FOOD ADUILa*E:RANTS AND THEIR DETECTION E.G. SOMAPALA Senior Assistant Government Analyst, Government Analyst's Department, Colomho 7. The story of adulterated food is an old one. The rele- vant ligislation on food enacted in Sri Lanka before the second world war ie., Bread ordinance and Milk Reg- ulations which related to the sale of Bread and Milk respectively. In 1949 Food and Drugs Act was intro- duced in Sri Lanka. The same was replaced in 1980 by the Food Act No: 26 of 1980. The present Food Act covers the manufacture, sale, distribution and import of Food and is applicable to the whole Island. A number of Regulations framed under this Act are A survey of different types of foods in Sri Lanka would .reveal the various adulterants present in those 'bods. 1. Ground Spices This includes mainly chillie powder, turmeric powder, condiment powder, pepper powder etc. The common type of adulterants are wheat flour, rice flour, corn flour, brick powder, powdered paddy husk, saw dust, and poonac. being implemented to ensure the safe food for the The detection of these foreign substances are carried consumers. The minimum quality requirements for out by the determination of total ash content, Acid most of the common foods are specified in these reg- Insoluble Ash content and finally the microscopic ex- ulations. The sale of adulterated food is an offense and amination. The addition of flours to any of these liable for heavy fines andlor imprisonment. speces will definitely bring down the total ash content What is Food Adulteration? Eventhough there is no proper definition, but can be explained as follows. "The addition of foreign matter to any food to incrcase the bulk by which to get more profit". Also in certain cases it may be the removal of certain portion of a food eg. extraction fat from milk. We cannot exclude the "artificial" preparation of foods such as preparation of turmeric powder using wheat flour and artificial col- owing matter ie. 100 percent adulteration. The prep- aration of foods using artificial ingredients and label them as natural products could also be considered as Food Adulteration. By all these means the end result is an enhanced profit. These adulterants may be harmless or harmful. eg. addition of flours to turmeric is harmless while the addition of paddy husk to chillie powder or the prep- aration of sugarlflour confectioneries using non per- mitted colouring matters such as Metanil Yellow (yellow) and Rhodarnine B(red) are harmful to the human body. proportionately as the flours do not contribute for the ash content. On the other hand the total ash and subsequently the acid insoluble ash content will be raised if the spices are adulterated with paddy husk, saw dust or brick powder. The confirmation of the presence of these foreign matters as well as the spices is done by microscopic examination. Since all these are plant matters (except brick powder which is rich in Silica crystals) the char- acteristics tissues and other microscopic structures could be identified under the nlicroscope. The values obtained for total ash content and acid insoluble ash content could be justified by microscopic estimation of the foreign matters. One of the coinmon food items found to be adulterated in the local market is arrowroot. It has been reported that maize starch is the frequent adulterant. Less frequently Manioc starch (tapioca starch) has been used to adulterate arrowroot. Of course the adultera- tion is the 100 percent and the detection of these foreign starches are only carried out by microscopic examination because the starch grain has its character- istic shape, size and hylum. k The rice flour found to be. adulterated with wheat flour. Also it is reported that Kurakkan flour to con- tain rice flour andlor wheat flour. The detection of these foreign starches are only done by the micro- scopic examination. 3. Ground Coffee The adulteration of ground coffee with roasted rice flour, roasted ground nut husks, roasted tammarine seeds are not new to the analyst. The detection of these foreign matters is done by the determination of total ash, water extractives and the caffeine content. The presence of rice flour will lower the total ash content while the presence of other vegetable matters will lead to the increase in the extract. Also it is accepted that the caffeined content of ground coffee should be not less than 1.25 percent. The addition of foreign matter will definitely lower this value and hence it is easily calculated the percent foreign matter. The final confirmation of the presence of coffee and other foreign matters will be carried out by micro- scopic examination. 4. Oils & Fats The important oils in the Sri Lankan market are coco- nut oil, gingelly oil and less commonly ghee. The main adulterant in coconut oil is palm oil. On the other hand it is very common that the quality of coconut oil avail- able for the consumers is far below the quality stan- dard required by the Food Miscellaneous Regulations 1989. ie high free fatty acid content. Lower quality coconut oil is the most common adul- terant present in gingelly oil. Also it is known that the cotton seed oil has been used in the adulteration of gingelly oil. The occassions of use of paraffin oil as an adulterant have been reported. The.detection of these foreign oils and other matters are carried out by the determination of two important parameters namely saponification value and iodine value. Ofcourse the high free fatty acid content is detected by simple titra- tion with a standard alkali after dissolving the oil ire neutral alcohol. The Sapodication value and Iodine value are characteristic of any oil. Coconut Gingelly Palm Oil Oil Oil eg. Sap. Value (av) 255 200 208 Iodine Value (av) 8 100 50 If gingelly oil is adulterated with coconut oil the sapon- ification value of the resultant mixture should be ifn between 255 and 200 depending on the proportions of each type of oil, ie. the higher the coconut oil content the higher the saponification value. On the other hand the Iodine value lies between 8 and 100. ie. the higher the gingelly oil content the higher the iodine value. When only two oils are present the proportions of each type of oil could be calculated conveniently using sa- ponification and Iodine values of the mixture. At the same time the qualitative tests to detect the presence of these oils are carried out, It has been reported that Ghee (mostly used as an Ayurvedic ingredient) is adulterated with palm oil, lard tallow or paraffin wax. There were occasions of the artificial preparations of ghee using palm oil (spe- cially stearing portion) and non permitted colouring matter-metanil yellow. The purity of ghee is assessed by the determination of the special parameters called Reichert, Polenske and Kirshner values. (The defini- tion of these values are beyond the context of this text). These values are characteristics of ghee and the devi- ation from these values will show the presence of foreign matters. eg. If butter is adulterated with margarine by the determination of the above three values it is possible to calculate the percent butter fat in the sample. The presence of paraffin wax is detected by Holder's test and the unsaponifiable matters (wax) could be estimated. Other than these classical methods it is possible to present. The two non permitted colouring matters determine the purity of these o l s & fats using the Gas used in these industries are Liquid Chromatography. 1. Metanil Yellow (yellow wlour) 6. Vinegar 2. Rhodamine B (Red Colour) Food Regulations requires Vinegar to contain a &- mum of 4 percent acetic acid. Vinegar could be pre- pared either naturally from the fermentation of coconut today (or malt) or artificially by the dilution of acetic acid. Obviously the most common adulterant is water. The acetic acid percentage is obtained by a simple titration with standard alkali solution. By labelling the artificial products as natural vinegars or by using a label with pictorial representations of coconut trees etc. to imply khc product is natural is not uncommon in Sri Lanka. This is an indirect way of adulteration by which the consumer is mislead. The secondary constituents such as ketones, aldehydes and ester etc. which are the by - products of the natural fermentation process are use- ful indicators in the differntiatio~ of the natural and artificial vinegars. The alkaline oxidation value, Acid oxidation Value, Ester Value and Iodine Value, of vinegar are used to differentiate between the two types. The use of formic acid in the manufacture of Vinegar has been detected. Even the mineral acids may be present in vinegars. The qualitative tests are carried out to determine the type of acid present in the vine- gars. ie. Acetic, formic & mineral acids. 7. Honey Money is another ingredient for Ayurvedic prepara- tions. The most common adulterant is sugar syrup. One can differentiate the natural honey and sugar by the determination of dextrose / fructose ratio. Also the prescnce of sugar syrup is detected by iden- tifying HMF which is only present in sugar syrups. 8. Sugar and Flour confectioneries Eventhough these food items are not adulterated, it is useful to consider the non permitted colouring matters The detection muad identification of these colouring matters are done by the extraction, followed by paper chromatographic seperation. Metanil yellow can be defecteed by the addition of few drops of dilute &erd acid (such as hydrochloricacid or Sulphuric acid - Battery acid) to the food. The change of colour from yellow to pink shows the pres- ence of this colouring matter. 9. Milk and M i k Products Milk is a liquid obtained from the complete emptying of the udder of a lactating cow. The main constituent of milk is water (87.5 percent) while protein, fat, car- bohydrate (lactose), minerals and vitamins are other inpedients. According to the Food (Standards) Reg- ulations 1989 the cows milk shouid contain a minimum of 3.5 percent fat and 8.5 percent of Milk Solids other than fat. There are number of types of liquid miks available in the market with different minimum levels of fat and milk solids other than fat. It is well k n o w that the milk is adulterated with the addition of water. On the other hand the extraction of fat from milk is also an adulteration. The adulteration of milk can be defected quantitatively by the determi- nation of fat and total solid content. 10. Ready to drink beverages rand cordials According to Food (miscellaneous) Regulations 1986 ready to drink beverages prepared with fruits should contain a minimum of 5% fruit juice, and cordials should contain not less than 25% fruit juice. On the other hand it is also possible to prepare tbese two drinks artificially using water, sugar colouring matters and artificial flavours. But they should be labelled as 'artificial' It has been found that the artificial preparat' L O ~ S are labeled as natural or use labels with pictorial represerm- tations of fruits of fruits to imply them as'naturd products. This is misleading the consumer. It could be considered as adulteration because the consumer is not getting what he wanted. By the adition of more water the fruit content will be lowered, hence the product is adulterated. The detec- tion of the fruit content is carried out by the determi- nation of the Potassium and Phosphorus content. By comparing these figures with the recorded levels one can calculate the percent fruit juices present in a par- ticular, product. Also it is possible to defect the natu- r a l a n d ar t i f ic ial f lavours by gas l iqu id chromatography. The other problems with these two types of drinks is the use of saccharin as an artificial sweetner. Accord- ing to Food (Non - nutritive Sweetners in Food) Reg- ulations 1990 saccharin is not allowed in any food. The sweetening power of saccharin is 550 times that of sucrose. So the use saccharin is profitable, and it has been found saccharin in some of the ready to drink bcvcrages specially in certain "drink packets". The quantitative detection of Saccharin is done by extraction with dieethyl other followed by titration with standard al- Acali using bromothymol blue as an indicator. The qualitative tests are carried out to confirm the identity of extracted saccharin. Adulterated food in the Srf kankan market is not very uncommon. The above given is a brief outline of cer- tain common food i tem. Under the Food Ace No: ini of 1980 a number of Regulations are framed and they are in effect now. The consumers must be vigilent against the food adulteration. The chairman of the local body, Medical Officer of Health of the area, the Public Health Inspector are the Authosised officers under the Food Act. Any complain regarding any food should bring to their notice without any delay. However the legal action alone cannot ixradicate such malpractices. The consumer as well as the producer must be given a knowledge on the food standards etc. This could be done through the media such as news papers, Radio and Television. Audio visual pro- grammes are the most successfuull in the education of public. Which is lacking in Sri Lanka. This knowjedge could also be given to the school children by way of conducting seminars, public lectures etc. The public awareness on the quality of foods is of greater import- ance. This will lead to the manufacture of quality foods. It should be born in mind of every citizen that every one is 'a consumer. The legal action against the food adulterations and the consumer / producer education would lead to guarnteed quality foods to the people. VIDU 14_384_24.pdf VIDU 14_384_24 (2).pdf VIDU 14_384_24 (3).pdf VIDU 14_384_24 (4).pdf