Comparação do teor de cianeto em snacks de semente de abóbora cruas e após torrefação, com e sem casca, por espectrofotometria de absorção molecular

Abstract

Pumpkin seeds contain beneficial nutrients such as fiber, lipids and proteins. However, the seed also has cyanogenic glycosides, harmful to health. The objective of the present study was to quantify and compare the cyanide concentration in pumpkin seeds snacks, before and after toasted, commercialized in supermarkets and natural products stores in natal/RN. Six samples of different labels were obtained. Total cyanide was measured by colorimetric method using alkaline picrate after acid hydrolysis of each sample. The cyanide values found in the crude and toasted samples ranged from 37.99 and 140.84 µg/g. Cyanide content was reduced in both samples after roasted. Total cyanide concentrations between 63.43 μg/g and 197.43 μg/g were observed in the shelled and unpeeled samples. The fact that the snacks are sold with or without peel does not seem to interfere with the cyanide content, since the highest cyanide contents, 197.43 μg/g and 140.84 μg/g, were found in samples E (without peel) and D (with peel). Considering that the tolerated daily dose established for foods containing cyanogenic glycosides is 90 μg cyanide/kg body, the samples are viable for daily consumption. Thus, up to 27.4 g of the highest cyanide sample can be consumed daily, following the tolerated daily dose of cyanide described above. These amounts would be close to three full tablespoons of seeds, recommending a controlled daily intake