Nitrite Content of Some Foods in Malaysia

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RINGKASAN. Nitrat and nitrit adalah bahan tambah yang biasa digunakan dalam pengkiuran daging. Bahan-bahan ini juga memberi warna dan perisa yang ...
Pertanika 7(2), 39-41 (1984)

Nitrite Content of Some Foods in Malaysia A. S. BABJI, AISHAH, Sand AMIN AH, A.

Department of Food Science and Nutrition Faculty of Life Sciences Universiti Kebangsaan Malaysia Bangi, Selangor, Malaysia.

Key words: Nitrite content; foods; Malaysia.

RINGKASAN Nitrat and nitrit adalah bahan tambah yang biasa digunakan dalam pengkiuran daging. Bahan-bahan ini juga memberi warna dan perisa yang baik dan dapat merencat penumbuhan mikroorganisma Clostridium botulinum. Nitrit boleh bertindak dengan amina sekunder dan membentuk sebatian nitrosamina. Nitrosamina inilah yang menjadi satu kontroversi berhubung dengan penggunaan nitrit kerana nitrosamine ini mempunyai kesan karsinogenik kepada manusia. Kajian analisis kandungan nitrit ke atas beberapa jenis makanan telah dilakukan. Paras reja nitrit dalam hasil-hasil daging adalah dalam julat 14 - 53 bpj, dalam jeruk buah-buahan dan sayur-sayuran adalah 7 - 81 bpj dan pada ikan-ikan kering 11 - 38 bpj. Hasil kajian ini menunjukkan bahawa paras reja nitrit dalam kebanyakan makanan adalah kurang dari paras 200 bpj yang dibenarkan.

SUMMARY Nitrate and nitrite are additives commonly used in meat curing for improvement of colour and flavour and as protection against the .grqwth of Clostridium botulinum. Nitrite can combine with secondary amines to form nitrosamines, the source of controversy in the use of nitrite as food additivies. Analysis of nitrite levels in several foods suspected of containing added nitrite was carried out. Levels of residual nitrite in meat products were in the range of 14 - 54 ppm, processed pickled fruits and vegetables 7 - 81 ppm and salted dried fish 11 - 3B-ppm. Results indicate the level of residual nitrite in most foods is below the permissable level of 200 ppm.

INTRODUCTION

In Malaysia, the use of nitrates and mtrItes is limited to the meat processing industry for the production of cured meat products. According to the Sale of Food and Drugs Ordinance and Regulations Malaysia, 1952, the permissible level of nitrite for cooked meat and raw meat are 200 and 500 ppm, respectively. Any other use in the food industry would be minimal since its functions are specific.

Sodium nitrite, commonly used in curing of meat is a derivative of sodium nitrate which is present in salt as an impurity. Although its use has been widely associated with certain types of cancer in laboratory animals, it is still continually being used in the food industry (Olsen and Mayer, 1976). Nitrite is deemed essential in cured meats because of its multiple functions. It prevents botulism, gives cured meat its special flavour and appearance, retards oxidation which otherwise causes an undesirable (warmed over) flavour. It is claimed that nitrite is the only substance that serves all these functions and no substitute has been found to replace it (American Meat Institute, 1978).

This study is aimed at providing some infor: mation on nitrite levels in some food products commonly used in Malaysia

MATERIALS AND METHODS Various food samples (imported and local) were purchased form local markets and supermarkets. Imported samples included corned

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A. S. BABJI, AISHAH, SAND AMINAH, A.

TABLE 1 Nitrite content in some imported and local foods in Malaysia

Sodium Nitrite level (ppm)*

Types of Food

Meat Products: Corned Mutton Beef (Australis)

32.7

Chicken Luncheon Meat (J apan)

36.0

Beef Cocktail Sausages (D'enmark)

14.0

Beef Hotdog Sausages (Denmark)

53.0

Beef Burger (Local)

14.0

Fruits Products:

24.7

Chan Pi Sar Char

7.0

Sweetened Plum Red Ginger

46.7

Red Cherry

ND**

Red pickled pear

81.7

Sour mango

18.7

Gambier (Red)

35.0

Haw flakes

20.7

Red sour lime

20.7

Fish Products: Salted dried fish (sepat)

32.7

Salted dried fish (selar)

28.0

Salted dried fish (Gelama)

30.0

Salted dried fish (Kembong)

14.0

Salted dried fish (Tenggiri)

11.7

Salted dried fish (Bulu ayam)

11.7

Salted dried fish (B iUs)

38.3 12.7

Fermented shrimp paste (Belacan)

7.0

Pickled vegetable (Brassica juncea, Chinese)

*

Mean of duplicate analysis

** ND : Not detected

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NITRITE CONTENT OF SOME FOODS IN MALAYSIA

mutton loaf (Australia), beef cocktail sausages (Denmark), beef hotdogs (Denmark) and chicken cocktail sausages (Japan). Local food included beef burger, pickled dried fruits and vegetables, salted fish and fermented shrimps. All meat samples were kept in the freezer at -20°C, while salted dried fish and dried fruits and pickled vegetable were stored at 3-5°C until ready for analysis.

low. The nitrite content of pickled vegetable, Sawi China (Brassica juncea) and fermented shrimp paste were 7 and 12.7 ppm, respectively. Thus, nitrite is present in many of our foodstuffs, even though sodium nitrate and nitrite are not added intentionally in many of the products. The American Meat Institute (1978) reported that more than 80% of the nitirte entering the human stomach originates in saliva and less than 20% comes from cured meat and poultry products. However. this should not be an excuse for us to stop- monitoring the use of chemicals such as nitrate and nitrite in the food industry in Malaysia.

The spectrophotometric sulfanilic acia method (AOAC 1975) was used to determine the nitrite content of food samples. The nitrite content in food products was calculated in parts per million (ppm) by the formula: A x 100lB where A is the NaN0 2 (micrograms) in the coloured solution as read from the standard curve and B is the volume in millilitres of aliquot used for colour development. Duplicate samples were analysed for each type of food item. A reference curve was plotted for absorbance (540 nm) versus concentration of nitrite.

CONCLUSION As nitrite is essential in cured meat, its utilization should be closely monitored. This is to' ensure that the level of nitrite in foods is within safe limits. Based upon this study, we can conclude that the nitrite content in most of our food is within the safe limit. As nitrite is essential in cure~ meat, its utilization should be closedly momtored. This is to ensure that the level of nitrite in foods is within safe limits.

RESULTS AND DISCUSSION Results of nitrite content in various food items analysed in this study is shown in Table 1. For the imported canned meat products the residual levels of nitrite ranged from 14 - 53 ppm. This level is below the 200 ppm maximum permissible limit as suggested by the Food and Drug Administration of the United States Department of Agriculture (Greenberg 1957). The levels although low were still effective in preserving the meat products with the cured colour. Zaika et at. (1976) reported that cured meat colour can be obtained with 50 ppm nitrite or 100 ppm nitrate in the cure mix.

REFERENCES American Meat Institute (1978): Nitrite. American Meat Institute. P. O. Box 3556 Washington D.C. 20007. AOAC, (1975). Offical Methods of Analysis. (12th ed.) Official Agticultural Chemists, Washington, D.C. GREENBERG, R.A. (1957): Update on nitrite and nitrosamine Proc. Meat Industry Researarch Cont. American Meat Institute Foundation p 71 - 76.

For local products such as beef burgers, the level of residual nitrite reported was 14 ppm. This indicates that there is no misuse of nitrite in the burger meat. However, in most beef burgers, food colours are used to get the red meat colour. This is because most producers include other non-meat proteins in their formulation.

OLSON, P and MEYER. O. (1976): Carcinogenicity Study on rats fed on canned heated nitrite-treated meat: Preliminary Communication. Proceeding of the Second International Symposium on Nitrite in Meat Products, Zeist. The Netherlands. p 275 - 278. The Sale of Food and Drug Ordinance and Regulations, 1952: Ministry of Health, Kuala Lumpur, Malaysia.

For the production of salted dried fish, sodium chloride is commonly used in the curing process. Thus, the residual nitrite level reflected the nitrate contaminants that are naturally present in the solar salt.

ZAIKA, L.A., ZELL T.E., SMITH. T.L., PALUMBO. S.A. and KISSINGER, J.C. (1975): The role of nitrite and nitrate in Lebanon Bologna, a fermented sausage. J. Food Sci. 41: 1457-1460.

For salted fruits that are pickled and cured with salt, the levels of nitrite reported were also

(Received 5 January, 1984)

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