Cooking Quality and Losses of Phytic Acid, Calcium, Magnesium and Potassium of Lentils Soaked in Different Solutions

Abstract

A good-cooking sample of Laird lentil (shear force 3.4kg/g) was stored at low and high temperature and humidity, soaked in water at different temperatures, and in acetate buffer pH 5.0 under various conditions. The shear force increased, except when soaking the lentil in water at 25°C, changing good-cooking lentil to poor-cooking. The change in shear force was accompanied by, in experiments 1 to 3, a 7.9 to 49.4% decrease in seed phytic acid (PA), 4.1 to 53.4% in P, 0 to 27.5% in Ca2+, 6.5 to 63.7% in Mg2+, and 18.9 to 79.4% in K+. Boiling the lentil in water for 15min followed by soaking in the acetate buffer or soaking in the buffer containing sodium fluoride, a phytase inhibitor, lowered the increase in shear force, particularly the latter treatment. Soaking a poor-cooking sample of Laird lentil (shear force 5.2kg/g) in the acetate buffer aggravated the poor-cooking condition, which was completely reversed on soaking in EDTA or sodium phytate solutions. The increase in shear force on soaking good-and poor-cooking lentil samples in water or acetate buffer seemed largely due to a decrease in PA. Phytase activity was not detected in any of the soaked samples.