Thermal stability of black turtle soup bean (Phaseolus vulgaris) lectins

Abstract

A method for determining the thermal stability of porcine thyroglobulin (PTG)-binding lectins in whole black turtle soup beans (Phaseolus vulgaris L) is described. The procedure utilises PTG-Sepharose affinity chromatography and the Folin-Ciocalteau protein assay.The majority of lectin activity in whole black turtle soup beans was destroyed by heating presoaked beans at 974°C for 10 min whereas unsoaked beans required 20 min of heat treatment at 97.8"C. Residual lectin activity was eliminated by thermally processing the presoaked and unsoaked beans for 25 and 50min at 97-8"C, respectively. Thermal inactivation of the lectin in the whole seed is a biphasic, first-order reaction mechanism.Lectin-rat intestinal epithelial cell binding studies indicated the presence of a second lectin in the BTS albumin protein fraction. The lectin lacked an affinity for PTG and was inactivated by heating unsoaked whole beans for 50 min at 974°C.

Phaseolus vulgaris lectins: A systematic review of characteristics and health implications

“…The total lectin activity (hemagglutination activity (HA)) as a function of time and temperature has been commonly used for the assessment of the effectiveness of heat treatment (He et al, 2014). Phaseolus vulgaris lectins in the whole beans or protected by their specific carbohydrates exhibited a first-order reaction kinetics during the thermal inactivation process with a biphasic mechanism (Boufassa et al, 1986;Bonorden and Swanson, 1992). Furthermore, the thermal inactivation of Phaseolus vulgaris lectin from black turtle bean also followed a first-order reaction kinetics, and could be well described by the Arrhenius model with a relatively high enthalpy increment, accompanied by a striking loss of definable HA of the lectin at 90 C for 5 minutes, which attested to the importance of temperature/time setting, in particular of high temperature, short time (HTST) treatment (He et al, 2014).…”

Detection of Lectin Protein Allergen of Kidney Beans (Phaseolus vulgaris L.) and Desensitization Food Processing Technology

“…108 Furthermore, to maintain the nutritional value of kidney beans and inactivate the lectin to the greatest extent, steam treatment at 119 °C for 5 or 10 min was recommended, and the hemagglutination activity was reduced by 85 and 98.5%, respectively, while the binding capacity of rabbit serum antibodies was reduced by 98.6 and 99.2%, respectively. 171 Direct heating of black kidney beans at 97 °C for 20 min could basically destroy the lectin activity, and the same effect could be achieved by heating at 97 °C for 10 min after soaking for 16 h. 172 According to the published papers, three kinds of presoaked kidney beans (red, white, and black kidney beans) combined with heating above 75 °C could significantly reduce the allergenicity. 173 Studies have pointed out that the allergenicity of lectins from soaked kidney beans could be completely boiling for 15 min.…”