Effect of fermentation on naturally occurring deoxynivalenol (DON) in Argentinean bread processing technology.

The stability of naturally occurring DON was evaluated during the fermentation stage of the bread-making process on a pilot scale. Two different products, French bread and Vienna bread, were prepared with naturally contaminated wheat flour (150 mg kg(-1)) under controlled experimental conditions. Dough was fermented at 30, 40 and 50 degrees C according to standard procedures employed in Argentinean low-technology bakeries. When the dough was fermented at 50 degrees C, the maximum reduction was 56% for the Vienna bread, with French bread being reduced by 41%. DON reduction during bread-making occurs not only in the baker due to thermal decomposition, but also during the fermentation step. The Argentinean traditional bread-making process might reduce DON levels during the fermentation stages if the dough is leavened at temperatures > 30 degrees C.

[Food consumption and intake of several nutrients in a population of the University of Luján, Argentina]. / Consumo de alimentos e ingesta de algunos nutrientes en la población de la Universidad Nacional de Luján, Argentina.

A dietary survey was carried out at the National University of Luján (Argentina), with the objective of evaluating: a) food consumption and energy supply of cereals; b) the adequation of the intake of protein, calcium, iron, vitamins A, B1, B2, C and niacin, regarding the Recommended Dietary Allowances (RDA). A representative sample of 827 people (16% of the total population of 1991, equally distributed in the four seasons) was assessed with a 24 hour dietary recall. Sample was composed by: males: 189, aged 18-24 ys (GIM); 189, aged 25-50 ys (G2M); females: 209, aged 18-24 ys (GIF); 240, aged 25-50 ys (G2F). The results showed that cereals, 90% deriving from wheat products, supplied 32% of the total energy intake in G1F and between 40% and 48% in the other three groups. The mean daily intake of meat ranged between 90.5 g and 128.7 in females and over 140.0 g in males. Dairy products consumption was quite low, as well as fruits and vegetables in the whole of the population. Protein intake was over 1.25 g/d in 50% of the population. Calcium intake was below the RDA in a great percentage of the population, the mean percentage of adequation being: G1F, 71%; G2F, 62%; G1M, 64%; G2M, 65%. Iron mean daily intake was quite good, ranging between 16.4 and 20.8 mg in females and between 17.5 and 19.2 mg in males. The percentage of iron supplied by meat was: G1F, 16%; G2F, 21%; G1M, 34% and G2M, 26%; therefore iron bioavailability can be considered high. Besides, "mate", which is drunk between meals, supplied between 25% and 29% of the total iron intake in females and between 12% and 56% in males. Vitamin A intake was below the RDA in 74% to 58% of the population. The mean intake of vitamin B1 was 89% of the RDA in G1M and over RDA in the other three groups. Intake and percentage of adequation of vitamin B2, vitamin C and niacin presented a great range, but the mean values were over the RDA. The overall results showed: a) a high protein intake, providing red meat between 26% and 39%; b) low consumption of dairy products, with the consequence of a low calcium and vitamin A intake; c) low consumption of fruits and vegetables, being in relation to the low intake of fibre and carotenes; d) high consumption of cereals, mainly wheat products, that must be controlled from the toxicological point of view, due to the variable presence of mycotoxins. These results are in agreement with other dietary surveys carried out in previous years and are a consequence of some characteristic feeding habits of the Argentine population. They show that nutritional education is necessary for promoting changes in the latter, with the aim of reaching a better nutritional status.

The effects of bakery processing on natural deoxynivalenol contamination.

The aim of this study was the evaluation of the influence of the breadmaking process on initial deoxynivalenol (DON) contamination. Samples (92) were taken from four batches of eight different types of products in a low-technology bakery. The final products, as well as the corresponding flours, doughs and fermented doughs were analyzed. Extracts were obtained with acetonitrile:water (84:16), the clean up was made with a multifunctional column and DON was quantified by thin layer chromatography by visual comparison with standards. Confirmation was made by electron capture gas chromatography. The contamination levels in flour samples ranged from 500 micrograms/kg to 2000 micrograms/kg on dry weight basis. The results showed a positive correlation between the initial contamination level and the reduction of DON after fermentation. A significant reduction was observed as a consequence of the breadmaking process.

Natural occurrence of deoxynivalenol in wheat, wheat flour and bakery products in Argentina.

The objective of this study was to evaluate the natural occurrence of deoxynivalenol (DON) in wheat, wheat flour and different kinds of breads and pastries widely consumed by the population in Argentina. Of 60 wheat samples analysed, 93.3% were contaminated. The average DON contamination level over all samples was 1798 micrograms/kg, and the minimum and maximum values were 100 micrograms/kg and 9250 micrograms/kg, respectively. The wheat flour samples (61 samples) were contaminated with DON at levels ranging from 250 micrograms/kg to 9000 micrograms/kg with an average of 1309 micrograms/kg. The frequency of DON contamination over 42 samples of different bakery products was 92.8%, with levels ranging from 200 micrograms/kg to 2800 micrograms/kg with an average of 464 micrograms/kg. These results suggest a high risk for consumers of wheat products and the need to monitor final products before consumption.