Thermal Denaturation of Pea Globulins (Pisum sativum L.)—Molecular Interactions Leading to Heat-Induced Protein Aggregation

Abstract

The heat-induced denaturation and aggregation of mixed pea globulins (8%, w/w) were investigated using differential scanning calorimetry (DSC), SDS-PAGE, and size-exclusion chromatography (SEC-HPLC). DSC data showed that the pea proteins denaturation temperature (T(d)) was heating-rate dependent. The T(d) value decreased by about 4 °C by lowering the heating rate from 10 to 5 °C/min. The SDS-PAGE analysis revealed that protein denaturation upon heating at 90 °C was mainly governed by noncovalent interaction. The SEC-HPLC measurements indicated that low-denatured legumin (≈350-410 kDa) and vicilin/convicilin (≈170 kDa) globulins were heat-denatured and most of their subunits reassociated into high-molecular weight, soluble aggregates (>700 kDa). The addition of N-ethylmaleimide slightly modified the aggregation route of pea globulins. However, partially insoluble macroaggregates were produced in the presence of dithiothreitol, reflecting the stabilizing effect of disulfide bonds within legumin subunits.

Modification of the structural, emulsifying, and foaming properties of an isolated pea protein by thermal pretreatment

“…Previous works have also shown that heat treatment of cowpea protein isolate at 70°C and 90°C (Peyrano et al, 2016) or whey proteins at 72°C and 140°C (Patel, Singh, Anema, & Creamer, 2004) did not produce changes in the polypeptide patterns after SDS-ME PAGE analysis. However, some of the proteins extracted by the SDS-ME buffer were too large to enter the gel as shown by the band at the origin (top of gel), which corroborates the data from native-PAGE and is consistent with previous reports (Chihi, Mession, Sok, & Saurel, 2016;Mession, Sok, Assifaoui, & Saurel, 2013;Shand et al, 2007).…”

On the thermal behavior of protein isolated from different legumes investigated by DSC and TGA

“…Only a few studies on the differential scanning calorimetry (DSC) analysis of almost dry soy and pea proteins have been reported . In contrast, the literature on the thermal behavior of protein solutions and highly hydrated proteins is quite huge . However, the behavior at different moisture contents is very different, and information on the dry state cannot be extracted from that in solution.…”

“…20,24,25 In contrast, the literature on the thermal behavior of protein solutions and highly hydrated proteins is quite huge. [26][27][28][29][30][31][32][33][34][35][36] However, the behavior at different moisture contents is very different, and information on the dry state cannot be extracted from that in solution. On the contrary, in order to extend the actual knowledge on protein processing, it is very important to investigate in detail the thermal behavior of proteins at low moisture content.…”

Plant RuBisCo: An Underutilized Protein for Food Applications

“…Using differential scanning calorimetry (DSC), a measure of the net difference between protein denaturation (endothermic process) and aggregation (exothermic process) occurring during heating, the main peaks for soluble leaf proteins were found to be 0.5, 0.8, and 1.8/100 g protein‐clarified alfalfa juice at 70, 68 and 65 °C, respectively. Besides these variations, RuBisCo shows a low denaturation temperature when compared to animal‐derived protein isolates such as egg protein and whey ( T d of 72 and 78 °C, respectively), and plant proteins such as soy ( T d of 73–90 °C), pea ( T d of 82 °C), and lupin proteins (66–91 °C) (Martin et al, ; Mession, Sok, Assifaoui, & Saurel, ; Munialo et al, ). A low denaturation temperature confers to RuBisCo the ability to rapidly form a gel at low concentrations under heating.…”