Multifunctionality of Rapeseed Meal Protein Isolates Prepared by Sequential Isoelectric Precipitation

Abstract

Rapeseed meal is a by-product of the oil-producing industry with a currently underestimated application. Two protein isolates, PI2.5–8.5 or PI10.5–2.5, were obtained from industrial rapeseed meal after treatment with an aqueous ethanol solution. The alkaline-extracted proteins were sequentially precipitated by two different modes, from pH 10.5 to 2.5, and vice versa, from 2.5 to 8.5, with a step of 1 pH unit. The preparation approach influenced both the functional and antioxidant properties of the isolates. The PI10.5–2.5 exhibited higher water and oil absorption capacities than PI2.5–8.5, reaching 2.68 g H2O/g sample and 2.36 g oil/g sample, respectively. The emulsion stability of the PI2.5–8.5, evaluated after heating at 80 °C, was either 100% or close to 100% for all pH values studied (from 2 to 10), except for pH 6 where it reached 93.87%. For the PI10.5–2.5, decreases in the emulsion stability were observed at pH 8 (85.71%) and pH 10 (53.15%). In the entire concentration range, the PI10.5–2.5 exhibited a higher scavenging ability on 2,2-diphenyl-1-picryl hydrazyl (DPPH) and hydroxyl radicals than PI2.5–8.5 as evaluated by DPPH and 2-deoxyribose assays, respectively. At the highest concentration studied, 1.0%, the neutralization of DPPH radicals by PI10.5–2 reached half of that exhibited by synthetic antioxidant butylhydroxytoluene (82.65%). At the same concentration, the inhibition of hydroxyl radicals by PI10.5–2 (71.25%) was close to that achieved by mannitol (75.62%), which was used as a positive control. Established antioxidant capacities add value to the protein isolates that can thus be used as both emulsifiers and antioxidants.

Transformation of the formula of fitness ginger based on green buckwheat enriched with rapse protein isolate: a systematic review

“…Изоляты рапсового белка -это «новые продукты», введенные в рацион человека [14]. Семена рапса -вторая по объему производства масличная культура в мире после сои.…”

Comparison and modeling of moisture sorption isotherms of deproteinized rapeseed meal and model extrudate

“…The European Union developed a concept for recycling waste and by‐products from food and agricultural industries and their reuse in innovative food products (EC, 2020). In this regard, characterization and investigation of the potential application of deproteinized rapeseed meal (DRM), appearing as a waste of protein isolation from industrial rapeseed meal, was initiated (Georgiev, Kalaydzhiev, Ivanova, et al, 2022; Georgiev, Kalaydzhiev, Slavov, et al, 2022). The rapeseed meal by itself is an underutilized by‐product of the oilseed extraction industry and upcycling it to numerous useful value‐added products would result in better and more efficient utilization of natural resources.…”