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Coconut water preservation and processing: A review

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Coconut water preservation and processing: A review

Abstract and Figures

The product. Coconut water (Cocos nucifera L.) is an ancient tropical beverage whose original properties have drawn the attention of manufacturers as a natural functional drink. Preservation. This refreshing liquid comes mainly from immature coconuts which are difficult to collect, store and thus to commercialise. Nevertheless, some studies, mostly from Asian countries, tend to prove that the shelf life of immature coconut fruits could be prolonged thanks to post-harvest treatments. Processing. Coconut water itself, extracted from the nut, is obviously easier to handle but is also very sensitive to biological and chemical injuries. Thermal treatment combined with chemical additives are already used by the industry but other technologies such as micro- and ultrafiltration are not yet available on an industrial scale. Whatever the process, taste, aroma and colour (linked to enzymatic activities) are still difficult to control. Discussion. Results of former and recent investigations are discussed. Finally, suggestions are made for further research to increase our knowledge of this original tropical juice.
Content may be subject to copyright.
Review
Fruits, vol. 67 (3) 157
Coconut water preservation and processing: a review.
Abstract The product. Coconut water (Cocos nucifera L.) is an ancient tropical beverage
whose original properties have drawn the attention of manufacturers as a natural functional
drink. Preservation. This refreshing liquid comes mainly from immature coconuts which are
difficult to collect, store and thus to commercialise. Nevertheless, some studies, mostly from
Asian countries, tend to prove that the shelf life of immature coconut fruits could be pro-
longed thanks to post-harvest treatments. Processing. Coconut water itself, extracted from
the nut, is obviously easier to handle but is also very sensitive to biological and chemical inju-
ries. Thermal treatment combined with chemical additives are already used by the industry
but other technologies such as micro- and ultrafiltration are not yet available on an industrial
scale. Whatever the process, taste, aroma and colour (linked to enzymatic activities) are still
difficult to control. Discussion. Results of former and recent investigations are discussed.
Finally, suggestions are made for further research to increase our knowledge of this original
tropical juice.
France / Cocos nucifera / coconuts / coconut water / plant developmental
stages / maturation / quality / storage / preservation / keeping quality /
processing
Conservation et transformation de l'eau de noix de coco : une synthèse.
Résumé Le produit. L’eau de coco (Cocos nucifera L.) est un breuvage tropical dont les
propriétés fonctionnelles naturelles intéressent aujourd’hui les industriels. Conservation.Ce
liquide rafraîchissant provient des noix de coco immatures dont la récolte et le stockage res-
tent délicats. Toutefois, certaines études menées essentiellement en Asie tendent à prouver
que des traitements post-récoltes pourraient prolonger la durée de vie des noix immatures.
Transformation. L’eau de coco extraite de la noix est évidemment plus simple à manipuler
et transporter, mais sa composition la rend particulièrement sensible aux dégradations biolo-
giques et chimiques. Des traitements thermiques combinés à l’usage d’additifs sont
aujourd’hui utilisés dans l’industrie mais d’autres technologies comme la micro ou l’ultrafiltra-
tion ne sont toujours pas disponibles pour ce produit. Quel que soit le procédé de stabilisa-
tion utilisée, le goût et la flaveur originels de l’eau de coco restent très difficiles à préserver.
Discussion. Dans cette synthèse, pour la première fois, les recherches sur l’eau de coco, des
plus anciennes aux plus récentes, sont présentées ; elles conduisent à proposer des pistes
pour améliorer notre connaissance de ce jus de fruit tropical atypique.
France / Cocos nucifera / noix de coco / eau de coco / stade de développement
végétal / maturation / qualité / stockage / préservation / aptitude à la
conservation / traitement
1Cirad-Persyst, UMR 95
Qualisud, TA B-95 / 16,
73 rue Jean-François Breton,
F-34398 Montpellier cedex 5,
France, alexia.prades@cirad.fr
2Montpellier SupAgro,
UMR 95 Qualisud,
TA B-95 / 16, 73 rue
Jean-François Breton,
F-34398 Montpellier Cedex 5,
France,
manuel.dornier@cirad.fr
3Inst. Technol. Aliment. (ITA),
route des Pères Maristes,
BP 2765, Dakar, Sénégal,
ndiop@ita.sn
4Univ. Montpellier II,
UMR 95 Qualisud, Place
Eugène Bataillon, F-34090
Montpellier, France,
jppain@polytech.univ-montp2.fr
Coconut water preservation and processing: a review
Alexia PRADES1*, Manuel DORNIER1,2, Nafissatou DIOP3, Jean-Pierre PAIN4
* Correspondence and reprints
Received 31 March 2011
Accepted 20 June 2011
Fruits, 2012, vol. 67, p. 157–171
© 2012 Cirad/EDP Sciences
All rights reserved
DOI: 10.1051/fruits/2012009
www.fruits-journal.org
RESUMEN ESPAÑOL,p.171
Article published by EDP Sciences and available at http://www.fruits-journal.org or http://dx.doi.org/10.1051/fruits/2012009
158 Fruits, vol. 67 (3)
A. Prades et al.
1. Introduction
Coconut (Cocos nucifera L.) is one of the
most important and extensively grown palm
trees worldwide. The inner part of the nut
(endosperm) is divided into two edible
parts: a white kernel and a clear liquid:
coconut water [1]. Both parts can be proc-
essed in many different ways and lead to
various products such as copra, virgin coco-
nut oil, coconut cream, coconut milk, des-
iccated coconut, coconut water, nata de
coco, etc. [2]. The market for canned coco-
nut milk, coconut cream and coconut juice/
water is increasing considerably [3–5]. Coco-
nut is no longer only an international oil
commodity but is becoming a valuable fresh
fruit.
Coconut water (CW), also called coconut
juice (not to be confused with coconut
milk), is a sweet refreshing drink taken
directly from the inner part of coconut fruits
[6]. It differs from coconut milk, which is the
oily white liquid extracted from the grated
fresh kernel. The coconut water consumed
as a beverage usually comes from immature
coconut fruits [7]. Due to its unique charac-
teristics, coconut water is considered as a
natural functional drink [8]. Its sugar content
and mineral composition make it an ideal
rehydrating and refreshing drink after phys-
ical exercise [9]. Previously considered as a
simple tropical refreshment or occasionally
as a medicine, coconut water is progres-
sively becoming a natural healthy drink. As
a beverage being extracted in few tropical
and subtropical areas and only processed in
some Brazilian or Asian industrial manufac-
turing plants, coconut water remains a tra-
ditional and under-used resource. In most
cases, coconut water comes from small and
scarce coconut tree plantations more related
to “gardens”, except in Brazil where the
growing market demand led growers to cre-
ate, a few years ago, large commercial coco-
nut plantations. An increasing international
demand for this product could be a highly
positive issue for thousands of African and
Asian small farmers. However, to compete
on the international beverage market, coco-
nut water still has to be carefully processed,
packed, transported and stored.
After suitable varieties have been identi-
fied, coconut palms have to be harvested at
the right stage of maturity and in optimal
conditions [10]. The immature fruits are
often consumed immediately after harvest
or sold, either on a local market (75% of the
production) or dispatched, with or without
pre-treatment, to the international market.
Most whole young tender coconuts from the
Asian and Pacific Coconut Community pass
through Hong Kong or Singapore markets
before being transported by plane to Tai-
wan, the US or the EU. However, a tender
coconut can be heavy [(0.8 to 2) kg], leading
to considerable air freight costs.
Apart from the market for whole young
tender coconuts, whose transport can be
expensive, thus limiting exports, coconut
water is also removed from the nut and
processed. Although coconut water is sterile
as long as it remains in the inner cavity of
the nut [11], it is very difficult to preserve.
As soon as the nut is opened, its biochemical
composition and physical appearance
change. Thermal and non-thermal treat-
ments, sometimes combined with additives,
have been tried with varying degrees of suc-
cess. In Asian countries and in Brazil,
canned, bottled or tetra-packed coconut
water is available. But those who have
tasted these manufactured juices are aware
that they differ from fresh coconut juice.
Prolonging the coconut water shelf life with-
out modifying its flavour and nutritious
properties remains a technical challenge.
Fermentation processes are also encoun-
tered but lead to fully different final prod-
ucts which do not resemble natural coconut
water. We drew a flow diagram of the dif-
ferent manufactured products made of
young coconut water (figure 1).
Current research on the post-harvest sec-
tor of coconut water is rare. Two different
fields have to be taken into account: pres-
ervation of the whole nut (the Young Tender
Coconut, YTC market) and processing of
coconut water. Nevertheless, we found in
the literature these two approaches that we
describe in detail in our review.
Coconut water preservation and processing
Fruits, vol. 67 (3) 159
2. Preservation and sale
of young tender coconuts
Young tender coconuts are still the best way
to preserve coconut water (inside its natural
container) but the nuts cannot be stored for
more than 6 days at ambient temperature
[12]. In Sri Lanka, the Coconut Research
Institute suggested some technical guide-
lines for the shipping of King Coconuts for
export [13]. Following their advice on prep-
aration, young tender coconuts can remain
fresh and safe for 3 weeks at (13 to 15) °C
and 70% RH (reefer containers). Similarly, a
project funded by the Indian Coconut
Development Board has provided a com-
plete supply chain for young tender coco-
nuts from the field to the kiosks and
retailers. The minimum processing consists
of dipping partially husked nuts in a solution
of 0.5% citric acid and 0.5% of potassium
metabisulphite for 3 min. The final product,
wrapped with polypropylene cling film, can
be stored for up to 24 days at (5 to 7) °C [14].
As for many tropical fruits, reducing the
temperature below 12 °C results in chilling
injury: the coconut skin rapidly browns. For
the whole nut without any treatment, pres-
ervation for 28 days at either 12 °C or 17 °C
gave the best results reported in the litera-
ture [15–17]. For the whole nut with treat-
ment such as sanitisation, i.e., immersion in
a specific solution for a few minutes [18], the
best result was obtained after 21 days at
12 °C [19]. Surprisingly, sanitisation did not
improve the shelf life of the nut. For the
whole nut with film wrapping, results were
equivalent or even better: 28 days at 12 °C
with PE film [16] and 30 days at 12 °C with
PVC film [19]. The longest shelf life for
Figure 1.
Flow diagram of the different
methods of processing young
coconut fruit.
160 Fruits, vol. 67 (3)
A. Prades et al.
whole young tender coconuts was obtained
with paraffin wrapping stored for 49 days at
12 °C [17].
The most common method to promote
the sale of young tender coconuts on local
markets, in supermarkets, or in restaurants
is to partially remove the tender mesocarp
(husk) up to the outer shell. The partially
husked young tender coconuts have
become so famous on Asian markets, espe-
cially in Thailand, that a prototype machine
has been designed to trim and open young
coconut fruits [20, 21].
However, the exposed trimmed husk
quickly turns brown, reducing the commer-
cial value of the fruit even though the coco-
nut water remains of good quality inside.
Without any packing or sanitisation, these
partially husked nuts can only be stored for
7 days at 17 °C. To overcome the problem,
the freshly-cut nut can be immersed in a
solution of anti-browning agent such as
sodium metabisulphite at a concentration of
about 2 g·L–1 for (5 to 10) min [22]. With
anti-browning treatment and a film wrap-
ping, the shelf life is estimated at 24 days at
5 °C [23]. Finally, immersion in carnauba
wax emulsion maintains the freshness of
partially husked young tender coconuts for
up to 30 days at 12 °C [24].
In conclusion, the best method for pro-
longing shelf life was obtained using wax
coatings: paraffin for whole young tender
coconuts for up to 49 days at 12 °C, and car-
nauba for partially husked fruits for up to
30 days at 12 °C. Other waxes should be
tested to preserve young tender coconuts
and to optimise conditions for the sale of this
natural product. Additional work is also
needed to optimise coatings and packaging.
A better understanding of the coconut fruit
ripening process and senescence could also
help design suitable storage conditions such
as modified atmosphere packaging (MAP).
3. Coconut water processing
3.1. Mature coconut water
processing
As early as 1977, Sison raised the question
of the disposal of the mature coconut water
[25]. Until now mature coconut water has
been considered as waste, especially in
coconut processing plants (desiccated coco-
nut factories, coconut milk factories, etc.).
Pramith estimated the total volume of coco-
nut water discarded by the Sri Lankan coco-
nut mills at 261 Mt per year [26]. The liquid
causes environmental pollution and is also
a waste of a valuable food [27].
3.1.1. An environmental problem
A desiccated coconut factory which splits
about 300,000 coconuts a day throws out
approximately 5.3 m3of pure coconut water
plus 44 m3of wash water, giving a total of
50 m3of effluent per day. Pure coconut water
has a BOD (Biological Oxygen Demand) of
29,000 mg·L–1 and wash water about
3,000 mg·L–1 so that the global liquid waste
from the factory has about 5,800 mg·L–1 of
BOD, which has to be reduced to the
accepted level of 50 mg·L–1 [25]. Several
conventional techniques can be used in Sri
Lankan conditions including letting the
coconut water settle and skimming off the
surface oily layer, which can be processed
into soap. Anaerobic treatment in an Upflow
Anaerobic Sludge Blanket (UASB) and aer-
obic treatment in ponds have also been sug-
gested [27]. The quality of the effluent to
discharge into inland surface waters includes
a pH of 6.5 to 8 and maximum allowed
amount of 300 mg·L–1, 30 mg·L–1 and
10 mg·L–1 for COD (Chemical Oxygen
Demand), BOD and oil, respectively [28].
3.1.2. A valuable food
First attempts to make use of the liquid
waste as food failed due to technical diffi-
culties involved in removing the residual
oil from the liquid. A membrane was tested
to separate the residual oil. The mature
coconut water was previously heated to
95 °C to precipitate the protein. Then pas-
teurisation gave a relatively high flux of up
to 42 L·h–1·m–2 at 60 °C and up to 245 kPa
with a 0.45-µm hydrophilic PVDF mem-
brane [26]. Fresh mature coconut water
was also concentrated by plate-and-frame
reverse osmosis using composite mem-
branes (DDS type HR98 with a cut-off of
less than 500 Da) at (2, 3 and 4) MPa inlet
pressures [29].
Coconut water preservation and processing
Fruits, vol. 67 (3) 161
The most economical and practical ways
to enhance the value of coconut water are
still making vinegar [30], using it as a growth
medium for yeasts [25], for xanthan gum
production [31], for the culture for various
lactic acid bacteria [32] or for Nata de coco
production [33]. Nata de coco is pure cellu-
lose, free of lignin and hemicellulose, pro-
duced by Acetobacter xylinum [34–36].
Besides its use as a food, the gel-like sub-
stance is also considered to impart extraor-
dinary mechanical strength when processed
into film or sheets [37, 38]. Nata de coco was
also tested as a natural coating for minimally
processed fruits [39]. Coatings containing 1%
and 2% of carboxymethyl cellulose from
Nata de coco, referred to as carboxymethyl-
nata, were applied to bell peppers to eval-
uate the effect of the polysaccharide coating
on the post-harvest life of the fruits. The
results suggested that this coating signifi-
cantly reduced the ripening rate. Jagannath
et al. studied the production of Nata de coco
by Acetobacter xylinum using tender coco-
nut water as a medium instead of the usual
mature coconut water [40].
3.2. Young coconut water
processing
Although some publications addressed the
processing of young coconut water before
the mid-1990s [41–43], the first paper pre-
senting detailed scientific results of thermal
treatment of young coconut water was pub-
lished in 1996. Since then, ten articles have
been published on pasteurisation and two
on sterilisation. Two additional publications
by the University of Sao Paulo, Brazil,
described microwave treatment of coconut
water. Besides conventional thermal tech-
niques, cooling and freezing are the two
processes currently used in the industry.
Surprisingly, they are only cited or
described in three articles and one manual.
As far as we know, membrane filtration
techniques, mentioned in seven papers,
have not yet been used industrially for
young coconut water.
No information was found in the litera-
ture on young coconut water aseptic extrac-
tion, whereas it is the first crucial operation
in coconut water processing. It is probably
due to the fact that this opening step is the
key issue to obtain a high-quality raw mate-
rial and each company wants to preserve its
know-how. Another explanation could be
that it is still a highly challenging technical
problem because of the rapid discoloration
and fermentation occurring just after the
coconut cracking.
3.2.1. Thermal treatments
3.2.1.1. Pasteurisation, sterilisation
and combined treatments
The first paper on the preservation of tender
coconut water was Indian [43]. Additives
such as nisin, minimum heating, and pack-
ing in polymeric pouches and metal cans
were cited as being used to achieve com-
mercial sterility. A more detailed process to
develop shelf-stable ready-to-serve green
coconut water was described by Chowd-
hury et al. [44]. The authors filtered the
freshly extracted coconut water, pasteurised
it at 85 °C for 10 min and cooled it. The
coconut water was then poured into metal
cans or glass bottles. Cans and bottles were
sterilised at 121 °C for 30 min and at 100 °C
for 15 min, respectively.
An experimental hot-fill process was also
compared with other commercial coconut
water subjected to cooling, freezing, aseptic
filling of cartons and industrialised hot-fill
processing [45]. The experimental process
consisted of filtration, addition of citric acid
to reduce the pH to 4.5, addition of fructose
to standardise the soluble solids content at
70 g·L–1 and sodium metabisulphite
(0.45 g·L–1), addition of sodium benzoate
(1.24 g·L–1) and ascorbic acid (0.0013 g·L–1),
pasteurisation at 90 °C for 2 min and pour-
ing into 200-mL glass bottles. Samples were
stored at ambient temperature (28 °C). The
experimental hot-fill samples were accept-
able even though they did not resemble
other commercial samples in terms of phys-
icochemical attributes.
In Taiwan, sterilisation is commonly used
as a thermal treatment to stabilise coconut
water and frequently causes non-enzymatic
browning of the liquid [46]. In order to
remove the brown colour, active carbon,
cation exchange resin, sulphur compounds
162 Fruits, vol. 67 (3)
A. Prades et al.
such as sulphite, acetyl-cysteine, glutathi-
one and cysteine were successfully tested.
3.2.1.2. Thermal treatment
and microbiological effects
The main objective of the thermal treatments
is to stop or eradicate the microbiological
load for consumer safety [47]. Thermal treat-
ments were applied to buko, a mix of coco-
nut water/distilled water (80/20) and,
respectively, (60 and 20) g of macerated
solid endosperm and refined sugar per litre
of beverage. Glass test tubes were immersed
in a hot water bath at (60, 70 and 80) °C for
different lengths of time. According to the
different temperatures and time treatments,
aDvalue was determined, i.e. the time (in
minutes) required for a 1 log10 reduction of
the survival of the reference strain. The cal-
culated Dvalues for Escherichia coli on buko
ranged from (0.26 ± 0.01) min at 80 °C to
(0.56 ± 0.08) min at 60 °C.
3.2.1.3. Thermal treatment
and thermophysical properties
Before the design or adaptation of specific
food processing equipment, an important
step is often left out: assessment of the effect
of temperature on the thermophysical prop-
erties of the raw material. Food composition
and temperature are important factors
which affect the thermal behaviour of a trop-
ical fluid such as coconut water. The density,
dynamic viscosity, thermal diffusivity, ther-
mal conductivity and specific heat of the
water of green Bahia coconuts (presumed
to be the Brazilian Green Tall or Dwarf vari-
ety) bought from a local market in Brazil
were measured using a range of tempera-
tures from 5 °C to 80 °C [48]. Temperature
significantly affected the above properties,
which displayed linear trends, except for
dynamic viscosity, which displayed an
exponential curve. Different equations and
models were proposed to fit the experimen-
tal data (table I).
3.2.1.4. Thermal treatment
and enzymatic browning control
The major problem encountered in coconut
water stabilisation is apparently not micro-
biological or chemical stability, since these
objectives have already been partially
achieved [44, 45], but the fact that enzymes
need to be inactivated to stabilise the colour
and taste of the final product. As is true for
many fruit juices, polyphenol oxydase
(PPO) and peroxydase (POD) enzymes are
present in young coconut water.
The consequence of PPO or POD activi-
ties in coconut water is discoloration. Yel-
low, brown or pink discoloration of the
coconut water can occur a few minutes or
a few hours after the nut is cracked. Discol-
oration can also occur after several weeks
of storage of processed coconut water. Even
though the mechanisms of PPO and POD
activities are well described from a bio-
chemical point of view [49], the same mech-
anisms remain to be explained during
ripening of the fruit and post-harvest. A
range of different factors affect the levels of
activities of the enzymes and are often dif-
ficult to control (temperature, pH, mechan-
ical impacts, oxygen concentration, etc.). To
prevent the consequences of PPO and POD
activities in coconut water, several authors
suggested inactivating the enzymes by ther-
mal treatments either using conventional
methods (pasteurisation, sterilisation) or by
microwave heating.
At a low temperature (90 °C), total inac-
tivation was obtained after 550 s for PPO
and after 310 s for POD [50]. At a tempera-
ture of 139 °C for 10 s combined with
200 mg·L–1 of ascorbic acid, PPO was
entirely inactivated, whereas POD was still
active at 40% of its original level [51]. Con-
trary to Campos et al., who underlined the
fact that PPO was more resistant than POD
to pasteurisation [50], Abreu and Faria con-
cluded that POD was inversely more ther-
mostable using sterilisation [51]. At
temperatures below 90 °C, the POD of the
coconut water is less thermostable than
PPO, like strawberry [52], but unlike apple
[53] or pineapple [54].
Other investigations of the kinetics of
inactivation of the two enzymes indicated
that the situation is more complex [55, 56].
In fact, two isoenzymes for PPO and POD
are present in young coconut water. The
thermal behaviour of the different fractions
was analysed and quantified during pas-
teurisation. Two different mathematical
Coconut water preservation and processing
Fruits, vol. 67 (3) 163
equations were developed to predict the
thermal resistance of PPO and POD frac-
tions using the same type of multicompo-
nent first-order model (table II).
The thermal resistance of POD can be
estimated by a Dvalue, i.e., the time
required to reduce the enzyme activity to
10% of its initial value. The temperature
required for a Dvalue of 5 min, which was
81.2 °C for coconut water POD [57], was
shown to be higher than the 44.5 °C
required for pepper [58], 75 °C for grape [59]
and 80.3 °C for carrot [60], but slightly lower
than the 83.2 °C for potato [60].
Apart from classical thermal treatments,
an unconventional technique, microwave
heating, has been used to inactivate PPO
and POD enzymes [57, 61]. First, the thermal
behaviour of solutions simulating the chem-
ical constituents of coconut water (PPO/
water, PPO/sugars, PPO/salts and PPO/sug-
ars/salts, and equivalent for POD) was
Table I.
Experimental values of thermophysical properties of coconut water and equations for their prediction (adapted
from Fontan et al. [48]).
Temperature
(°C)
Density
(ρ)
Thermal diffusivity
(α)
Dynamic viscosity
(μ)
Specific heat
(cp)
Thermal conductivity
(K)
(kg·m–3) (10–7 m2·s–1) (10–3 Pa.s) (J·kg–1·°C–1) (W·m–1·°C–1)
5 1021.72 1.36 1.54 4056.5 0.56
20 1016.75 1.39 1.00 4056.5 0.57
35 1011.33 1.46 0.69 4056.5 0.60
50 1007.12 1.50 0.45 4056.5 0.61
65 1000.03 1.55 0.43 4056.5 0.63
80 996.72 1.58 0.36 4056.5 0.64
Thermophysical properties Equations
Density ρ= 1023·4651 – 0.3416 · T
Thermal diffusivity α= 1.343·10–7 + 3.119·10–10 ·T
Dynamic viscosity μ= 2.838·10–4 + 1.540·10–3 · exp(–3.956·10–2 ·T)
Specific heat
with
Thermal conductivity K= 0.5581 + 1.08·10–3 ·T
Ccal: calorific capacity of calorimeter (J.°C–1); cw: specific heat of water (J.kg–1.°C–1); mc: cold water
mass (kg); mh: hot water mass (kg); ms: sample mass (kg); mw: mass of water inside the calorimeter
(kg); Tc: calorimeter + cold water temperature (°C); Teq: equilibrium temperature (°C); Th: hot water
temperature (°C); T0: calorimeter + initial temperature of water (°C); Ts: initial temperature of the
sample (°C).
Cp
cwmw
Ccal
+()Teq T0
()
msTsTeq
()
------------------------------------------------------------------=
C
cal
mhcw
ThTeq
()mccw
Teq Tc
()
Teq Tc
()
----------------------------------------------------------------------------------------------------------=
164 Fruits, vol. 67 (3)
A. Prades et al.
characterised. The influence of sugars and
salts on enzyme activity was demonstrated.
Sugars, especially fructose, were more det-
rimental to POD than to PPO inactivation.
Salts significantly affected PPO and POD sta-
bility. At temperatures above 77 °C, PPO
was found to be more thermally resistant to
microwave heating than POD, corroborat-
ing the results of Campos et al. [50]. The
presence of salts in the simulated solutions
combined with microwave heating reduced
both enzymatic activities to undetectable
levels. In addition, the thermal behaviour of
natural coconut water was compared with
that of the simulated solutions [57]. It
appeared that natural enzymes were more
thermo-resistant than commercial ones. The
authors used a first-order kinetic model to
describe the experimental results and deter-
mined Dparameters for PPO, D92.20 °C =
52 s, and for POD, D92.20 °C = 16 s. The ther-
mal inactivation of both enzymes was faster
with microwave processing than with con-
ventional pasteurisation.
3.2.1.5. A simple thermal treatment:
refrigeration
Cold preservation of young coconut water
has been studied by the FAO for a few
years with the aim of extending the shelf
life of this fragile product. A manual enti-
tled “Good practice for the small-scale pro-
duction of bottled coconut water” [62] was
designed for use as a learning resource for
small and micro-entrepreneurs as well as a
training resource for extension workers
and trainers. The manual describes meth-
ods for harvest, storage conditions and san-
itisation of the coconut fruits. It then
explains how to extract, filter on cheese-
cloth, pour into bottles and store the coco-
nut water at 4 °C. No peer-reviewed article
was found on international databases on
Table II.
Mathematical models of polyphenoloxydase (PPO) and peroxydase (POD) thermal inactivation in coconut
water.
Enzyme Enzymatic activity
(U·mL–1·min–1)
T
(°C)
Model
[55]
Coefficient of multicomponent first-order model
αk1(s–1)k2(s–1)R2
PPO 16.5 80 0.6559 1.70E–03 1.98E–03 0.938
POD 3.6 80 0.5826 2.19E–02 –7.12E–04 0.893
85 0.2068 1.28E+00 3.01E–03 0.953
90 0.5983 2.36E–02 2.39E–02 0.970
Enzyme Activity
(U·mL–1·min–1)
T
(°C)
Model
[56]
Coefficient of multicomponent first-order model
Tref
(°C)
α
(% of activity
of isoenzyme 1)
D1
(s)
z1
(°C)
D2
(min)
z2
(°C)
R2
PPO 0.15–34.8 75 86.9 0.88 6.0 5.7 11.3 5.5 0.82
80
85
POD 0.13–6.18 75 86.9 0.95 8.6 3.4 26.3 6.9 0.74
80
85
A: enzymatic activity (U·mL–1·min–1); A0: initial enzymatic activity (U·mL–1·min–1); α: fraction of the initial activity of the isoenzyme 1
(%); t: time (s); Tref: reference temperature (°C); D: decimal reduction time (min); z: temperature increase that reduces D-value by 90%.
A
A0
------ ek1t()
1()ek2t()
+= αα
A
A0
------ A1
A01
---------
⎝⎠
⎛⎞
1()
A2
A02
---------
⎝⎠
⎛⎞
+= αα
A1
A01
---------
⎝⎠
⎛⎞
log t
D1
------= A2
A02
---------
⎝⎠
⎛⎞
log t
D2
------=
D
1Dref1aTref T
z1
-------------------
⎝⎠
⎛⎞
log=
D
2Dref2aTref T
z2
-------------------
⎝⎠
⎛⎞
log=
Coconut water preservation and processing
Fruits, vol. 67 (3) 165
this popular and frequently-used proce-
dure for the preservation of coconut
water.
3.2.2. Non-thermal treatments
Non-thermal treatments such as membrane
filtration are interesting alternatives to sta-
bilise delicate aromatic fruit juices. The orig-
inal flavour of coconut water is sensitive to
temperature and microfiltration (MF) could
help to pasteurise the product at ambient
temperature while preserving its aroma.
Moreover, ultrafiltration (UF) is used for the
extraction of small molecules from a solu-
tion and enzymes, such as PPO and POD,
are small molecules of, respectively,
73.8 kDa and 49.2 kDa [63].
Several authors tried to stabilise coconut
water using either MF or UF (table III). The
FAO has also taken out a patent [64] claiming
that high-speed centrifugation followed by
microfiltration and aseptic packaging can
preserve young coconut water for a period
of at least 6 months.
Working on a semi-industrial microfiltra-
tion unit, Diop observed relatively high
steady-state flux at 150 L·h–1·m–2 and a loss
of only 3% of coconut water at a VRF (Volu-
mic Reduction Factor) of 25 [65].
To prevent enzymatic discoloration, a
few authors tried to use ultrafiltration imme-
diately after microfiltration to remove PPO
and POD from the coconut water. Ultrafil-
tration retained 92% and 91% of PPO and
POD activity thanks to a 10 kDa cut-off
membrane [65]. In all cases, PPO activity was
considerably reduced and POD activity was
undetectable. Equations were developed
for ultrafiltration to estimate and predict its
performance [66].
Another way to cope with coconut water
pinking is to mix it with a coloured fruit juice
such as cashew apple juice [67–69], acerola
Table III.
Microfiltration and ultrafiltration conditions of immature coconut water.
Treatment Membrane
porosity
(µm)
Membrane
molecular
cut-off
(kDa)
Surface
(m²)
Membrane Temperature
(°C)
Transmembrane
Pressure
(kPa)
Filtration
type
Permeate
flux
(L·h–1·m–2)
References
Microfiltration
(MF)
0.2 – Not
available
Not available 6 Not available Not
available
Not
available
[64]
0.1 0.72 Plate and frame
polysulphone
25 200 Dead-end 20 [75]
0.2 0.22 Tubular ceramic 20–25 140–158 Cross Flow
7 m·s–1 150 [65]
0.2 0.013 Plate and frame
cellulose nitrate
20 16 Dead-end Not
available
[76, 77]
Ultrafiltration
(UF)
0.1,
0.025
– Not
available
Plate and frame
cellulose ester
Not available Not available Dead-end Not
available
[78]
10, 30, 50 0.09 Plate and frame
regenerated
cellulose (10 kDA)
and
polyethersulphone
(30 and 50 kDa)
25 60 Dead-end Not
available
[65]
20, 50, 100 0.72 Plate and frame
polysulphone
25 200 Dead-end 5 [75]
50 0.0035 Plate and frame thin
film composite
polyamide
Ambient
temperature
276–690 Stirred cell
800–
1600 rpm
25–130 [66]
166 Fruits, vol. 67 (3)
A. Prades et al.
[70] or maracuja [71]. The association of the
two fruit juices combines their sensory and
nutritional properties, while cumulating
their respective advantages.
Other investigations tried to prevent
“pinking” of coconut water by using differ-
ent types of food-grade resins: polyvinyl-
polypyrrolidone (PVPP), calcium bentonite
and gelatin [72], as commonly used in wine
and beer processing. None of the tested res-
ins was successful in controlling discolora-
tion but further investigations are required
to improve the experimental methodology.
Continuous dense-phase CO2(DPCD), a
very recent technology, also failed to pre-
vent discoloration at ambient temperature
[73].
Hence, from a microbiological point of
view, microfiltration appears to be a satis-
factory way to stabilise coconut water but
has no effect on enzyme activity since the
enzymes cross the membrane. Ultrafiltration
retains PPO and POD enzymes. The discol-
oration of coconut water is still not
completely elucidated. Thus, emerging
technologies such as high-pressure, pulsed
electric field or ohmic heating should be
investigated.
3.2.3. Shelf life and quality
of processed young coconut water
Few studies have dealt with the quality and
shelf life of processed coconut water. Con-
cerning shelf life, it is clear that neither
classical thermal pasteurisation, nor sterili-
sation, nor microfiltration were sufficient to
obtain a shelf-stable product without addi-
tives. Efficient results were obtained by
adding molecules such as nisin [43], ascorbic
acid [50] or citric acid and sodium metabi-
sulphite [74]. In these cases only, it was
possible to preserve pasteurised coconut
water for 2 to 3 months at ambient temper-
ature or refrigerated. Sterilisation prolonged
the shelf life of coconut water to 10 months
at ambient temperature and to 12 months at
4 °C [44]. The storage stability of the canned
and bottled green coconut water was satis-
factory but the addition of citric acid did
change the taste of the processed product.
Microfiltration did not significantly influ-
ence pH, acidity, total soluble solids or total
solids of clarified coconut water but
increased clarity (measured as luminance L
with a Hunter-Lab system), decreased tur-
bidity and protein content by 24% [75]. With
different equipment and membranes, a sim-
ilar increase in clarity, and a decrease of 13%
in protein content and turbidity were also
observed in clarified coconut water [76, 77].
Furthermore, microfiltration caused a signif-
icant decrease in the ash content of the per-
meate. K, Mg, Ca, Fe and Cu concentrations
decreased by, respectively, (10, 16, 19, 20
and 22)%. Only calcium concentrations
remained stable. Physical properties such as
surface tension and viscosity changed,
whereas the specific gravity was not affected
[76, 77].
Microfiltration obviously did not stop the
pink coloration of the clarified coconut
water. The pink coloration occurred in
microfiltered coconut water from Dwarf
varieties but not from Tall varieties when
stored at ambient temperature. When stored
at 9 °C to 10 °C just after processing, discol-
oration did not occur in any of the samples.
However, the samples from Dwarf varieties
still became pink when placed at ambient
temperature after cold storage [64, 65].
Finally, the taste of the microfiltered
coconut water was found to be very similar
to that of fresh coconut water but the aroma
was lost during processing, even though the
overall acceptability of the final product by
a panel of consumers was good [76, 77].
Ultrafiltration retained PPO and POD
enzymes. Retention percentages of protein
of, respectively, (25, 38 and 43)% for the
(100, 50 and 20) kDa cut-off membranes
were confirmed [66, 75]. The assessment of
the effect of three different processes (ultra-
filtration, pasteurisation and freezing) on
the mineral composition of young coconut
water showed that the ultrafiltration mem-
brane retained most of the minerals present
in coconut water. In contrast, pasteurisation
tended to increase Cu, Fe and Zn concen-
trations, whereas freezing completely
changed the mineral distribution [78]. Ultra-
filtration was able to retain PPO and POD
enzymes but also retained minerals, and
these are major quality criteria and a strong
marketing argument for the young coconut
water beverage.
Coconut water preservation and processing
Fruits, vol. 67 (3) 167
As the market for processed coconut
water is constantly growing in Brazil,
Luvielmo et al. performed a quantitative
descriptive analysis of Brazilian branded
coconut waters to compare the effects of dif-
ferent types of processing: freezing,
pasteurisation and microwave heating [79].
Contrary to microwave-heated samples, the
frozen coconut water samples showed the
best values for typical characteristics of
green coconut water. This is the first time a
list of twelve descriptors has been drawn up
for green coconut water by an expert jury.
Unfortunately, this study was performed
using commercialised samples of different
origin and without a reference sample (i.e.,
fresh coconut water without treatment).
Four other articles compared, respectively,
9, 3, 3 and 26 different coconut water brands
sold in Brazilian supermarkets. Marked var-
iability of the analysed samples was
observed: De Sousa et al. in mineral com-
position [80], Abreu et al. in organoleptic
quality [81], and Pinheiro et al. and Fortes
et al. in physicochemical and organoleptic
characteristics [82, 83]. This variability was
nevertheless in accordance with the Brazil-
ian standard. On the other hand, 100% of the
analysed samples were microbiologically
contaminated beyond legal limits.
Nunes et al. studied the hygienic condi-
tions and characteristics of commercial
foods marketed in Brazil and especially fruit
juices [84]. They confirmed the previous
results of Fortes et al. regarding the bad
hygienic conditions during processing and
handling of young coconut fruits [83]. They
also confirmed the results of an investiga-
tion by Walter et al., who demonstrated that
Listeria monocytogenes was a possible con-
taminant of young coconut water and grew
easily on this media even at 4 °C [85]. There-
fore, better care needs to be paid to pack-
aging [86] and storage [87], training of the
processors and vendors and adequate man-
agement of wastes during fruit juice process-
ing.
Attention also needs to be paid to con-
trolling the physicochemical and microbio-
logical quality of young coconut product
sold. As far as we know, only Brazil [83] and
India [88] already have or will soon have
official standards for processed young coco-
nut water.
4. Conclusion and future
prospects
Coconut water is not a common fruit juice
and thus not easy to stabilise. Since its pH
is high, it is subject to rapid deterioration.
The Young Tender Coconut market could be
a solution for regional markets but research
on the preservation of the fruits will need
future efforts, especially in the coating and
packaging fields. Concerning coconut water
itself, thermal treatment combined with
chemical additives are already used by the
industry but other technologies such as
micro- and ultrafiltration are not yet availa-
ble on an industrial scale for coconut water.
Microfiltration and ultrafiltration can pre-
serve the taste of the fresh coconut water but
not the aroma. Ultrafiltration can drastically
change the mineral composition of coconut
water. Whatever the process, taste, aroma
and colour (linked to enzymatic activities)
are still difficult to control. Therefore,
emerging technologies such as high-pres-
sure, pulsed electric field or ohmic heating
should be investigated.
Coconut water extracted from young
coconut fruits appears to be a natural
healthy beverage and a good alternative to
artificial sport drinks. Despite the lack of sci-
entific knowledge on this raw material, the
market for it is continuously expanding
worldwide.
To satisfy demand, coconut producing
countries have been planting Dwarf coco-
nut palm trees for more than 10 years.
Green Dwarf in Brazil, King coconut in Sri
Lanka, Aromatic Green Dwarf (Nam hon) in
Thailand and Chowgat Orange Dwarf in
India are some of the most popular cultivars
for tendernut consumption around the
world. In the future, combined efforts by
breeders, biochemists and food processing
scientists accompanied by innovative man-
ufacturers will probably increase the quality
of young coconut water and give a chance
to millions of coconut smallholders to
increase the value of their production.
168 Fruits, vol. 67 (3)
A. Prades et al.
Acknowledgements
The authors wish to acknowledge Dr.
Olivier Gibert and Mrs Daphne Goodfellow
for the English revision of the manuscript.
References
[1] Pieris W.V.D., L'eau de coco, constituant
liquide de l'endosperme de la noix de coco.
Note sur la terminologie, Oléagineux 26
(1971) 383–390.
[2] Woodroof J.G., Coconut storage and proces-
sing, and minor uses of products of the coco-
nut tree, in: Coconuts: production, proces-
sing, products, AVI (Ed.), Westport, U.S.A.,
1970.
[3] Batugal P.A., Ramanatha Rao V., Bong C.,
Promoting multi–purpose uses and competi-
tiveness of the coconut, in: Batugal P.A.,
Ramanatha Rao V., Bong C.E. (Eds.), IPGRI,
Chumphon, Thailand, 1996.
[4] Chandrasekharan V.G., Remany G., Mathew
T.M., Exploring trade opportunities for coco-
nut products – An experience from New Delhi,
Indian Coconut J. 35 (2004) 22–24.
[5] De Leon S.Y., Delores M.I., Coconut, in:
BarrettD.M.,SomogyiL.P.,Ramaswamy H.S.
(Eds.), Processing fruits: science and techno-
logy, Boca Raton, Florida, U.S.A., 2005.
[6] Steiner I., Desser A., Coconut water – com-
position, properties and processing,
Ernährung 32 (2008) 513–516.
[7] Dupaigne P., Un jus de fruit peu ordinaire :
l'eau de coco,Fruits 26 (1971) 625–627.
[8] Prades A., Dornier D., Diop N., Pain J.P.,
Coconut water uses, composition and pro-
perties: a review, Fruits 67 (2012) 87–107.
[9] Saat M., Singh R., Gamini Sirisinghe R.,
Nawawi M., Rehydration after exercise with
fresh young coconut water, carbohydrate-
electrolyte beverage and plain water, J. Phy-
siol. Anthr. Appl. Hum. Sci. 21 (2002) 93–104.
[10] Rao G.V.S., Naik B.J., Giridharan M.P., Ste-
phen R., Balakrishnan P.C., Identification of
superior coconut cultivars suitable for tender
nut purpose, J. Plant. Crops 36 (2008) 204–
206.
[11] Anzaldo F.E., Kintinar Q.L., Recto P.M.,
VelascoR.U.,De LaCruz F.,JacalneA., Coco-
nut water as intravenous fluid, Philipp. J.
Coconut Stud. 10 (1985) 31–43.
[12] GatchalianM.M.,DeLeonS.Y., YanoT., Com-
parative profiles of young coconut (Cocos
nucifera L.) from fresh and stored nuts, Food
Qual. Prefer. 4 (1993) 193–200.
[13] Ranasinghe C.S., Wimalasekara R., Techni-
cal guidelines to enhance shelf-life of tender
King coconut for the export market, Indian
Coconut J. 37 (2006) 17–19.
[14] Thamban C., Subashbabu K., Venugopal R.,
Muralidharan K., Integrated approach for
marketing of minimally processed tender
coconuts,Indian Coconut J. 37 (2007) 2–7.
[15] ConsignadoT.O.,Tabora P.C.,CreenciaR.P.,
Physico–chemical changes in stored young
coconut, Philipp. Agric. 60 (1976) 256–270.
[16] Maciel M.I., Oliveira S.L., Da Silva I.P., Effects
of different storage conditions on preserva-
tion of coconut (Cocos nucifera) water,J.
Food Process. Preserv. 16 (1992) 13–22.
[17] Queiroz R., Aroucha E., Tomaz H., Pontes F.,
Ferreira R., Analise sensorial da agua-de-
coco durante o armazenamento dos frutos da
cultivar anao verde, Rev. Caatinga 22 (2009)
1–1.
[18] Walter E.H.M., Nascimento M.S., Kuaye A.Y.,
Efficacy of sodium hypochlorite and perace-
tic acid in sanitizing green coconuts,Lett.
Appl. Microbiol. 49 (2009) 366–371.
[19] Assis J.S. de, Resende J.M., Oliveira e Silva
F., Ribeiro dos Santos C., Nunes F., Tecnicas
para colheita e pos-colheita do coco verde,
Comun. Tec. Embrapa Semi-Arido, 2000,
Brazil, 6 p.
[20] Jarimopas B., Kuson P., A young-coconut-
fruit-opening machine,Biosyst. Eng. 98
(2007) 185–191.
[21] Jarimopas B., Ruttanadat N., Development of
a young coconut fruit trimming machine, J.
Food Eng. 79 (2007) 752–757.
[22] Wazir S.K.S., Technologies on environment–
friendly young tender coconuts, in: Proc.
Cocotech Meet., APCC (Ed.), Manila, Phi-
lipp., 1997.
[23] Raju V.K, Zahida P.M, Minimal processing of
tender coconut,Indian Coconut J. 37 (2007)
22–23.
[24] Viana F.M.P., Uchoa C.N., Vieira I.G.P., Freire
F.C.O., Saraiva H.A.O., Mendes F.N.P., Mini-
mal processing, modified atmosphere, che-
mical products and cooling to control post-
harvest basal rot of fresh green coconut fruits
(Cocos nucifera),Summa Phytopathol. 34
(2008) 326–331.
[25] Sison B.C.J., Disposal of coconut processing
waste, Philipp. J. Coconut Stud. 11 (1977)
39–41.
Coconut water preservation and processing
Fruits, vol. 67 (3) 169
[26] Pramith P., Oil separation from coconut water
by microfiltration method, Rep. No. 62 17, Ntl.
Food Res. Inst., Tsukuba, Ibaraki, Japan,
1998.
[27] Joson L., Coconut water utilization, Cocon-
uts Today 7 (1989).
[28] Wickramasinghe R.H., Biomedical and envi-
ronmental aspects of some coconut–derived
products and their production processes in
Sri Lanka, Cocos 13 (1998–1999) 8–20.
[29] Del Rosario E.J., Papa G.M., Reyes C.S.,
Concentration of coconut water by plate-
and-frame reverse osmosis using composite
membranes,Philipp. J. Coconut Stud. 13
(1988) 36–42.
[30] Sanchez P.C., Collado L.S., Gerpacio C.L.,
Lapitan H., Village level technology of proces-
sing coconut water vinegar, Philipp. Agric.
(1985) 439–448.
[31] Angeles O.R., Baraquio W.L., Dalmacio I.F.,
Segubre E.M., Optimization and cost of xan-
than gum production from coconut water by
Xanthomonas campestris pv. campestris
NRRL 1459, 29th Annu. Convention Philipp.
Soc. Microbiol., Inc. Laoag, Ilocos Norte, Phi-
lipp., 2000.
[32] Prasad V., Reeja S., Development of a selec-
tive media for bifidobacteria using coconut
water, Indian J. Dairy Sci. 59 (2006) 144–150.
[33] Banzon A.J., Gonzalez O.N., De Leon S.Y.,
Sanders P.C., Coconut as food, PCRDF,
Quezon City, Philipp., 1990.
[34] Alaban C.A., Studies on the optimum condi-
tions for "nata de coco" bacterium or "nata"
formation in coconut water, Philipp. Agric. 45
(1962) 490–516.
[35] Budhiono A., Rosidi B., Taher H., Iguchi M.,
Kinetic aspects of bacterial cellulose forma-
tion in nata-de-coco culture system, Carbo-
hydr. Polym. 40 (1999) 137–143.
[36] Hegde S.V., Bio-confectionaries from coco-
nut water, Indian Food Pack. (1996) 50–52.
[37] Iguchi M., Yamanaka S., Budhiono A., Bac-
terial cellulose: a masterpiece of nature's art,
J. Mater. Sci. 35 (2000) 261–270.
[38] Nishi Y., Uryu M., Yamanaka S., Watanabe K.,
Kitamura N., Iguchi M., Mitsuhashi S., The
structure and mechanical properties of
sheets prepared from bacterial cellulose. II.
Improvement of the mechanical properties of
sheets and their applicability to diaphragms
of electroacoustic transducers, J. Mater. Sci.
25 (1990) 2997–3001.
[39] Sabularse V., Montalbo M., Hernandez H.,
Serrano E., Preparation of nata de coco-
based carboxymethylcellulose coating and
its effect on the post-harvest life of bell pep-
per (Capsicum annuum l.) fruits, Int. J. Food
Sci. Nutr. 60 (2009) 206–218.
[40] Jagannath A., Kalaiselvan A., Manjunatha
S.S., Raju P.S., Bawa A.S., The effect of pH,
sucrose and ammonium sulphate concentra-
tions on the production of bacterial cellulose
(nata-de-coco) by Acetobacter xylinum,
World J. Microbiol. Biotechnol. 24 (2008)
2593–2599.
[41] Magda R.R., Coco-softdrink: health beve-
rage from coconut water, Food Mark. Tech-
nol. (1992) 22–23.
[42] Montenegro H.M., Coconut oil and its bypro-
ducts, J. Am. Oil Chem. Sci. 62 (1985) 259–
261.
[43] Srivatsa A.N., Sankaran R., Preservation of
tender coconut water in polymeric pouches
and metal cans, Indian Coconut J. 26 (1/2)
(1995) 13.
[44] Chowdhury M.M., Aziz M.G., Uddin M.B.,
Development of shelf-stable ready-to-serve
green coconut water, Biotechnol. 4 (2005)
121–125.
[45] Costa L.M.C., Maia G.A., Costa J.M.C.,
Figueiredo R.W. de, Souza P.H.M. de, Avalia-
cao de agua-de-coco obtida por diferentes
metodos de conservacao, Cienc. Agrotec.
(Brazil) 29 (2005) 1239–1247.
[46] Tzeng E., Chen H.E., Preventing nonenzyma-
tic browning in coconut water during sterili-
zation, Food Sci. (Taiwan) 25 (1998) 304–313.
[47] Gabriel A.A., Cruz K.G.S., Guzman J.A.D.D.,
Thermal death times of Escherichia coli in
young coconut endosperm beverage, J.
Food Process. Preserv. 33 (2009) 136–144.
[48] Fontan R. da C.I., Santos L.S., Bonomo
R.C.F.,LemosA.R.,RibeiroR.P., VelosoC.M.,
Thermophysical properties of coconut water
affected by temperature, J. Food Process
Eng. 32 (2009) 382–397.
[49] FoxP.F., Foodenzymology, ElsevierSci. Publ.
Ltd., Barking, U.K., 1991.
[50] Campos C.F., Souza P.E.A., Coelho J.V.,
Gloria M.B.A., Chemical composition,
enzyme activity and effect of enzyme inacti-
vation on flavor quality of green coconut
water,Philipp. J. Coconut Stud. 20 (1996)
487–500.
[51] Abreu L.F., Faria J. de A.F., Influencia da tem-
peratura e do acido ascorbico sobre a esta-
bilidade fisico-quimica e atividade enzima-
tica da agua de coco (Cocos nucifera L.)
acondicionada assepticamente, Cienc. Tec-
nol. Aliment. 27 (2007) 226–232.
170 Fruits, vol. 67 (3)
A. Prades et al.
[52] Terefe N.S., Yang Y.H., Knoerzer K., Buckow
R., Versteeg C., High pressure and thermal
inactivation kinetics of polyphenol oxidase
and peroxidase in strawberry puree, Innov.
Food Sci. Emerg. Technol. 11 (2010) 52–60.
[53] Valderrama P., Marangoni F., Clemente E.,
Efeito do tratamento térmico sobre a activi-
dade de peroxidase (POD) e polyphenoloxi-
dase (PPO) en maçã (Mallus comunis),Cienc.
Tecnol. Aliment. 21 (2001) 321–325.
[54] Lee T.H., Chua L.S., Tan E.T.T., Yeong C., Lim
C.C., Ooi S.Y., Aziz R.B., Aziz A.B., bin
Sarmidi M.R., Kinetics of thermal inactivation
of peroxidases and polyphenol oxidase in
pineapple (Ananas comosus), Food Sci. Bio-
technol. 18 (2009) 661–666.
[55] Kikuda A.T., Tadini C.C., Fernandes R.,
Modelo de primeira ordem multicomponente
para inativação térmica em processo des-
contínuo da peroxidase e polifenoloxidase
presentes na água de coco verde (Cocos
nucifera L.), in: SBCTA (Ed.), XVIII Congr.
Bras. Ciênc. Tecnol. Aliment., Porto Alegre,
Brazil, 2002.
[56] Murasaki-Aliberti N.D., Silva R.M.C. da, Gut
J.A.W., Tadini C.C., Thermal inactivation of
polyphenoloxidase and peroxidase in green
coconut (Cocos nucifera) water, Int. J. Food
Sci. Technol. 44 (2009) 2662–2668.
[57] Matsui K.N., Gut J.A.W., Oliveira P.V., Tadini
C.C. de, Inactivation kinetics of polyphenol
oxidase and peroxidase in green coconut
water by microwave processing,J. Food Eng.
88 (2008) 169–176.
[58] Serrano-Martínez A., Fortea M.I., del Amor
F.M., Núñez–Delicado E., Kinetic characteri-
sation and thermal inactivation study of par-
tially purified red pepper (Capsicum annuum
L.) peroxidase, Food Chem. 107 (2008) 193–
199.
[59] Fortea M.I., López-Miranda S., Serrano-Martínez
A., Carreño J., Núñez-Delicado E., Kinetic
characterisation and thermal inactivation
study of polyphenol oxidase and peroxidase
from table grape (Crimson Seedless),Food
Chem. 113 (2009) 1008–1014.
[60] Anthon G.E., Barrett D.M., Kinetic parame-
ters for the thermal inactivation of quality-
related enzymes in carrots and potatoes, J.
Agric. Food Chem. 50 (2002) 4119–4125.
[61] Matsui K.N., Granado L.M., Oliveira P.V. de,
Tadini C.C., Peroxidase and polyphenol oxi-
dase thermal inactivation by microwaves in
green coconut water simulated solutions,
LWT - Food Sci. Technol. 40 (2007) 852–859.
[62] Rolle R., Good practice for the small–scale
production of bottled coconut water, Agricul-
tural and food engineering training and
resource materials, FAO, Training guide,
Rome, Italy, 2007.
[63] Duarte A.C.P., Coelho M.A.Z., Leite S.G.F.,
Identification of peroxidase and tyrosinase in
green coconut water, Cienc. Tecnol. Aliment.
3 (2002) 266–270.
[64] Satin M., Amorrigi G., Coconut beverage,
FAO, Patent GB2318969 depos. 13 May
1998, Rome, Italy, 1998.
[65] Diop N., Caractérisation physico-chimique
de l'eau de la noix de coco verte (Cocos
nucifera L.) et essais de stabilisation par
techniques membranaires, ENSIA–SIARC,
Master thesis, Montpellier, France, 2005,
132 p.
[66] Jayanti V., Rai P., Dasgupta S., De S., Quan-
tification of flux decline and design of ultrafil-
tration system for clarification of tender
coconut water, J. Food Process Eng. 33
(2010) 128–143.
[67] Carvalho J.M. de, Maia G.A., Figueiredo R.W.
de, Brito E.S. de, Rodrigues S., Storage sta-
bility of a stimulant coconut water-cashew
apple juice beverage, J. Food Process. Pre-
serv. 31 (2007) 178–189.
[68] CarvalhoJ.M.de, Maia G.A.,Figueiredo R.W.,
Brito E.S. de, Rodrigues S., Development of
a blended beverage consisting of coconut
water and cashew apple juice containing caf-
feine, Int. J. Food Sci. Technol. 42 (2007)
1195–1200.
[69] Carvalho J.M. de, Maia G.A., Brito E.S. de,
Crisostomo L.A., Rodrigues S., Composicao
mineral de bebida mista a base de agua–de–
coco e suco de caju clarificado, Bol. Cent.
Pesqui. Process. Aliment. 24 (2006) 1–12.
[70] Lima A.D, Maia G.A., Sousa P.H.M. de, Prado
G.M. do, Rodrigues S., Storage stability of a
stimulant coconut water-acerola fruit juice
beverage, Int. J. Food Sci. Technol. 44 (2009)
1445–1451.
[71] Silva F.V.G. da, Maia G.A., Sousa P.H.M. de,
Lima A.S. da, Costa J.M.C. da, Figueiredo
E.A.T. de, Evaluation of the stability of mixed
beverage elaborated with coconut water and
passion fruit juice, Acta Sci. Technol. 28
(2006) 191–197.
[72] Garcia B., Masa D.B., Rodriguez M.J., Rolle
R., Control of pink discoloration in coconut
water, Cord 23 (2007) 67–83.
[73] Damar S., Balaban M., Sims C., Continuous
dense–phase CO2processing of a coconut
Coconut water preservation and processing
Fruits, vol. 67 (3) 171
water beverage, Int. J. Food Sci. Technol. 44
(2009) 666–673.
[74] Costa L.M.C., Maia G.A., Costa J.M.C. da,
Figueiredo R.W. de, Rodrigues M. do C.P.,
Sousa P.H.M. de, Pinheiro A.M., Qualidade e
vida de prateleira da agua de coco obtida
pelo processo de enchimento a quente, Rev.
Bras. Armazenamento 31 (2006) 95–102.
[75] Magalhaes M.P., Gomes F. dos S., Modesta
R.C.D., Matta V.M. da, Cabral L.M.C.,
Conservação de ágna de coco verde per fil-
tração con membrana, Ciênc. Tecnol. Ali-
ment. 25 (2005) 72–77.
[76] Reddy K.D., Das M., Das S.K., Nonthermal
sterilization of green coconut water for pac-
kaging,J. Food Qual. 30 (2007) 466–480.
[77] Reddy K.V., Das M., Das S.K., Filtration resis-
tances in non–thermal sterilization of green
coconut water, J. Food Eng. 69 (2005) 381–
385.
[78] Naozuka J., Murasaki N.C., Tadini C.C.,
Oliveira P.V. de, Estudo da Influência de Pro-
cessos de Conservação na Distribuição de
Espécies Elementares em Água de Coco, in:
SBCTA (Ed.), XIX Congr. Bras. Ciênc. Tecnol.
Aliment., Recife, Brazil, 2004.
[79] Luvielmo M. de M., Vasconcelos M.A.M. de,
MarquesG.R.,Silva R.P.G.da, DamasioM.H.,
Influencia do processamento nas caracteris-
ticas sensoriais da agua-de-coco,Bol. Cent.
Pesqui. Process. Aliment. 22 (2004) 253–270.
[80] De Sousa R.A., Silva J.C., Baccan N., Cadore
S., Determination of metals in bottled coco-
nut water using an inductively coupled
plasma optical emission spectrometer, J.
Food Compos. Anal. 18 (2005) 399–408.
[81] Abreu L.F., Araujo A.V., Araujo E.A.F., El-Ouar
A.A., Neumann D., Morais M.M., Silva
M.A.A.P. da, Perfil sensorial e aceitabilidade
de amostras de agua-de-coco obtidas por
diferentes processos de fabricacao, Bol.
Cent. Pesqui. Process. Aliment. 23 (2005)
397–412.
[82] Pinheiro A.M., Machado P.H., Costa J.M.C.
da, Maia G.A., Fernandes A.G., Rodrigues M.
do C.P., Herreyra Hernandez F.F., Caracteri-
zaçao química, físico–química, microbiolo-
gica e sensorial de diferentes marcas de agua
decocopelo processo asseptico,Rev.Ciênc.
Agron. 36 (2005) 209–214.
[83] Fortes E.P., Lima A. de, Cronemberger M.G.
de O., Crispim L. da S., Qualidade físico–quí-
mica e microbiologica das aguas-de-coco
envasadas, comercializadas em Teresina,
Piaui, Rev. Hig. Aliment. 20 (2006) 87–90.
[84] Nunes B.N., Cruz A.G., Faria J.A.F., Sant’Ana
A.S., Silva R., Moura M.R.L., A survey on the
sanitary condition of commercial foods of
plant origin sold in Brazil, Food Control 21
(2010) 50–54.
[85] Walter E.H.M., Kabuki D.Y., Esper L.M.R.,
Sant’Ana A.S., Kuaye A.Y., Modelling the
growth of Listeria monocytogenes in fresh
green coconut (Cocos nucifera L.) water,
Food Microbiol. 26 (2009) 653–657.
[86] Gobin A., Falade K., Akingbala J., Effect of
packaging on physical, chemical and sensory
attributes of coconut water during storage, J.
Food Agric. Environ. 7 (2009) 62–65.
[87] Cesario M.C. de P., Andrade M.V.V., Coelho
A.A., Pereira S.M.de F., Martins M.L.L., Henry
F. da C., Avaliação físico–química da água de
coco, Hig. Aliment. 23 (2009) 39–42.
[88] Sabapathy S.N., Bawa A.S., Standards for
packed and preserved tender coconut water,
Indian Coconut J. 38 (2007) 2–8.
Conservación y transformación del agua de coco: una síntesis.
Resumen El producto. El agua de coco (Cocos nucifera L.) es un refresco tropical, cuyas propiedades
funcionales naturales interesan hoy a los industriales. Conservación. Este líquido procede de los cocos
inmaduros, cuya cosecha y almacenamiento son delicados. No obstante, algunos estudios llevados a cabo
sobre todo en Asia, tienden a demostrar que podrían existir tratamientos posteriores a la cosecha para
prolongar la duración de vida de los cocos inmaduros. Transformación. Lógicamente, el agua de coco
extraída del fruto es más fácil de manipular y transportar, pero su composición hace que sea particular-
mente sensible a las degradaciones biológicas y químicas. Hoy en día, en la industria, se emplean tra-
tamientos térmicos combinados con el uso de aditivos, sin embargo, otros tratamientos, tales como la
micro o la ultrafiltración, aún no están disponibles para este producto. Independientemente del proceso
de estabilización empleado, sigue siendo difícil preservar el sabor y el aroma originales del agua del coco.
Discusión. En la presente síntesis, por primera vez, se presentan los estudios sobre el agua de coco,
desde los más antiguos hasta los más recientes. Éstos dan lugar a proponer ideas para mejorar nuestro
conocimiento acerca de este singular zumo de frutas tropical.
Francia / Cocos nucifera / coco / agua de coco / etapas de desarrollo de la planta /
maduración / calidad / almacenamiento / preservación / aptitud para la conservación /
procesamiento
... Coconut water is largely consumed in tropical countries, appreciated for its sweetness and freshness, rich in sugars and minerals, and it is taken directly from the inner part of the fruit (Walter et al., 2014;Prades et al., 2012). The World Health Organization highly recommends this drink for rehydration in the cases of cholera and diarrhea due to its high content in potassium, which makes it also a natural isotonic drink for athletes (Walter et al., 2014). ...
... Coconut water is also a major by-product in coconut processing plants, such in the processing of ready-to-eat coconut, namely fresh minimally processed or desiccated coconut (Prades et al., 2012). Nevertheless, due to its low pH (5.8) and high water activity, in addition to high sugar content, this product allows a fast microbial growth, which requires an extra care when using this product (Prades et al., 2012;Walter et al., 2014) Grape pomace is also another major industrial by-product that has been described as bioactives source, due to the presence of polyphenols, oligosaccharides, minerals that provide its aqueous extract with antioxidant, antimicrobial and prebiotic potentials (Costa et al., 2019a). ...
... Coconut water is also a major by-product in coconut processing plants, such in the processing of ready-to-eat coconut, namely fresh minimally processed or desiccated coconut (Prades et al., 2012). Nevertheless, due to its low pH (5.8) and high water activity, in addition to high sugar content, this product allows a fast microbial growth, which requires an extra care when using this product (Prades et al., 2012;Walter et al., 2014) Grape pomace is also another major industrial by-product that has been described as bioactives source, due to the presence of polyphenols, oligosaccharides, minerals that provide its aqueous extract with antioxidant, antimicrobial and prebiotic potentials (Costa et al., 2019a). GP as a source of phenols and fiber has been applied in the formulation of a wide variety of functional foods, including fermented milks, yogurt, ice-creams, salad dressing and cheeses (Dos Santos et al., 2017;Karnopp et al., 2017;Hwang et al., 2009;Lucera et al., 2018;Tseng and Zhao, 2013). ...
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A bioactive grape pomace extract (GPE) rich in polyphenols was encapsulated into alginate (GPE-Alg) or chitosan (GPE-CS) microparticles, later incorporated into coconut water. Biological and sensory properties were evaluated. Storage was performed at 4 ˚C followed by quality assessment. Evaluation of coconut water after gastrointestinal digestion on the growth pathogens and probiotic bacteria showed that the fortification with GPE-Alg and GPE-CS decreased the growth rate of pathogens when compared to non-fortified water, while promoted the growth of different bifidobacteria and lactobacilli strains. Sensory analysis allowed to conclude that the incorporation of GPE-Alg and GPE-CS did not promote significant differences in most of evaluated attributes, including aroma and flavor. The storage at 4 ˚C allowed a reduced degradation rate of total phenolics and anthocyanins for GPE-Alg and GPE-CS fortified beverage, with the half-life time of phenolic acids higher for GPE-Alg beverage and the half-life time of anthocyanins higher for GPE-CS fortified water. This study opens the opportunity in the application of food by-products in the development of novel efficient functional foods and beverages.
... It is very rich in potassium, sodium, chloride, and carbohydrate, and meets the hydration and improved performance indices of a sports drink (Ismail et al., 2007;Idárraga and Aragón-Vargas, 2010;Kalman, 2012). Coconut water also has antioxidants that help in neutralizing reactive oxygen species produced during long duration of exercise (Prades et al., 2012;Dayrit, 2015). ...
... The beverage is consumed either as sweetened/flavored coconut water or as plain coconut water. Further, commercial packaging offers variants such as chilled or frozen, chilled pasteurized, carbonated or micro-filtered products (Prades et al., 2012). Such a beverage however is largely unexplored in the African countries, despite significant coconut production. ...
... It is very rich in potassium, sodium, chloride, and carbohydrate, and meets the hydration and improved performance indices of a sports drink (Ismail et al., 2007;Idárraga and Aragón-Vargas, 2010;Kalman, 2012). Coconut water also has antioxidants that help in neutralizing reactive oxygen species produced during long duration of exercise (Prades et al., 2012;Dayrit, 2015). ...
... The beverage is consumed either as sweetened/flavored coconut water or as plain coconut water. Further, commercial packaging offers variants such as chilled or frozen, chilled pasteurized, carbonated or micro-filtered products (Prades et al., 2012). Such a beverage however is largely unexplored in the African countries, despite significant coconut production. ...
... It is very rich in potassium, sodium, chloride, and carbohydrate, and meets the hydration and improved performance indices of a sports drink (Ismail et al., 2007;Idárraga and Aragón-Vargas, 2010;Kalman, 2012). Coconut water also has antioxidants that help in neutralizing reactive oxygen species produced during long duration of exercise (Prades et al., 2012;Dayrit, 2015). ...
... The beverage is consumed either as sweetened/flavored coconut water or as plain coconut water. Further, commercial packaging offers variants such as chilled or frozen, chilled pasteurized, carbonated or micro-filtered products (Prades et al., 2012). Such a beverage however is largely unexplored in the African countries, despite significant coconut production. ...
Chapter
Full-text available
This chapter discusses the potential application of Cocus nucifera (Coconut) in bioremediation to sustainably improve soil health. Environmental pollution over the years has adversely affected agricultural soils leading to low yield and food insecurity. Conventional and physical methods have proven expensive and ineffective. The potential use of coconut in remediation of waste water pollution and agricultural soils have been discussed in this chapter as well as strategies to achieve optimum bioremediation. The environmental impact of cultivating coconut has shown potential in different parts such as leaves, stems, fibers and shell or the whole plant in bioremediation. The strategy of incorporating coconut cultivation, as a means of alleviation of soil pollutions, and improving productivity should provide a new avenue to the agricultural practices.
... Coconut water is highly valued due to its nutritional characteristics and special flavor. It contains a remarkable content of salts, minerals, vitamins, sugars, amino acids and enzymes [1][2][3]. Among these compounds, sugars are the main component of soluble solids in coconut water, and the sweetness is an important criterion for evaluating the quality [4]. ...
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Full-text available
In this study, tender coconuts were treated with high-intensity ultrasound (US) for 20 min at a frequency of 20 kHz and a power of 2400 W. Compared with control group, US treated coconut water had a higher content of total soluble solid and sugar/acid ratio along with a lower pH value and conductivity, and the contents of sucrose, fructose and glucose were also higher. Results from HS-SPME/GC–MS showed that there was no significant difference in the content of volatile compounds in coconut water before and after US treatment. The activities of sugar metabolism enzymes such as sucrose phosphate synthase, sucrose synthase, acid invertase (AI) and neutral invertase were inhibited by US, of which AI had the strongest inactivation. Circular dichroism and fluorescence spectra showed that the secondary and tertiary structure of AI molecule were destroyed with the increase of US intensity and time, which was confirmed by the change of particle size distribution pattern and scanning electron microscopy. Molecular docking and molecular dynamics showed that US treatment prevented the recognition and binding of sucrose and AI molecules, thereby inhibiting the decomposition of sucrose. In conclusion, our results indicate that US can inhibit the activity of AI and maintain the sugar content to increase the quality as well as extend the shelflife of coconut water, which will bring more commercial value.
... Coconut (Cocos nucifera L) water is an energizing, refreshing, and nourishing drink that is widely consumed in tropical countries [1]. According to Prades [2], coconut water signifies between 15% and 30% of the weight of the nut. The amount of coconut water that can be harvested from each nut is about 300 ml. ...
... Immature coconuts, when they reach about 5 months of age, are gathered from the coconut tree to collect coconut water. Young coconuts contain sweet, flavourful water and are often sold in the tropics by native street vendors with a hole punched into them for a straw [4]. Coconut water collected from coconuts younger than 5 months are bitter. ...
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The aim of the present research is to observe the changes in pH, acidity, and ethanol content during the storage of water from Salalah and Sri Lanka cultivar coconuts in the presence and absence of dry yeast. Coconut water from Salalah and Sri Lanka cultivars were subjected to aerobic fermentation in shaker flasks at room temperature of 252 C and 50 rpm for 28 days. pH, acidity and ethanol content were observed every 7 days. pH decreased while acidity and ethanol content increased with increase in fermentation time. Finally, Salalah coconut water was found to be suitable for use as a fermented energy drink than Sri Lanka coconut water grown in Salalah, Oman.
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Coconut water (CW) is a nutritious drink containing highly complex components. Therefore, CW has an interesting unique physicochemical nature to investigate. This study aims to know the UV-Vis spectra of CW as flour solvent of soybean, black rice, and red rice. Each flour was homogenized with ratio of 1:10 (w/v) in fresh CW (f-CW) or heated-CW at 50°C (h-CW). The homogenized flour was centrifuged at 4500 rpm, 4°C, for 5 minutes. The supernatant was analyzed based on UV-vis spectra, pH, and turbidity. Flour that dissolved in CW shows peaks only in the UV spectrum, whereas the flour dissolved in water shows peaks in the UV-vis spectrum. Generally, flour component more dissolves in the CW than in the water. Turbidity value of flour dissolved in the CW lower than those dissolved in the water. The flour dissolved in the CW slightly acid than in the water. The flour dissolved in h-CW shows a slight decrease in absorbance value compared to the f-CW, meanwhile, flour dissolved in water generally have relatively the same spectrum profile.
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The effect of storage temperature and time on physicochemical (total soluble solids, pH, titratable acidity, and optical density) and microbiological (total plate count and yeast and mould count) properties of green (GC) and mature coconut (MC) water were determined between 4 and 35 °C for up to 24 h. When held at temperatures above 25 °C, total soluble solids of coconut water reduced slightly, whereas pH decreased concomitantly with the increase in titratable acidity. These changes correlate positively with storage temperature and occurred at a faster rate in MC water than in GC. Both GC and MC could be held at temperatures between 25 and 35 °C for up to 12 and 6 h, respectively, after which the samples could become acidified and microbiologically unsafe to be consumed. At 4 °C, both GC and MC could be held for 24 h with acceptable microbiological counts.
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Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR), in combination with chemometrics, was explored as a rapid method of detecting sugar adulteration in coconut water. In a simulated experiment, coconut water was substituted with binary sugars, mixed sugars, and high fructose corn syrup and discriminated using the fingerprint infrared band region between 1200-950 cm⁻¹. Principal component analysis (PCA) performed on data pre-processed by the Savitzky-Golay smoothing and gap-segment derivative, revealed data clusters discernible by the type and level of substituted sugars, enabling visual diagnosis of the similarity and anomalous features in the dataset. Statistical performance metrics following a cross-validated partial least square (PLS) regression indicated the prediction of adulterant sugars at single-digit percent substitutions. A parallel exploratory analysis of 31 different commercial coconut water samples showed a distinct PCA clustering for samples bearing the label “added sugar”, suggesting the potential use of the methods to screening samples for undeclared sugar additions.
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The objective of the present study was to characterize some coconut water samples commercialized in supermarkets of the Southeastern (Brazil) region and to correlate such characteristics to the different manufacture technologies employed. Quantitative descriptive analysis was utilized to determine the sensorial profile of three commercial coconut water brands (cooled, frozen and sterilized), available in the market of Campinas-SP (Brazil) and the consumer acceptance of the samples was evaluated applying an affection test. It was observed that the samples were deprived of the sensorial characteristics, presenting strange flavors and aromas (off-flavors) described as tonic water, rust and putridity, as well as a low acceptance. These result can be directly related to the type of processing applied to the product, evidencing the necessity of a fast improvement of the coconut water processing.
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The heat tolerance and the inactivation kinetics of peroxidase (POD) and polyphenol oxidase (PPO) in pineapples (Ananas comosus) were studied in the temperature range 45-95°C. The kinetic parameters, such as deactivation rate constant (k), activation energy (E.,), and decimal reduction rate (D) of the thermal inactivation process, were determined. POD in pineapples showed biphasic inactivation behavior at temperatures range 45-75T but was monophasic at 85-95°C. This indicate that POD has 2 isozymes, namely heat labile and heat resistant, with Ea of 68.79 and 93.23 kJ/mol, respectively. On the other hand, the heat denaturation of pineapple PPO could be described as simple monophasic first-order behavior with Ea of 80.15 kJ/mol. Thus, the results of this study is useful in blanching technology where it shows a shortened time with higher temperature can be applied. The determination of the heat tolerance and inactivation POD and PPO, at different temperature range as done in the present work, was very important to improve the blanching process. This also will help to optimize the pineapple canning process which is one of the most important food industries in many tropical regions.
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The coconut palm is said to have been introduced to Sri Lanka over 2300 years ago. Several industries have grown up to process products from this tree. Many of these production units have traditionally been located in rural areas and any adverse environmental impacts have in the past been considered negligible or not very serious. However, with the development of these industries and the increasing density of population more concern is being taken to identify and mitigate any adverse environmental effects and biomedical effects on workers in these industries as well as the general public. The industries examined in this article relate to the production of I) coconut oil, 2) desiccated coconut, 3).charcoal and activated carbon and 4) husk fibre and coir pith. Biomedical aspects of some of these products are also noted as well as articles which can serve as guides to the literature in each area.
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The pink discoloration in coconut water is a result of the initial enzymatic action of polyphenol oxidase (PPO) on the phenolic substrates which are naturally present in the product. Activity of the enzyme is further enhanced by metal contamination such as copper and exposure of the product to high temperature during its processing and storage. The optimum copper concentration to initiate pinking in coconut water was established at 3.96 x 10-04 mM. The PPO level was also shown to vary among coconut varieties and ages. When subjected to optimum conditions for enzymatic activity, the water from younger nuts (7-8 months old) went pink while mature nuts (9-10 months old) showed no discoloration. Application of food-grade resins to remove the phenolic substrates in coconut water was deemed as a possible solution to prevent the discoloration. Further testing in this area needs to be done.
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O extrato enzimático foi preparado a partir da polpa e casca da maçã de cultivares Fuji e Gala utilizando tampão fosfato de sódio 100mM, pH 5,0 como solução extratora. Dentre as análises determinou-se a concentração de proteína nos extratos enzimáticos concentrados de polpa e casca, sendo que o cultivar Fuji apresentou teores mais elevados em comparação ao cultivar Gala. Os tratamentos térmicos foram realizados nas temperaturas de 60, 65, 70 e 75°C por períodos que variaram de 1 a 10 minutos, sendo observado diminuição da atividade de POD e PPO com o aumento da temperatura e tempo; no entanto a POD não chegou a ser inativada em nenhum dos tratamentos realizados. A PPO foi inativada totalmente após 10 minutos de tratamento a 75°C. A eletroforese mostrou uma composição diferente de isoenzimas aniônicas e catiônicas da peroxidase.