Nickerson: Development of Formulated Canola Protein-based Ingredients for the Food Industry

Date: April 2014
Term:
5 years
Status: Completed
Researcher(s): Michael Nickerson, University of Saskatchewan
SaskCanola Investment: n/a
Total Project Cost: n/a
Funding Partners: ADF

Project Summary

Canola proteins represent an emerging plant-based alternative, with tremendous opportunity for growth, based on their functional and nutritional properties. Researchers at the University of Saskatchewan initiated a five-year multi-component project in 2010, with the overall goal to develop formulated canola protein-based ingredients that could then be tailored to specific food applications. Researchers evaluated the use of canola proteins as emulsifiers, gelling agents and in the development of edible biodegradable films/package, as an example of a value-added application. As a result of the project, researchers identified optimal solvent and conditions for producing the formulated protein ingredients and developed in-house standardized methods for assessing ingredient functionality. A Protein Functionality Manual, which describes basic testing for the following functional attributes: solubility, emulsification, foaming and water hydration/oil holding properties, was also developed and is currently being used by industry.

Protein ingredients represent a multi-billion dollar industry, presently dominated by animal proteins. Market trends are shifting towards lower cost and abundant plant-based alternatives, however the wide spread use of plant proteins has been hindered by their reduced solubility (and functionality) relative to animal-based products. Canola proteins represent an emerging plant-based alternative with tremendous opportunity for growth. Researchers have been trying to improve the functionality via improved processing practices, enzymatic hydrolysis or through chemical modification over the past number of decades.

Researchers at the University of Saskatchewan initiated a five-year multi-component project in 2010, with the overall goal to develop formulated canola protein-based ingredients that could then be tailored to specific food applications, such as baking, meats, beverages and/or dairy alternatives (i.e., coffee whiteners). The research project included four separate studies focused on the development of formulated canola protein-based ingredients, and evaluation of the use of canola proteins as emulsifiers, gelling agents and in the development of edible biodegradable films/packages, as an example of a value-added application. The research will aid in developing a currently large untapped market (i.e., food industry) for canola producers, which will lead to high value applications for underutilized meal fractions and increased product demand.

1. Development of formulated canola protein-based ingredients

The focus of this study was to explore an alternative non-invasive, low cost consumer-friendly approach by creating formulated canola protein ingredients using coacervation technology. The formation of soluble and insoluble complexes was investigated involving a canola protein isolate (rich in cruciferin) or a napin protein isolate with a variety of polysaccharides as a function of pH and biopolymer mixing ratio. Researchers then evaluated the functionality of insoluble and soluble complexes, and commercial protein isolates as a reference point. Specifically, protein solubility, foaming capacity and stability, and emulsion capacity and stability were tested.

The study results showed that the functionality of protein-polysaccharide complexes involving cruciferin-rich or napin-rich canola protein isolates had a neutral or negative effect on protein functionality. Solubility and foaming capacity were the greatest properties negatively affected in all cases. Overall, the canola protein produced performed much better than expected as a control material, and had very comparable functionality relative to commercial protein ingredients derived from egg and milk. Solubility (at pH 6) for the canola protein isolate was found to be comparable to that of animal-derived proteins from whey and eggs (>97%), and significantly higher than those from other plant sources, such as soy (~15%), pea (~5%) and wheat (<1%).

Although the results did not show an improvement in protein functionality with the addition of the polysaccharide, the findings will help the food industry in understanding complex ingredient interactions occurring in food and in formulation throughout the product development process when canola proteins are present. In addition, the ability to reduce solubility of protein in the presence of a polysaccharide may have implications in the development of new separation procedures for isolating proteins from canola meal or in clarification applications in the future.

2. Canola proteins as emulsifiers

Researchers examined the effect of pH and NaCl concentration on the physicochemical and emulsifying properties of a crucferin-rich and napin-rich isolate to better understand how solvent and properties of the proteins lead to either the stability or instability of emulsions. Overall, the emulsifying properties of canola protein isolates were strongly influenced by the physicochemical properties of the protein, pH and NaCl content. Emulsion stability was also reduced with the addition of NaCl at all tested pH levels.

The results showed that despite cruciferin-rich and napin-rich protein isolates having quite different surface characteristics (charge and hydrophobicity) and solubility, the emulsifying forming and stabilizing effects were similar. Therefore from a commercial standpoint, the results suggest that separation of the two proteins from the isolate ingredient may not be necessary if emulsification is the only functional role of the proteins.

3. Canola proteins, as gelling agents

In this study, researchers examined the gelation properties of a mixed canola protein isolate as a function of protein concentration, temperature, ionic strength and in the presence of network destabilizing agents using various laboratory techniques. The gelling properties of canola protein isolates were also compared to the performance of a commercial soy protein isolate product. Overall, canola protein isolates formed stronger gels with less dependence on disulfide and hydrogen bonds than soy protein isolates. For both proteins, there was no significant difference (~77°C - ~90°C) in gelling temperature as the protein concentration increased.

4. Canola proteins, as film forming agents

Researchers also assessed the film forming properties of a mixed canola protein isolate in response to plasticizer-type and concentration, and the presence of a non-toxic natural fixative. Specifically, the mechanical, water vapor and optical properties were assessed, and then related to literature values. Overall, canola protein isolate films were less flexible, had better water vapor barrier properties, and comparable film strength relative to other plant protein-based films. Plasticizer-type and concentration, and the presence of fixatives all had a significant impact on film performance. Based on this research, canola protein isolates show promise as a potential material for the development of edible films/packaging in the future.

As a result of the project, researchers successfully identified optimal solvent and biopolymer (i.e., proteins or polysaccharides) conditions for producing the formulated protein ingredients and developed in-house standardized methods for assessing ingredient functionality. A Protein Functionality Manual, which describes basic testing for the following functional attributes: solubility, emulsification, foaming and water hydration/oil holding properties, was also developed. This manual is intended to help guide employees, buyers and managers of food companies working directly or indirectly with protein-based ingredients; researchers in their experimental designs; and for educational purposes.

Scientific publications.

Stone, A.K., Teymurova, A., Chang, C., Cheung, L. and Nickerson, M.T. 2014. Formation and functionality of canola protein isolate with both high- and low-methoxyl pectin under associative conditions. (Submitted to Food Science and Biotechnology, August 2014)

Cheung, L., Wanasundara, J. and Nickerson, M.T. 2014. The effect of pH and NaCl levels on the emulsifying properties of a napin protein isolate. Food Biophysics. (Accepted June 2014)

Chang, C. and Nickerson, M.T. 2014. Effect of protein and glycerol concentration on the mechanical, optical, and water vapor barrier properties of canola protein isolate-based edible films. Food Science and Technology international (Accepted Aug 2013)

Stone, A.K., Teymurova, A. and Nickerson, M.T. 2014. Formation and functional attributes of canola protein isolate – gum Arabic electrostatic complexes. Food Biophysics, 9, 203-212

Cheung, L., Wanasundara, J. and Nickerson, M.T. 2014. The effect of pH and NaCl levels on the physicochemical and emulsifying properties of a cruciferin protein isolate. Food Biophysics. 9, 105-113.

Stone, A.K., Teymurova, A., Dang, Q., Abeysekara, S., Karalash, A. and Nickerson, M.T. 2014. Formation and functional attributes of electrostatic complexes involving napin protein isolate and anionic polysaccharides. European Food Research and Technology, 238, 773-780.

Chang, C. and Nickerson, M.T. 2014. Effect of plasticizer-type and genipin on the mechanical, optical, and water vapor barrier properties of canola protein isolate-based edible films. European Food Research and Technology, 234:35-46

Stone, A.K., Cheung, L., Chang, C. and Nickerson, M.T. 2013. Formation and functionality of soluble and insoluble electrostatic complexes within mixtures of canola protein isolate and (k-, i- and l-type) carrageenan. Food Research International, 54, 195- 202.

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