Food and Nutrition Sciences, 2015, 6, 869-874
Published Online July 2015 in SciRes. http://www.scirp.org/journal/fns
How to cite this paper: Aguiar, J.P.L. and Souza, F.C.A. (2015) Antioxidants, Chemical Composition and Minerals in
Freeze-Dried Camu-Camu (Myrciaria dubia (H.B.K.) Mc Vaugh) Pulp. Food and Nutrition Sciences, 6, 869-874.
Antioxidants, Chemical Composition
and Minerals in Freeze-Dried Camu-Camu
(Myrciaria dubia (H.B.K.) Mc Vaugh) Pulp
Jaime Paiva Lopes Aguiar*, Francisca das Chagas do Amaral Souza
Coordination Society Environment and Health—CSAS, National Institute for Amazonian Research—INPA,
Received 3 June 2015; accepted 19 July 2015; published 22 July 2015
Copyright © 2015 by authors and Scientific Research Publishing Inc.
This work is licensed under the Creative Commons Attribution International License (CC BY).
Camu-camu (Myrciaria dubia (H.B.K.) Mc Vaugh) is a fruit native to the Amazon region and is con-
sidered the greatest natural source of vitamin C worldwide. It is also a promising source of many
phenolic compounds, including flavonoids and anthocyanins. Given the growing rates of chronic
non-communicable diseases such as dyslipidemia, obesity and diabetesworldwide, freeze-dried
camu-camu can be used for its functional properties, which can reduce the incidence of these dis-
eases. Hence, the objective of this study was to produce freeze-dried camu-camu pulp and present
it as an alternative functional food because of its high production and use potential, adding value
to this fruit in particular, not very demanded by the food industry. Freeze-dried camu-camu pulp
is a pink, homogeneous powder with great antioxidant capacity, 52,000 µmol TE/g, six times
greater than freeze-dried acai powder. It is also very rich in vitamin C (20.31 g/100g), potassium
(796.99 mg/100g), carbohydrates (47.00 g/100g), dietary fiber (19.23 g/100 g), many amino acids,
other vitamins, and anthocyanins (0.739 mg/g). The camu-camu freeze-drying process is an effec-
tive alternative way to preserve the fruit, preserving its macronutrient and vitamin C contents.
Camu-camu is also an excellent source of other bioactive compounds, such as minerals and other
phenolic compounds. In conclusion, camu-camu can be used to introduce bioactive compounds
into food products and to delay or prevent many human diseases.
Functional Foods, Ascorbic Acid, Freeze Drying, Antioxidant Capacity
J. P. L. Aguiar, F. C. A. Souza
The Amazon has numerous potentially lucrative plant species, and camu-camu (Myrciaria dubia (H.B.K.) Mc
Vaugh) stands out among them. Camu-camu is a wild fruit from the family Myrtaceae. It occurs in the margins
of Amazonian rivers and lakes, but it is not well known in the rest of Brazil . However, great volumes of ca-
mu-camu have been exported to Japan and the United States of America (USA). Camu-camu is a round fruit
with a diameter of 2 to 4 centimeters, and smooth and shiny skin. Its mean weight is 8.4 grams. The color varies
from dark red to purplish-black when ripe. Each fruit has one to four, more commonly two to three, kidney-
shaped, ellipsoid seeds covered with fibril filaments . Interest in camu-camu has grown because of its notable
vitamin C content, varying from 1600 to 2994 mg/100g of pulp  Even higher concentrations were found by in
three camu-camu batches from east Roraima, 3571 to 6112 mg/100g of pulp, making it the fruit with the highest
vitamin C content in the world .
Despite the discovery and dissemination of the high ascorbic acid content of camu-camu and its adaptability
to solid ground, this fruit is not yet widely consumed by the general population, and its demand by the food in-
dustry is low. One of the factors that hinder its consumption is the extreme acidity of the pulp and bitterness of
the skin, so studies are necessary to increase camu-camu use. It is important to develop new products that pre-
serve camu-camu’s nutritional quality and simultaneously have a reasonable shelflife without the need of adding
considerable amounts of preservatives. Thus, the present study produced freeze-dried camu-camu pulp and
presents it as a new functional food with high production and use potentials, adding value to a fruit that is lowly
demanded by the food industry.
2. Material and Methods
The study camu-camu was collected manually during the commercial ripening stage in Rio Branco, Roraima
(RR), in a region called Santa Izabel de Boiaçú, municipality of Rorainópolis, RR, with the following geograph-
ic coordinates: 0˚23'27.3"S to 61˚48'22.5"W. The fruits were placed in sterile plastic bags and transported to the
Physical and Chemical Food Laboratory (LFQA) of the Society, Environment, and Health Coordination (CSAS)
of the National Research Institute of Amazônia (INPA).
The excessively ripe fruits and those with sanitary or mechanical injuries were discarded. The remainder were
rinsed with running water, immersed in 10% sodium hypochlorite for 30 minutes, and then rinsed again with
potable water. The pulps were extracted by an automatic pulp ejector (Itametal, mesh of 1.5 mm). The extracted
pulps were immediately placed on stainless steel trays, frozen to −80˚C, and dried by the lyophilizer SP Scien-
tific model 25 L GENESIS, at a working temperature of −70˚C to produce freeze-dried camu-camu pulp powder
(Figure 1). All freeze-dried samples were homogenized in a blender before the physical and chemical analyses
to quantify minerals, amino acids, lipids, some vitamins, and antioxidants.
2.2. Sample Preparation
The moisture, ash, protein, lipid, and carbohydrate contents of the freeze-dried powder were analyzed three
times as recommended by Instituto Adolfo Lutz , and amino acids also three times as recommended by
Schuster . Moisture was determined by drying the sample in an incubator at 105˚C until the weight of the
sample became constant; ash content was determined by incineration; lipids were analyzed by Soxhlet extraction;
protein content was determined by the Kjeldahl’s method; soluble and insoluble fiber contents were determined
by the method proposed by Asp et al.  and carbohydrate content was given by subtracting all other weights
from the total weight. Energy content was calculating by multiplying the carbohydrate, protein, and lipid con-
tents in grams by 4, 4, and 9 kcal/g, respectively . Ph was measured by a digital potentiometer (Micronal,
model B474). Vitamin C content was measured three times by high-performance liquid chromatography (HPLC)
following the method proposed by Maeda et al. . Anthocyanins and vitamin B12 were determined as recom-
mended by the American Organization of Analytical Chemists . Calcium, sodium, potassium, magnesium,
manganese, iron, zinc, and copper contents were determined by digesting the sample (CEM Coorporation, mod-
el MD-2591) and reading the solution with an atomic absorption spectrometer (Variam Spectra AA, model 220
J. P. L. Aguiar, F. C. A. Souza
Figure 1. Camu-camu fruits on the plant for processing (a); extracted pulp for freeze-drying (b); and freeze-dried camu-camu
2.3. Antioxidant Capacity
Antioxidant capacity was determined as recommended by Brand-Williams, Cubelier, and Berset  using
2,2-dyphenyl-picrylhydrazil (DPPH). Ten grams were extracted with 100 ml of 60% ethanol under constant stir-
ring at 30˚C for 24 hours. The extracts were filted by filter paper number one and the fluid portions were ana-
lyzed for antioxidant content. The absorbance was read three times at 515 nm, and the antioxidant capacity was
calculated as µmol of Trolox equivalents (TE) per gram. The results were described descriptively and the con-
tents were expressed as mean ± standard deviation (SD).
3. Results and Discussion
Table 1 shows that freeze-dried camu-camu has a high concentration of vitamin C, approximately 20.31 g/100g,
naturally much higher than that in fresh pulp (between 2.0 and 6.5 g/100g). Vitamin C content in camu-camu
was also higher than in other traditional Brazilian fruits, such as acerola (1357.0 ± 9.5 mg/100g of fresh fruit)
and acai (84.0 ± 10 mg/100g of fresh fruit) . Soluble and insoluble fiber contents are also very high, making
camu-camu a good natural source of these nutrients. Studies have shown that high-fiber diets have great thera-
peutic potential against dyslipidemia, cardiovascular diseases, and some types of cancer . Fibers also de-
crease intestinal transit time and glucose absorption, with consequent lowering of glycemia and blood cholester-
ol. Potassium was the most abundant mineral in freeze-dried camu-camu, with a concentration of 796.99
mg/100g. Calcium is usually low in Amazonian diets. Freeze-dried camu-camu can help Amazonians to achieve
their recommended calcium intake.
In addition to these components, camu-camu has high levels of phenolic compounds, such as flavonoids and
anthocyanins. Freeze-dried camu-camu has an anthocyanin content of 0.739 mg/g and flavonoids of 16.93
mg/100g. However, Reynertoson et al.  found that the total anthocyanin content of freeze-dried camu-camu
powder was very low (0.01 mg/g of dry weight), varying greatly. This variation may be attributed to the fact that
J. P. L. Aguiar, F. C. A. Souza
Table 1. Nutritional composition of freeze-dried camu-camu pulp.
Moisture (g/100g) 94.1 ± 0.1
Protein (g/100g) 6.65 ± 0.14
Ash (g/100g) 3.67 ± 0.21
Crude fiber (g/100g) 19.23 ± 0.00
Soluble fiber (g/100g) 11.11 ± 0.00
Insoluble fiber (g/100g) 8.12 ± 0.00
Lipids (g/100g) 0.98 ± 0.07
Carbohydrates (g/100g) 47.00 ± 0.00
Vitamin C (g/100g) 20.31 ±0.04
Sodium (mg/100g) Tr*
Potassium (mg/100g) 796.99 ± 43.94
Calcium (mg/100g) 22.12 ± 2.54
Magnesium (mg/100g) 33.47 ± 1.30
Iron (mg/100g) 2.23 ± 0.12
Manganese (mg/100g) 1.29 ± 0.08
Zinc (mg/100g) 1.26 ± 0.07
Copper (mg/100g) 0.84 ± 0.03
pH 2.61 ± 0.02
Antioxidant capacity (µmol TE/g) 52.000
Vitamin B 12 (µg/g) 0.0034
Anthocyanins (µg/g) 0.739
Flavonoids (mg/100g) 16.93
camu-camu is a deciduous fruit, that is, the pigments are predominantly found in the skin, hence removing the
skin results in smaller extractions. The degree of ripeness is another variable that affects anthocyanin levels.
Macheix et al.  found a higher concentration of phenolic compounds in the skin than in the pulp.
Table 1 shows that freeze-dried camu-camu has extremely high antioxidant activity, 52,000 µmol TE/g, six
times more than freeze-dried acai. The ripening process is a critical variable in camu-camu bioactive properties,
especially with respect to its reduction potential. These results agree with the antioxidant activity measured dur-
ing ripening. The antioxidant potential may be related to the phenolic composition of the extracts, but other
components may also make an important contribution.
4. Amino Acid Profile
Table 2 shows the amino acid contents of freeze-dried camu-camu expressed as g/100g of sample. Table 2 lists
some essential amino acids. The most abundant amino acids in camu-camu are arginine (0.692 g/100g) and glu-
tamic acid (0.619 g/100g). The lysine content (0.196 g/100g) in camu-camu is similar to that of wheat flour
(0.11%), one of the most important plant sources of this amino acid. Despite the great variety of amino acids
found in camu-camu, it is not possible to consider it a good protein source because its total protein content of
3.86% is similar to that of other dried fruits amendoim (3.1%), nozes (2.3%).
Camu-camu fruits are excellent sources of different bioactive compounds, such as vitamin C, fibers, minerals,
J. P. L. Aguiar, F. C. A. Souza
Table 2. Amino acids present in freeze-dried camu-camu expressed as g/100g of sample.
Amino acid Content Amino acid Content
Aspartic acid 0.375 Leucine 0.219
Threonine 0.124 Tyrosine 0.141
Serine 0.228 Phenylalanine 0.128
Glutamic 0.619 Lysine 0.196
Proline 0.168 Histidine 0.110
Glycine 0.229 Arginine 0.692
Alanine 0.180 Cystine 0.101
Valine 0.176 Methionine 0.058
Isoleucine 0.124 Total 3.868
and phenolic compounds. Camu-camu fruits show high antioxidant capacity as compared to other fruits. In con-
clusion, camu-camu fruits can be used to increase the amount of bioactive compounds in food products and to
delay or prevent many human diseases.
The authors thank the financial support of Conselho Nacional de Desenvolvimento Científico e Tecnológico
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