Influence of the environment in 40K concentration in Brazilian common beans

The consumption of beans constitutes an important dietary habit in many Latin American, Asian and African countries. Carioca beans and the black type stand out among the many consumed common beans in Brazil. 40K was used as a natural radiotracer to evaluate the influence of the season growing and the bean type in the potassium content into grain. The activity concentrations of 40K and 137Cs were evaluated on samples of beans by γ-ray spectrometry. 137Cs was less than 1.3 Bq kg −1. The highest potassium content in the grain were observed in the dry and winter seasons. The black beans showed higher potassium content than the carioca type. The potassium levels were compared with that of beans grown and consumed in other regions of the world. A method to estimate the bean consumption rates in Brazil independently of the location of the meal is proposed. The ingestion of common beans was estimated in 14.6 kg year−1 per person. The two regions with the highest consumption are the Southeast (19.2 kg year−1) and the Middle West (18.7 kg year−1), whose account for about 60 % of the intake of common beans is related to consumption out home.