Rapeseed protein concentrate

Table XII. Kidney calcium in rats fed casein and rapeseed protein concentrates for 16 weeks (yg/g dry weight)...

Hermansson et al. (36) used pepsin and papain to solubilize rapeseed protein concentrate. Papain had a lower solubilizing effect than did pepsin. However, the fact that pepsin has an optimum pH for activity at about 1.6, far below the pH range of most foods, made it possible to study the effects of controlled hydrolysis. At pH 7.0, all hydrolysates were more soluble than the original rapeseed protein concentrate. 

Hermansson et al. (36) examined the stability ratings for protease-treated emulsions of rapeseed protein concentrate at pH... 

Pepsin and papain hydrolysates of rapeseed protein concentrate increased foam volumes and decreased drainage compared to the untreated control (36). Foaming properties could be further enhanced by adding a stabilizer such as carboxymethylcellulose. 

Rapeseed. one of the five most widely produced oilseeds, is cultivated mainly in India. Canada, Pakistan, France, Poland, Sweden, and Germany. Past objections to using rapeseed as a source of edible protein has been its content of deleterious glucosinolales. Considerable research has been conducted in Sweden to develop a rapeseed protein concentrate. The first full-scale production plant using a new process was installed in Alberta, Canada. The plant, with a capacity of 5000 tons/year produces a material containing 65% protein. Rapeseed is rich in essential amino acids, with exception of methionine, which soybeans also lack. 

Hermansson et al. (19) determined the effects of pepsin and papain treatments on the solubility of rapeseed protein concentrate (RPC). The original RPC had a solubility of 11-12% at pH values between 4.0 and 7.0. However, hydrolysis with pepsin for 24 hr increased the solubility to 82-90% over this same pH range. On the other hand papain digestion increased the solubility to only 38-43%. 

Inconsistent data on foaming properties of rapeseed protein concentrates and isolates [74,75] underline the important influence of the technological process used to obtain the protein preparations upon FC. Thus native rapeseed globulin, which gave a very high FC comparable to that of napin, did not show a reduction of FC after moderate or high succinylation [75], Succinylation of rapeseed meal prior to protein extraction resulted, however, in modified isolates with poor foaming properties [74],... 

The protein sources, a soybean protein isolate (Promine F, Central Soya, Chic.) and a rapeseed protein concentrate (prepared by FRI-71 process at the Food Research Institute, Agriculture Canada, Ottawa) were suspended (10% W/V) in 0.1 N NaOH and heated at 60 C for 4 or 8 h with continuous agitation. Treatment was stopped by the rapid addition of 6 N HCl followed by cooling, adjustment of pH to 4.5, and centrifugation for 15 min at... 

Rapeseed proteins possess besides their high nutritional value a distinct functional potential enabling stabilization of emulsions and foams as well as formation of gel-like and other structured systems with high water-binding capacity. Therefore, a lot of new value-added applications in human nutrition, animal feeding (like the use of rapeseed protein concentrates in aquaculture) and for different technical purposes may be expected. 

Within a joint project, together with Gesellschaft fiir Marine Aquakultur, Biisum, Germany, rapeseed protein concentrates and isolates as fish meal replacers in the diets of common carp, turbot, wels catfish, turbot and rainbow trout were tested. The results are to be published by Slawski (2011) and Adem (2011). 

Rapeseed. Methods employed in processing of rapeseed protein products influence emulsion capacities (48, 49). Kodagoda et al. (48) showed that rapeseed protein isolates from water extracts emulsified more oil than isolates from acid or alkali extracts (Table VIII). Rapeseed isolates emulsified more oil than their concentrate counterparts. Rapeseed isolates and concentrates from acid extracts were far superior in emulsion stability to rapeseed protein products from water or alkali extracts. 

Use as Human Food. Rapeseed, as a protein source for humans, has many obstacles to overcome. The glucosinolate and fiber contents require application of new processing technology (22, 30) to eliminate antinutritional qualities. Rapeseed flours, protein concentrates, and isolates are lower in protein but higher in crude fiber and ash contents than corresponding soybean products. Rapeseed flours are comparable to soybean flour in water adsorption and give much higher fat adsorption, oil... 

One of the most important applications of hydrogen peroxide in the food industry is reported to be preservation (53). This simple oxidant has been recognized as an alternative antimicrobial agent in milk systems (54). Such recognition has prompted a number of studies of the alteration of milk proteins by hydrogen peroxide (55). Hydrogen peroxide has also been evaluated in the production of a peanut protein concentrate (56) and for the detoxification of rapeseed flour for food use (57). 

While foaming is favored by increased viscosity, hydrophobicity, and solubility, the increase of net charge density caused by succinylation tends to decrease foam stability (FS), since it prevents optimum protein-protein interactions required in a continuous film around air bubbles. Therefore a number of succinylated proteins showed a drop of the FS with increasing degree of modification. This was reported for protein preparations from faba beans [86], peas [72], cottonseed [69], oat [66], and cheese whey protein concentrate [88] for instance. The unfavorable charge effect of succinylation can be overcome by foaming at sufficiently high protein concentration, as shown for faba bean protein isolates [86] and napin from rapeseed [84]. 

After deoiling, rapeseed proteins can be extracted and purified in order to get concentrates, isolates, or pure albumin and cruciferin fractions which are suitable for a wide range of applications in human and animal nutrition as well as for chemical and technical purposes. 

Investigations have focused on the content of polyphenoHcs, tannins, and related compounds in various foods and the influence on nutrient availabiHty and protein digestibiHty. It has been estabHshed that naturally occurring concentrations of polyphenoloxidase and polyphenols in products such as mushrooms can result in reduced iron bio availabiHty (75). Likewise, several studies have focused on decreased protein digestibiHty caused by the tannins of common beans and rapeseed (canola) (76—78). 

Hypothyroidism disrupts many organ systems and results in, e.g., impaired digestion (Levin, 1969) and disturbed protein and energy metabolism. Pigs made hypothyroid by diets with rapeseed feed without added iodine, i.e., < 100p,g.iodine/g thyroid, undetectable or traces of T4 in serum (< lOnmol/1), decreased, increased, or normal T3 serum concentration, showed ... 

ELISA Systems Mustard Seed Protein Residue kit was released in June 2007. A polyclonal rabbit antiserum was raised and used to develop a quantitative sandwich ELISA that has been demonstrated to detect mustard seed protein from aU three species of mustard plants S. alba, B. nigra, and B. juncea [5]. The detection limit of the kit has been shown to be less than 0.5 ppm (mg/kg) of soluble mustard protein, which corresponds to mustard seed concentrations below 3.4ppm S. alba, below 4.9 ppm B. nigra, and below 5.5 ppm B. juncea. An example of a calibration curve is presented in Figure 23.1. Cross-reactivity studies were conducted on full-strength extracts from 50 plants and other common foods, and cross-reactivity was observed only with rapeseed (Canola), Brassica napus. This cross-reactivity was approximately 50%, but purified canola oil did not cross react. 

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