Protein hydrolysates and isolates from canola are ‘wholly comparable to soy protein isolate’ for amino acid bioavailability in humans, says a new study from Germany.
Consumption of 30 grams of protein from canola or soy produced similar amino acid responses, while the canola protein produced an earlier response, according to results published in Clinical Nutrition .
“From the results of the bioavailability study dealing with potentially new protein sources it can be concluded that the [canola] proteins investigated are of relevance to the nutrition in general and to the clinical nutrition, too,” wrote researchers from Friedrich Schiller University and Georg August University.
The study used BioExx Specialty Proteins’ canola proteins. The Canadian firm already manufactures canola proteins on a small scale at a plant in Saskatoon. A report from GEA Process Engineering last year showed that BioExx’s technology was scalable.
“This is maybe the biggest opportunity in the biggest global protein market in 50 years,” said BioExx chief executive Chris Schnarr in March 2012 .
The results of the new study indicate the canola proteins – both hydrolysates and isolates – can match soy for amino acid responses in health men.
“It has been shown that canola protein hydrolysate tended to result in a more rapid absorption of amino acids into plasma compared with its isolate and with soy protein isolate,” wrote the researchers.
“It is conceivable that the faster digestibility of smaller peptides is responsible for this absorption kinetics. Moreover, the bioavailability determined by the N balance showed no statistical differences between the three proteins, when added to a defined diet.”
The German scientists recruited 28 healthy men with an average age of 25 and randomized them to consume 30.0 grams of protein as canola protein isolate, canola protein hydrolyzate, or soy protein isolate in a double-blind, cross-over design.
Results showed that all the protein forms, mixed in a drink, led to significant rises in amino acids levels. The canola protein hydrolysate produced an earlier response than the isolates, but the total amino acid response.
High digestibility of rapeseed protein was found in rats. In humans, this is the first intervention study showing rapeseed protein (both isolate and hydrolyzate) as having a high nutritional quality and can be considered to be as efficient as soy protein for a postprandial amino acid response.
“[Canola] proteins are well balanced in essential amino acids (EAA),” wrote the researchers. “In the current study, rapeseed proteins contained 31.9% (CPI) and 37.6% (CPH) EAA and hence measure up to soy protein (35.1%) in terms of source of essential amino acid.
“Compared to soy protein, canola protein had substantially higher contents of sulfur-containing amino acids which is important because sulfur-containing amino acids and their metabolites, such as glutathione and homocysteine, are effective regulators in antioxidant defense processes.”
Source: Clinical Nutrition
Published online ahead of print, doi: 10.1016/j.clnu.2012.11.005
“Nutritional evaluation of rapeseed protein compared to soy protein for quality, plasma amino acids, and nitrogen balance e A randomized cross-over intervention study in humans”
Authors: M. Fleddermann, A. Fechner, A. Rossler, M. Bahr, A. Pastor, F. Liebert, G. Jahreis