Rapeseed: Constituents and protein products Part 2: Preparation and properties of protein‐enriched products

Abstract

literature is reviewed about the preparation and functional properties$nd application of defatted meals, protein concentrates and isolates of Brassica seeds. Especially the influence of physico-chemical, microbiological and enzymatical treatments is represented on antinutritional compounds, glucosinolates, their splitting products and phytic acid. General classification of processes and productsAs protein-enriched manufactured products from Brassica seed are recognised seed meals, protein concentrates and isolates, which differ from one another in their composition, properties and possible applications [22, 30, 77, 82, 85, 90, 93, 104, 107, 109, 113a, 131, 132, 136, 152, 163, 1641. Seed-meals are extracted from seeds and their manufactured products, so called "industrial meals", if necessary in connection with dehulling by non-extractive pre-or posttreatment.Hull-rich products with low raw protein content (< 45 %) are used exclusively as components of mixed fodder in animal feeding. Dehulled products with high raw protein content (>45 %) have importance mainly as components for human nourishment.Protein concentrates are obtained by extracting anti-nutritive constituents of seeds or seed meal with aqueous and/or non-aqueous solvents. Concentrates from dehulled raw materials (raw protein content > 60 %) are potentially useful for the food industry, those from hull-rich raw materials (raw protein content < 60 %) for fodder.Protein isolates are obtained by extraction the proteins from seeds or seed meals and precipitation or ultra-filtration. Isolates (raw protein content > 90 %) are of prospective importance for human nourishment.For economic reasons industrial processes of the detoxification of Brassica seed meal is impractical at present, with the exception of thermal pre-treatment (toasting, steaming) of industrial meals. Protein-enriched products have been produced under large-scale re-' Physical TreatmentPhysical treatments either lead to myrosinase inactivation and thus work against the formation of toxic autolysis products or cause a volatilisation or a transformation into biologically more passive compounds. The effects of such treatments are summarised in Tables 1 and 2.The main possibilities for inactivating myrosinase are treating the seeds by heating, cooking or dipping in hot water or diluted soda-lye and micro-wave radiation. It is worth to remark in this connection, that various Brassica species and varieties exhibit different thermal stabilities of myrosinase [88]. The degree of enzyme inactivation depends on the time and temperature of the heating, as well as on the humidity regime. In this a short time treatment of intact seeds at temperatures of 100 "C and high humidity generally proves to be more effective than longer time (30 min) heating at temperatures below 100 "C and limited water content [37, P24, P30).In closed systems, i.e. with constant water content, the efficiency of thermal inactivation is higher than in open systems. A 15 min heating of intact seeds at 90 "C and 8% water conten...

Influence of enzymatic hydrolysis, pH and storage temperature on the emulsifying properties of canola protein isolate and hydrolysates

“…Hydrolysis contributed to a remarkable improvement in the solubility of CPHs at pH 4.0 and 7.0; however, CPI had the highest solubility at pH 9.0. This may have contributed to the high nitrogen yields that are normally obtained for the isolate under strong alkaline extraction conditions (Mieth et al ., ). The molecular weight range of the hydrolysates as previously described ranged from 6.47–0.027 kDa for Alcalase; 0.711–0.027 for chymotrypsin, 2.45–0.052 kDa for pepsin and 6.75–0.347 kDa for trypsin (Alashi et al ., ).…”

Canola Proteins for Human Consumption: Extraction, Profile, and Functional Properties

“…The use of alkali, as shown by Sosulski (1983) and Mieth and others (1983) , produce strong conditions (pH 11 to 12) that were necessary to obtain high nitrogen extraction yield and a high protein extraction rate from canola meal. Tzeng and others (1988a) maintained the pH of the solution by the addition of 50% w/w NaOH solution.…”

“…Canola protein was made up of approximately 70% of salt soluble globulins, up to 20% of alcohol soluble prolamins, and 10% to 15% water-soluble albumins. Prolamins in rapeseed exist exclusively as oleosin, the structural proteins associated to the oil bodies ( Mieth and others 1983 ). Klockeman and others (1997) , however, reported that the isolated canola proteins were primarily glutelins and globulins.…”

Production of Sustainable Green Adhesives from Proteinaceous Biomass with an Emphasis on Waste-Derived Protein Residuals: A Review

“…While sufficient for adhesive production, extraction of proteins requires additives to improve protein recovery yield . Proteins are able to be isolated from the rapeseed meal using pH-altering solvents and centrifugation. − To minimize competition between food and adhesive industries with respect to soy protein, rapeseed proteins in combination with other protein-rich components detail superior adhesion tendencies due to combined protein molecular weight distributions …”