The influence of the method of processing rapeseed seeds on their protein complex

Abstract

Relevance. The recycling of secondary rapeseed raw materials is a perspective trend for increasing the efficiency of production of this agricultural crop.Methods. Degreasing of the rapeseed kernel fraction was carried out by hexane extraction, wateralcohol treatment of the low—fat rapeseed kernel with a mixture of water + ethanol (3:7). The fractional composition of the rapeseed protein complex was determined by sequential extraction with distilled water, 7% NaCl solution and 0.1M NaOH solution. Protein isolation: extractant — NaCl solution (70 g/l), pH — 9.0, T — 50 °С, duration — 90 min. The protein was precipitated at pH 4.8 and dried in a microwave oven at 500 W for 3–4 minutes. Absorption spectra of protein fractions of rapeseed seeds were recorded on a PE-5400 UV spectrophotometer using the SC5400 program.Results. It was shown that degreasing by hexane extraction contributed to an increase in the content of globulins (by 8.5%) with a decrease in albumins (by 3.0%) and glutelins (by 3.3%). Analysis of the UV spectra of these protein fractions showed the presence of synaptic acid in the fractions of albumins and globulins. The water-alcohol treatment of the skimmed rapeseed kernel, carried out to remove phenolic compounds, contributed to the partial removal of protein from the raw material (protein content decreased from 39.06 to 32.34%), limited protein denaturation, which leads to a decrease in protein solubility and protein yield in the extract, as indicated by a decrease in the yield of the protein product relative to the raw material from 26.4 to 15.3%, a decrease in protein yield relative to the protein contained in the raw material, from 28.9 to 20.3%.