Maria Cecilia de Figueiredo Toledo

Determination of benzoic and sorbic acids in Brazilian food

Different brands of soft drink, fruit juice, margarine, yoghurt and cheese available on the Brazilian market were analysed for benzoic and sorbic acids by high performance liquid chromatography (HPLC) with a photodiode array detector. The levels of benzoic and sorbic acids were, respectively, in the range of not detected to 804 mg/l and not detected to 1371 mg/kg, respectively. Only one sample presented a preservative level above that permitted by the legislation in force in Brazil. According to the results it can be predicted that the real utilisation of benzoates and sorbates is significantly lower than the maximum authorised levels.

Polycyclic aromatic hydrocarbons in Brazilian vegetables and fruits

Abstract Polycyclic aromatic hydrocarbons (PAHs) occur as contaminants in different types of food predominantly from environmental pollution, food packaging and food processing and the levels found depend on the source of the contamination. PAHs emissions from automobile traffic and industry activities were shown to influence the PAHs levels and profiles in vegetables and fruits grown nearby. The present study was carried out to determine the levels of PAHs in samples of lettuce, tomato, cabbage, apple, grape and pear, and use these data to further estimate the dietary exposure of Brazilians to PAHs. Samples of each fruit and vegetable were collected in six different places and analysed for ten PAHs. The analytical method involved saponification with methanolic KOH, liquid–liquid extraction with cyclohexane, clean-up on silica gel column and determination by high performance liquid chromatography using fluorescence detection. The mean levels of total PAHs were 13.53 μg/kg in lettuce, 9.50 μg/kg in tomato, 8.86 μg/kg in cabbage, 4.05 μg/kg in apple, 3.77 μg/kg in grape and 3.87 μg/kg in pear. Of the carcinogenic PAHs, benzo(a)anthracene was the most representative, being found in 89% of all samples analysed. Chrysene was not detected in any sample.

Acute toxicity of endosulfan to the fishHyphessobrycon bifasciatus andBrachydanio rerio

Acute toxicity of endosulfan to zebra fish (Brachydanio rerio) and yellow tetra (Hyphessobrycon bifasciatus) was determined by semi-static bioassay. The 24-h LC50 values were 2.6 (2.3–2.9) and 1.6 (1.3–2.1) μg/L forHyphessobrycon bifasciatus andBrachydanio rerio, respectively. Behavioral changes including hyperactivity, erratic swimming and convulsions were observed at the highest exposure levels. Histological studies showed predominant acute effects in the gills, with inflammatory infiltration necrosis and separation of respiratory gill epithelium. Degradation studies with endosulfan showed that both α- and β-isomers were very unstable under the test conditions, presenting half-lives of approximately 24 h.

Benzo(a)pyrene in olive oils on the Brazilian market

Abstract Benzo(a)pyrene (B(a)P), the best known of the carcinogenic PAHs, has been found at variable concentrations in several foods. In this study 40 samples of various olive oils available in Brazil were analysed for B(a)P. The analytical method involved extraction by liquid-liquid partition, clean-up on silica gel and analysis by high performance liquid chromatography with a fluorescence detector. Benzo(a)pyrene was found in almost all samples, at levels up to 164 μg/ kg. The lowest levels of B(a)P were detected in olive oils imported from the major European countries. Olive oils imported from Europe but packed in Brazil and olive oil blended with soybean and corn oils showed relatively higher levels of B(a)P, ranging from 0.9 to 9.7 μg/kg and from 2.2 to 9.2 μg/kg, respectively.

Chá-mate e café como fontes de hidrocarbonetos policíclicos aromáticos (HPAs) na dieta da população de Campinas

In order to estimate the contribution of mate tea and regular coffee as a source of PAHs in the diet of the population of Campinas, SP, Brazil, different batches and brands of these products, totaling 18 samples, were analysed for PAH. The consumption data were obtained from a dietary survey (frequency recall), which took place in Campinas in 1993. PAH levels in the products were determined by high performance liquid chromatography with fluorescence detection. Different PAHs were detected in all samples of coffee, at levels varying with the brands and the beverage preparation technique. The mean total PAH content in coffee was 10.12mg/kg, while mate tea showed a relatively lower level of contamination (S=0.70mg/kg). Considering the per capita average daily consumption estimates of 69.79g of mate tea and 86.77g of coffee, one can assume that mate tea and coffee contribute with approximately 0.05mg and 0.88mg of total PAHs, respectively, to the dietary intake of these contaminants by the studied population (n=600).

Determination of acrylamide levels in selected foods in Brazil

Selected carbohydrate-rich foods available on the Brazilian market (111 samples representing 19 product categories) were analysed for acrylamide content using a liquid chromatography–tandem mass spectrometry method. A limit of detection of 10 µg kg–1, a limit of quantitation of 20 µg kg–1 and mean recoveries ranging 100 to 115% were obtained during a laboratory validation procedure. The concentration of acrylamide in the samples ranged from <20 to 2528 µg kg–1, with a considerable variation between individual foodstuffs within the same food product class. The highest levels were found in potato products processed at high temperature and in instant coffee, while the lowest concentrations were detected in cassava- and maize-based products, bread and beer. These results are comparable with those reported in other countries.

Furan levels in coffee as influenced by species, roast degree, and brewing procedures.

Brazilian green coffee beans of Coffea arabica and Coffea canephora species were roasted to light, medium, and dark roast degrees and analyzed in relation to furan content by using an in-house validated method based on gas chromatography coupled to mass spectrometry preceded by headspace solid-phase microextraction. Furan was not detected in green coffees, whereas levels between 911 and 5852 μg/kg were found in the roasted samples. Higher concentrations were found in Coffea canephora species and darker ground coffees. Some of the potential furan precursors were observed in significant amounts in green coffee, especially sucrose and linoleic acid, but their concentrations could not be correlated to furan formation. Additionally, coffee brews were prepared from roasted ground coffees by using two different procedures, and furan levels in the beverages varied from <10 to 288 μg/kg. The factor that most influenced the furan content in coffee brew was the brewing procedure.

Potential intake of intense sweeteners in Brazil

A survey of intense sweetener intakes was carried out in the winter of 1990 and summer of 1991 in Brazil. Data on the potential intake of the intense sweeteners aspartame, cyclamate and saccharin were generated, based on a representative sample of 673 individuals who completed a questionnaire designed to collect information on demographic details and habitual usage of sweetener-containing food and drinks. The respondents were randomly chosen among intense sweetener consumers living the cities of Campinas, São Paulo and Curitiba, Paraná. Potential daily intakes by individuals were calculated for each sweetener by combining each persons consumption of sweetener-containing food and beverages with information generated by the determination of the concentrations of the sweeteners used in these products. The data showed that 72% of the studied population consumed saccharin, 67% cyclamate and 40% aspartame. The main reasons alleged for the use of intense sweeteners were weight-control diet (36%), diabetes (35%) and weight loss (23%). Table-top sweeteners were the major source of sweeteners, followed by soft drinks. The median daily intake of aspartame, cyclamate and saccharin represented approximately 2.9, 15.5, and 16-4% of the corresponding ADI, respectively. Diabetics in general had a much higher intake within the studied population.

HPLC determination of caffeine in tea, chocolate products and carbonated beverages

Different brands of mate and black tea, chocolate products and carbonated beverages available on the Brazilian market were analysed for caffeine by high-performance liquid chromatography with a UV-vis detector at 254 nm. The column was a reverse phase C18 and the mobile phase consisted of methanol–water (30:70, v/v), acetonitrile–water (10:90, v/v) and methanol–water (25:75, v/v) for tea, chocolate products and soft drinks respectively. Caffeine content ranged from 1.05 to 15.83 mg per cup in mate tea, from 32.21 to 36.23 mg per cup in black tea, from 0.14 to 0.95 mg g−1 in chocolate products from 2.73 to 7.49 mg per can in guarana-type soft drinks and from 19.81 to 45.89 mg per can in cola soft drinks. These data indicate that the levels of caffeine in Brazilian teas, chocolates and soft drinks are within the ranges reported for similar products in other countries. © 1999 Society of Chemical Industry

Benzo(a)pyrene in Brazilian vegetable oils

Samples of vegetable oils on the Brazilian market including rape seed, corn, soybean, sunflower, rice, palm and garlic were analysed for benzo(a)pyrene (B(a)P). The analytical method involved liquid-liquid extraction, clean-up on silica gel column and determination by high performance liquid chromatography using fluorescence detection. The limit of detection was 0.5 microgram/kg. Benzo(a)pyrene was detected in almost all samples, at levels up to 58.9 micrograms/kg. The mean levels of B(a)P in rice, sunflower, soybean, corn and palm oils were 1.8, 0.2, 2.2, 10.8 and 2.1 micrograms/kg respectively. No B(a)P was detected in garlic and rape seed oils. The data indicate that the levels of B(a)P found in Brazilian corn oils are relatively higher than those published in the literature for European corn oils.