Effects of High Pressure and Heat Treatments on Physicochemical and Gelation Properties of Rapeseed Protein Isolate

Effect of maleylation on physicochemical and functional properties of rapeseed protein isolate

“…The amount of free SH groups in the control were found to be 20.2 μM/g, which is comparatively close to the value reported for native rapeseed protein by He et al (2014). In relation to the control, maleylation resulted in remarkable decreases in SH and S-S content (p < 0.05) (Fig.…”

“…Lower MW fractions (16 and 5.8 kDa) were the most abundant, possibly due to the reducing effect of sodium sulfite used in protein extraction protocol (cleaves disulfide linkages to form smaller polypeptides) (Li et al 2012). High MW minor fraction (ranging from 219 to 239 kDa) probably represented cruciferin (He et al 2014), whose amount reduced successively till 0.4MA and finally disappeared at 0.8MA. This is because cruciferin is highly susceptible to dissociation upon acylation (Gruener and Ismond 1997;Schwenke et al 2000).…”

Of proteins and processing: mechanisms of protein damage upon rapeseed processing and their effects on nutritional value

“…After autoclaving at 120°C for 20 min, an increase in the relative amount of random coil conformation in different whole ingredients was reported (30) . Heating at 100°C for 15 min also increased the proportion of random coils in rapeseed protein isolate from 23% in the unheated material to 28% after heating, whilst increasing simultaneously the proportion of β-sheets from 10 to 33% (63) . Formation of random coils is an indication of successful protein denaturation, also linked to a positive correlation with in vitro digestibility (r = 0.91) (30) .…”

“…Already at 80°C, 31% of the protein content in rapeseed protein isolate formed insoluble aggregates, compared with 0% in the unheated material (63) . In the isolate, cruciferin (globulin) was more susceptible to aggregate formation than napin (albumin) (63) . Most studies agree on a decreased solubility of a protein after a thermal treatment, compared with that of the native protein (57,(79)(80)(81) .…”

“…Upon thermal processing of rapeseed protein isolates, the globulin fraction (cruciferin) was more affected and formed a larger amount of aggregates than the albumin fraction (napin) (63) . Similar results have been reported for soyabean proteins, in which β-conglycinin is more heat-sensitive than glycinin due to the disulfide bonds present in the latter protein type (51) .…”