High Metal Chelating Properties from Rapeseed Meal Proteins to Counteract Lipid Oxidation in Foods: Controlled Proteolysis and Characterization

Abstract

Rapeseed meal proteins (RP) are enzymatically hydrolyzed using three individual proteases (Alcalase, Flavourzyme, and Prolyve) and the enzymatic mechanism is studied. Rapeseed hydrolysates are produced under controlled conditions and the Prolyve hydrolysate is separated by membrane filtration. Their capacity to reduce free radicals (by transfer of hydrogen or electron) or transition metals (by electron transfer) in the absence of an oxidizable substrate, their metal chelating capacity as well as the antioxidant performances in model (conjugated autoxidizable triene assay) are investigated. All hydrolysates show a reduction capacity (by transfer of hydrogen or electron) and antioxidant activities, in a dose‐dependent manner, which are however not significantly increased in comparison to the native proteins. A noteworthy metal chelating activity of the peptides produced with Prolyve is highlighted. These results indicate the potential of valorization of RP as a source of high metal chelating peptides to counteract lipid oxidation in foods. Practical applications: Over the last decade, the antioxidative potential of peptides from plant biomass has been evidenced by much research. Considering the myriad of possible sources and the diversity of technology and means to obtain peptides from protein materials, it is reasonable to expect more applications. Concomitantly, preventing lipid oxidation, especially with the polyunsaturated fat‐based products, is a major concern in sectors such as agri‐food and cosmetic. Although the efficacy of synthetic antioxidants is recognized, both consumers and manufacturers are looking for more innovative, healthy, environmental‐friendly processes and quality products. In this context, a controlled proteolysis of proteins from plant by‐products can be used as a sustainable strategy to produce antioxidant peptides. Among them, new peptides released from rapeseed proteins with Prolyve can provide interesting metal chelators to counteract lipid oxidation in foods.

Multifunctionality of Rapeseed Meal Protein Isolates Prepared by Sequential Isoelectric Precipitation

“…Proteins/peptides were able to donate protons and neutralize free radicals to terminate the radical chain reactions [ 62 ]. Durand et al [ 63 ] reported metal chelating activity of the peptides produced from rapeseed meal proteins with Prolyve (a non-specific microbial endoproteinase with subtilisin activity). Yoshie-Stark et al [ 64 ] demonstrated that pepsin-assisted hydrolysates, obtained from rapeseed protein concentrate, had significant scavenging abilities against DPPH radical.…”

Optimization of Selective Hydrolysis of Cruciferins for Production of Potent Mineral Chelating Peptides and Napins Purification to Valorize Total Rapeseed Meal Proteins

“…Isolate of total rapeseed meal proteins (RPI) was hydrolyzed with the industrial acid protease Prolyve ® , in the recently reported reaction conditions [ 23 ], i.e., at pH 3, 50 °C and E/S of 1/500, during 7 h. Figure 1 shows SEC chromatograms obtained for RPI before hydrolysis and after 7 h hydrolysis.…”

“…Rapeseed proteins isolate (RPI) was produced from a ground rapeseed meal provided by Olead (Pessac, France): the starting protein content in the meal was 34.4%, based on dry matter basis. Then, the extraction of total proteins was made from the meal with the same protocol described by Durand et al [ 23 ]. The purity of the obtained extract (called RPI) was analyzed by Kjeldahl method with 6.25 nitrogen-to-protein conversion factor.…”

“…The method used was the same as described by Durand et al [ 23 ]. Chelating capacity was measured according to the following Equation (11): where was the absorbance of the control (blank FeCl 2 and Ferrozine without sample), the absorbance of sample without reactant, and the sample absorbance with FerroZine™ reactant.…”

“…Attention has been given to the production of metal-chelating peptides either to prevent lipid oxidation in foods or to increase essential micronutrients absorption for nutritional and health purposes. A recent study highlighted a noteworthy metal-chelating activity of peptides (61.4 ± 5.90 µM of chelating iron (II)/mg peptide) from rapeseed meal proteins produced with the Prolyve ® enzyme [ 23 ]. This is all the more interesting since these peptides were produced mainly from the cruciferins resulting in intact napins fraction.…”