From
1996 through 1999, 499 and 386 samples of Chinese
New Year Foods were tested for preservatives
and colouring matter against the statutory standards.
These foods were classified into five categories:
steamed puddings, fried dumplings, sweetened
fruits and vegetables, glutinous rice balls,
and seeds. Of 499 samples tested for preservatives,
15 (3.0%) were reported unsatisfactory. Seven
of 275 steamed puddings examined contained benzoic
acid, which is not permitted in these flour-made
products. Eight of 71 samples of sweetened fruits
and vegetables examined were found to contain
sulphur dioxide exceeding the permitted level.
The most common items incriminated were sweetened
melon and sweetened water chestnut. Of 386 samples
tested for colouring matter, 15 (3.9%) contained
non-permitted ones. Thirteen of 175 samples
of steamed puddings examined contained Orange
II, and two out of 72 samples of fried dumplings
contained Rhodamine B. However, such practices
have become less common in the last two years.
Samples of glutinous rice balls and seeds examined
were all satisfactory. Since Chinese New Year
Foods were mainly consumed during festive seasons
and the proportion of unsatisfactory samples
was small, it was unlikely to have caused significant
adverse impact on public health. The trade is
advised to adhere to Good Manufacturing Practice.
Risk Assessment
Studies -
Chemical Hazards Evaluation
-
An evaluation of the food surveillance findings in Hong
Kong 1996-1999
Introduction
Chinese
New Year is the beginning of the lunar year, generally
coincides with late January or February of the commonly
used civil calendar. It signifies hope and joy, and
is among the most important festivals in the Chinese
culture. A number of special foods are taken during
this period as part of the celebration and they exemplify
strong local features. In Hong Kong, as the majority
of residents are from Southern China, the Chinese New
Year Foods are closely related to Guangdong cultures.
2.
In this paper, we classify the Chinese New Year Foods
commonly consumed in Hong Kong into five categories
and examine preservatives and colouring matter in these
food items using the food surveillance findings collected
in 1996 to 1999.
Five
Categories of Chinese New Year Foods
3.
As the name implies, Chinese New Year Foods refer to
a spectrum of food items that are commonly consumed
during Chinese New Year. According to their compositions
and manufacturing processes, Chinese New Year Foods
can be classified into five categories –
steamed puddings, fried
dumplings, sweetened fruits and vegetables, glutinous
rice balls and seeds. Many of these foods carry cultural
meanings. The characteristics of these foods are listed
in Table 1.
Food
additives
4.
Food additives, which are generally chemical in nature,
may be potentially hazardous. The nature and magnitude
of such hazards determine the suitability of these chemicals
for use in food. The choice of food additives also depends
on the effectiveness of additives to which the food
is applied. According to Codex Alimentarius Commission,
food additive means any substance not
normally consumed as a food by itself, the intended
use of which may reasonably be expected to result, directly
or indirectly, in its becoming a component or otherwise
affecting the characteristics of any food (1). From
the legal perspective, as listed under the Food
and Drugs (Composition and Labelling) Regulations
in Hong Kong, additive means any substance, not commonly
regarded or used as food, which is added to, or used
in or on, food at any stage to affect its keeping qualities,
texture, consistency, appearance, taste, odour, alkalinity
or acidity, or to serve any other technological function
in relation to food, and includes processing aids in
so far as they are added to, or used in or on food (2).
In this paper, we focus on two commonly used additives
in Chinese New Year Foods, namely preservatives
and colouring matter. Reviewing the findings
of food surveillance from 1996 to 1999, we examine the
hazards originated from inappropriate use of preservatives
and colouring matter in the five categories of Chinese
New Year Foods.
Preservatives
5.
Preservatives are used to prolong shelf life of a food
by protecting against deterioration caused by microorganisms
(1). Their uses in foods are sometimes necessary when
the foods are not consumed immediately after production.
From the legal perspective, as listed under the Preservatives
in Food Regulations in Hong Kong, preservative
means any substance which is capable of inhibiting,
retarding or arresting the process of fermentation,
acidification or other deterioration of food or of masking
any of the evidence of putrefaction (2).
Colouring
matter
6.
The colour of a food is affected by processing and storage.
To meet the consumers’ expectations,
manufacturers may add colouring agents to certain foods
to produce the appetizing and attractive appearance.
Colouration of food may also be a reflection of different
cultures and life style (3). To this end, food
colouring matter is defined as any substance
that adds or restores colour in a food (1). 7. Colour
carries special meaning in the Chinese culture. For
instance, red means "luck and happy". Some food items are coloured in red, such as "red
egg" and
"birthday
bun"
for birthday celebration. Barbecued pork is also coloured
red to make it more appealing. There are practical reasons
for the use of colouring matter in Chinese New Year
Foods:
To provide
a colourful appearance to food for sacrifice and
celebration. For example, sesame balls are coloured
to create festive and joyful appearance.
To correct
natural variations in colour, for example, New Year
Pudding.
To offset
colour loss due to exposure to light, air, extremes
of temperature, moisture and storage conditions,
for example, sweetened fruits and vegetables.
Legal
provision in Hong Kong
8.
The uses of preservatives and colouring matter are stipulated
in the regulations made under Part V of the Public Health
and Municipal Services Ordinance (Cap. 132). No food
intended for sale for human consumption shall contain
any colouring matter or preservatives which is not specified
in the schedule, and no person shall sell, or import
into Hong Kong, any such food which does not comply
with the provisions of these regulations.
9.
The permitted preservatives for use in foods are stipulated
in the First Schedule to the Preservatives in Food Regulations
made under section 55 of the Public Health and Municipal
Services Ordinance (Cap. 132), which specifies the permitted
preservatives for use in respective foods, as well as
the relevant maximum permitted levels.
10.
The types of permitted colouring matter for use in food
are stipulated in the First Schedule to the Colouring
Matter in Food Regulations made under section 55 of
the Public Health and Municipal Services Ordinance (Cap.
132).
Results
of Chinese New Year Foods Surveillance in Hong Kong
1996-1999
11.
The surveillance results from 1996 through 1999 were
reviewed to examine the potential hazards related to
preservatives and colouring matter in the locally sold
Chinese New Year Foods. A total of 499 and 386 samples
were sent to Government Laboratory for testing of preservatives
and colouring matter respectively. Fifteen samples (3.0%)
were found to have used preservatives that were either
not appropriate for the specified food or at higher
than permitted level (Table 2). For colouring matter,
15 samples (3.9%) were found to contain non-permitted
colouring matter (Table 3).
Steamed
Puddings
12.
Preservatives are generally used in steamed puddings
to extend the shelf life. Like flour confectionery and
other bakery products, the permitted preservatives in
steamed puddings are sorbic acid and propionic acid.
However, it was found that some manufacturers used benzoic
acid in a number of steamed puddings, namely New Year
Pudding, Taro Pudding, and Turnip Pudding, during the
period from 1996 to 1998.
13.
The use of non-permitted preservatives in Chinese New
Year steamed puddings has decreased -
none of the 107 samples taken in 1999 was found to contain
the non-permitted benzoic acid.
14.
Colouring matter may also be used in steamed puddings.
A total of 13 samples of steamed puddings, namely New
Year Pudding, Coconut New Year Pudding, Taro Pudding,
and Water Chestnut Pudding, have been found to contain
Orange II in the past four years. However, a closer
examination revealed a downward trend. The use of Orange
II in steamed puddings has decreased from 9 out of 29
samples in 1997 to 2 out of 65 samples in 1999 (Table
3).
Fried
Dumplings
15.
Traditionally sesame balls may be given a red spot to
add festive feelings. In two consecutive years 1996
and 1997, Rhodamine B was found in two samples of sesame
balls. Testing in the subsequent years did not found
such phenomenon (Table 3).
Sweetened
fruits and vegetables
16.
Preservatives are commonly used in the preparation of
sweetened fruits and vegetables. In the past three years,
a total of eight sweetened melon or water chestnut samples
were found to contain sulphur dioxide at levels above
the maximum permitted concentration stipulated in the
Regulations.
Glutinous
rice balls and seeds
17.
There were no irregularities detected in the surveillance
of glutinous rice balls and seeds for preservatives
and colouring matter.
Discussion
18.
In this study, we have identified that benzoic acid
and sulphur dioxide are the predominantly misused preservatives
whereas Orange II is still an occasionally abused colour
in Chinese New Year Foods.
Preservatives
19.
Two preservatives found to exceed statutory limits in
the Food Surveillance Programme on Chinese New Year
Foods between 1996 and 1999 are benzoic acid and sulphur
dioxide. Both are among the most widely used preservatives.
20.The use of benzoic acid in flour confectionery is not permitted in the
Public Health and Municipal Service Ordinance (Cap.
132). On the other hand, propionic acid or sorbic acid
are recommended to be used because they are more effective
in minimizing spoilage in flour confectionery products
including steamed puddings (4,5,6). The maximum permitted
levels of preservatives may vary with its chemical nature
and composition of the foods. For examples, for flour
confectionery the law permits the use of 1000 parts
per million (ppm) of sorbic acid or propionic acid (2).
21.
When exposed to an excessive amount of benzoic acid,
individuals may suffer from adverse reactions such as
asthmatic attacks or neurological abnormalities (4,5).
The present surveillance findings suggested that manufacturers
might have chosen the inappropriate preservatives for
the steamed puddings. Strengthening the delivery of
relevant information to the food trade may be helpful.
22.
Sulphur dioxide is commonly used in fruits,
vegetables, wine, meat and sausages. Its activity usually
covers yeast, moulds and bacteria. It also acts as an
antioxidant, which prevents unwanted enzymatic browning
in fruits and vegetables (7). It is most effective in
acidic foods. Allergic reactions to sulphur dioxide
were reported in sensitive persons, such as those with
asthmatic history (4).
23.
In the unsatisfactory sweetened melon and water chestnut
samples, the levels of sulphur dioxide have exceeded
the maximum permitted limit. It is likely to be related
to insufficient quality control during manufacturing
process in the trade.
Colouring
matter
24.
The two types of non-permitted colouring matter identified
in the present study, namely Rhodamine B and Orange
II, are industrial dyes. Their uses in foods are forbidden.
25.
Rhodamine B is a dye for wool and silk. It produces
a brilliant red colour to the food. It was found in
traditional Chinese food items such as red buns and
pastries previously. Rhodamine B may cause irritation
to lungs, eyes, throat, nose and intestines but details
of toxic effects have not been reported. Erythrosine
(BS) is recommended to replace Rhodamine B for food
colouring purposes.
26.
Orange II is an industrial dye which was occasionally
detected in siu mei, lo mei, vegetarian food and bakery
products. It produces a golden-yellow colour to the
food. It has been forbidden for use in food in Hong
Kong since 1994. Sunset Yellow FCF can be used to give
the golden-yellow colour similar to Orange II.
27.
Data collected in food surveillance is not sufficient
to identify why the non-permitted colouring matter is
used. However, it is speculated that the small-scale
food manufacturers might have been adopting traditional
materials in food preparation. Others might have used
food ingredients that may contain non-permitted colouring
matter.
Recommendations
Advice
to the Public
28.
This study revealed that the inappropriate use or excessive
use of preservatives and colouring matter in Chinese
New Year Foods has been infrequent in the past four
years. As they are seasonal foods, the dietary intake
is relatively small. It is therefore unlikely to have
posed major health hazards to the consumers. Nevertheless,
the public is recommended to maintain
a balanced diet even during the festive seasons.
Strengthening
communication with trade
29.
This study highlights the importance of communication
with the trade - especially
the food manufacturers regarding the use of these food
additives. A systematic communication with the wider
public shall enhance the message further. Most importantly,
these food additives should be used in accordance with
good manufacturing practice such that levels of these
additives are just appropriate to achieve their intended
purposes.
Role
of the Government
30.
The Government has the statutory role to enforce the
relevant regulations with a robust food surveillance
system. Warning letters and/or prosecution will be issued
to those manufacturers or vendors who fail to comply
with the laws.
Codex
Alimentarius. General Requirement (Volume 1A).
Food and Agriculture Organization of the United
Nations/World Health Organization; 1995.
2.
Hong
Kong Special Administrative Region Government.
Public Health and Municipal Services Ordinance
(Cap. 132).
3.
U.S.
Food and Drug Administration/International Food
Information Council Foundation. Food Color Fact.
In: U.S. Food and Drug Administration. January
1993.
URL: http://www.fda.gov
(November 1999)
4.
Luck,
E. Jager M. Antimicrobial Food Additives: Characteristics,
Uses, Effects. Berlin: Springer; 1980.
Samples
of Chinese New Year Foods were obtained from restaurants,
bakery shops, supermarkets and other retail outlets
during the Chinese New Year period (usually in January
and February) from 1996-1999.
Laboratory
analysis
(1)
Preservatives
Preservatives
tested in Chinese New Year puddings, fried dumplings,
glutinous rice dumplings and seeds are sorbic acid,
benzoic acid, esters of b -hydroxybenzoic acid and salicyclic
acid using High Performance Liquid Chromatography (HPLC).
For
sweetened fruits & vegetables, preservatives determined
include sulphur dioxide, benzoic acid and esters of
b -hydroxybenzoic acid. Sulphur dioxide isolated from
food samples was quantified by titration with iodine
solution.
(2)
Colouring matter
Samples
were sent to Government Laboratory for chemical analysis.
Colouring matter being analysed in Chinese New Year
Food samples include those listed in the First Schedule
to the Colouring Matter in Food Regulations made under
section 55 of the Public Health and Municipal Services
Ordinance (Cap. 132), as well as the most common non-permitted
colouring matters, such as Crocein Scarlet 7B, Orange
II, and Rhodamine B. Paper or Thin Layer Chromatography
(TLC) is used to identify colouring matter present in
food samples.
The
Codex Alimentarius is a collection of internationally
adopted food standards presented in a uniform manner.
The food standards aim at protecting consumers' health
and ensuring fair practices in the food trade.
Colour
According
to Codex Alimentarius, Colour refers to any substance
which adds or restores colour in a food.
Deterioration
Deterioration,
in relation to food, means deterioration due to the
action of bacteria, yeasts or moulds.
(Public
Health and Municipal Services Ordinance Cap. 132)
Food
Food
includes –
drink;
chewing
gum and other products of a like nature and use;
smokeless
tobacco products; and
articles
and substances used as ingredients in the preparation
of food or drink or of such products,but does not
include –
live animals,
live birds or live fish (excluding shell fish);
water,
other than –
aerated
water;
distilled
water;
water
from natural springs, either in its natural
state or with added mineral substances; and
water
placed in a sealed container for sale for human
consumption;
fodder
or feeding stuffs for animals, birds or fish;
or
articles
or substances used only as drugs.
(Public
Health and Municipal Services Ordinance Cap. 132)
Food
additive
According
to Codex Alimentarius, Food Additive means any substance
not normally consumed as a food by itself and not normally
used as a typical ingredient of the food, whether or
not it has nutritive value, the intentional addition
of which to food for a technological (including organoleptic)
purpose in the manufacture, processing, preparation,
treatment, packing, packaging, transport or holding
of such food results, or maybe reasonably expected to
result, (directly or indirectly) in it or its by-products
becoming a component of or otherwise affecting the characteristics
of such foods. The term does not include "contaminants" or
substances added to food for maintaining or improving
nutritional qualities.
It
may also mean any substance, not commonly regarded or
used as food, which is added to, or used in or on, food
at any stage at affect its keeping qualities, texture,
consistency, appearance, taste, odour, alkalinity or
acidity, or to serve any other technological function
in relation to food, and includes processing aids in
so far as they are added to, or used in or on food.
(Public
Health and Municipal Services Ordinance Cap. 132)
Food
Surveillance
Food
Surveillance is a programme designed to collect and
analyze samples (e.g. chemical and bacteriological analyses)
from various points in the food chain. The purpose of
the programme is to ensure that food products for sale
are hygienic and safe.
Good
Manufacturing Practice (GMP)
According
to Codex Alimentarius, Good Manufacturing Practice means
–
the quantity
of the additive added to food shall be limited to
the lowest possible level necessary to accomplish
its desired effect;
the quantity
of the additive that becomes a component of food
as a result of its use in the manufacturing, processing
or packaging of a food and which is not intended
to accomplish any physical, or other technical effect
in the food itself, is reduced to the extent reasonably
possible; and,
the additive
is prepared and handled in the same way as a food
ingredient.
Hazard
According
to Codex Alimentarius, Hazard is a biological, chemical
or physical agent in, or condition of, food with the
potential to cause an adverse health effect.
Permitted
Coluring Matter
Permitted
Colouring Matter means any colouring matter inasmuch
as its use is permitted by the Colouring Matter in Food
Regulations (Cap. 132 sub. leg.).
(Public
Health and Municipal Services Ordinance Cap. 132)
Permitted
Preservative
Permitted
Preservative means any preservative specified in Column
2 of Part I of the First Schedule or, subject to the
provisions of paragraph (3) of this regulation, a preservative
specified in Column 2 of Part III of the First Schedule
of the Preservative in Food Regulations (Cap. 132 sub.
leg.).
(Public
Health and Municipal Services Ordinance Cap. 132)
Preservative
According
to Codex Alimentarius, Preservative refers to any substance
which prolongs the shelf-life of a food by protecting
against deterioration caused by microorganisms.
It
may also means any substance which is capable of inhibiting,
retarding or arresting the process of fermentation,
acidification or other deterioration of food or of masking
any of the evidence of putrefaction but does not include
–
any permitted
antioxidant;
any permitted
colouring matter;
common salt
(sodium chloride).
(Public
Health and Municipal Services Ordinance Cap. 132)
This
is a publication of the Food and Public Health Branch
of the Food and Environmental Hygiene Department of
HKSAR Government. Under no circumstances should the
research data contained herein be reproduced, reviewed,
or abstracted in part or in whole, or in conjunction
with other publications or research work unless a written
permission is obtained from the Department. Acknowledgement
is required if other parts of this publication are used.
Correspondence:
Risk Assessment
Section
Food and Environmental Hygiene Department
43/F, Queensway Government Offices,
66 Queensway, Hong Kong.
Last
review date: 19-01-2005