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Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017 427 ISSN: 1517-8595
Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017
EFFECT OF THE STORAGE TIME AND DRYING ON CHEMICAL AND
PHYSICOCHEMICAL PROPERTIES OF CASHEW KERNEL OIL
Anna Sylvia Ramos de Rangel Moreira Cavalcanti1 Robert K. Kross2,
Maria Elita Martins Duarte3, Mario Eduardo R.M. Cavalcanti3
ABSTRACT
This article deals with oil extraction of the cashew kernels by using a hydraulic press. The
samples were submitted to thin-layer drying, by using hot air in the temperatures of 50 and 70 oC. The samples of the cashew kernel oil were stored in glass bottles of 70 mL with an internal
space above the liquid of 5 mL. During the storage, the luminosity effect was studied, by
placing some samples exposed to the light, while other samples were completely isolated and, in
this case, the bottles were covered with aluminum foil and stored in a closed box. The pre-
treatment of the cashew kernels by drying didn’t affect the physicochemical properties of the
oil. The other properties (color, appearance and aroma) were not affected by the operational
conditions of this experiment. According to the obtained results, the cashew kernel oil can be
included in the list of other commercial vegetable oils.
Keywords: vegetable oils; cashew kernel; thin-layer drying
EFEITO DO TEMPO DE ARMAZENAGEM E SECAGEM EM PROPRIEDADES
QUÍMICAS E FÍSICO-QUÍMICAS DO ÓLEO DE CASTANO DE CAJU
RESUMO
Este artigo trata da extração de óleo da castanha de caju utilizando uma prensa hidráulica. As
amostras foram submetidas a secagem em camada delgada, utilizando ar quente nas
temperaturas de 50 e 70 °C. As amostras do óleo da castanha de caju foram armazenadas em
garrafas de vidro de 70 mL com um espaço interno acima do líquido de 5 mL. Durante o
armazenamento, o efeito da luminosidade foi estudado, colocando-se algumas amostras
expostas à luz, enquanto outras amostras foram completamente isoladas e, neste caso, as
garrafas foram cobertas com papel alumínio e armazenadas em uma caixa fechada. O pré-
tratamento das castanhas de caju feita por secagem não afetou as propriedades físico-químicas
do óleo. As outras propriedades (cor, aparência e aroma) não foram afetadas pelas condições
operacionais deste experimento. De acordo com os resultados obtidos, o óleo da castanha de
caju pode ser incluído na lista de outros óleos vegetais comerciais.
Palavras-Chave: óleos vegetais, castanha de caju; secagem em camada delgada
Protocolo 70 2015 23 de 20/03/2014 1 Profa. Dra em Engenaharia de Materias de, FAVIP, Caruaru , PE, E-mail: cavalcantiannas@gmail.com 2 Químico Industrial, Dr. em Engenaharia de Processos, Anaton de Kom University of Suriname, Suriname, Email:
robert.kross@usv.edu 3 Prof.(a) Titular, Unidade Academica de Engenharia Alimentos – UFCG, Email: mcavalcantimata@gmail.com;
melitamd@gmail.com
428 Effect of the storage time and drying on chemical and physicochemical properties of cashew kernel oil Cavalcanti et al.
Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017
INTRODUCTION
The economic exploitation of the cashew
tree, a plant native to Brazil, is concentrated in
the states of Ceará, Piauí and Rio Grande do
Norte. These states account for 91% of the
national production, on 700,000 ha (IBGE
2012). The cashew agroindustry represents a
significant portion of the economy of the
Northeast of Brazil, generating annually about
217,062 tons of cashew nut.
Generally, the main products of cashew
processing are the cashew kernel, cashew nut
shell liquid and the juice from the cashew
apple. From the cashew nut several other non-
food products such as paint, isolating material
and insecticides can be produced.
In Brazil, the whole cashew nuts are
normally exported, while the pieces, the so-
called splits, are destined for the local market to
be used as raw material for ice-cream and other
products.
Although these pieces are of low commercial
value, they still preserve their nutritional and
organoleptic properties, presenting itself with a
great amount of valuable nutrients. So, this
rejected material from the cashew nut
processing industries could be used to improve
other valuable final products, considering their
nutrition facts. Due to the fact that these pieces
(splits) are practically off priced in the trade
market, it would be interesting to process them
into high value-added products, which is the
main objective of this work, trying to produce a
kind of salad dressing oil, comparable with the
olive oil.
The main objective of this article is to
extract the oil from cashew kernel in pieces,
aiming a new high value-added product. In
order to extract the cashew kernel oil, three
drying levels are considered: (1) kernels not
dried with a moisture content of 5% w.b.; (2)
kernels dried at a temperature of 50 oC and a
final moisture content of 3% w.b.; and (3)
kernels dried at a temperature of 70 oC and a
final moisture content of 1% w.b. In addition,
the chemical and the physicochemical
(physicochemical) properties of the produced
cashew kernel oil, considering each drying
level, are also determined.
MATERIAL AND METHODS
Raw Material A special variety of the cashew, a clone
called CCP 06 processed in an industry of
Barreiras, Ceará, Brazil, was used as raw
material. It was a mixture of non-dried kernels
classified as the type S (Splits), S1, S2 and S3,
packaged as recommended, which is the Bulk
Vacuum Packaging (50 Lbs.), in multilayer
laminate packaging material. The flowchart of
this case study can be presented as in Figure 1.
Figure 1. Flowchart of the cashew kernel oil production and its characterization.
Effect of the storage time and drying on chemical and physicochemical properties of cashew kernel oil Cavalcanti et al. 429
Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017
Selection
The first selection and classification of
the cashew kernels was realized at the cashew
nut processing industry, according to pre-
established procedures from the Food and
Agriculture Organization (FAO, 2005),
Carteira de Comércio Exterior do Banco do
Brasil S.A. – CACEX and also the Ministry of
Agriculture of Brazil. Classified cashew kernels
of the type S: S1, S2 and S3 were selected.
Although the samples were already selected and
classified, they were submitted once again to
this process aiming a uniform sampling before
drying.
Drying
Before the drying process, the initial
moisture contents of the cashew kernels were
determined, according to the official methods of
the Association of Official Agricultural
Chemists (AOAC, 2005), where samples are
dried at the temperature of 105 ± 2 oC during 72
hours. Afterwards, these samples were
submitted to a thin-layer drying process, where
they were placed on a stainless steel tray in a
stove with air circulation. For each temperature
in this study, 50 and 70 oC, the drying process
was realized until the pre-established moisture
content.
Oil Extraction The oil extraction of the cashew kernels
was according to the Cold Pressed Method, by
using a hydraulic press of 30 tons and batches
of 2 kg. In statistical terms, this experiment
consisted of 3 levels of drying treatments: (1)
oil from non-dried cashew kernels; (2) oil from
cashew kernels submitted to a drying process at
50 oC; and (3) oil from cashew kernels
submitted to a drying process at 70 oC.
Afterwards the oil was clarified by filtration
and centrifuging.
Storage The samples of the cashew kernel oil
were stored in glass bottles of 70 mL with an
internal space above the liquid of 5 mL. During
the storage, the effect of the luminosity was
studied, by placing some samples exposed to
the light, while other samples were completely
isolated and, in this case, the bottles were
covered with aluminum foil and stored in a
closed box (Figure 2).
The samples were stored for 120 days,
and every 30 days samples were analyzed for
their values (acidity, peroxide, saponification
value, unsaponifiable matter and the refractive
index), specific mass, appearance, color and
aroma.
Figure 2. Bottling and Storage of the cashew kernel oil.
Characterization of the cashew kernel oil:
determination of the chemical and
physicochemical values
The following properties were
determined: acidity-, peroxide-, saponification
value and unsaponifiable matter, refractive
index as well as the specific mass, appearance,
color and aroma. Analyses were realized
according to the official methods of the AOAC
(2012), as shown in Table 1.
Table 1. Determination of the properties according to the official methods of the AOCS (2006).
Determination Method
Acidity AOCS Cd 3d-63
Peroxide AOCS Cd 8-53
Saponification AOCS Tl 1a-64
unsaponifiable matter AOCS Ca 6b-53
Refractive index (40°C) AOCS Cc 7-25
430 Effect of the storage time and drying on chemical and physicochemical properties of cashew kernel oil Cavalcanti et al.
Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017
Statistical Analysis
Statistical analysis of the data was
performed using a completely randomized
design with 3 treatments of drying, 2 of
packaging and 5 storage times in a 3 x 2 x 5
factorial scheme with runs in duplicate, in this
way having: a) 3 drying levels: without drying;
with drying at 50 oC and with drying at 70 oC;
b) 2 packaging levels: with and without
exposure to light; c) 5 levels of storage: t = 0, t
= 30, t = 60, t = 90, and t = 120 days.
For the statistical analysis, the software
Assistat 7.5 beta (Silva and Azevedo, 2006)
was used.
RESULTS AND DISCUSSION
Determination of the physicochemical and
chemical properties
In Tables 2 and 3, the results of the
properties of the different cashew kernel oil
samples are presented.
Table 2. Characterization of the cashew kernel oil with 3 drying levels stored not exposed to light.
Level of
Drying 0 days 30 days 60 days 90 days 120 days
Acidity Value
no drying 0.90 ± 0.01 1.45 ± 0.04 1.63 ± 0.02 1.80 ± 0.04 1.91 ± 0.06
T = 50 oC 0.89 ± 0.06 1.38 ± 0.04 1.60 ± 0.06 1.81 ± 0.03 1.99 ± 0.03
T = 70 oC 0.92 ± 0.03 1.44 ± 0.03 1.65 ± 0.04 1.81 ± 0.04 2.01 ± 0.04
Peroxide Value (%)
no drying 0.92 ± 0.03 1.44 ± 0.03 1.65 ± 0.04 1.81 ± 0.04 2.01 ± 0.04
T = 50 oC 0.82 ± 0.01 0.88 ± 0.01 0.92 ± 0.01 1.49 ± 0.01 2.02 ± 0.01
T = 70 oC 0.89 ± 0.06 1.38 ± 0.04 1.60 ± 0.06 1.81 ± 0.03 1.99 ± 0.03
Saponification Value (%)
no drying 197.2 ± 0.6 195.2 ± 0.3 199.0 ± 0.7 198.9 ± 0.3 198.0 ± 0.7
T = 50 oC 196.9 ± 2.8 195.9 ± 2.1 198.4 ± 1.7 197.4 ± 1.7 197.8 ± 3.4
T = 70 oC 195.9 ± 0.6 196.7 ± 1.9 196.1 ± 2.2 196.9 ± 1.3 199.1 ± 0.8
Unsaponifiable matter (%)
no drying 0.17 ± 0.03 0.19 ± 0.00 0.19 ± 0.01 0.18 ± 0.02 0.16 ± 0.02
T = 50 oC 0.21 ± 0.03 0.22 ± 0.04 0.20 ± 0.01 0.20 ± 0.01 0.18 ± 0.01
T = 70 oC 0.21 ± 0.03 0.18 ± 0.01 0.20 ± 0.01 0.19 ± 0.00 0.22 ± 0.04
Refractive Index
no drying 1.4615 1.4615 1.4615 1.4615 1.4615
T = 50 oC 1.4615 1.4615 1.4615 1.4615 1.4615
T = 70 oC 1.4615 1.4615 1.4615 1.4615 1.4615
Specific Mass (g/mL)
no drying 0.9766±0.0004 0.9823 ± 0.0002 0.9990±0.0001 0.9956±0.0004 0.9900±0.0001
T = 50 oC 0.9701±0.0001 0.9802±0.0005 0.9561±0.0001 0.9652±0.0005 0.9861±0.0005
T = 70 oC 0.9800±0.0008 0.9789±0.0006 0.9799±0.0006 0.9800±0.0001 0.9834±0.0003
Appearance
no drying Liquid Clear Liquid Clear Liquid Clear Liquid Clear Liquid Clear
T = 50 oC Liquid Clear Liquid Clear Liquid Clear Liquid Clear Liquid Clear
T = 70 oC Liquid Clear Liquid Clear Liquid Clear Liquid Clear Liquid Clear
Color
no drying yellow yellow yellow yellow yellow
T = 50 oC yellow yellow yellow yellow yellow
T = 70 oC yelllow yelllow yelllow yelllow yelllow
Aroma
no drying Typical Typical Typical Typical Typical
T = 50 oC Typical Typical Typical Typical Typical
T = 70 oC Typical Typical Typical Typical Typical
Effect of the storage time and drying on chemical and physicochemical properties of cashew kernel oil Cavalcanti et al. 431
Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017
Table 3. Characterization of the cashew kernel oil with 3 drying levels stored and exposed to light.
Level of
Drying 0 days 30 days 60 days 90 days 120 days
Acidity Value
no drying 0.90 ± 0.03 1.91±0.04 2.21±0.04 2.44±0.03 2.66±0.04
T = 50 oC 0.89±0.03 1.88±0.01 2.20±0.07 2.42±0.03 2.70±0.05
T = 70 oC 0.92±0.03 1.92±0.03 2.22±0.01 2.43±0.02 2.71±0.04
Peroxide Value (%)
no drying 0.82 ± 0.02 1.53±0.02 1.80±0.03 2.51±0.05 3.98±0.08
T = 50 oC 0.80±0.03 1.51±0.03 1.81±0.03 2.58±0.08 4.02±0.06
T = 70 oC 0.81±0.04 1.50±0.03 1.82±0.03 2.54±0.03 4.06±0.04
Saponification Value (%)
no drying 197.2 ± 1.6 188.3±0.9 199.2±0.8 199.1±5.0 197.3±1.6
T = 50 oC 196.9±1.3 190.9±2.2 193.9±1.3 198.7±1.2 197.9±1.3
T = 70 oC 195.9±2.2 191.1±2.8 198.0±0.7 198.1±1.5 199.1±2.9
Unsaponifiable matter (%)
no drying 0.19 ± 0.01 0.19 ± 0.00 0.18 ± 0.01 0.21± 0.01 0.21 ± 0.02
T = 50 oC 0.19 ± 0.01 0.20 ± 0.01 0.20 ± 0.01 0.18 ± 0.02 0.22 ± 0.04
T = 70 oC 0.17±0.03 0.20 ± 0.01 0.20 ± 0.01 0.22 ± 0.04 0.19 ± 0.01
Refractive Index
no drying 1.4615 1.4615 1.4615 1.4615 1.4615
T = 50 oC 1.4615 1.4615 1.4615 1.4615 1.4615
T = 70 oC 1.4615 1.4615 1.4615 1.4615 1.4615
Specific Mass (g/mL)
no drying 0.9766±0.00
04
0.9856±0.0023 0.9888±0.000
6
0.9979±0.0006 0.9872±0.00
05
T = 50 oC 0.9701±0.00
05
0.9901±0.0069 0.9900±0.000
3
0.9888±0.0008 0.9679±0.00
01
T = 70 oC 0.9800±0.00
04
0.9896±0.0004 0.9891±0.001
1
0.9923±0.0009 0.9833±0.00
23
Appearance
no drying Liquid
Clear
Liquid Clear Liquid Clear Liquid Clear Liquid
Clear
T = 50 oC Liquid
Clear
Liquid Clear Liquid Clear Liquid Clear Liquid
Clear
T = 70 oC Liquid
Clear
Liquid Clear Liquid Clear Liquid Clear Liquid
Clear
Color
no drying yellow yellow yellow yellow yellow
T = 50 oC yellow yellow yellow yellow yellow
T = 70 oC yelllow yelllow yelllow yelllow yelllow
Aroma
no drying Typical Typical Typical Typical Typical
T = 50 oC Typical Typical Typical Typical Typical
T = 70 oC Typical Typical Typical Typical Typical
Results of the saponification value,
refractive index and specific mass are also in
agreement with the ones mentioned in the
literature, respectively given by 137 mg
KOH/g, 1.458 and 0.962 g/mL for Akinhanmi
and Akintokun (2008); and 168.3 mg KOH/g;
1.654 and 0.964 g/mL for Aremu et al. (2007).
According to the analysis of variance
(ANOVA) of the chemical and
physicochemical properties (Table 4), it can
be noticed that only the acidity and peroxide
values presented significant differences,
considering the effects along the storage period.
Furthermore it can be concluded that there are
no significant differences for the 3 variables:
drying, packaging and storage time.
Acidity value
For the statistical analyses considering
the interaction between the variables drying and
storage time, it can be observed that there was
432 Effect of the storage time and drying on chemical and physicochemical properties of cashew kernel oil Cavalcanti et al.
Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017
no influence of the drying process on the
acidity value and that it is increasing along the
storage time. More results are shown in Table 5
and the corresponding Figure 3.
Table 5. Results of the interaction, considering the variables drying and storage time for the acidity
value.
Drying treatment Storage time
(Days)
0 30 60 90 120
Without drying 0.8875 aE 1.6800 aD 1.9000 aC 2.0950 aB 2.2500 bA
Drying at 50 °C 0.8575 aE 1.6200 aD 1.8550 aC 2.1350 aB 2.3375 aA
Drying at 70 °C 0.9000 aE 1.6600 aD 1.9175 aC 2.0975 aB 2.3850 aA MSD for the columns = 0.0441 (lowercase)
MSD for the rows = 0.0627 (uppercase)
Values with the same lowercase means that there was no significant change caused by the factor luminosity; Values with
the same uppercase means that there is no significant difference between these values, because of the storage time.
aE aE aE
aD aD aD
aC aC aC
aB aB aB
bA aA aA Without drying T=50 °C T=70 °C
0 30 60 90 120
Storage time (days)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
Aci
dit
y v
alu
e (%
)
Figure 3. Histogram graphic for the acidity values, considering the interaction between the variables
drying and storage time.
According to these results it can be
noticed that only by the end of the storage, the
acidity value of the cashew kernel oil samples
that were not submitted to any drying process
presented statistical differences corresponding
by lower values; furthermore it is observed that
the acidity value is increasing along the storage
time.
For the statistical analyses considering
the interaction between the variables
packaging and storage, taking into account the
effect of the light, it was clear that the acidity
value increased along the storage time.
Another important fact is that the samples
exposed to the light always presented higher
acidity values than samples not exposed to the
light. These results are shown in Table 6 and
its corresponding histogram in Figure 4.
The increase of the acidity value was
also confirmed by Vacca et al. (2006) and
Guitierrez et al. (2001) who studied the
stability of olive oil during a storage time of
180 days, with and without exposure to the
light. In this study, the increase was caused by
hydrolyses reactions of free fatty acids (FFA).
The same phenomenon was observed by
Mendez and Falque (2005), when they were
studying the effect of the storage time and the
type of packaging on the quality of extra virgin
oil; they attributed this behavior to the
hydrolytic processes of the triglycerides.
Effect of the storage time and drying on chemical and physicochemical properties of cashew kernel oil Cavalcanti et al. 433
Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017
Table 6. Results of the interaction, considering the variables packaging and storage time for the acidity
value.
Packaging
Storage time
(Days)
0 30 60 90 120
Exposed to the
light
0.8800 aE 1.3983 bD 1.6000 bC 1.7933 bB 1.9717 bA
Not exposed to
the light
0.8833 aE 1.9083 aD 2.1817 aC 2.4250 aB 2.6767 aA
MSD for the columns = 0.0441 (lowercase)
MSD for the rows = 0.0627 (uppercase)
Values with the same lowercase means that there was no significant change caused by the factor luminosity; Values with
the same uppercase means that there is no significant difference between these values, because of the storage time.
0 30 60 90 120
Storage time (days)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
aE aE
bD
aC
bB
aB
bA
aA
bC
aD
With exposure to the light Without exposure to the light
Aci
dit
y v
alue
(%)
(%)
Figure 4. Histogram graphic for the acidity values, considering the interaction between the variables
packaging and storage time.
Peroxide value
The results of the analysis of variance
(ANOVA) of the peroxide values are presented
in Table 7.
According to Table 7 there was a
significant difference for the variables
packaging and storage. On the other hand, there
was no influence of the drying process on these
values.
Table 7. Analysis of variance of the peroxide values of the cashew kernel oil stored for 120 days.
Source. D.F. M.S.
Drying (D) 2 0.00052 ns
Packaging (P) 1 1.35788 **
Storage time (S) 4 9.13638 **
D x P 2 0.00330 ns
D x S 8 0.00373 *
P x S 4 1.50896 **
D x P x S 8 0.00085 ns
Residual 30 0.00137 **= significant at a level of 1% of probability (p < 0.01); * = significant at a level of 5% of probability (0.01 < p < 0.05); ns =
not significant (p > 0.05); D.F = Degrees of Freedom; M.S.= Mean Squares
434 Effect of the storage time and drying on chemical and physicochemical properties of cashew kernel oil Cavalcanti et al.
Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017
For the statistical analysis, considering
the interaction between the variables drying and
storage, it was observed that the peroxide
values are increasing along the storage time and
that this value wasn’t affected when cashew
kernels were submitted to the drying process,
except at the end of the storage time for the oil
samples from cashew kernels which were not
submitted to any heat treatment. The results for
these analyses are shown in Table 8 and its
corresponding histogram in Figure 5.
Table 8. Results of the interaction, considering the variables drying and storage time for the peroxide
value.
Drying treatment Storage time
(Days)
0 30 60 90 120
Without Drying 0.8300 aE 1.1950 aD 1.3475 aC 1.9775 aB 2.9650 bA
Drying at 50 °C 0.7800 aE 1.1600 aD 1.3325 aC 1.9900 aB 3.0450 aA
Drying at 70 °C 0.7825 aE 1.1725 aD 1.3450 aC 1.9950 aB 3.0600 aA MSD for the columns = 0.0644 (lowercase)
MSD for the rows = 0.0761 (uppercase)
Values with the same lowercase means that there was no significant change caused by the factor luminosity; Values with the
same uppercase means that there is no significant difference between these values, because of the storage time.
0 30 60 90 120
Storage time (days)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Per
ox
ide
val
ue
Without Drying Drying at 50 o C Drying at 70 o C
aE aE aE
aD aD aD aC aC aC
aB aB aB
bA aA aA
Figure 5. Histogram graphic for the peroxide values, considering the interaction between the variables
drying and storage time.
For the statistical analysis, considering
the interaction of packaging and storage it was
observed that the peroxide value increased
along the storage time. This increment was
always higher for samples exposed to the light.
The results of the interaction, considering the
variables Packaging and Storage time for the
peroxide value is shown in Table 9
.
Table 9. Results of the interaction, considering the variables Packaging and Storage time for the
peroxide value.
Packaging Storage time (Days)
0 30 60 90 120
Not exposed to
the light
0.7950 aD 0.8567 bCD 0.8933 bC 1.4683 bB 2.0433 bA
Exposed to the
light
0.8000 aE 1.4950 aD 1.7900 aC 2.5067 aB 4.0033 aA
MSD for the columns = 0.0437 (lowercase)
MSD for the rows = 0.0621 (uppercase)
Values with the same lowercase means that there was no significant change caused by the factor luminosity; Values with
the same uppercase means that there is no significant difference between these values, because of the storage time.
Effect of the storage time and drying on chemical and physicochemical properties of cashew kernel oil Cavalcanti et al. 435
Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017
The corresponding histogram of these results is plotted in Figure 6.
Per
ox
ide
val
ue
val
ue
0 30 60 90 120 0.0
0.5
1.0
1,5
2.0
2.5
3.0
3.5
4.0
4.5 With exposure to the light
Without exposure to the light
aD
aD
aE bCD bC
aC bB
aB
bA
aA
Storage time (days)
Figure 6. Histogram graphic for the peroxide values, considering the interaction between the variables
packaging and storage time.
The increase of the peroxide values was
also confirmed by Caro et al. (2006) and
Vacca et al. (2006) when studying the storage
and exposure influence on extra virgin olive oil
components. This rise probably occurred due
to auto-oxidation reactions of the lipids and
fatty acids. In the propagation stage all these
reactions are stopped when all the free radicals
are deactivated. Exposure to light accelerates
the kinetics of this process. Even more,
Guitierrez and Fernandez (2002) and Mendez
and Falque (2005) also added the effects of the
permeability of the packaging as an important
factor, when they studied the storage
parameters of some vegetable oils, confirming
in this way the increase of the peroxide values.
Oxygen accelerates the production as well as
the decomposition of hydro peroxides into
volatile compounds of low molecular weight,
responsible for the unpleasant aroma and taste.
At the other side, the light also catalysis
the photo-oxidation, reason why samples
exposed to the light presented higher
increments than the other ones not exposed.
Saponification value and unsaponifiable
matter
According to the analysis of variance of
the Saponification value and Unsaponifiable
matter, considering the different drying levels
as well as the 3 effects (variables: drying,
packaging and storage) there was no
significant difference at the interactions of
these variables. These results were also
observed by Morello et al. (2004), when
studying the modifications of olive oil during
its storage with and without exposure to the
light for a period of 12 months. The results of
these interactions are presented in the Tables
10 and 11.
Table 10. Analysis of variance of the saponification values of the cashew kernel oil stored for 120 days.
Source D.F. M.S.
Drying (D) 2 3.25617 ns
Packaging (P) 1 9.92267 ns
Storage time (S) 4 32.87642 **
D x P 2 11.34117 ns
D x S 8 5.74242 ns
P x S 4 9.56392 ns
D x P x S 8 5.62242 ns
Residual 30 3.63133 **= significant at a level of 1% of probability (p < 0.01); ns = not significant (p > 0.05); D.F = Degrees of Freedom; M.S.=
Mean Squares.
436 Effect of the storage time and drying on chemical and physicochemical properties of cashew kernel oil Cavalcanti et al.
Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017
Table 11. Analysis of variance of the unsaponifiable matter of the cashew kernel oil stored for 120
days.
Source D.F. M.S.
Drying (D) 2 0.00100 ns
Packaging (P) 1 0.00008 ns
Storage time (S) 4 0.00007 ns
D x P 2 0.00092 ns
D x S 8 0.00022 ns
P x S 4 0.00056 ns
D x P x S 8 0.00074 ns
Residual 30 0.00039 ns = not significant (p > 0.05); D.F = Degrees of Freedom; M.S.= Mean Squares
Specific mass
According to the analysis of variance of the specific mass (Table 12) there was a significant
difference for all the effects (variables), nevertheless it was impossible to establish any tendency or
correlation between these values and the effects.
Table 12. Analysis of variance of the specific mass of the cashew kernel oil stored for 120 days.
Source D.F. M.S.
Drying (D) 2 0.00056 **
Packaging (P) 1 0.00035 **
Storage time (S) 4 0.00021 **
D x P 2 0.00020 **
D x S 8 0.00012 **
P x S 4 0.00022 **
D x P x S 8 0.00013 **
Residual 30 0.00000 ** **= significant at a level of 1% of probability (p < 0.01); D.F = Degrees of Freedom; M.S.= Mean Squares
As can be observed in Figure 7, the
values are spread between 0.9678 and 0.9991
g/mL, which could possibly be caused by
experimental or random errors.
0 30 60 90 120
0.90
0.91
0.92
0.93
0.94
0.95
0.96
0.97
0.98
0.99
1.00
With exposure to the light
Without drying
T=50 °C T=70 °C
Without exposure to the light
Without drying
T=50 °C
T=70 °C
Spec
ific
mas
s (g
.mL
-1)
Time (days)
Figure 7. Dispersion graph of the specific mass values of the cashew kernel oil along the storage time.
Effect of the storage time and drying on chemical and physicochemical properties of cashew kernel oil Cavalcanti et al. 437
Revista Brasileira de Produtos Agroindustriais, Campina Grande, v.19, n.4, p.427-437, 2017
CONCLUSIONS
The pre-treatment of the cashew kernels
by drying at a temperature of 50 and 70 oC
didn’t affect the physicochemical properties of
the oil;
The peroxide and acidity values
increased along the storage time of 120 days;
Exposure to light resulted in a
significant increase of the peroxide and acidity
values;
The other properties (color, appearance
and aroma) were not affected by the operational
conditions of this experiment;
Considering the International Food
Safety Regulations, the cashew kernel oil can
be included in the list of other commercial
vegetable oils, because of its nutritional aspects
and stability.
LITERATURE CITED
Akinhanmi, T.F.; Akintokun, P.O. Chemical
composition and physicochemical properties
of cashew nut (Anacardium occidentale) oil
and cashew nut shell liquid. Agricultural,
Food and Environmental Sciences, n.2,
p.1-7, 2008.
AOAC. Official methods of analysis of AOAC
International (19th ed.), Gaithersburg, M.D.
USA. 2012.
AOCS. 2006. American Oil Chemists’ Society,
Official Methods and Recommended
Practices of the American Oil Chemits’
Society, 4th ed, Champaign, USA.
Aremu, M.O., Ogunlade, I.; Olonisakin, A.
2007. Fatty acid and amino acid composition
of protein concentrate from cashew nut
grown in Nasarawa State, Nigeria. Pakistan
Journal of Nutrition, 6, 419-423.
Caro, A., Vacca, V., Poiana, M., Fenu, P. and
PIGA, A. 2006. Influence of technology,
storage and exposure on components of
extra virgin oil (Bosana cv) from whole and
de-stoned fruits. Journal of Food
Engineering, 98, 311-316.
FAO. 2005. Food and Agriculture Organization
of the United Nations. Commodities and
trade technical paper. Small Island
Developing States Agricultural Production
and Trade, Preferences and Policy. Rome.
Gutiérrez, F., Arnaud, T. and Garrido, A. 2001.
Contribution of poliphenols to the oxidative
stability of virgin olive oil. Journal of the
Science of Food and Agriculture, 81, 1463-
1470.
Gutiérrez, F., Fernández, J. L. 2002.
Determinant parameters and components in
storage of virgin olive oil. Prediction of
storage time beyond which the oil is no
longer of extra quality. Journal of
Agricultural and Food Chemistry, 50, 571–
577.
Holanda, L.F.F. 1988. Cashew kernel
(Anacardium occidentale L.): a mechanical
process for extracting the almonds. Thesis
(Titular Professor) – Department of Food
Technology, CCA, Federal University of
Ceará, Fortaleza, CE, Brazil.
Lima, A.C., Garcia, N.H.P. and Lima, J.R.
2004. Preparation and characterization of
the main products of cashew. B.CEPPA,
Curitiba, 28, 281-288.
Mendez, A.I. and Falque, E. 2005. Effect of the
storage time and container type on the
quality of extra-virgin oil. Food Control, 18,
521-529.
Morello, J., Motilva, M., Tovar, M. and
Romero, M. 2004. Changes in commercial
virgin olive oil (cv Arbequina) during
storage, with special emphasis on the
phenolic fraction. Journal of Food
Engineering, 85, 357-364.
Paula Pessoa, P.F.A., Paiva, F.F.A., Silva Neto,
R.M.and Leite, L.A.S. 2003. Cashew.
Starting a small profitable agribusiness:
cashew kernel. SEBRAE/EMBRAPA, 1, 11-
38.
Silva, F.A.S. and Azevedo, C.A.V. 2006. A
new version of the Assistat -Statistical
Assistance Software. In: World Congress on
Computers in Agriculture, Orlando.
Proceedings... Reno, RV: American Society
of Agricultural and Biological Engineers,
393-396.
Vacca, V., Caro, A., Poiana, M. and Piga, A.
2006. Effect of storage period and exposure
conditions on the quality of Bosana extra-
virgin-oil. Journal of Food Quality, 29, 139-
150.
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