.4. Extraction of Free Fatty Acids in Cheese
Extraction of free fatty acids (FFA) was performed
using the modified procedures of Deeth et al. [22]. A 1.5
g cheese sample was shredded and placed in a
screw-capped test tube, and the internal standard (5 mL)
C5 and C17 in diethyl ether, 0.3 mL 4 N H2SO4, 2.5 g
Na2SO4, and hexane (5 mL) were added to the tube. The
tube mixture was shaken for 1 min using a vortex mixer.
Samples were allowed to stand for two hours. Then lipid
extract was applied to a polypropylene column (Biorad,
Los Angeles, CA, USA), which was conditioned with 5
mL hexane/diethyl ether (1:1, v/v) and the extract passed
through the column a second time. This was followed by
2x5 mL hexane/diethyl ether (1:1, v/v) to remove all
triacylglycerols. FFAs were eluted with 2 mL diisopro-
pyl ether containing 6% formic acid (Merck, Darmstadt,
Germany) and centrifuged at 2000 × g for 5 min. A 2 mL
aliquot of the supernatant was used for gas chroma-
tographic analysis. For each sample, two extractions of
FFAs were carried out, and two chromatographic injec-
tions made for each extract.
2.4.5. Quantification of Free Fatty Acids in Cheeses
FFA concentrations of cheese samples were quantified
using a gas chromatograph (17A-GC, Shimadzu Co.,
Japan) equipped with a fused silica capillary column
(DB-FFAP; 30 m × 0.25 mm i.d. × 0.25 μm, Agilent
Technologies, Wilmington, DE). Injector and detector
temperature were 250 and 280˚C, respectively. Oven
temperature was programmed from 50˚C to 230˚C at a
rate of 5˚C per minute, with initial and final hold times
of 5 and 20 min, respectively, and run time was 61 min-
utes. The injection mode was splittless for 1 min, and the
injection volume was 2 µL, with helium as carrier gas
for 1 mL/min. Analyses were carried out in triplicate.
2.4.6. Extraction and Quantification of Total Fatty
Acids (TFA) in Cheeses
The extraction and quantification of all fatty acids
were performed using fatty acids methyl esters (FAME)
according to A. O. C. S. procedure [23] with some modi-
Total fatty acid compositions were determined by us-
ing a gas chromatograph (17A-GC, Shimadzu Co., Japan)
equipped with a fused silica capillary column (60 m
length × 0.25 mm i.d. × 0.2 μm; SP 2380, Supelco Inc.,
Bellfonate, PA) with a flame ionization detector (FID).
Oven temperature was programmed from 50˚C to 250˚C
at a rate of 4˚C /min, with initial and final hold times of
2 and 10 min. Injector and detector temperatures were
220 and 250˚C, respectively. The injection mode was
split injection, and injection volume was one µL. The
carrier gas was helium at a rate of 2 mL/min.
2.5. Statistical Analysis
The experimental data were analyzed for analysis of
variance, correlation coefficients and Duncan’s multiple
mean comparison as described by Steel and Torrie [24].
All data for unbalanced data were also analyzed by the
general liner models procedure of SAS program [25].
Basic nutrient compositions of experimental LF and
FF goat milk and their respective cheeses are shown in
Tab le 1 . The respective fat contents (%) of LF and FF
goat milk were 0.41 and 3.66, while those of LF and FF
cheeses were 1.30 and 25.6, indicating substantial dif-
ferences (P < 0.01) in fat contents in LF and FF milk and
cheeses. The protein contents of LF and FF milk were
slightly different, whereas those of LF and FF cheeses
were significantly (P < 0.01) different because fat was
removed in the LF cheese which had more dense protein
matrix than FF cheese.
When the acid degree values (ADV) were tested for
the experimental cheeses, LF cheese regardless of the
storage treatment did not have any detectable levels of
ADV due to the original very low contents of fat in the
cheeses (Table 2). However, the FF goat cheese showed
continuous increase in ADV as the storage period ad-
vanced from 0 month to 3 months, indicating that no
detectable lipolysis occurred in LF cheese while gradual
increase in lipolysis occurred in FF cheese (Table 2).
However, there were no differences in pH values be-
tween the FF and LF cheeses, nor between 0, 1 and 3
moths storage periods as shown in (Table 2). In a previ-
ous report, pH of hard type goat cheeses were increased
as the aging time advanced up to 6 months due to the
formation of NH3 by catabolism of cheese proteins [16].
The FFA profiles of both FF and LF cheeses are
shown in Ta bl e 3. Among all the detected free fatty ac-
ids, only C6:0, C10:0 and C12:0 showed significant (P <
0.05) differences between the two cheeses during the 3
months storage period. The FF cheese contained the
highest concentration of all these three free fatty acids
after 3 months storage, indicating that FF cheese showed
greater lipolysis evidenced by higher FFA level (Tables
2 and 3). All other free fatty acids except these 3 fatty
acids did not show any statistically significant differ-
ences between treatments, even if a few values appeared
to be a little high but not different due to the higher
variations in concentration between samples. It was also
observed that the relative abundance of FFA after 3
months refrigerated aging of FF goat cheese in the de-
scending order of our cheese samples were: C18:0,
W. Nouira et al. / Open Journal of Animal Sciences 1 (2011) 17-23
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/OJAS/
Table 1. Basic composition (%) of LF and FF goat milk and their respective cheeses.
Total solids Fat Protein Ash
FF 11.72a 1.52 3.66a0.08 3.22a0.11 0.69a 0.01
FF 47.7a 1.46 25.6a0.48 22.5b1.34 3.70b 0.29
X is mean, and SD is standard deviation values. a,b Means with different superscripts within same columns are significantly different P < 0.01 or 0.05). The
differences for fat and protein contents between FF and LF milk and cheese groups are significant at P < 0.01. The mean comparisons are made separately for
milk samples and for cheese samples within the same columns.
Table 2. Summary of mean pH and ADV of FF and LF goat milk cheeses during 3 months refrigerated storage.
0 month 1 month 3 month
pH 5.40a 0.01 5.42a 0.01 5.43a 0.01 5.43a 0.02 5.28a 0.0 5.48a 0.02
ADV 0.70a 0.08 0.0 - 1.06 b 0.05 0.0 - 1.34bc 0.07 0.0 -
X is mean; SD is standard deviation; a,b,c Means with different superscript within same row is different (P < 0.05)
Table 3. Comparison of mean free fatty acid concentration (mg/g cheese) of full-fat (FF) with low-fat (LF) goat milk cheeses aged
for 3 months under refrigeration.
0 month 1 month 3 month
C4:0 0.0202a 0.072a 0.0104a 0.0325a 0.0524a 0.034a
C6:0 0.0701ab 0.0353b 0.0497ab 0.0565ab 0.2153a 0.0925ab
C8:0 0.0609a 0.0551a 0.0575a 0.0411a 0.1222a 0.0638a
C10:0 0.1805b 0.1066b 0.1620b 0.1007b 0.4706a 0.1253b
C12:0 0.0729b 0.0474b 0.0649b 0.0558b 0.2511a 0.0501b
C14:0 0.1744a 0.1119a 0.1575a 0.1173a 0.2231a 0.1492a
C16:0 0.5794a 0.1520a 0.3839a 0.1451a 0.5113a 0.2401a
C18:0 0.3076a 0.2022a 0.1892a 0.1540a 0.7423a 0.1111a
C18:1 0.5211a 0.1740a 0.3332a 0.6455a 0.4816a 0.2332a
C18:2 0.0572a 0.0255a 0.0875a 0.1000a 0.2744a 0.1175a
Total FFA 2.0443b 0.982d 1.4957bc 1.4485bc 3.3443a 1.2168c
Total fatty acids 24.226ab 7.917c 23.719ab 8.568c 27.798a 8.574c
FFA/TFA ratio 8.44 12.4 6.31 16.9 12.03 14.2
a,b,c,d Means with different superscripts in same row are different (P < 0.05 or P < 0.01). All FFA values are means of 3 batches of cheeses, and each batch
samples were analyzed in duplicates.
C16:0, C18:1, C10:0, C12:0. C14:0, and C6:0 acid. At-
taie and Richter [26] reported that aging time greatly
influenced levels of volatile FFA in goat Cheddar cheese
for the first 3 months, then remained relatively un-
W. Nouira et al. / Open Journal of Animal Sciences 1 (2011) 17-23
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/OJAS/
changed for the rest of the 6 months aging period. They
also observed the descending order of the relative abun-
dance of FFA in their goat Cheddar cheese were: C10:0,
C12:0, C8:0, C6:0 and C4:0 acid, which may not be di-
rectly comparable to our results, since they determined
the concentrations of volatile fatty acids (C4:0 to C12:0).
With respect to total FFA and total fatty acid (TFA)
concentrations, the respective levels of the FF goat milk
cheese for the 0, 1 and 3 months aging were: 2.04, 24.2;
1.50, 23.7; 3.34, 27.8, whereas the LF cheese of the cor-
responding aging periods were 0.982, 7.917; 1.449,
8.568; 1.217, 8.574, respectively. These results also
clearly show that the LF cheese contained considerably
lower levels of FFA and TFA, compared to the FF cheese
(Tab le 3). Total FFA concentrations of FF and LF goat
cheeses after 3 months refrigerated storage increased
from 2.044 to 3.344, and 0.982 to 1.217 mg/g cheese,
respectively. These results indicate that some increase
(1.30 mg/g cheese) in lipolysis occurred in FF goat milk
cheese, but very minimal change (0.235 mg/g cheese)
occurred in LF goat cheese during the 3 months experi-
mental storage period. These FFA concentrations are
reflected with the results of ADV values shown in Table
2. Positive correlations were found between lipolyzed
flavor, fat acidity, and short-chain FFA contents [6,11,17]
Even-numbered fatty acids, from butyric to lauric acid,
in milk and dairy products account for the major contri-
bution to rancid flavor [11,14].
In light of total FFA to total fatty acids (TFA) ratios of
both FF and LF cheeses, LF cheese showed relatively
higher ratio than that of FF cheese. However, the actual
increase in FFA content of LF cheese was much smaller
than that of FF cheese, simply because LF cheese con-
tained substantially lower fat content than FF cheese
(Ta b l es 1 and 3; Figure 1). Figure 1 demonstrates that
total fatty acid concentrations of FF cheeses were sub-
stantially higher than those of LF cheeses, regardless of
storage times. The figure also shows that the differences
in concentration (mg/g cheese) between FFA and TFA
are much greater in FF cheese than LF cheese through-
out the storage periods. The relatively greater FFA/TFA
ratio in LF cheese compared to that in FF cheese can be
attributed to the disrupted fat globule membranes of LF
cheese which can have a greater chance of exposure to
lipolytic enzymes by cream separation as well as cheese
processing and storage. The origin of enzymes responsi-
ble for lipolysis in cheese include the indigenous milk
lipase (lipoprotein lipase: LPL), rennet preparation, and
microbes that develop during cheese ripening either in-
tentionally (starter bacteria and specific molds or yeasts)
or unintentionally (nonstarter acid bacteria and adventi-
tious molds or yeasts) that should not be present at sig-
nificant numbers [12,17,27]. The LPL activity, although
lower in goat than in cow milk, is more bound to the fat
globules and better correlated to spontaneous lipolysis in
goat milk [28]. On the other hand, the undisrupted fats
without cream separation in FF cheese would have less
exposure to the lipase enzymes, resulting in less chance
of lipolysis in the FF cheese. Although the milk was
pasteurized before cream separation, there would be
chances of the intentional and unintentional microbial
lipases activities during processing and storage
of our experimental goat cheeses.
Reports also have shown that lipolysis of milk and
dairy products can occur by three different sources: 1)
induced lipolysis, 2) spontaneous lipolysis and 3) micro-
bial lipolysis [11,29]. Induced lipolysis is influenced by
several factors, such as processing factors including agi-
tation, separation, pumping, mixing, foaming, presence
of air, homogenization, activation by temperature
changes, freezing and thawing, storage and processing
[11,29,30]. Spontaneous lipolysis can occur through two
main factors, such as milk processing factors, and milk-
ing animal factors including stage of lactation, feed,
season, breed, mastitis, milk and fat yield, and physio-
logical factors. Microbial lipolysis is caused by many
microorganisms that contaminate dairy products. These
organisms produce lipase which develop rancid flavor.
The psychrotrophic bacteria are most common sources
of these lipases [11]. Bacterial lipases are different from
milk lipases, are not inactivated by pasteurization, and
can attack the intact fat globules in milk [12,27,30].
Since LF cheese manufacture after cream separation in
this study could be prone to be involved in these three
types of lipolysis, higher lipid hydrolysis might have
been occurred in the LF cheeses, causing a higher pro-
portional increase of FFAs in LF cheeses even though
the FFA amount was small.
Concentration (mg/ g cheese)
0mon-LF0 mon-FF1 m on-LF1 mon-FF3 mon-LF3 mon-FF
Total FFA
Total FA
Figure 1. Comparison of levels (mg/g cheese) of total free
fatty acids (FFA) and total fatty acids (TFA) between LF and
FF goat milk cheeses for 3 months refrigerated storage [Dif-
ferences between LF and FF cheeses were significant (P <
W. Nouira et al. / Open Journal of Animal Sciences 1 (2011) 17-23
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/OJAS/
The profiles of free fatty acid compositions of the 0 to 3
months aged FF and LF caprine cheeses revealed that FF
cheeses contained higher levels of all types of free fatty
acids, except for the butyric acid in the initial cheeses.
The total FFA contents of LF cheese were 48.0, 96.8 and
36.4 % of FF cheeses for 0, 1 and 3 months aging, indi-
cating that the 1 month aged cheeses contained higher
FFA than the 0 and 3 month stored ones. The LF cheese
revealed more proportional increase in FFA compared to
the FF cheese, although the actual amount of FFA in LF
cheese was much lower than that in FF cheese. This re-
sult may account for the higher lipolytic enzyme activi-
ties in LF cheese by the indigenous milk enzymes, or
microbial enzymes of intentional and unintentional mi-
croorganisms which can have a greater access to the dis-
rupted fat globule membranes by cream separation and
subsequent cheese processing and storage. Further stud-
ies may be necessary to ascertain what exact sources or
mechanisms are involved in the elevation of FFA in LF
caprine cheeses in order to prevent the increased lipoly-
sis which may deteriorate the quality of low-fat goat milk
This study was supported by USDA 1890 Capacity Building Grant,
Award No. 2007-38814-18518. The authors greatly appreciate Mr.
Schauston Miller and Carlton Green for collection of goat milk and
processing, and Ms. Ruby Ragan for her assistance in cheese manufac-
ture. Dr. Zehra Güler was supported by the Scientific and Technological
Research Council of Turkey, with 2219-postdoctoral research fellow-
ships (TÜBİTAK-TURKEY, 2008) for a visiting scientist at Fort Valley
State University, Fort Valley, GA, USA.
[1] Thayer, A.M. (1992) Food Additives. Chemical Engi-
neering News, 70, 26.doi:10.1021/cen-v070n024.p026
[2] Jameson, G.W. (1990) Cheese with less fat. Australian
Journal of Dairy Technology, 11, 93.
[3] Mistry, V.V. (2001) Low fat cheese technology. Interna-
tional Dairy Journal, 11 , 413-422.
[4] Olson, N.F. and Johnson, M.E. (1990) Light cheese prod-
ucts: characteristics and economics. Food Technology, 44,
[5] Honer, C. (January 1993). Second thoughts. Dairy Field.
[6] Drake, M.A., Herrett, W., Boylston, T.D. and Swanson,
B.G. (1995) Sensory evaluation of reduced fat cheeses.
Journal of Food Science, 60, 898-901.
[7] Ashfield, M.A., Ma, L., Drake, M.A., Barbosa-Canovas,
G.V. and Swanson, B.G. (1997) Rheology of full-fat and
low-fat Cheddar cheeses as related to type of fat mimetic.
[8] Carunchia Whetstine, M.E., Karagul-Yuceer, Y., Avsar, Y.
and Drake, M.A. (2003) Identification and quantification
of character aroma components in fresh Chevre-style
goat cheese. Journal of Food Science, 68, 2441-2447.
[9] Fox, P.F. (1989) Proteolysis during cheese manufacture
and ripening. Journal of Dairy Science, 72, 1379-1400.
[10] McSweeney, P. and Sousa, M. (2000). Biochemical path-
ways for the production of flavor compounds in cheese
during ripening: A review. Lait, 80, 293-324.
[11] Park, Y.W. (2001) Proteolysis and lipolysis of goat milk
cheese. Journal of Dairy Science, 84 (E. Suppl.),
[12] Velez, M.A., Perotti, M.C., Wolf, I.V., Hynes, E.R. and
Zalazar, C.A. (2010) Influence of milk pretreatment on
production of free fatty acids and volatile compounds in
hard cheeses: Heat treatment and mechanical agitation.
Journal of Dairy Science, 93, 4545-4554.
[13] Guler, Z. (2005) Quantification of free fatty acids and
flavor characteristics of Kasar cheeses. Journal of Food
Lipids, 12, 209-221.
[14] Ha, J.K. and Lindsay, R.C. (1991) Contributions of cow,
sheep, and goat milks to characterizing branched-chain
fatty acid and phenolic flavors in varietal cheeses. Jour-
nal of Dairy Science, 74, 3267-3274.
[15] Day, E.A. (1960) Autoxidation of milk lipids. Journal of
Dairy Science, 43, 1064.
[16] Jin, Y.K. and Park, Y.W. (1995) Effects of aging time and
temperature on proteolysis of commercial goat cheeses in
the US. Journal of Dairy Science, 78, 2598-2608.
[17] Collins, Y., McSweeney, P.L.H. and Wilkinson, M. (2003)
Lipolysis and free fatty acid catabolism in cheese: A re-
view of current knowledge. International Dairy Journal,
13, 841-846.doi:10.1016/S0958-6946(03)00109-2
[18] Kosikowski, F.V. (1977) Cheese and fermented milk
foods, 2nd Edition, Edwards Brothers, Inc., Ann Arbor,
[19] Le Jaouen, J.-C. (1987) The fabrication of farmstead goat
cheese. Cheesemaker’s Journal,Ashfield,MA 01330, 45.
[20] AOAC. (1985) Official methods of analysis. 14th Edition,
The Association of Official Analytical Chemists, Wash-
ngton, D.C. No. 43.292. 7.001, 7.009, 7.006.
[21] Case, R.A., Bradley, R.L. Jr. and Williams, R.R. (1985)
Chemical and physical methods. In: Richardson, G.H. Ed.,
Standard Methods for the Examination of Dairy Prod-
ucts.15th Edition, American Public Health Association,
Washington, D.C., 327.
[22] Deeth, H.C., Fitz-Gerald, C.H. and Snow, A.J. (1983) A
GC method for the quantitative assay of free fatty acids.
New Zealand Journal of Science and Technology, 18,
[23] AOCS. (1975) Official methods and recommended prac-
tices of the american oil chemists’ society. American Oil
Chemists’ Society, Champaign, No. 1, 3A and 6, 7-15.
[24] Steel, R.G.D. and Torrie, J.H. (1960) Principles and Pro-
W. Nouira et al. / Open Journal of Animal Sciences 1 (2011) 17-23
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/OJAS/
cedures of statistics. McGraw-Hill, New York, 190.
[25] SAS Institute. (1999) User’s guide: statistics, 8th Edition.
SAS Institute, Inc., Cary.
[26] Attaie, R. and Richter, R.L. (1996) Formation of volatile
free fatty acids during ripening of Cheddar-like hard goat
cheese. Journal of Dairy Science, 79, 717-724.
[27] Hickey, D.K., Kilcawley, K.N., Beresford, T.P. and Wil-
kinson, M.G. (2007) Lipolysis in cheddar cheese made
from raw, thermized, and pasteurized milks. Journal of
Dairy Science, 90, 47-56.
[28] Chilliard, Y., Ferlay, A., Rouel, J. and Lamberet, G. (2003)
A review of nutritional and physiological factors affecting
goat milk lipid synthesis and lipolysis. Journal of Dairy
Science, 86, 1751-1770.
[29] Deeth, H.C. and Fitz-Gerald, C.H. (1976) Lipolysis in
dairy products: A review. Australian Journal of Dairy
Technology, 31, 53-64.doi:10.1016/j.idairyj.2004.01.005
[30] Evers, J.M. (2004) The milkfat globule mem-
brane-Compositional and structural changes post secre-
tion by the mammary secretory cell. International Dairy
Journal, 14, 661-674.