Major physicochemical and antioxidant changes during peach-palm (Bactris gasipaes H.B.K.) flour processing

Abstract

Introduction. Several studies have demonstrated that food processing affects nutrients such as bioactive compounds, protein, starch, fat, fiber, minerals and antioxidant capacity. Our study examined how heat changes the physicochemical composition and antioxidant capacity of peach-palm fruit (Bactris gasipaes H. B. K.) during flour production. Materials and methods. Five commercial batches of fruit were assessed for total contents of phenolic compounds and carotenoids, and hydrophilic oxygen radical absorbance capacity (H-ORAC). The fruit was then cooked and eventually processed into flour. Results and discussion. No significant changes were found for contents of fat, protein, starch and dietary fiber during flour production. Cooked peach-palm fruit is a source of Mg, Mn, Cu and K, with 100 g of fruit containing between 5% and 13.5% of the recommended daily intake. Cooking also increased carotenoids by 17%, thus helping to compensate for the 28% loss during drying. No stage of processing affected polyphenol contents or H-ORAC. Conclusion. Because of its high bioactive compound content, peach-palm flour shows potential for use in the development of functional foods.

Full text

Original article
Fruits, vol. 67 (6) 1
Major physicochemical and antioxidant changes during peach-palm (Bactris
gasipaes H.B.K.) flour processing.
Abstract – Introduction. Several studies have demonstrated that food processing affects
nutrients such as bioactive compounds, protein, starch, fat, fiber, minerals and antioxidant
capacity. Our study examined how heat changes the physicochemical composition and
antioxidant capacity of peach-palm fruit (Bactris gasipaes H.B.K.) during flour production.
Materials and methods. Five commercial batches of fruit were assessed for total contents of
phenolic compounds and carotenoids, and hydrophilic oxygen radical absorbance capacity
(H-ORAC). The fruit was then cooked and eventually processed into flour. Results and dis-
cussion. No significant changes were found for contents of fat, protein, starch and dietary
fiber during flour production. Cooked peach-palm fruit is a source of Mg, Mn, Cu and K, with
100 g of fruit containing between 5% and 13.5% of the recommended daily intake. Cooking
also increased carotenoids by 17%, thus helping to compensate for the 28% loss during
drying. No stage of processing affected polyphenol contents or H-ORAC. Conclusion.
Because of its high bioactive compound content, peach-palm flour shows potential for use in
the development of functional foods.
Costa Rica / Bactris gasipaes / fruits / processing / drying / proximate
composition / carotenoids / polyphenols / antioxidants
Principales modifications physico-chimiques et antioxydantes au cours de la
fabrication de farine de pejibaie (Bactris gasipaes H.B.K.).
Résumé –Introduction. Plusieurs études ont montré que la transformation des aliments
affectait les nutriments tels que les composés bioactifs, protéines, amidon, graisses, fibres,
minéraux, et la capacité antioxydante. Notre étude a examiné comment la chaleur modifiait la
composition physico-chimique et la capacité antioxydante des fruits de pejibaie (Bactris gasi-
paes HBK) au cours de la production de farine. Matériel et méthodes. Cinq lots commer-
ciaux de fruits ont été évalués pour leur contenu total en composés phénoliques et
caroténoïdes, et leur capacité hydrophile d’absorption des radicaux oxygénés (H-ORAC). Les
fruits ont ensuite été cuits et éventuellement transformés en farine. Résultats et discussion.
Aucun changement significatif n’a été trouvé quant au contenu des fruits en matières grasses,
protéines, amidon et fibres alimentaires durant la production de farine. Le fruit de pejibaie
cuit est une source de Mg, Mn, Cu, et K, dont 100 g de fruits contiennent entre 5 % et 13,5 %
de l’apport quotidien recommandé. La cuisson a permis également d’augmenter de 17 % la
teneur en caroténoïdes, ce qui contribue à compenser la perte de 28 % observée au cours lors
du séchage. Aucune étape de la transformation n’a affecté les teneurs en polyphénols ou la
valeur de H-ORAC. Conclusion. En raison de sa haute teneur en composés bioactifs, la
farine de pejibaie est potentiellement intéressante à utiliser pour le développement d’aliments
fonctionnels.
Costa Rica / Bactris gasipaes / fruits / traitement / séchage / composition
globale / caroténoïde / polyphénol / antioxydant
1CITA-UCR, 11501–2060 San
José, Costa Rica,
carolina.rojasgarbanzo@ucr.ac.
cr, ana.perez@ucr.ac.cr
2Esc. Tecnol. Aliment., UCR,
11501–2060 San José, Costa
Rica,
maria.pinedacastro@ucr.ac.cr
3CIRAD-Persyst UMR 95
Qualisud, TA B-95 / 16, 73 rue
Jean-François Breton, F-34398
Montpellier cedex 5, France,
fabrice.vaillant@cirad.fr
Major physicochemical and antioxidant changes during peach-
palm (Bactris gasipaes H.B.K.) flour processing
Carolina ROJAS-GARBANZO1*, Ana Mercedes PÉREZ1, María Lourdes Pineda CASTRO2, Fabrice VAILLANT3
* Correspondence and reprints
Received 30 November 2011
Accepted 9 February 2012
Fruits, 2012, vol. 67, p. 1–13
© 2012 Cirad/EDP Sciences
All rights reserved
DOI: 10.1051/fruits/2012035
www.fruits-journal.org
RESUMEN ESPAÑOL,p.13

2Fruits, vol. 67 (6)
C. Rojas-Garbanzo et al.
1. Introduction
Recent studies have demonstrated that
many traditional foods contain components
that may benefit health. The intake of these
components, present in fruits and vegeta-
bles, inversely correlates with the incidence
of degenerative diseases such as diabetes,
cardiovascular diseases, coronary heart dis-
eases, macular degeneration, certain can-
cers, and age-related cataracts [1–5]. Even
so, deficiencies of micronutrients such as
iron affect one-third of the world’s popula-
tion [3]. Research on deficiencies and the
positive properties of these compounds has
led to recommendations for increased con-
sumption of fruits and vegetables rich in bio-
active compounds [3].
Antioxidant compounds in foods include
vitamins, minerals (e.g., Se and Zn), natural
pigments (carotenoids and anthocyanins),
tocopherols, and other plant compounds.
These compounds can slow down or pre-
vent the oxidation of organic molecules by
reducing chemical reactions involving oxy-
gen. They can neutralize the oxidative
action by scavenging reactive oxygen spe-
cies (ROS) and reactive nitrogen species
(RNS), or preventing their generation [6, 7].
Although the tropics produce numerous
edible fruits, their consumption is limited,
despite their high contents of bioactive com-
pounds. Low availability, lack of invest-
ment, and poor knowledge of production
systems or conservation issues are related to
the low use of tropical fruits for direct con-
sumption or by food-processing industries
[3].
In food technology, controlling free rad-
icals is important for preventing oxidation
and the development of rancidity. Lipid per-
oxidation gives rise to chemical compounds
that cause unpleasant aromas and flavors,
which can be prevented by using antioxi-
dants such as carotenoids [8]. Likewise,
polyphenols — compounds that have
proven antioxidant activity — influence the
quality of beverages by imparting bitterness
or astringency, significantly affecting texture
and mouth feel [9]. Thus, food processing
may play an important role in preserving
and enhancing the bioavailability of bioac-
tive compounds [10].
However, microwaving, blanching, boil-
ing, deep-frying and baking usually result in
substantial losses of carotenoids [11]. Apply-
ing or removing heat can also transform
fruits and vegetables by changing their con-
tent of bioactive compounds and their anti-
oxidant capacity [12]. Such effects suggest
that the contents of bioactive compounds
will also change in peach-palm fruit when
it is processed into flour.
Bactris gasipaes H.B.K. is also known as
pejibaye in Costa Rica, chontaduro in Ven-
ezuela, pibá in Panamá, pupunha in Brasil,
and peach-palm in English-speaking coun-
tries [13]. Native to the American tropical
rainforests, this palm produces abundant
fruit that is nutritionally probably the most
balanced of the tropical fruits. A promising
source of antioxidant compounds such as
carotenoids and polyphenols [13–15], the
fruit also has high nutritional value in terms
of high fiber and β-carotene contents; high
starch and fat levels, and therefore high
energy content [16]; high mineral contents
(e.g., Se and Zn); and low sodium and sugar
levels [17].
The fruit thus represents a highly inter-
esting opportunity [7, 14] for exploiting its
nutritional composition and high accepta-
bility to prevent major diseases caused by,
for example, vitamin A deficiency, which
affects the Costa Rican population [18]. Yet,
despite its nutritional qualities, peach-palm
fruit is underused.
To promote peach-palm fruit as a regular
component of the diet, ways must be found
to develop stable products such as flour that
conserve the fresh fruit’s nutritive value.
Such products must also be easily stored and
sold at accessible prices. Peach-palm flour
is an excellent product from which a wide
range of products can be developed and
marketed [14].
The physicochemical characteristics of
peach-palm fruit have already been described
[3, 10, 18], but its characterization should be
expanded to include contents of bioactive
compounds. Components such as caroten-
oids and fiber define peach-palm fruit as a
functional food [10, 18], These findings must

Changes during peach-palm flour processing
Fruits, vol. 67 (6) 3
be complemented by determining the fruit’s
antioxidant capacity.
Our study examines the changes in phys-
icochemical composition and bioactive com-
pound contents (Zn, carotenoids, polyphe-
nols and dietary fiber) that occur in peach-
palm fruit when it undergoes processing into
flour. Such processing involves the critical
steps of cooking and drying; that is, heat
treatment.
2. Materials and methods
2.1. Raw material
Five batches of 60 kg of fruit each were har-
vested in Tucurrique, Costa Rica
(9°59’40” N; 83°36’14” W) from a random
selection of different palms and bunches
growing in a plantation located 703 m
above sea level, with an average tempera-
ture of 23 °C. The individual fruits them-
selves were selected according to color
(orange to red), ensuring that both scratches
and microbiological deterioration were
absent.
2.2. Processing of peach-palm fruit
Peach-palm flour was processed at a pilot
level, as described by Rojas-Garbanzo et al.
[14]. Each batch was cleaned and disinfected
with a solution of 100 mg sodium hypochlo-
rite (NaClO)·L–1 for 15 min. The fruit was
then cooked in boiling water for 30 min,
cooled, and peeled and deseeded manually.
After slicing (0.25-mm thick slices), the fruits
were dried at 72 °C to a 10% moisture con-
tent in a conventional oven, milled (0.084-
cm mesh opening), and vacuum-packed
into aluminum bags to prevent deterioration
before analysis.
2.3. Reagents
Reagents were obtained from J.T. Baker
(México) as follows: sulfuric acid, boric acid,
sodium and potassium hydroxides, metha-
nol, acetone, ethyl ether and hexane, all at
reagent grade. Other reagents, obtained
from Sigma-Aldrich Co., LLC (St. Louis, MO,
USA), were α-amyloglucosidase (EC 3.2.1.3),
glucoxidase, glucose, sodium carbonate,
gallic acid, Folin–Ciocalteu reagent, 6-
hydroxy-2,5,7,8-tetramethylchroman-2-car-
boxylic acid (Trolox), sodium fluorescein,
2,2′-azobis (2-amidinopropane) dihydro-
chloride (AAPH), monobasic and dibasic
sodium phosphates, and Total Dietary Fiber
Kit TDF-100A (heat-stable α-amylase, amy-
loglucosidase and protease).
2.4. Chemical analysis
2.4.1. Chemical composition
Moisture, fat, protein, dietary fiber, ash, sol-
uble solids, total acidity and pH contents
were determined by using standard AOAC
methods; that is, 920.151, 991.20, 920.152,
985.29, 940.26, 932.12, 942.15 and 981.12,
respectively [19]. The minerals P, Ca, Mg, K,
S, Na, Fe, Cu, Zn, Mn and B were analyzed
by atomic absorption spectrophotometry, as
described by Jones et al. [20]. Nitrogen was
analyzed by dried combustion as described
by Schweizer et al. [21]. Starch content was
determined as described by Southgate [22].
2.4.2. Total carotenoid content
Carotenoids were extracted from 5-g sam-
ples according to methods described by
Schiedt and Liaaen-Jensen, and Rojas-Gar-
banzo et al. [14, 23]. The analysis was con-
ducted with a UV-visible spectrophotometer
(Shimadzu UV-1700 PharmaSpec, Kyoto,
Japan), using a wavelength of 450 nm. Total
carotenoid content was calculated, using an
extinction coefficient of 2500 for a 1% n-hex-
ane solution, and expressed as micrograms
(µg) of β-carotene equivalents per gram (dry
weight).
2.4.3. Preparation of the acetone
extracts for total polyphenol content
and antioxidant capacity
The acetone extracts were prepared accord-
ing to Georgé et al. [7]. Samples (3 g) of
peach-palm fruit were homogenized with
20 mL of acetone solution (at 70/30 of dis-
tilled water) in a 25-mL Erlenmeyer flask
covered with aluminum foil. The mixture

4Fruits, vol. 67 (6)
C. Rojas-Garbanzo et al.
was then gently agitated for 10 min in a mag-
netic agitator and ultrasonic bath, and trans-
ferred to a 50-mL volumetric flask, filtering
it through a Whatman No. 41 filter paper.
2.4.4. Total polyphenol content
Total polyphenols were determined, using
the Folin–Ciocalteu spectrophotometric
method as described by Georgé et al. [7].
Gallic acid was used as the standard, and
ascorbic acid and reducing sugar interfer-
ences were eliminated by using OASIS®car-
tridges (Waters Corporation, Milford, MA,
USA). Absorbance was measured with a UV-
visible spectophotometer (Shimadzu UV-
1700 PharmaSpec, Japan), using a wave-
length of 765 nm against a reagent blank.
The polyphenols were quantified, using the
external calibration curve of gallic acid with
a linearity range of 10–80 mg gallic acid
Eq·L–1. Good correlation was obtained
(r2= 0.9996), reporting the concentration of
total polyphenols as milligrams (mg) of gal-
lic acid equivalent (GAE) per 100 g (dry
weight).
2.4.5. Hydrophilic antioxidant capacity
Hydrophilic oxygen radical absorbance
capacity (H-ORAC) was determined as
described by Huang et al. [24]. The assays
were conducted on a spectrofluorometer
(Synergy HT, BioTek Instruments, Inc.,
Winooski, VT, USA), using fluoroscein as an
indicator of peroxyl radical damage. The
excitation wavelength was set at 493 nm
and emission wavelength at 515 nm. The H-
ORAC was expressed as micromoles (µmol)
of Trolox equivalents (TE) per gram (dry
weight), using an external calibration curve
of Trolox (4.0-32.3 µmol TE·L–1) with good
correlation (r2= 0.9993).
2.4.6. Color
Color was determined with a HunterLab
colorimeter (2° standard observer angle and
illuminant C; Hunter Associates Laboratory
Inc., Reston, VA, USA). Color was expressed
as L*,a* and b* values. The parameters hue
(h*), chroma (c*) and total color difference
(ΔE*) were obtained, as described by
Gonnet [25]: h= tan–1 (b* /a*);
c=[(a*)2+(b*)2]1/2;ΔE*=[(∆L*)2+(∆c*)2
+(∆h*)2]1/2.
2.4.7. Statistical analysis
To evaluate the effects of different stages of
flour production on the physicochemical
composition, bioactive compounds and
antioxidant capacity of peach-palm fruit,
five replications were performed. The study
followed a randomized complete block
design, with three treatments (raw and cooked
peach-palm fruit, and peach-palm flour).
Significant differences between treatments
were determined by performing an ANOVA
(α= 0.05) and Tukey’s test, using JMP 4.1
software (SAS, Cary, NC, USA). Data were
expressed as the mean ± standard deviation.
3. Results and discussion
3.1. Effects of flour production on
physicochemical composition
3.1.1. Macronutrients
After cooking, moisture content increased
significantly by 5% (table I). Peach-palm
fruit was in direct contact with water, which
softened cell walls, facilitating water transfer
to the pulp [13]. This allowed carbohydrates
such as starch, cellulose and hemicellulose
to absorb water during cooking [26]. Mois-
ture content in raw and cooked peach-palm
pulp was therefore significantly different
(p> 0.05) at (56 ± 5) g·100 g–1 and
(59 ± 4) g·100 g–1, respectively.
The flour, however, was dried to a final
moisture content of (13 ± 3) g·100 g–1,to
comply with the standard CODEX STAN 152-
1985 for wheat flour [27]. As expected, dry-
ing decreased the moisture content of
peach-palm flour by 78%. Low moisture
content allows long shelf life, as both micro-
biological growth and deterioration from
enzymatic reactions are less likely to occur [28].
Fat, protein, ash and starch contents were
not significantly affected by cooking and
drying during flour production. These
results differ from those of Fernández et al.
and Clement [26, 29], who reported fat content
as decreasing by more than 20% during
cooking. The melting point of fatty acids is

Changes during peach-palm flour processing
Fruits, vol. 67 (6) 5
40 °C, with the fatty acids transferring, as a
surface layer, to water [26]. In our study, fat
content did not change (p> 0.05) during
flour production; the configuration of fatty
acids may have changes [13].
Protein content did not change after
cooking and drying (p> 0.05). Peach-palm
fruit, being fruit, was expected to have a low
content of this constituent. Even so, the val-
ues for both fruit and flour showed an inter-
esting nutritional level at (5.0 ± 1.0) g·100 g–1
(dry weight)1. Although this level is lower
than in legumes such as pea, chickpea, lentil
and bean [ranging from (17 to 30) g·100 g–1
dw] [30], world protein requirements are
such that it continues to be a global issue,
with heightened concerns about food secu-
rity and protein malnutrition [30]. Peach-
palm fruit can therefore function as a sup-
plementary food towards achieving the
daily recommended protein intake.
Cooked peach-palm fruit is a traditional
snack. A serving of two cooked peach-
palm fruits (peeled and seeded), with an
average mass of 50 g, can supply about
4.3% of a person’s daily protein needs,
according to the FDA1. This fruit also has
the advantage of supplying eight of the
ten amino acids that are essential in the
adult diet [17].
The starch content of cooked peach-
palm fruit was (68 ± 4) g·100 g–1 dw, not
being significantly different (p> 0.05) to
that of flour (table I). Keeping starch con-
tent constant is essential for products
where starch influences sensory charac-
teristics.
Soluble solids, total acidity and pH vari-
ables were not significantly affected by the
cooking process (p> 0.05). Such results
enable these components to be used as
quality control parameters during peach-
palm flour production.
3.1.2. Micronutrients
The results obtained when producting
peach-palm flour showed that heat treat-
ment had no significant effect (p> 0.05) on
the flour’s mineral content (table II). This is
an attractive feature because this flour
would be used as raw material for several
products such as bread, biscuits, cakes and
pastas. In such products, where combina-
tion of components in product formulation
can reduce mineral contents, peach-palm
flour would be a good vehicle by which to
add micronutrients, thereby enriching the
Costa Rican diet.
In our study, peach-palm fruit presented
both macro-minerals (K, P, Mg and Ca) and
micro-minerals (Fe, Cu, Zn, Mn and B).
However, in general, the mineral content
profile of Costa Rican peach-palm fruit dif-
fers from that of the peach-palm fruit of the
Colombian rainforests. According to
Leterme et al., the Colombian fruit pre-
sented higher contents of Ca, Mg, S, Zn and
Na, but fruits from both regions presented
similar contents of P, K, Mn, Fe and Cu [3].
1FDA. 21 CFR 101.9 Nutrition labeling of food.
DRAFT 2011-04-28. http://
www.accessdata.fda.gov/scripts/cdrh/cfdocs/
cfcfr/CFRSearch.cfm?fr=101.9, 2009.
Table I.
Changes in the physicochemical composition (g·100 g–1 dry weight) during the production of peach-palm
flour (average of five samples).
Component Moisture Fat Protein Starch Dietary
fiber
Ash Soluble
solids
Acidity1pH
Raw 56±5b 14±3a 5.0 ± 1.1 a 70 ± 4 a 11± 1a 1.8 ± 0.1 a 4.6 ± 0.3 b 0.23 ± 0.10 a 5.3 ± 0.6 a
Cooked 59±4a 13±3a 5.0 ± 1.1 a 68 ± 4 a 12±1a 1.8 ± 0.1 a 4.6 ± 0.4 b 0.13 ± 0.05 a 5.6 ± 0.6 a
Flour 13±3c 13±2a 5.0 ± 1.0 a 67 ± 7 a 10±1a 1.78 ± 0.03 a 14±3a 0.16 ± 0.04 a 6.1 ± 0.2 a
Means in the same column with different letters are significantly different (p< 0.05).
1Expressed as citric acid equivalents per 100 g of dry weight.

6Fruits, vol. 67 (6)
C. Rojas-Garbanzo et al.
According to Blanco et al., who analyzed
peach-palm from the same region, cooked
Costa Rican fruits presented a sodium (Na)
content of (9.1 ± 0.6) mg·100 g–1 (dw) [18],
whereas the results from our study showed
no content for this mineral. These authors
also reported K at (0.549 ± 0.005) g·100 g–1
(dw), Mg at (16.6 ± 4.1) mg·100 g–1 (dw),
and Fe at (0.8 ± 0.0) mg·100 g–1 (dw). These
concentrations were lower than those of our
study: K, (0.66 ± 0.06) g·100 g–1 (dw); Mg,
(0.042 ± 0.004) g·100 g–1 (dw); and Fe,
(14.60 ± 1.67) mg·kg–1 (dw). The differ-
ences may have resulted from the varieties
of peach-palm used, and their climatic, soil
and environmental conditions [13, 17]. This
hypothesis is supported by results obtained
by Yuyama et al. [17], who reported lower
Mg, Zn and Fe contents, but similar Ca con-
tent, and a higher K content compared with
those of our study.
The recommended daily intake (RDI) of
minerals, as suggested by the FDA1, is much
higher than the levels found in 100 g of
cooked peach-palm fruit (table III). Techni-
cal regulations suggest that nutrient con-
tents may be declared when these
contribute at least 5% of the RDI per 100 g
[31]. If a serving of two cooked peach-palm
fruits were to be presented as a final prod-
uct, the label would declare contributions to
RDI only for Mg (5%), Mn (8%), Cu (9.5%)
and K (13.5%).
Even so, taking into account all the min-
erals found in peach-palm fruit, this fruit can
supplement other foods in the Costa Rican
diet to provide the minimum RDIs for min-
erals.
3.2. Effects of flour processing on
bioactive compound content
In many fruits and their products, thermal
treatment either reduces or increases bioac-
tive compounds such as carotenoids,
polyphenols or dietary fiber [2, 3, 5, 9, 18,
32, 33].
Table II.
Changes in the mineral content during the production of peach-palm flour (average of five samples).
•Macronutrients
Peach palm fruit
N P Ca Mg K S Na
(g·100 g–1 dry weight)
Raw 0.79 ± 0.02 a 0.078 ± 0.005 a 0.032 ± 0.005 a 0.042 ± 0.005 a 0.65 ± 0.06 a 0.10 ± 0.01 a Not detected
Cooked 0.83 ± 0,.17 a 0.078 ± 0.004 a 0.028 ± 0.004 a 0.042 ± 0.004 a 0.66 ± 0.06 a 0.11 ± 0.01 a Not detected
Flour 0.86 ± 0.21 a 0.074 ± 0.005 a 0.026 ± 0.005 a 0,042 ± 0,004 a 0.66 ± 0.04 a 0.10 ± 0.01 a Not detected
•Micronutrients
Peach palm fruit
Fe Cu Zn Mn B
(mg·kg–1 dry weight)
Raw 13.40 ± 1.34 a 3.80 ± 1.30 a 3.20 ± 0.45 a 3.20 ± 1.10 a 1.60 ± 0.55 a
Cooked 14.60 ± 1.67 a 4.20 ± 1.79 a 3.60 ± 0.89 a 3.80 ± 0.84 a 2.20 ± 0.35 a
Flour 15.40 ± 1.67 a 4.60 ± 0.55 a 3.20 ± 0.45 a 3.60 ± 0.89 a 2.00 ± 0.71 a
Means in the same column with different letters are significantly different (p< 0.05).

Changes during peach-palm flour processing
Fruits, vol. 67 (6) 7
3.2.1. Dietary fiber
Dietary fiber was not affected by flour pro-
duction. Cooked fruit and flour had high
dietary fiber contents [(12 ± 1) g·100 g–1
and (10 ± 1) g·100 g–1 (dw), respectively].
This attribute provides health benefits such
as reducing low-density triglycerides and
cholesterol and preventing constipation
[33]. Because of its high dietary fiber content
[(5.0·100) g–1 (fw)], cooked peach-palm
fruit may be considered as a food source of
this compound [31].
3.2.2. Total carotenoid content
Total carotenoid content was significantly
affected (p< 0.05) by cooking and drying
(figure 1). Carotenoid content increased
by 17% from raw to cooked peach-palm
fruit, probably because cooking softens
both the cell walls and macromolecules
such as fatty acids and proteins that
encapsulate carotenoids, thus making
them more available [13]. According to
Miglio et al., cooking in water preserves
antioxidant compounds, especially caro-
tenoids, and releases them from the food
as the heat disrupts protein-carotenoid
complexes [34].
Table I.
Nutritional value of cooked and peeled peach-palm fruit (traditional method of consumption) according to
the Recommended Daily Intake (RDI)1.
•Macronutrients
Nutritional value
N P Ca Mg K S Na
(g·100 g–1 fresh weight)
Traditional method of consumption (TWC) 0.34 0.03 0.01 0.02 0.27 0.04 Not detected
(g·100 g–1 or fresh weight)
Recommended daily intake (RDI)1– 1.0 1.0 0.4 2.0 – 0.5
Contribution (%) – 3.0 1.0 5.0 13.5 – 0
•Micronutrients
Nutritional value
Fe Cu Zn Mn B
(mg·100 g–1 fresh weight)
Traditional method of consumption (TWC) 0.6 0.17 0.15 0.16 0.09
(mg·kg–1 fresh weight)
Recommended daily intake (RDI)118.0 2.0 15.0 2.0 –
Contribution (%) 3.3 9.5 1.0 8.0 –
Figure 1.
Changes in carotenoid content
during the production of
peach-palm flour (n= 5).
Different letters or numbers
indicate significant differences
after heat treatment steps at
p< 0.05.

8Fruits, vol. 67 (6)
C. Rojas-Garbanzo et al.
The level of increase in carotenoid con-
tent for cooked peach-palm fruit is impor-
tant because it governs the bioavailability
of bioactive compounds. Carotenoid
availability in fruit depends on the asso-
ciations occurring between proteins or
lipids and carotenoids [28]. The efficiency
of absorption of carotenoids in the diet is
affected by several factors; for example, the
amount of carotenoid ingested; how the
food is processed or cooked; the presence
of other dietary ingredients that may stimu-
late (e.g., type and amount of dietary fat) or
inhibit (fiber) absorption; matrix effects, and
interactions between carotenoids, etc. [35].
The effects of cooking on carotenoid
content in peach-palm fruit shown in this
study differ from the results reported by
Jatunov et al. [13]. These authors used
fruits from six different varieties. Immers-
ing the fruits in boiling water for 30 min
showed no effects. Our results also dif-
fered from those of Rojas-Garbanzo et al.,
who reported a 23% decrease in caroten-
oid content in heat-treated peach-palm
fruits [14]. However, the cultivars these
authors used also differed from those of
our study. Overall, we found cooking to
increase carotenoid availability, thus
helping to compensate for the caroten-
oids lost during drying.
The total carotenoid content in peach-
palm flour decreased by 28% compared
with cooked fruit. Carotenoids may have
been reduced through enzymatic and oxi-
dation reactions, and molecules degraded
through prolonged heat treatment (3 h)
[11]. The total decrease (15%) in caroten-
oid content from raw fruit to flour was not
significant (p> 0.05).
According to Rojas-Garbanzo et al.,
peach-palm fruit has at least nine caroten-
oids with provitamin A activity, all of which
are significantly affected by cooking and
drying with hot air [14]. Because the bioa-
vailability of carotenoids can increase after
cooking (through release from macromole-
cules) [13],the amount of carotenoids
present in the flour reinforces the idea of
peach-palm fruit being a functional food, as
it is a source of antioxidants and provitamin-
A compounds.
Peach-palm flour and cooked fruit,
respectively, presented a total carotenoid
content of (123 and 79) µg of β-carotene
Eg·g–1 (fw). Cooked peach-palm fruit has
a higher carotenoid content than other
fruits such as banana cv. ‘Comprida’,
guava, mango cv. ‘Rosa’, melon cv.
‘Japonés’, papaya cv. ‘Hawaii’, and water-
melon ( µg), with (10.62, 42.98, 24.98,
23.97, 46.39 and 40.09) µg of β-carotene
Eq·g–1 (fw), respectively [36], These
colored fruits are frequently consumed by
the population.
Peach-palm fruit may be compared with
other fat-rich fruit such as dabai (Canarium
odontophyllum Miq.), which is another
underused fruit found in tropical rainforests
and eaten by indigenous people. Although
peach-palm fruit must be cooked before
being eaten and dabai can be eaten fresh,
the peach-palm fruit presented a higher total
carotenoid content at 79 µg of β-carotene
equivalents per gram (fw) versus 55.5 µg
for dabai [5].
Carotenoid release during processing is
evident in the changing pulp color of
peach-palm fruit. Several studies have
previously correlated color with caroten-
oid content of different fruits and vegeta-
bles. Thus, color represents a rapid
estimate of the amount of this pigment [13]
present in the fruit. Raw peach-palm fruit
is light orange, turning deep orange when
cooked. The color parameters (table IV)
showed a significant increase in red (a*),
which was enhanced from 17 in raw fruit
to 27 in cooked peach-palm fruit, and yel-
low (b*), which increased from 53 to 71.
These color changes result from the
increased exposure of carotenoids after
cooking, which generates more intense
reds and yellows. Luminosity (L*)
declined significantly (p< 0.05) from 75
to 61.
Color changes are explained by the sof-
tening of cell walls, which led to increased
levels of those carotenoids with 9 to 11
conjugated double bonds such as all-
trans-β-carotene and lycopene [11, 14, 28].
Carotenoids with more conjugated dou-
ble bonds are able to express more color.
According to Rojas-Garbanzo et al., lyco-
pene, the carotenoid with the highest

Changes during peach-palm flour processing
Fruits, vol. 67 (6) 9
conjugated double bonds, is also present
in peach-palm fruit [14]. The authors
reported an increase of 6% for this caro-
tenoid after cooking. This explains the
changes in color obtained in our study.
The hue angle significantly (p< 0.05)
dropped in value after cooking but, after
drying, the hue angle increased again.
This explains the initial light orange color
in raw peach-palm fruit, which is less than
90º, and the strong orange color in cooked
fruit as carotenoids increased, generating
the deeper red color. Increased hue angle
after drying means a weaker red color,
which is linked to reduced carotenoid
content [13].
The chroma value (i.e., color intensity)
rose significantly after cooking and is not
affected by drying. Because the raw peach-
palm fruit’s light orange color turned deep
orange when cooked and processed into
flour, increased chroma value was expected
(table IV). Cooked peach-palm fruit has an
intense orange color that is linked to higher
carotenoid content.
The total color difference value (ΔE*)
between raw and cooked peach-palm
fruit was 25, while cooked fruit differed
from flour by 8. These differences in color
were perceptible to the human eye, as ΔE*
values were higher than 5 [25].
3.2.3. Total polyphenol content
The effect of heat treatment on total
polyphenol content was also evaluated; this
is the first time that polyphenols have been
reported in peach-palm fruit processing.
Cooking and drying had no significant effect
(p> 0.05), with cooked fruit and flour pre-
senting a total polyphenol content of
(70 ± 4) mg GAE·100 g–1 and (63 ± 2) mg
GAE·100 g–1 (dw), respectively (figure 2).
These results are surprising, as cooking
and drying, that is, heat treatment, were
expected to reduce total polyphenol con-
tents [32]. Other factors that may also
induce rapid deterioration of antioxidant
compounds are enzymatic reactions and
oxidation [32], and exposure to light and
oxygen during peeling and slicing.
To explain why the polyphenol content
in the peach-palm fruits we studied was
not affected, it is necessary to examine the
polyphenol profile during flour produc-
tion. The constant values for polyphenol
content during flour production could be
attributed to the formation of phenolic
compounds in an intermediate state of
oxidation by enzymatic or chemical reac-
tions that generates molecules able to
Table IV.
Color characteristics of peach-palm fruit at successive steps of flour processing
(average of five samples).
Color parameter a* b* L* °Hue Chroma
Raw 17±2c 53±4b 75±1a 72±1a 56±4b
Cooked 27±2a 71±5a 61±5c 69±1b 76±5a
Flour 24±2b 69±5a 69±3b 71±1a 73±5a
Means in the same column with different letters are significantly different (p< 0.05).
ΔE* (total color difference value) = 25 between raw and cooked peach-palm fruit, and ΔE*=8
between cooked fruit and flour.
Figure 2.
Changes in polyphenol content
and hydrophilic antioxidant
capacity during the production
of peach-palm flour (n= 5).
Different letters or numbers
indicate significant differences
after heat treatment steps at
p< 0.05.

Changes during peach-palm flour processing
Fruits, vol. 67 (6) 10
stabilize the π-electron system in the aro-
matic ring, leading to high antioxidant
properties [32].
Compared with avocado [667 mg
GAE·100 g–1 (dw)], raw and cooked peach-
palm fruit presented a lower polyphenol
content than that of other lipophilic-com-
ponent-rich food [36]. Despite low total
polyphenol contents, peach-palm fruit
can be considered as an alternative source
of this type of antioxidant compound.
The polyphenol content of another tra-
ditional fruit from Costa Rica – the tropical
highland blackberry (Rubus adenotrei-
chus) – is also affected by heat treatment
(blanching). Even so, the final product
(i.e., juice) presented higher polyphenol
content than cooked peach-palm fruit
[(5050 ± 1) mg GAE·100 g–1 (dw)] [37].
3.3. Effects of flour processing on
hydrophilic antioxidant capacity
Hydrophilic antioxidant capacity was not
affected by peach-palm flour production;
that is, no significant differences appeared
after cooking and drying (figure 2). When
food is exposed to drastic heat treatment
such as cooking and drying, sources of
antioxidant activity, which include
hydrophilic compounds such as polyphe-
nols, vitamin C, Se and Zn, and lipophilic
compounds such as carotenoids, may be
either generated or lost [3, 5, 12, 32].
If they are generated, oxygen radical
absorbance capacity (ORAC) values may
be enhanced, giving stability to the final
product [32]. The behavior of each anti-
oxidant compound during peach-palm
flour production must be discovered to
determine if heat affects its antioxidant
activity or if its behavior results from the
generation of intermediate compounds
with such characteristics [32].
Compared with other fruits, the antioxi-
dant capacity of cooked peach-palm fruit
[36 µmol TE·g–1 (dw)] is lower than that
reported for fruits such as blueberries,
blackberries and cranberries, the values
for which range between (90 and
160) µmol TE·g–1 (dw). At the same time,
its antioxidant capacity is higher than for
other fruits traditionally consumed such
as watermelon, melon and mango, the
values for which range from (16 to 24)
µmol TE·g–1 (dw) [38]. Compared with
legume flours, peach-palm flour had a
similar antioxidant capacity to cannellini-
bean flour [38 µmol TE·g–1 (dw)], but a
lower value than that of pinta-bean flour
[96 µmol TE·g–1 (dw)] [39].
For each stage, antioxidant capacity is
underestimated because H-ORAC is an
analysis that includes only hydrophilic
components. It does not take into account
the antioxidant activity of lipophilic com-
pounds such as carotenoids [7]. To know
the total antioxidant potential of peach-
palm fruit, the lipophilic antioxidant
capacity must also be determined.
4. Conclusions
The thermal processes – specifically cook-
ing and drying – used to produce flour did
not affect the principal physicochemical
compounds (fat, protein, starch and dietary
fiber) of peach-palm fruit. The nutritional
and energy values of starch and fat remained
very high in cooked fruit and flour.
The peach-palm fruit is rich in bioactive
compounds, with significant antioxidant
capacity. It may be considered as a func-
tional food because of its high carotenoid
and dietary fiber contents. The total carote-
noid content of traditionally cooked peach-
palm fruit was higher than those reported
for other tropical fruits such as banana,
mango, melon and papaya. Peach-palm
flour can also be used as an ingredient, rich
in bioactive compounds, for functional food
formulation.
Acknowledgments
This work was financially supported by the
European Union (PAVUC project, INCO no.
015279) and the Vice Rectory for Research
of the University of Costa Rica (Project VI
735-A8-163).

Changes during peach-palm flour processing
Fruits, vol. 67 (6) 11
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Changes during peach-palm flour processing
Fruits, vol. 67 (6) 13
Principales cambios físico-químicos y antioxidantes en la fabricación de
harina de pejibaye (Bactris gasipaes H.B.K.).
Resumen – Introducción. Varios estudios han demostrado que el procesamiento de ali-
mento tiene un efecto sobre nutrientes como compuestos bioactivos, proteína, almidón,
grasa, fibra, minerales y sobre la capacidad antioxidante. En nuestro estudio se analiza como
el calor cambia la composición físico-química y la capacidad antioxidantes durante el proce-
samiento de la harina de pejibaye (Bactris gasipaes H.B.K.). Materiales y métodos. Cinco
lotes de fruta disponible comercialmente fueron analizados para determinar el contenido total
de polifenoles y carotenoides; así como la capacidad hidrofilia de absorción de radicales de
oxígeno (H-ORAC). Posteriormente, la fruta se cocinó y se procesó para obtener la harina.
Resultados y discusión. No se encontró diferencia significativa en el contenido de grasa,
proteína, almidón y fibra dietética durante la producción de la harina. La fruta de pejibaye
cocinado es una fuente de Mg, Mn, Cu, y K; 100 g de fruta cocinada contiene entre 5% y
13.5% de la ingesta diaria recomendada. La cocción aumenta el contenido de carotenoides en
un 17% lo que compensa el 28% de pérdida que se da durante el secado. Las etapas de pro-
cesamiento de harina de pejibaye no afectan el contenido de polifenoles ni el valor de H-
ORAC. Conclusión. Dado el alto contenido de compuestos bioactivos, la harina de pejibaye
representa una alternativa potencial para el uso en el desarrollo de alimentos funcionales.
Costa Rica / Bactris gasipaes / frutas / procesamiento / secado / composición
aproximada / carotinoides / polifenoles / antioxidantes