Cyanide content, nutritional quality, and sensory acceptance of raw and cooked lima bean grain varieties

Abstract

The Phaseolus lunatus L. (lima bean) is a species of the Fabaceae family widely cultivated in the Northeast region of Brazil and is an important source of nutrients for the population. The lima bean has high genetic variability, which results in many cultivated varieties. However, there is little information about the cyanide levels, nutritional quality and sensory acceptance of these varieties, as well as about the changes caused by the cooking process, especially with regard to free cyanide contents. Therefore, the objective of this work was to evaluate the cyanide contents, nutritional quality and sensory attributes of lima bean varieties. Potential and free cyanide levels, quality attributes and a Qualitative Descriptive Analysis (QDA) were evaluated in raw and cooked grains. The study was carried out in a completely randomized design, with five lima bean varieties (Orelha de Vó, Branca, Roxinha, Rosinha, and Cearense), in 4 replications. Relatively to the raw ones, cooked grains presented larger size and smaller contents of ash, proteins, carbohydrates, potential cyanide and free cyanide, in the studied varieties. The Orelha de Vó lima bean showed higher mass of raw and higher firmness of cooked grains, which was judged to have the bitterest flavor among the others but showed safe levels of free cyanide after cooking. When cooked, Branca lima bean had a greater intention of purchase and global acceptance, due to its greater intensity of characteristic aroma and lower residual bitter taste.