Levels of Polycyclic Aromatic Hydrocarbons in Some Brands of Pastas in Nigerian Market: an Assessment of Possible Potential Health Risk
CHAPTER ONE
OBJECTIVES OF STUDY
- Determine the level of some polycyclic aromatic hydrocarbons in different brands of locally produced and imported pasta
- To assess the level of compliance to guideline values of this PAHs from international
- To correlate the levels of PAHs in the different brands
- Compare the concentration of polycyclic aromatic hydrocarbons in both Nigerian and imported brands of pastas
- Estimate any possible potential health risk involved in the consumption of these pasta
CHAPTER TWO
LITERATURE REVIEW
PAHs in Food
High PAH concentrations have been reported in charcoal grilled / barbecued foods such as fatty meat and meat products grilled under prolonged and severe conditions, in foods smoked by traditional techniques (fish in particular), and in mussels and other seafood from polluted waters.8 Evaluation of PAHs in roasted foods snacks in Amassoma, Niger delta have been reported with benzo [a] pyrene and benzo [b] fluoranthene found in appreciable amount. No PAH was detected in roasted plantain and in the raw food items.23 Non-carcinogenic PAHs were present at high proportions (60-100%) with phenanthrene showing the highest mean concentration (54.9ugkg-1) was studied in various grilled and smoked foods.24 In Spain, current highest levels of total PAH were detected in meat and meat products followed by oils and fats.25 The presence of PAHs in coffee has also been reported and it has been suspected to be due to either a contamination of green coffee beans during the drying step or an endogenous formation in the coffee beans during the roasting process.
The influence of different smoking techniques on the PAH levels in the processed food commodities has been investigated by numerous authors. They studied the influence of the type of smoking kilns on the PAH levels in processed products by determining the levels of 13 PAHS in smoked fishery products from modern smoking kilns with external smoke generation and from traditional smoking kilns.28 The average benzo [a] pyrene concentration of all 35 samples from commercial smoking kilns with external smoke generation concentration was 0.1μg/kg (wet weight) and the average concentration of the sum of the carcinogenic compounds determined in the study was 9.0 μg/kg.
Investigation on the possible presence of PAHs in 7 commercial types of cheese smoked by traditional techniques was carried out in order to provide an indication of the PAH contamination in the cheeses that are commonly consumed. The samples were manufactured with milk from cows, sheep, goats, or a mixture of them, and purchased in local super- markets. The results revealed the presence of several PAHs in the exterior zone of the samples, some of the PAHs having methyl groups. In all cases, the concentrations of PAH compounds of low molecular weight were much higher than those of high molecular weight.29 Dependent on the technological process the PAH levels in smoked food may be subject to changes over time. Investigation carried out shows benzo[a]pyrene content in fermented salami during the technological processes of cold smoking, ripening and storage. They found that the changes in benzo[a]pyrene content were not so great as in products smoked with hot smoke. However, the decrease in benzo[a]pyrene content caused by photodegration was compensated by successive dehydration of the fermented product.
Considerable differences in the PAH levels can be found in grilled products depending on the heat source as well as the type and geometry of the grill. This is especially important for home cooking practices. A study on the effects of frying, grilling, barbecuing, toasting and roasting on the formation of PAHs in food prepared in the home and from catering outlets has been reported. The study comprised 77 retail cooked food samples and 256 samples from in-house cooking experiments. It was discovered that only three cooked retail products, all beef burgers, contained benzo[a]pyrene at concentrations of 8.4μg/kg, 9.8 μg/kg and 20.4 μg/kg. With respect to home cooking practices, in general, there was little evidence of PAH formation during the grilling, frying, roasting and toasting experiments.
CHAPTER THREE
MATERIALS AND METHODS
SAMPLE COLLECTION AND PREPARATION
Different brands of locally manufactured and imported pastas were collected between 11th and 21st November, 2014 from 2 major cities in Nigeria (Abuja and Enugu). The choice of the samples was carefully made to reflect different origins and popular brands consumed by different income classes. The samples were categorized into three (3): Noodles, Spaghetti and Macaroni. The manufacturer details of each product including brand name, batch numbers, production and expiry dates and net weights were obtained from the packaging of each product as shown in Tables 2 and 3. A total of 30 samples were randomly collected, each sample representing a product in two of its batches. Each sample was ground into powder with a porcelain mortar and pestle and sieved through a thin fine cotton and labeled for analysis. The samples were stored at 4oC prior to analysis.
SAMPLES EXTRACXTION AND CLEAN UP
15 g of the sample was homogenized with 5 g of Na2SO4 until a completely dry homogenate was obtained. The homogenate was carefully transferred into the thimble and place in the extraction chamber of the soxhlet extractor. The extractions were carried out using 100 mL mixture of n-hexane and dichloromethane (1:1 V/V) for 16 h. The extracts were evaporated to 2-3 mL using a rotary evaporator and purified by passing through or column packed with silica gel. The column was pre-rinsed with 30 mL of n-hexane and subsequently eluted with 50 mL mixture of n-hexane and dichloromethane ( 1: 1 V/V). The eluted extract were combined and evaporated to 1.0 mL.
CHAPTER FOUR
RESULTS AND DISCUSSION
Recovery Analysis
This study involved inclusion of recovery analysis of standard reference material (SRM 822
- 275872 – 11) as analytical quality assurance measures for PAH determination in the pasta samples. The results for recovery studies are presented below on Table 5. Recoveries for the PAH compound varied between 97.1% and 100%. The uncertainty calculated for this PAHs is ± 5% which represent the estimated standard deviation. The recovery results obtained shows that the method is very accurate and precise.
CHAPTER FIVE
Conclusion and Recommendations
Conclusion
Polycyclic Aromatic Hydrocarbons (PAHs) constitute a large class of organic compounds that are composed of two or more fused aromatic rings. They are primarily formed by incomplete combustion or pyrolysis and generally occur in complex mixtures. Currently the PAHs of greatest concern are those that are genotoxic and carcinogenic. Therefore, the evaluation focused on the 16 PAHs included in the United State Environmental Protection Agency (USEPA) list of priority organic pollutants.
The concentrations of Σ16 PAHs, ΣLMW-PAHs and ΣHMW – PAHs in different brands of Nigerian pastas were generally high compared to imported pastas. However, 75% of the Nigerian brands had Bap concentration less than 0.001mgkg-1 permissible limit specified for processed cereal food by European Commission and was 100% for imported brands. PAH2, PAH4 and PAH8 which are also markers of carcinogenicity were found higher in Nigerian brands of pastas compared to imported brands.
The Margin of Exposure (MOE) values for generally exposed individuals were lower than 10,000 in 25% and 0% of Nigerian brands based on PAH8 concentration for the child and adult scenarios and for typically exposed individuals, it were 38% and 0% for child and adult scenarios.
For imported brands of pastas, the MOE values were found to be far higher than 10,000 for generally and typically exposed individuals in both child and adult scenarios. According to European Food Safety Authority (EFSA), MOE value less than 10,000 indicates a potential concern for the consumer’s health. Therefore, there is a potential concern for individuals who consume Nigerian brands of pastas especially for children and a low concern for consumers of imported brands of pastas.
Recommmendation
The levels of PAHs found in these samples demonstrate the need for limits for PAHs in foods in Nigeria. Continuous demand for analytical monitoring and increased research efforts concerning Nigerian brands to ensure adequate protection of human health and possible risk management action should be advocated.
It is also recommended that the following further research work can be carried out on the different brands of pastas in Nigerian markets:
- The level of nutritional factors
- The level of anti-nutritional content
REFERENCES
- EFSA (European Food Safety Authority). (2005) Opinion of the scientific committee on a request from EFSA related to a harmonized approach for risk assessment of substances which are both genotoxic and carcinogenic. The EFSA Jounal 282: 1-31. http://www.efsa.europa.eu/EFSA/scientific-opinion/sc-op-ej282-gentox-en3,o.pdf (Accessed August, 2015).
- European food safety authority (EFSA). (2008). Scientific opinion of the panel on contaminants in the food chain on a request from the European commission on polycyclic aromatic hydrocarbons in The EFSA journal, 724: 1- 114.
- Fromberg, A, Hojgard, A and Duedahl – olesen, L. (2007). Analysis of polycyclic aromatic hydrocarbons in vegetable oils combining gel permeation chromatography with solid – phase extraction clean – up. Food additives and contaminants, 24: 758 – 767.
- Guillen, M. D and Sopelana, P. (2003). Polycyclic aromatic hydrocarbons in drivers’ foods in P.F.D mello (Ed.). Food safety: contaminants and toxins (1st Ed.). CABI Publishing, Oxon UK; PP.175-198.
- European commission scientific committee on foods (2002). Opinion of the scientific committee on food on the risks to human health of polycyclic aromatic hydrocarbons in food expressed on fourth December 2002. Brussels, Europeans commission, health and consumer protection Directorate – general, 2002 (document SCF /CS/ CNTM/PAH/29 Final available on (http:// europa. ev.int/comm./food /fs/scf/ outcome–en.html)
- Liobet, J.M., Falco; G.,Bocio, A., Domingo, J.L. (2006). Exposure to polycyclic aromatic hydrocarbons of edible marine species in Catalonia, Spain. Journal of Food Protection, 69: 2493-2499.
- FAO/WHO. (2008). Report of a joint FAO/WHO expert consultation, march 31- April 04,2008; Food and Nutrition paper. Rome: FAO,