 *Corresponding author.

Email: budi11agro@gmail.com

eISSN: 2550-2166 / © 2019 The Authors. Published by Rynnye Lyan Resources

  Food Research 4 (4) : 957 - 963 (August 2020)
  Journal homepage: http://www.myfoodresearch.com

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The quality of nata de coco from sawarna and mapanget coconut varieties to the

time of storing coconut water

1,*Santosa, B.,2Wignyanto, W., 2Hidayat, N. and 2Sucipto, S.

1Department of Agro Industrial Technology, Tribhuwana Tunggadewi University, Malang, Indonesia
2Department of Agro Industrial Technology, Brawijaya University, Malang, Indonesia

Article history:

Received: 9 November 2019

Received in revised form: 3

December 2019

Accepted: 3 December 2019

Available Online: 23

December 2019

Keywords:

Nata de coco,

Coconut,

Storage time

DOI:
https://doi.org/10.26656/fr.2017.4(4).372

Abstract

This study was aimed to find out the type of coconut water and its storage time in order to

get the best of nata de coco quality. The design of experiments conducted in this study

nested random design 2 factors. The main factor coconut varieties consisting of two

levels: palm fruit varieties sawarna and the coconut fruit varieties mapanget, the storage

time of coconut water is nested in palm varieties which consists of 5 levels i.e. 0, 6, 12, 18

and 24 hrs. Each treatment was repeated 3 times so that the total of all 30 samples. The

results showed that the nata de coco best coconut water obtained from fresh. However, it

demonstrated that coconut water stored for 6 hrs of varieties of sawarna, the quality of

nata de coco generated no difference from nata de coco coconut water varieties of fresh

mapanget (0 hrs of storage) and reducing sugar in coconut water varieties sawarna is an

important factor as the carbon source for Acetobacter xylinum. Thus, in order to get nata

de coco with the best quality, coconut water of sawarna varieties which is still fresh or has

been stored for 6 hrs can be used.

1. Introduction

Coconut water as a product of coconut fruits

processed can be used as raw materials for making nata

(Hamad et al., 2011; Lestari et al., 2014). Nata raw

material is also easily obtained, available at any time and

there are in each area. Indonesia has the largest land oil

plants in the world with a total area of 3.82 million

hectares with a production of 15.9 billion grains of

coconuts per year which are mostly used to meet

domestic needs (Rukmana and Yudirachman, 2016).

This suggests that the use of coconuts by Indonesian

society is very high, which means coconut water waste

generated is also high.

The utilization of coconut water as raw material for

making nata de coco so far is still derived from a mixture

of various coconut varieties. Nutrient content, especially

sugar in coconuts, is different for each variety. Varieties

that are easily obtained, especially in Indonesia, are

coconut varieties, especially coconut varieties in

Sawarna (DSA) and coconut in Mapanget (DMT)

(Rukmana and Yudirachman, 2016). This potential is

one of the supporters of the continued supply of nata de

coco raw materials.

DMT and DSA varieties have the same pH of 5.5

and total DMT solids are 5.95% higher than DSA of

5.69%. DSA reduction sugar by 3.95% is greater than

DMT by 3.11%, whereas DMT potassium content is

greater, ie 280 mg/100 g compared to DSA of 249.7

mg/100 g. DSA varieties with DMT have the same

sodium content of 51 mg/100 g, while the vitamin C

content of DMT is greater (2.46 mg/100 g) when

compared to DSA (2.24%). Calcium content of DMT is

greater, which is 40 mg/100 g when compared to DSA of

35.3 mg/100mL (Runtuwu et al., 2011)

Nata de coco fiber in the form of cellulose at 2.5%

(Hidayat et al., 2006; Gea et al., 2010; Ma et al., 2012).

In addition to the high fiber content, this product has

other advantages that the manufacturing process is easy

and does not require a long time. This differs from the

fruits and vegetables that require a long time to be

consumed as a source of fiber.

Workmanship for using coconut water from a

mixture of different varieties of coconuts while the use

of coconut water from one variety to the manufacture of

this product has not been done. The content of nutrients,

especially sugar in the coconut fruit is different for each

variety. Sugar in the making of this beverage products

plays a very important because cellulose fiber is formed

during the fermentation of sugars derived from (Jung et

al., 2010; Castro et al., 2011; Anas et al., 2012;

Sunagawa et al., 2013).

https://orcid.org/0000-0003-0150-4190

https://orcid.org/0000-0001-6005-7656

https://orcid.org/0000-0002-4345-9060

https://orcid.org/0000-0002-2450-1542

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Coconut water use in the manufacture of these

products is generally nata maker cannot use fresh

coconut water directly due to various factors such as the

distance between the source of raw materials to the place

of production, transportation constraints and limitations

of the production site. Factors that cause coconut water

should be kept by the manufacturer before it is processed

further nata.

During storage, fermented coconut water will be

carried out by the natural microbes that may cause

deterioration in chemical nutrients, especially in sugar

because sugar is the best carbon source for microbial

growth (Naufalin and Wibowo, 2004; Zeng et al., 2011;

Alwi et al., 2015). Decreased levels of this sugar will

affect the quality of the resulting cellulose fibers.

Research on the use of coconut water that has undergone

a process of storage as a raw material of nata de coco has

not been conducted so far. This study was aimed to

investigate the type of coconut water and its storage time

to obtain the best quality of nata de coco.

2. Materials and methods

2.1 Raw material

The materials used in this study were the coconut

water from coconut varieties sawarna (DSA) and

varieties mapanget (DSM) enough old, obtained from

Dampit village of Malang. Old age criteria from coconut

husk are dark brown color, flesh thickness of 1.5 cm and

coconut milk can be taken. Figure 1 shows the epidermis

color and thickness of coconut flesh between Sawarna

(DSA) and Mapanget (DMT) varieties. Acetobacter

xylinum obtained from the Microbiology Laboratory of

the UB, sucrose, glucose, extracts of yeast, peptone

bacto, glacial acetic acid, Na2HPO4, MgSO47H2O,

gelatin, H2SO4, NaOH, Aquadest, K2SO4 and CaCO3.

2.2 Breeding Acetobacter xylinum in starter

Starter namely strains A. xylinum cultured in the

medium. Making the starter is done by growing a pure

strain into the coconut water from coconut varieties

sawarna and the coconut fruit varieties mapanget were

enriched using nutrients in the form of sucrose and

ammonium sulfate and pH of the media was made into a

4 by adding glacial acetic acid. The number of A.

xylinum that will be inoculated into the fermentation

medium uniform i.e. 2 x 107 cells/mL. To reach the cell

number is calculated directly using hemocytometer

(Oliveira et al., 2015; Sulistyani et al., 2016)

2.3 Nata de coco production

Good coconut water from coconut varieties sawarna

and varieties mapanget is boiled at 100°C for 15 mins.

Further thereto are added nutrients in the form of sucrose

2% and 0.06% ammonium sulfate number then boiled

again. After the media poured into fermentation tanks

and closed using parchment paper and further straining

cloth is tied using a rubber band. Media were allowed to

cool for 12 hrs after it was made into a media pH 4 by

adding glacial acetic acid into 20 mL of media. Starter

inoculation A. xylinum into the media so that it ferments

further incubated for 14 days.

2.4 Experimental design

The experimental design used in this study is a

randomized design nested 2 factors. The first factor

coconut varieties consisting of two levels, namely Vr1 =

varieties sawarna (DSA), Vr2 = varieties mapanget

(DMT). While the second factor old coconut water

storage which consist of 5 level including P1 = 0 hr, P2 =

6 hrs, P3 = 12 hrs = 18 hrs P4, P5 = 24 hrs. The second

factor is nested on the first factor, each treatment was

repeated 3 times, so we obtained 30 samples.

2.5 The observation of nata de coco

Observation of pH in the nata de coco fermentation

media was carried out every day for 14 days (Brooks et

al., 2013), cell development of A. xylinum methods Total

Plate Count/ TPC (AOAC, 2002) and the thickness of

nata (Gayathry, 2015). Whereas, the weight parameters

(Gayathry, 2015) and the total fiber content of nata de

coco (McCleary, 2014) were observed on day 14 after

harvesting.

2.6 Data analysis

Data obtained during the study were analyzed using

Analysis of Variance (ANOVA). If there is a real

difference then a further test by using Honestly

Significant Difference (HSD) at α = 5% is conducted

(Hanafi, 2012; Kumalaningsih, 2012).

3. Results and discussion

3.1 pH

Different varieties of coconut and coconut water

storage time significantly affect the condition of l growth

A. xylinum in the process of nata pellicle formation. The

stages of the formation of nata takes place during the

fermentation process. During the fermentation process,

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Figure 1. Color the epidermis as well as the thickness of the

coconut meat DSA and DMT

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the pH of the media as one of the conditions for the

growth of A. xylinum had decreased since the first days

of fermentation. It can be seen in Figure 2.

Varieties of media pH DSA and DMT are

significantly different. DMT varieties pH is more acidic

than varieties DSA though, during fermentation, a

decrease in pH between the two varieties is likely to be

similar. Different coconut water storage time

significantly gave an effect on the condition of the media

pH. The pH of fresh coconut water varieties DMT (0 hrs

of storage) gives the average pH more acidic than other

treatments do. The longer the storage time of coconut

water, growing media pH rise although still under acidic

conditions. Fresh coconut water (0 hrs of storage) had a

pH ranging from 3.20 to 3.33 while coconut water that

had been stored for more than 6 hrs of storage (6, 12, 18

and 24 hrs of storage) had a higher pH than the pH of

fresh coconut water. This shows that the longer the

storage time of coconut water, the more increasing the

pH of the media. This typical pH conditions may affect

the growth of A. xylinum as the pH of the media is one of

the requirements that must be met in order that A.

xylinum can grow well in the process of nata pellicle

formation.

During the 14-day fermentation, the pH of the

growing medium of A. xylinum decreased gradually,

increasingly acidic. This condition caused the activity of

the A. xylinum increased so nata pellicle formation

process could run well. These conditions will produce

nata de coco with good quality. Lestari et al. (2014)

stated that A. xylinum can grow well in a medium with

some condition that sufficient nutrients mainly

containing a carbon source, a source of nitrogen,

minerals, vitamins and media pH is acidic pH. In the

process of nata pellicle formation, pH is necessary for

the growth of A. xylinum which is ranging between 3-4

(Castro et al., 2011; Gea et al., 2011). During

fermentation, the pH of the growing medium of coconut

varieties that vary with a different time storage, media

pH coconut water as a medium for growing A. xylinum is

still under acidic conditions (ranging in Figure 2) so that

the condition is still supporting activity of A. xylinum in

the process of formation of pellicle nata.

3.2 Growth of Acetobacter xylinum

Graphic of the growth of A. xylinum for nata

fermentation pellicle formation can be seen in Figure 3.

The graphic above shows that the different coconut

varieties did not affect the growth of A. xylinum

significantly during fermentation. Different coconut

water storage time significantly gives effect on the

growth of A. xylinum. The average growth of A. xylinum

is the highest on the media which are still fresh coconut

water (0 hrs of storage) in both the DSA and DMT

varieties. The growth A. xylinum continued to increase

from the first day until the day of fermentation to-9

fermentation. The highlight of the growth A. xylinum

reached an average of the highest value on day 9 of the

fermentation. Today the 10th until the 14th day of growth

suffered a sharp decline. On the 14th day, nata de coco

was harvested. This bacterium is an obligate aerobic

bacterium that works to synthesize cellulose from sugar

in the womb of a material (Alwi et al., 2015). The

growth A. xylinum can run well on a medium with the

requirements of sufficient nutrients, especially glucose

(Jung et al., 2010).

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Figure 2. Graphic of growing media of pH A. xylinum during fermentation (14 days) on DSA and DMT on different time

coconut water storage

Figure 3. Graphic of growth of A. xylinum during fermentation

(14 days) in coconut water media variety mapanget (DMT)

with different coconut water storage time

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A. xylinum will continue to grow over the nutrients

as long as the support growth is still available. It is

visible on the first day until the 9th day of fermentation.

The graphic of A. xylinum growth continued to increase

since glucose (sugar) was much provided. On the 10th

day of the fermentation, the growth of A. xylinum

decline. This is possible because the nutrients necessary

for the growth of A. xylinum has been reduced so that its

growth is also slowing. Such conditions will certainly

affect the quality of nata de coco generated. Wijayanti et

al. (2016) suggested the formation stages nata pellicle

layer in the form of cellulose hydrolysis process begins

with the sucrose produces glucose and fructose using

enzymes sucrase and invertase. When sucrose is in the

growing medium has reduced the activity of A. xylinum

also be decreased and nata produced is also unlikely to

grow significantly when compared to the beginning of

fermentation. That's why the common nata were

harvested on the 14th day of fermentation.

3.3 Nata de coco quality

The quality observation parameter of nata de coco

includes thickness, weight and crude fiber of nata. This

can be seen in Table 1. Table 1 shows the varieties and

coconut water storage time affects the quality of nata de

coco generated. DSA varieties are better than DMT in

improving the quality of nata de coco. This is because

the reducing sugar content of DSA variety coconut water

is higher than DMT (Runtunuwu et al., 2011). Coconut

water containing sugar reduction in high levels has great

potential as a medium for fermentation because it

contains sugar which can serve as a fermentable sugar as

well as a carbon source for the microbes (Yanuar and

Sutrisno, 2015). In making nata de coco, sugar plays an

important role as a source of carbon that can be changed

by A. xylinum cellulose layer nata (Bhanthumnavin et al.,

2016; Sainz et al., 2017).

Coconut water storage time also significantly affects

the quality of nata de coco generated on all parameters

nata observations in thickness, weight and crude fiber of

nata. The use of fresh coconut water (0 hrs of storage)

nata de coco provides the best quality when compared

with coconut water that has been stored for 6, 12, 18 or

24 hrs. Nata de coco produced from coconut water stored

in various storage periods with an interval of 6 hrs

produces nata de coco with different qualities. The

longer it is stored coconut water, nata de coco quality

resulting in a decline in all parameters of observation in

Figure 4.

The quality of nata de coco of fresh DSA variety (0

hrs of storage) is better than fresh DMT variety with the

thickness of 1.87 cm, the weight of 246.67 g, the crude

fiber of 2.01%, sugar reduction of 3.25% compared to

storage treatment for 6.12 and 24 hrs. DSA varieties with

a storage time of coconut water for 6 hrs, the quality of

nata de coco is still better than fresh DMT varieties with

a thickness of 1.62 cm, a weight of 210 g, the crude fiber

of 1.91% and a sugar reduction of 3.14%. DSA varieties

with 12 hrs long storage have better nata de coco quality

compared to DMT, namely with a thickness of 1.43 cm,

a weight of 173.33 g, the crude fiber of 1.58% and a

sugar reduction of 3.034%. The quality of nata de coco

in 18 hrs storage time, DSA variety was better than DMT

variety with nata thickness difference of 0.08 cm, nata

weight of 33.34 g, the crude fiber of 0.10% and sugar

reduction of 0.36%. The quality of nata de coco in 24 hrs

storage time, DSA variety is better than DMT variety

with nata thickness difference of 0.16 cm, nata weight of

28.33 g, crude fiber of 0.13% and sugar reduction of

0.56%. This difference is one of them caused by the

reducing sugar content of DSA which is higher than

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 Treatment Nata thickness (cm) Nata Weight (g)  Nata crude fiber (%) Sugar reduction (%)

DSA 0 hrs 1.87±0.03 246.67±5.77 2.01±0.05 3.25±0.01

DSA 6 hrs 1.62±0.03 210.00±10.00 1.91±0.05 3,14±0.01

DSA12 hrs 1.43±0.06 173.33±5.77 1.58±0.02 3.03±0.01

DSA 18 hrs 1.25±0.05 146.67±5.77 1.40±0.03 2.85±0.01

DSA 24 hrs 1.11±0.01 123.33±5.77 1.31±0.03 2.68±0.01

DMT 0 hrs 1.48±0.02 206.67±11.55 1.81±0.03 3.01±0.01

DMT 6 hrs 1.32±0.02 163.33±5.77 1.56±0.04 2.99±0.01

DMT 12 hrs 1.21±0.01 138.33±2.89 1.40±0.05 2.97±0.01

DMT18 hrs 1.17±0.02 113.33±5.77 1.30±0.07 2.49±0.01

DMT 24-hour  0.94±0.04 95.00±5.00 1.18±0.02 2.02±0.01

Table 1.Variety effect of coconut and coconut water storage time on the quality of nata de coco

Figure 4. Nata de coco from coconut water varieties DSA and

DMT

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DMT.

The stages of nata formation take place during the

fermentation process. Stages of nata formation involve

microorganisms, namely A. xylinum. This bacterium is

an obligate aerobic bacterium that works by synthesizing

cellulose from sugar in the content of an ingredient

(Alwi et al., 2011). A. xylinum can grow well in a

medium with several conditions, namely adequate

nutrition, especially containing carbon (C), a source of

nitrogen (N), minerals, vitamins, and media pH is an

acidic pH (Lestari et al., 2014). The carbon element can

be obtained from natural sugars contained in a material

such as glucose, fructose and sucrose, so that the bacteria

can work and can form a layer of nata (Pratiwi and

Aryawati, 2012; Lempang, 2013). Wijayanti et al. (2016)

stated the stages of the formation of a layer of nata

pellicle in the form of cellulose begin with the hydrolysis

of sucrose or starch which produces glucose and fructose

using the enzyme sucrase and invertase enzymes.

Glucose or fructose that is formed is then converted

into cellulose by A. xylinum. The formation of cellulose

from glucose begins with the process of phosphorylation

in glucose to glucose-6-phosphate which is catalyzed by

the enzyme glucokinase. Furthermore, undergo an

isomerization process which is catalyzed by the enzyme

phosphoglucomutase to glucose-1-phosphate. After that,

the formation of UDP-glucose is aided by the enzyme

UDPG firophosphorylase and the formation of cellulose

strings outside the cell with the help of the enzyme

cellulose synthase (Anas et al., 2012; Sunagawa et al.,

2013). Sugar plays an important role in making nata de

coco, because as a carbon source that can be converted

by A. xylinum into a layer of cellulose nata

(Bhanthumnavin et al., 2016; Sainz et al., 2017).

Most makers of nata de coco cannot immediately

take advantage of fresh coconut water to be used as nata

because of distance factor between the source of coconut

water to the plant that is quite far, limited transportation

or means of production, so sometimes coconut water is

stored for several hrs before they were made into nata de

coco, from the research that has been conducted, it is

indicated that the best nata de coco produced was from

fresh coconut water. However, it demonstrated that

coconut water stored for 6 hrs of varieties of DSA, the

quality of nata de coco generated no different with nata

de coco coconut water varieties of fresh DMT (0 hrs of

storage). This means that reducing the sugar content of

coconut water varieties stored DSA for 6 hrs is still

insufficient to meet the needs of a carbon source of A.

xylinum the formation cellulose nata layer. Reducing

sugar in coconut water varieties DSA is an important

factor as the carbon source for A. xylinum. Although it

kept for 6 hrs, the reduction of sugar levels is still

sufficient for the microbial source of carbon for forming

a layer of cellulose. Thus, to get nata de coco with the

best quality can use coconut water varieties DSA is still

fresh or has been stored for 6 hrs.

4. Conclusion

Good quality nata de coco is obtained from DSA

variety coconut water with coconut water storage time

for 6 hrs with a thickness of 1.62 cm, the weight of 210

g, the crude fiber of 1.91% and sugar reduction of

3.14%. The quality of nata de coco produced from DSA

variety coconut water with a long storage time of

coconut water for 6 hrs is better than the quality of nata

de coco produced from fresh DMT variety (0 hrs of

storage) coconut water which in this study was used as a

control treatment.

Conflict of Interest

The authors declare no conflict of interest.

Acknowledgments

The author would like to thank all those who have

helped in the conduct of the research and all parties who

have helped in this research, especially to Brawijaya

University and Tribhuwana Tunggadewi University.

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Central Bank of Malaysia (Amendment) 1

laws OF MalaYsIa

act a1448

central bank OF MalaYsIa (aMendMent)
act 2013

JW000084 A1448 (B1).indd   1 1/22/13   9:20:16 AM

Laws of Malaysia2

Date of Royal Assent  ... ... 18 January 2013

Date of publication in the
Gazette ... ... ... 22 January 2013

Publisher’s copyright   c
Percetakan nasIOnal MalaYsIa berhad
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means
electronic, mechanical, photocopying, recording and/or otherwise without the prior permission of Percetakan nasional Malaysia berhad
(appointed Printer to the Government of Malaysia).

Act A1448

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Central Bank of Malaysia (Amendment) 3

An Act to amend the Central Bank of Malaysia Act 2009.

 [ ]

enacted by the Parliament of Malaysia as follows:

short title and commencement

1. (1) This Act may be cited as the Central Bank of Malaysia
(Amendment) Act 2013.

 (2) This Act comes into operation on a date to be appointed
by the Minister by notification in the Gazette.

amendment of section 2

2. The Central Bank of Malaysia Act 2009 [Act 701], which
is referred to as the “principal Act” in this Act, is amended in
subsection 2(1)—

 (a) by substituting for the definition of “derivatives” the
following definition:

 ‘ “derivative” means any agreement, including an
option, a swap, futures or forward contract, whose
market price, value, delivery or payment obligations
is derived from, referenced to or based on, but not
limited to, securities, commodities, assets, rates
(including interest rates, profit rates or exchange rates)
or indices;’;

laws OF MalaYsIa

act a1448

central bank OF MalaYsIa (aMendMent)
act 2013

JW000084 A1448 (B1).indd   3 1/22/13   9:20:17 AM

Laws of Malaysia4

 (b) by inserting after the definition of “director” the following
definition:

 ‘ “financial collateral” means any of the following
that is subject to an interest or a right that secures
payment or performance of an obligation in respect
of a qualified financial agreement or that is subject
to a title transfer credit support agreement:

 (a) cash or cash equivalents, including negotiable
instruments and demand deposits;

 (b) security, a securities account or a right to
acquire securities; or

 (c) futures agreement or futures account;’;

 (c) by inserting after the definition of “prescribed” the
following definitions:

 ‘ “qualified financial agreement” means—

 (a) a master agreement in respect of one or more
qualified financial transactions under which
if certain events specified by the parties to
the agreement occur—

 (i) the transactions referred to in the agreement
terminate or may be terminated;

 (ii) the termination values of the transactions
under paragraph (a) are calculated or
may be calculated; and

 (iii) the termination values of the transactions
under  paragraph (a) are netted or
may be netted, so that a net amount
is payable,

  and where an agreement is also in respect of
one or more transactions that are not qualified
financial transactions, the agreement shall be
deemed to be a qualified financial agreement

Act A1448

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Central Bank of Malaysia (Amendment) 5

only with respect to the transactions that
are qualified financial transactions and any
permitted enforcement by the parties of their
rights under such agreement;

 (b) an agreement relating to financial collateral,
including a title transfer credit support
agreement, with respect to one or more
qualified financial transactions under a master
agreement referred to in paragraph (a); or

 (c) any other agreement in respect of a financial
transaction that may be entered into by parties
in the financial markets that is prescribed
as a qualified financial agreement by the
Bank, other than a standardized derivative
or an agreement in respect of securities
transactions entered into under the rules
of a stock exchange and approved clearing
house as defined in subsection 2(1) of the
Capital Markets and Services Act 2007
[Act 671];

 “qualified financial transaction” means—

 (a) a derivative, whether to be settled by payment
or delivery; or

 (b) a repurchase, reverse repurchase or buy-sell back
agreement with respect to securities;’;

 (d) by substituting for the full stop appearing at the end of
the definition of “supervisory authority” a semi-colon;
and

 (e) by inserting after the definition of “supervisory authority”
the following definition:

 ‘ “title transfer credit support agreement” means an
agreement under which title to property has been
provided for the purpose of securing the payment or
performance of an obligation in respect of a qualified
financial agreement;’.

amendment of section 15

3. Subsection 15(6) of the principal Act is amended by substituting
for the words “such written law” the words “any written law”.

JW000084 A1448 (B1).indd   5 1/22/13   9:20:17 AM

Laws of Malaysia6

substitution of section 31

4. The principal Act is amended by substituting for section 31
the following section:

“Measures for financial stability

 31. (1) Where the Bank considers it necessary in the interest
of financial stability, the Bank may—

 (a) specify measures, which in the opinion of the Bank would
contribute to the resilience of the financial system or
limit the accumulation of any risk to financial stability,
to a class, category or description of persons engaging
in financial intermediation; or

 (b) issue an order in writing requiring any person within a
class, category or description of persons, including a
class, category or description of persons engaging in
financial intermediation, to take such measures as the
Bank may consider necessary or appropriate to avert
or reduce any risk to financial stability.

 (2) Before issuing an order under paragraph (1)(b), the Bank
shall give the person an opportunity to make representation.

 (3) Notwithstanding subsection (2), an order under
paragraph (1)(b) may be issued first and the opportunity to
make representations shall be given immediately after the
order has been issued if any delay would aggravate the risk
to financial stability.

 (4) An order issued under paragraph (1)(b) may be amended
or modified where the representation is made after the order
is issued.

 (5) The person referred to in subsection (1) shall comply
with such measure or order from the date as the Bank may
specify notwithstanding the provisions of any other written
law or of any obligations under any contract, agreement or
arrangement to the contrary.

Act A1448

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Central Bank of Malaysia (Amendment) 7

 (6) The Bank may conduct due diligence or require such
person to submit any document or information or appoint an
auditor or any other person approved by the Bank to carry out
an assessment, to determine whether the person has complied
with such measure or order under subsection (1).

 (7) The remuneration of the auditor or such other person
as approved by the Bank under subsection (6) and other
expenses relating to such assessment shall be paid by the
person referred to in subsection (1).

 (8) Notwithstanding subsection (5), any measure or order
issued under subsection (1) shall not affect the enforcement
by the parties of their rights under a qualified financial
agreement.

 (9) Any person who fails to comply with subsection (5) or
any requirements imposed by the Bank under subsection (6)
commits an offence and shall, on conviction, be liable to a
fine not exceeding ten million ringgit or to imprisonment for
a term not exceeding ten years or to both.”.

amendment of section 32

5. Section 32 of the principal Act is amended by inserting after
subsection (1) the following subsection:

  “(1a) The enforcement by the parties of their rights under
a qualified financial agreement shall not be affected by the
making of an order for the vesting of, the whole or part of
the business, assets or liabilities of, or all or any of the shares
or other capital instruments issued by, a financial institution
pursuant to subparagraph (1)(c)(iii).”.

amendment of section 37

6. Section 37 of the principal Act is amended by substituting
for subsection (4) the following subsection:

  “(4) The Secretary General to the Treasury shall be informed
of and be invited to all meetings of the Financial Stability
Executive Committee.”.

JW000084 A1448 (B1).indd   7 1/22/13   9:20:17 AM

Laws of Malaysia8

amendment of section 38

7. Section 38 of the principal Act is amended by substituting
for subparagraph (1)(a)(i) the following subparagraph:

 “(i) under paragraph 31(1)(a) for a measure to be specified
to a class, category or description of persons engaging
in financial intermediation or under paragraph 31(1)(b)
for an order to be issued to such person within a class,
category or description of persons; or”.

amendment of section 48

8. Section 48 of the principal Act is amended—

 (a) by deleting the word “and” appearing at the end of
paragraph (1)(d);

 (b) by inserting after paragraph (1)(d) the following
paragraph:

 “(da) establish a body corporate or acquire or hold
shares of a body corporate, wholly or partly,
for the purposes of carrying out the functions
of a bridge institution under any written law
enforced by the Bank; and”; and

 (c) in subsection (5), by substituting for the words
“paragraph (1)(d)” the words “paragraphs 1(d) and (da).”.

amendment of section 77

9. Section 77 of the principal Act is amended by substituting
for subsection (1) the following subsection:

  “(1) Notwithstanding the provisions of this Act, the Board
may, for the purpose of giving effect to the objects of the
Bank or safeguarding the balance of payments position, by
notice in writing give directions to, or impose requirements
on, any person including financial institutions in respect of
or relating to—

 (a) transactions between residents, non-residents or
residents and non-residents, in ringgit or foreign

Act A1448

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Central Bank of Malaysia (Amendment) 9

currency, or involving gold, other precious
metals, securities or other financial instruments
including derivatives; or

 (b) the receipt, surrender or retention of foreign
currency, gold or other precious metals:

  Provided that any direction given or requirement imposed
shall not affect the enforcement by the parties of their
rights under a qualified financial agreement.”.

amendment of section 82

10. Subsection 82(1) of the principal Act is amended in the
national language text by inserting after the words “membuat
peraturan-peraturan” the word “atau”.

amendment of third schedule

11. The Third Schedule to the principal Act is amended in
paragraph 2—

 (a) in subparagraph (5), by substituting for the words
“A vesting order” the words “Subject to subsection 32(1a),
a vesting order”; and

 (b) by inserting after subparagraph (5) the following
subparagraphs:

 “(5a) Where a vesting order is made and a qualified financial
agreement is transferred pursuant to such order, the
transferee shall assume all rights and obligations under
any qualified financial agreement of the transferor from
whom such agreement was transferred.

 (5b) Where the qualified financial agreement is transferred
to a transferee, the enforcement by the parties of their
rights under such qualified financial agreement shall be
in accordance with the terms of such agreement as if the
transferee had always been a party to such agreement.

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Laws of Malaysia10

 (5c) Where the qualified financial agreement of the transferor
is transferred to a transferee and where a person is a
counterparty to two or more qualified financial transactions
under a qualified financial agreement with the transferor,
all or none of such qualified financial transactions shall
be transferred to the transferee.

 (5d) Where a qualified financial agreement relating to financial
collateral that applies to any property of the transferor
is transferred, that property shall be transferred to the
transferee.”.

DICETAK OLEH
PERCETAKAN NASIONAL MALAYSIA BERHAD,
KUALA LUMPUR
BAGI PIHAK DAN DENGAN PERINTAH KERAJAAN MALAYSIA

Act A1448

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 *Corresponding author.

Email: zakariae.hajri@gmail.com

eISSN: 2550-2166 / © 2023 The Authors.

Published by Rynnye Lyan Resources

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Food Research 7 (6) : 1 - 10 (December 2023)
Journal homepage: https://www.myfoodresearch.com

Dietary exposure assessment to sulfites (SO2) in the Moroccan adult population

1,*Hajri, Z., 2Chigr, M., 1Oussama, A., 1Kzaiber, F. and 1Boutoial, K.

1Laboratory of the Engineering and Applied Technologies, Higher School of Technology, Sultan Moulay

Slimane University, Beni Mellal, Morocco
2Laboratory of Bio-Organic and Analytical Chemistry, Faculty of Science and Technology, Sultan Moulay

Slimane University, Beni Mellal, Morocco

Article history:

Received: 15 December 2022

Received in revised form: 2

February 2023

Accepted: 1 May 2023

Available Online: 12

November 2023

Keywords:

Sulfites,

Exposure,

Assessment,

Health risk

DOI:
https://doi.org/10.26656/fr.2017.7(6).625

Abstract

Sulfites are a group of chemical food preservatives widely used in the food industry and

may cause sensitivities and health adverse. Thus, sulfites are subject to an Acceptable

Daily Intake (ADI) of 0.7 mg/kg of body weight. An exposure assessment was conducted

to estimate the potential daily intake of sulfites in the Moroccan adult population. Dietary

exposure assessment to sulfites was performed by combining analytical concentrations of

selected foods, according to the optimized Monier-Williams method, and sulfites-

containing food consumption data derived from an online food frequency questionnaire.

For the total population, the mean dietary intake of sulfites was only 18% of the ADI. For

the consumer group, the mean intake was well below the ADI, accounting for 27% of the

ADI. Dietary exposure to sulfites of the regular consumer group exceeds the ADI at the

mean of 137%. Dietary exposure to sulfites was also assessed in the adult asthmatic

population, where the ADI is exceeded only at the 95th percentile of female asthmatic

consumers, up to 113% of the ADI. The highest food contributors to sulfites intakes were

potato chips, olives, and barbecue sausage. The results showed that the risk of exceeding

the ADI is observed for a limited part of the population (regular consumers). However, for

the asthmatic population, possibly more sensitive to sulfites, the consumption of sulfites-

containing foods should be limited and controlled.

1. Introduction

Sulfur dioxide (SO2) and sulfating agents (identified

in Europe by codes E220-E228) are among the most

widely used chemical preservatives in processed foods

because of their antibacterial, antifungal, and antioxidant

properties (Taylor et al., 1986). These food additives are

authorized in Morocco by national regulation in more

than 100 foods with Maximum Permitted Levels (MPL).

Moreover, any use of sulfites in foods at a level of 10 mg

or more (per kg or liter) must be declared on the labeling.

However, several studies have reported that sulfites can

cause sensitivities and adverse reactions, including

symptoms of allergic response in specific subsets of the

population, particularly for asthmatics (Lester, 1995;

Gad, 2014). Other adverse effects have been attributed to

sulfites, including anaphylaxis, hives, diarrhoea,

abdominal pain and cramps, nausea and vomiting,

pruritus, fainting, headache, and skin rashes (Wilson and

Bahna, 2005; Vally et al., 2009; Taylor et al., 2014).

However, health adverse and sensitivity to sulfites are

strongly dependent on the degree of exposure from all

sources (Gad, 2014).

The International Agency for Research on Cancer

(IARC) published in 1992 a report evaluating the

carcinogenic risks to humans of sulfur dioxide and

sulfites. This evaluation concluded that there is

inadequate evidence of the carcinogenicity of sulfur

dioxide and sulfites in humans and limited evidence of

carcinogenicity in experimental animals of sulfur dioxide

(IARC, 1992). Therefore, the IARC considered that

sulfur dioxide, sulfites, bisulfites and metabisulfites are

not classifiable due to their carcinogenicity to humans

(Group 3).

Assessment of dietary exposure to food additives is

one of the four steps that make up the risk assessment

process of food additives, and it constitutes the spine of

this process. There are two data types must be available

to achieve a dietary exposure assessment: food

consumption data and the concentration of food additives

2 Hajri et al. / Food Research 7 (6) (2023) 1 - 10

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in foods. The risk characterization must be obtained by

comparing the resulting dietary exposure estimate with

the acceptable daily intake (ADI) for each studied food

additive (FAO/WHO, Codex Alimentarius, 1989). The

Joint FAO/WHO Expert Committee on Food Additives

(JECFA) has established an ADI for sulfites of 0.7 mg/

kg body weight expressed as sulfur dioxide (JECFA,

1974). This ADI is based on studies conducted in

laboratory animals.

Dietary exposure to sulfites has been estimated in

many countries using different approaches. The JECFA

noted in a technical report (JECFA, 2009) that in all

countries for which data on dietary exposure to sulfites

were available, the ADI for the whole population did not

exceed the mean but likely exceeded at high percentiles

of exposure. In the same report, dietary exposure reached

twice the ADI in children and teenagers in some

countries. The main food contributors to total dietary

exposure to sulfites differ from one country to another.

However, alcoholic beverages remain among the main

contributors, particularly in Europe (JECFA, 2009).

It would be inconclusive to extrapolate the results of

previous studies on dietary exposure to sulfites from

other countries because dietary habits and industrial/

commercial practices differ from one country to another.

Therefore, an exposure assessment to sulfites in the

Moroccan population using specific national data is

necessary, especially in the absence of official data or

published studies.

The objective of the present study was to assess

dietary exposure to sulfites in the Moroccan adult

population for the first time, using a deterministic

approach based on mean analytical levels of sulfites in a

selected list of foods combined with consumption data

from a food frequency questionnaire.

2. Materials and methods

This study combines average analytical

concentrations of sulfites in food products and individual

food consumption data derived from an online food

frequency questionnaire. This combination has led to

estimating dietary exposure to sulfites. The obtained

results were then compared with the ADI values

established by the JECFA to characterize the level of

public health risk.

The selected foods are analyzed to determine their

average concentration of sulfites. Only foods with a

concentration above the limit of quantification (10 mg/kg

of SO2) are included in the food frequency questionnaire.

According to the Moroccan Regulation (Ministry of

Agriculture/Ministry of Health, 2014) and Regulation

(EC) No. 1333/2008 (EC, 2008), an SO2 content of not

more than 10 mg/kg or 10 mg/L is not considered to be

present.

2.1 Sulfites concentrations in foods

2.1.1 Samples

Sulfites use is permitted by Moroccan regulation

(with a maximum level) in 20 food groups and over 100

food products (Ministry of Agriculture/Ministry of

Health, 2014). This regulation also provides restrictions

for foods that are not allowed to contain sulfites. To

obtain a refined list of foods and beverages to be

sampled, the list provided by the regulation was sorted

by eliminating foods unavailable on the local market

(such as sago and pearl barley, marinated nuts,

horseradish pulp, bottled white heart cherries, rehydrated

dried fruit, angelica and citrus peel).

Foods, not part of eating habits in Morocco (such as

dried pears and peaches, breakfast sausages, and dried

salted fish) or are unlikely to be consumed in significant

quantities (such as syrups for pancakes, flavoured syrups

for milkshakes and ice cream, fruit fillings for pastries,

molasses, vacuum-packed sweet corn, lychees and

vinegar) are also excluded from the sampling list.

A total of twenty types of food products potentially

treated with sulfites are identified following the sorting

and selection operation (6 foods where the addition of

sulfites is prohibited and 14 foods where the addition of

sulfites is permitted).

2.1.2 Sampling and sample handling

Samples were collected from local groceries and

supermarkets in the Beni Mellal region (north-central

Morocco) from April to November 2021. The number of

samples for each food is determined according to the

number of brands available in the market, respecting a

minimum representativeness rate of 80%. In the case of

non-packaged foods (in bulk), a minimum of ten samples

per food is applied. A unique code identifies each

collected sample. Various data are recorded in a

sampling form, such as place and date of sampling, taken

samples portion, brand name, lot number, storage

conditions, manufacturer name, and declaration or not of

the presence of sulfites on the labelling.

The composite samples of the same food are then

prepared for analysis. The weight of each sample to be

included in the composite sample is determined based on

the availability of the brand and the consumer's preferred

purchase sources. As far as possible, composite samples

were analyzed upon receipt and preparation at the

laboratory.

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All selected foods are analyzed as collected (without

any cooking) except for meat products and shrimp

prepared according to standard/traditional Moroccan

recipes before analysis.

2.1.3 Analytical method

The determination of sulfites concentrations was

performed according to the optimized Monier-Williams

method (Association of the Analytical Chemists

(AOAC), 2000). This method has a limit of

quantification (LOQ) of 10 mg/kg. It allows the

measurement of free sulfites and the reproducible

portions of bound sulfites, such as carbonyl addition

products in foods (AOAC, 2000).

A 50 g (mL for liquid samples) portion of the sample

is ground in a blender with an ethanol/water mixture

(5%/95%). The ethanol/water solution sample is

transferred to a round-bottom flask and heated under

reflux with a hydrochloric acid solution (90 mL) for 105

mins to transform the sulfites into sulfur dioxide (SO2).

A stream of nitrogen injected into the refluxing solution

allows the sulfur dioxide to be carried away to the

neutral solution of hydrogen peroxide (3%) contained in

a bubbler. Upon arrival in this solution, the sulfur

dioxide is oxidized and transformed into sulfuric acid,

titrated by a standard sodium hydroxide solution.

All samples were analyzed twice (two tests per

analysis). Analysis results are reported with all the

necessary information in an individual analysis report.

2.2 Food consumption data

An online food frequency questionnaire was

developed using Google Forms (Google Docs Editors,

Google Inc. USA) and sent randomly to the maximum

number of adult participants over 18 years old living in

all Moroccan regions from December 2021 to Mars

2022. No detailed national food consumption data were

available.

This survey aimed to identify the part of consumers,

regular and asthmatic consumers of sulfites-containing

foods, the frequency of consumption, the way of

consumption and the approximate consumed amounts.

The food consumption survey is divided into two parts.

First, respondents were asked to fill out a general

questionnaire with general information, such as area of

residence, gender, age, estimated weight, current

occupation and asthmatic and food allergy status. Then,

they were asked to complete the second part of the

survey, which focuses on the consumption of sulfites-

containing foods. For each sulfites-containing food, the

participant is asked to answer five questions. First,

whether or not they consume the food concerned, then if

the answer is yes, they are asked whether they are

regular consumers of this food (once a week). If the

respondent is a regular consumer, the third question is

about the frequency of consumption (once a week, twice,

thrice, or more than thrice). The fourth question concerns

how the participant consumes the food (cooked, raw).

The last question was related to the approximate

consumed amounts of this food by giving, if necessary,

validated references to facilitate the choice (for example,

soup spoon = 20 g, small bag = 30 g, large plate = 150

g). The daily consumed amount of each food is

calculated by dividing the declared amount consumed at

each meal by the frequency of consumption (e.g. if the

respondent consumes 30 g of the food with a frequency

of twice a week, the daily consumed amount in this case,

is 30×02/07).

Data collected from the survey were statistically

analyzed using the integrated module on Google Forms

combined with Microsoft Office Excel (version 2010,

Microsoft, USA).

2.3 Exposure assessment to sulfites

Estimates of dietary exposure to sulfites were made

by combining mean levels of sulfites in selected foods

with food consumption data retrieved from an online

food frequency questionnaire developed for this purpose.

After the analytical determination of sulfites

concentrations, foods for which all analyzed samples are

below the LOQ are considered sulfites-free and are not

included in the survey. The same approach was used in

the 21st Australian Total Diet Study (Food Standards

Australia New Zealand (FSANZ), 2005).

The estimated daily intake (EDI) of sulfites for the

whole population (all respondents), the consumers, the

regular consumers (at least once a week) and the

asthmatic consumers was calculated by multiplying the

average daily food consumption (g) for each sulfites-

containing food by the mean analytical levels of sulfites

(mg/g). The total intakes of sulfites from all foods were

then summed. The average body weight reported by the

total population was used to compare the EDI of sulfites

with their respective ADI value (0.7 mg/kg bw/day) and

get a dietary exposure in mg/kg bw/day. The 95th

percentile values were also calculated for the regular

consumers and asthmatic population.

Dried fruits are consumed in Morocco both raw and

cooked. Results from our previous study on the effect of

cooking treatments on the residual level of sulfites in

dried fruits (Hajri et al., 2022) were used to obtain a

more refined exposure estimate to sulfites from dried

fruits. Therefore, the EDI was calculated with the

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 average sulfites concentrations of raw and cooked dried

fruits.

3. Results and discussion

3.1 Concentrations of sulfites in selected foods

A total of 232 samples from twenty foods were

analyzed to determine their sulfites levels. Table 1

presents the mean concentrations of sulfites, the number

of samples, the percentage of samples with a level above

the limit of quantification (LOQ) and the MPLs for each

food. Sulfites were detected, with an average

concentration ranging from 20 to 2460 mg/kg, in 10

foods (50%), 3 of which are not authorized by national

regulations to contain the food additive. The analyzed

foods were shown in this study for all samples, either

level above or below the limit of quantification. Thus,

the World Health Organization (WHO)

recommendations for evaluating low-level contamination

of food (WHO, 1995) have not been applied.

Dried apricots contain the highest concentration of

sulfites in all foods tested, with an average of 2460 mg/

kg, which exceeds the national MPL of 2000 mg/kg.

Other studies reported mean concentrations that exceed

the MPL. For example, the 21st Australian Total Diet

Study reported a mean concentration of 2097 mg/kg,

with a maximum level of 3420 mg/kg (FSANZ, 2005).

Daniels et al. (1992) found a mean sulfites concentration

of 2791 mg/kg, with a range of 2259-3722 mg/kg.

However, cooking in boiling water can reduce sulfites by

nearly 40% in dried apricots (Hajri et al., 2022). This

cooking method is widely used in Morocco to precook

dried apricots before using them in traditional dishes. We

used sulfites concentrations in cooked dried apricots to

refine the sulfites dietary exposure estimates.

Mustard samples showed an average concentration

of 499.2 mg/kg, close to the national MPL (500 mg/kg).

Other studies reported average concentrations

significantly lower than those found in our study.

Ishiwata et al. (2003) reported a mean level of 67 mg/kg

in mustard from Japan. Leclerc et al. (2000) found a

mean level of 185 mg/kg in 3 samples from Italy, while

Vandevijvere et al. (2010) reported only 18 mg/kg in a

study from Belgium. All tested samples of raisins

contain sulfites with a mean level of 374 mg/kg, lower

than concentrations found in a study from France, which

reported a mean level of 173 mg/kg (Mareschi et al.,

1992). As dried apricots, cooking reduced the initial

sulfites content of raisins by nearly 40% (Hajri et al.,

2022).

Commercial potato chips contain a mean level of

680 mg/kg, widely above the national MPL (100 mg/kg).

A study in France detected a mean level (without zero

values) of 104.3 mg/kg in processed potatoes (Bemrah et

Food
No. of

samples
Mean concentration

(mg/kg)
% of samples>

LOQ
National MPLs*

(mg/kg)
CA MPLs**

(mg/kg)
Dried apricots 12 2460 100 2000 1000

Mustard 4 499.2 100 500 250
Dried figs 12 < LOQ 0 2000 1000

Dried beans 14 < LOQ 0 50 50
Crackers 10 < LOQ 0 50 50
Raisins 20 373.9 100 2000 1000
Sugar 8 < LOQ 0 10 15

Dried plums 10 < LOQ 0 2000 1000
Potato chips 18 680.2 100 100 50

Confectionery 20 31.8 100 50 NP
Sausages and mortadellas 8 < LOQ 0 NP NP

Fruit juice 9 < LOQ 0 250 50
Frozen fries 8 20 100 100 NP

Unpackaged olives 12 438.3 100 NP NP
Canned olives 9 < LOQ 0 NP NP

Fruit jams 16 < LOQ 0 100 100
Mayonnaise 8 37.3 100 NP NP

Fresh barbecue sausage 14 332.2 100 NP NP
Shrimp 8 42.2 100 150 100

Ground beef 12 < LOQ 0 NP NP
Total 232 - - - -

Table 1. Mean concentrations of sulfites (SO2) in selected foods (mg/kg) and the corresponding maximum permitted levels

(MPL).

CA: Codex Alimentarius. MPLs: maximum permitted levels. NP: not permitted. LOQ: limit of quantification

*Ministry of Agriculture/Ministry of Health, Morocco (2014). **FAO/WHO, Codex Alimentarius (2021).

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al., 2009). In Lebanon, Soubra et al. (2006) found a 195

mg/kg mean analytical level in 8 samples of potato chips.

Industrial confectionery products in Morocco (such as

candies, lollypops, and gum) contain an average of 32

mg/kg, while frozen fries have an average content of 20

mg/kg. Shrimps (peeled, frozen) have been tested after

pan-frying and showed an average concentration of 42.2

mg/kg. Raw fresh shrimps showed an average sulfites

concentration of 78.4 mg/kg in a study conducted in

Morocco (Dahani et al., 2018).

Moroccan regulation does not permit sulfites use in

olives, fresh sausage (Moroccan merguez) and

mayonnaise. However, sulfites were detected in all

composite samples of these three foods. For olives

(purchased in bulk from different specialized stores), an

average content of 438 mg/kg was found. In the relevant

recent studies, sulfites concentrations analysis was rarely

performed. For example, sulfites have not been detected

in olives in the 21st Australian Total Diet Study (FSANZ,

2005). However, in a study from the Basque Country,

sulfites were found in 15% of the tested olives samples

(Urtiaga et al., 2013). The high sulfites content of

unpackaged olives was predicted. A preliminary survey

revealed that unpackaged olives (prepared and marketed

under uncontrolled conditions) might be illicitly treated

with sulfites.

The mean concentration of sulfites in composite

samples of fresh sausage (tested after cooking) was 332

mg/kg, similar to other studies, including in Australia

(275 mg/kg; FSANZ, 2005), UK (322 mg/kg; Ministry

of Agriculture, Fisheries and Food, United Kingdom

(MAFF), 1995) and the Basque Country (317.5 mg/kg;

Urtiaga et al., 2013). The mean concentrations of sulfites

found in mayonnaise were nearly 37 mg/kg.

All other foods tested (dried figs, beans, crackers,

sugar, dried plums, sausages and mortadellas, fruit juice,

canned olives and fruit jams) showed results well below

the LOQ. Therefore, these food types are excluded from

the list to be included in the food consumption survey.

3.2 Food consumption data

Responses from the online food frequency

questionnaire were collected from October 2021 to

February 2022, with 1155 respondents over 18 years old.

This online survey provided general information (such as

body weight and gender) and data on the consumption of

sulfites-containing foods.

Table 2 describes the study population. Most

respondents are from urban areas (86%) with a wide

range of available foods. The female population (n =

653) represents 56.5%, while the male population (n =

502) represents 43.5% which is in line with the

Moroccan demography. Home-prepared foods (including

mayonnaise, olives, French fries and barbecue sausage)

are automatically considered sulfite-free.

Table 3 presents food consumption data for all

studied population categories. The total population

consumes, on average, 25.5 g/day of sulfites-containing

foods (24 g/day for males and 27 g/day for females),

Gender Respondents (%)
Average body

weight (kg)

No. of

asthmatic (%)

No. of food

allergic (%)

Area of residence

Urban (%) Rural (%)

Male 502 (43.5%) 70 18 (3.5%) 48 (9.5%) 409 (81.5%) 93 (18.5%)

Female 653 (56.5%) 60 39 (6%) 94 (14%)  583 (89.3%) 70 (10.7%)

Total 1155 - 57 (5%) 142 (12%) 992 (86%) 163 (14%)

Table 2. Description of the study population.

Table 3. Food consumption (g/day) for all respondents, consumers, regular consumers, and asthmatics consumers.

Food

Sulfites-containing food consumption (g/day)

All respondents Consumers Regular consumers Asthmatic consumers

Mean % Mean % Mean P95 % Mean P95

Dried apricots 0.4 52.5 0.7 3.5 10.4 15.0 2.4 0.2 1.8

Mustard 0.4 41.0 1.0 12.3 3.5 7.4 3.0 0.4 3.9

Raisins  3.7 89.5 4.2 27.0 13.6 30.4 4.0 4.0 21.8

Potato chips 3.0 63.0 4.3 19.3 14.2 32.8 3.5 1.8 7.2

Confectionery 1.3 57.0 2.3 24.5 5.2 14.6 3.5 1.1 5.1

Frozen fries 5.4 78.0 6.9 34.3 15.8 28.5 3.4 4.3 15.7

Olives 5.0 73.5 6.9 36.0 14.0 33.3 3.6 4.8 17.7

Mayonnaise 1.3 65.5 2.1 23.3 5.6 12.9 3.3 0.8 3.8

Barbecue sausage 3.6 52.0 6.8 9.8 36.3 82.9 3.3 5.6 37.2

Shrimp 1.4 60.5 2.3 10.8 12.4 31.3 3.2 3.2 34.0

Total 25.5 - 37.5 - 131.0 289.2 - 26.2 148.2

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while consumers take a mean of 37.5 g/day (37.2 g/day

for males and 37.8 g/day for females). For regular

consumers (at least once a week), an average of 131 g of

sulfites-containing foods consumed per day (122 g/day

for males and 140 g/day for females), while at the 95th

percentile (P95), the consumed amount of sulfites-

containing foods was 289 g/day (271 g/day for males and

307 g/day for females). Self-reported asthmatics take a

mean of 26.2 g/day (25 g/day for males and 27.5 g/day

for females), while at the P95, they consume a mean of

148 g/day (137 g/day for males and 159 g/day for

females).

Thus, the amounts of potentially sulfites-containing

foods are significant only for some regular consumers

(average and P95). This category would be potentially

exposed to a risk of exceeding the ADI. In addition,

olives, barbecue sausage, and French fries (frozen) are

the main contributors to the daily consumption of sulfites

-containing foods.

3.3 Exposure assessment of sulfites in the Moroccan

adult population

Dietary exposure estimates to sulfites were

calculated separately for male and female respondents

using the corresponding average body weight (60 kg for

females and 70 kg for males). The estimation

calculations concerned the total population (all

respondents), consumers only, regular consumers, and

the self-reported asthmatics population (Tables 4 and 5).

The mean estimated daily intake of sulfites for the total

population was 0.10 mg/kg bw/day for males,

corresponding to only 14% of the recommended ADI,

and 0.15 mg/kg bw/day for females, corresponding to

22% of the ADI. Similar results have been reported in

France (Bemrah et al., 2012), Ireland (Vin et al., 2013),

New Zealand (Cressey and Jones, 2009) and Australia

(FSANZ, 2005). However, in a study conducted in Italy

by Vin et al. (2013) using chemical data provided by the

food industry, the estimated daily intake of sulfites for

the total population was only 0.017 mg/kg bw/day (2%

of the ADI). However, in Italy (Leclercq et al., 2000),

dietary exposure to sulfites using analytical levels in

realistic sulfites-containing meals slightly exceeded the

ADI for adults (120%) and children (110%).

The difference between males and females regarding

mean dietary exposure to sulfites remains insignificant

for the total population. It is mainly due to the body

weight variance. However, in the Basque Country,

Urtiaga et al. (2013) revealed a considerable difference

between the exposure to sulfites of men compared with

women, mainly due to the high consumption of alcoholic

beverages by men (0.48 mg/kg bw/day for men,

corresponding to 69% of the ADI vs. 0.14 mg/kg bw/day

for women, corresponding to 21% of the ADI).

The average dietary exposure to sulfites for the

consumers was well below the ADI, with 0.16 mg/kg

bw/day (23% of the ADI) for male consumers and 0.22

mg/kg bw/day for female consumers (31% of the ADI).

A close result is observed in a study conducted in New

Zealand with no difference between males and females

(0.197 mg/kg bw/day for females and 0.2 mg/kg bw/day

for males (Cressey and Jones, 2009). A study carried out

in Lebanon (Soubra et al., 2006) reported mean dietary

exposure to sulfites of 0.44 mg/kg bw/day (63% of the

ADI) for the consumer group (students).

In the high-intake scenario (regular consumers), the

ADI is exceeded in both the male and female

populations, with a notable difference between them due

to differences in body weight and the amounts of certain

consumed foods. The mean daily intake of sulfites was

0.74 mg/kg bw/day for males (105% of the ADI) and

1.18 mg/kg bw/day for females (168% of the ADI). At

the 95th percentile (heaviest regular consumers), dietary

exposure to sulfites was 1.47 mg/kg bw/day for males

(210% of the ADI) and 2.25 mg/kg bw/day for females

(322% of the ADI).

The differences between male and female regular

consumers regarding the mean dietary exposure to

sulfites are due to average body weight (men have a

higher average weight than women) and to the higher

consumption of certain sulfites-containing foods by

women, particularly potato chips. Exposure assessment

to sulfites of high adult consumers in France (Bemrah et

al., 2012), Lebanon (Soubra et al., 2006), Australia

(FSANZ, 2005) and Austria (Mischek and Krapfenbauer

-Cermak, 2012) was 120%, 215%, 130% and 243% of

the ADI, respectively. However, the ADI did not exceed

in studies from China (33% of the ADI; Zhang et al.,

2014) and Ireland (97% of the ADI; Vin et al., 2013) in

the high-intake scenario.

The ADI is not exceeded for the self-reported

asthmatic subjects at the mean. Nevertheless, it is likely

exceeded in the high-intake scenario (P95) for female

asthmatic consumers. The mean dietary exposure to

sulfites in this population category (considered as more

sensitive to sulfites) was 0.10 mg/kg bw/day for males

(14% of the ADI) and 0.14 mg/kg bw/day for females

(19% of the ADI). At the P95, dietary exposure to

sulfites was 0.50 mg/kg bw/day for males (72% of the

ADI) and 0.79 mg/kg bw/day for females (113% of the

ADI). No comparative data were found concerning the

dietary exposure to sulfites for asthmatic subjects.

Table 6 presents dietary exposure estimates to

sulfites and the corresponding ADI after considering the

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Food
Average

concentration
(mg SO2/g )

Mean intake of
all respondents

Mean intake of
consumers

 Intake of regular
consumers (mg SO2/day)

Intake of asthmatic
consumers (mg SO2/day)

(mg SO2/day) (mg SO2/day) Mean P95 Mean P95

Raw dried apricots 2.46 0.98 1.97 20.17 30.75 0.74 8.61

Mustard 0.50 0.15 0.50 1.60 3.50 0.30 1.50

Raw raisins 0.37 1.07 1.22 4.51 9.25 1.48 5.55

Potato chips 0.68 0.88 1.63 5.98 13.60 0.34 1.97

Confectionery 0.03 0.04 0.08 0.16 0.40 0.03 0.14

Frozen fries 0.02 0.11 0.15 0.31 0.57 0.08 0.29

Unpackaged olives 0.44 2.51 3.43 6.42 14.65 2.02 5.50

Mayonnaise 0.04 0.04 0.08 0.19 0.52 0.02 0.11

Fresh sausage 0.33 1.12 2.24 11.75 28.31 1.72 9.41

Shrimp 0.04 0.07 0.13 0.58 1.37 0.18 2.10

Total intake of SO2 (mg/day) 7 11.4 51.7 103 7 35

Exposure to SO2 (mg/kg bw/day) 0.1 0.16 0.74 1.47 0.1 0.5

% of the ADI 14% 23% 105% 210% 14% 72%

Table 4. Dietary exposure to sulfites (SO2) in the Moroccan male adult population and percentage of the ADI.

Notes: Acceptable daily intake for sulfites (ADI): 0.7 mg/kg bw/day (JECFA, 1974). Average body weight for males: 70 kg.

Food
Average

concentration
(mg SO2/g )

Mean intake of
all respondents

Mean intake of
consumers

 Intake of regular
consumers (mg SO2/day)

Intake of asthmatic
consumers (mg SO2/day)

(mg SO2/day) (mg SO2/day) Mean P95 Mean P95

Raw dried apricots 2.46 0.74 1.23 30.75 43 0 0
Mustard 0.5 0.25 0.55 1.85 4 0.10 2.40
Raw raisins 0.37 1.63 1.85 5.55 13.21 1.52 10.55
Potato chips 0.68 3.13 4.22 13.26 31.08 2.18 7.75
Confectionery 0.032 0.04 0.07 0.17 0.53 0.04 0.19
Frozen fries 0.02 0.10 0.13 0.32 0.57 0.09 0.34
Unpackaged olives 0.44 1.94 2.60 5.94 14.65 2.16 10.12
Mayonnaise 0.037 0.06 0.07 0.23 0.43 0.04 0.17
Fresh sausage 0.33 1.22 2.24 12.21 26.40 1.98 15.18
Shrimp 0.042 0.04 0.07 0.46 1.26 0.09 0.76

Total intake of SO2 (mg/day) 9.15 13 70.75 135.2 8.2 47.46
Exposure to SO2 (mg/kg bw/day) 0.15 0.22 1.18 2.25 0.14 0.79

% of the ADI 22% 31% 168% 322% 19% 113%

Table 5. Dietary exposure to sulfites (SO2) in the Moroccan fermale adult population and percentage of the ADI.

Notes: Acceptable daily intake for sulfites (ADI): 0.7 mg/kg bw/day (JECFA, 1974). Average body weight for females: 60 kg.

Total intake of SO2

(mg/day)

Exposure to SO2  Percentage of the

ADI (mg/kg bw/day)

Males Females Males Females Males Females

All respondents (mean) 6.16 8.22 0.09 0.14 13 20

Consumers (mean) 10.14 11.8 0.14 0.2 21 28

Regular consumers (mean) 41.43 55.65 0.59 0.93 85 133

Regular consumers (P95) 86.43 112 1.23 1.87 176 267

Asthmatic consumers (mean) 6.04 7.62 0.09 0.13 13 18

Asthmatic consumers (P95) 29.43 43.47 0.42 0.72 60 104

Table 6. Dietary exposure to sulfites and the corresponding percentage of the ADI after considering the reducing effect of

cooking on the residual level of sulfites in dried fruits.

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effect of cooking on the residual level of sulfites in dried

apricots and raisins. The refined dietary exposure

estimates to sulfites showed a slight decrease in the daily

sulfites intake. However, the ADI is still exceeded for

regular consumers. The results also showed a slight

exceeding of the ADI (106%) for female asthmatic

consumers at the high-intake scenario (P95), mainly due

to body weight difference and high consumption of

potato chips.

The ADI for sulfites in this study is exceeded in the

high-intake scenarios (regular consumers) as in most

other studies from different countries. Therefore, the

potential health adverse due to the ingestion of sulfites-

containing foods are insignificant for the total

population. Nevertheless, national food risk managers

must pay particular attention to the potential health risks

from sulfites-containing foods, particularly for regular

consumers who exceed the recommended ADI.

Therefore, sulfites use and overuse control in primary

and processed foods should be enhanced. Thus, the

revision of national MPLs could eventually limit dietary

sulfites exposure.

The list of foods selected in this study is not

exhaustive. Other food categories in which sulfites may

be used as food additives were not included in this study,

which may lead to underestimating the dietary intake of

sulfites. Sulfites intake from other non-food sources

(such as environment and drugs) or naturally sulfites-

containing foods such as onions (Brahimi et al., 2022)

may also lead to underestimating sulfites exposure. On

the other hand, cooking treatments and storage

conditions could reduce the sulfites concentrations in

certain foods (Vandevijvere et al., 2010). The sulfites

exposure estimate from dried fruits was conducted based

on raw dried apricots and raisins. However, these foods

are also consumed after cooking in traditional dishes. In

this case, dietary exposure to sulfites would be

overestimated.

Further study on the consumption of sulfites-

containing foods by asthmatic subjects (with a more

significant number of respondents) and by children and

teenagers is strongly recommended to assess further the

dietary exposure to sulfites in these consumer categories

and the current level of public health risk.

3.4 Contribution of food types to dietary exposure to

sulfites

Table 7 presents the contribution percentage of all

foods to the mean dietary intake of sulfites in the

consumers and asthmatic consumers. Results showed

that, for male consumers, sulfites intake was essentially

due to the consumption of olives (30%), barbecue

sausage (20%), and dried apricots (17%). For female

consumers, potato chips (32%), olives (20%), and

barbecue sausage (17%) were the significant contributors

to sulfites exposure. Olives and barbecue sausage are

still the major contributors to sulfites exposure for male

and female asthmatic consumers, with a notable

contribution from raisins and potato chips. Except for

dried apricots and raisins, all other major contributors are

not authorized to contain sulfites by national regulations

(olives and barbecue sausage) or found to contain levels

well above the maximum permitted levels (potato chips).

Dried apricots and dried fruits were also among the

most contributors to sulfites intake in Australia (FSANZ,

2005), in France (Bemrah et al., 2009), and for children

in Austria (Mischek and Krapfenbauer-Cermak, 2012).

In a study from the Basque Country (Urtiaga et al.,

2013), children were mainly exposed to sulfites from

meat products, especially fresh sausage. Processed

potatoes were also significant contributors to the dietary

intake of sulfites in France (Bemrah et al., 2009) and

Belgium (Vandevijvere et al., 2010). Thus, dietary

exposure studies in several countries show that alcoholic

beverages, particularly wines, are the main contributors

to sulfites intake in adults.

Food
% of contribution for consumers % of contribution for asthmatic consumers

Male Female Male Female
Dried apricots 17.2 9.4 10.7 0
Mustard 4.3 4.2 4.4 1.2
Raisins 10.7 14.2 21.4 18.5
Potato chips 14.3 32.4 4.9 26.6
Confectionery 0.7 0.5 0.5 0.5
Frozen fries 1.3 1 1.1 1.1
Olives 30 20 29.3 26.3
Mayonnaise 0.7 0.6 0.3 0.5
Barbecue sausage 19.7 17.2 24.8 24.2
Shrimp 1.1 0.5 2.6 1.1

Table 7. Food type contribution (%) to mean estimated dietary exposure to sulfites.

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4. Conclusion

This study first showed that sulfites were detected in

foods not permitted by Moroccan regulations

(mayonnaise, olives, and barbecue sausage). Other tested

foods contain sulfites levels exceeding the regulatory

MPL (dried apricots and potato chips). Except for

asthmatic subjects, dietary exposure to sulfites in

Morocco must represent a low level of public health risk.

However, estimated dietary exposure to sulfites of

Moroccan adults showed that the risk of exceeding the

recommended ADI is likely possible for regular

consumers and a limited part of the asthmatic population.

Thus, illegal practices (overuse and abuse) contribute

significantly to excessive dietary exposure to sulfites in

high-intake scenarios. The use of sulfites as food

additives in local and imported foods should be

controlled and supervised, especially in foods that

contribute significantly to dietary exposure to sulfites.

Conflict of interest

The authors declare no conflict of interest.

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