ZA200403972B - Canola protein isolate functionality II. - Google Patents

Description

TITLE OF INVENTION

CANOLA PROTEIN ISOLATE FUNCTIONALITY I

REFERENCE TO RELATED APPLICATIONS

’ [0001] This application claims priority under 35 USC 119(e) from United States

Patent Applications No. 60/330,479 filed October 23, 2001 and 60/375,711 filed April 29, 2002.

FIELD OF INVENTION

[0002] The present invention relates to a canola protein isolate and its functionality in a wide range of applications.

BACKGROUND TO THE INVENTION

. [0003] In US Patent Nos. 5,844,086 and 6,005,076 (“Murray II”), assigned to the assignee hereof and the disclosures of which are incorporated herein by reference, there is described a process for the isolation of protein isolates from oil seed meal having a significant fat content, including canola oil seed meal having such content. The steps involved in this process include solubilizing proteinaceous material from oil seed meal, which also solubilizes fat in the meal and removing fat from the resulting aqueous protein solution. The aqueous protein solution may be separated from the residual oil seed meal before or afer the fat removal step. The defatted protein solution then is concentrated to increase the protein concentration while maintaining the ionic strength substantially constant, after which the concentrated protein solution may be subjected to a further fat removal step. The concentrated protein solution then is diluted to cause the formation of a cloud-like mass of highly aggregated protein molecules as discrete protein droplets in micellar form. The protein micelles are allowed to settle to form an aggregated, coalesced, dense amorphous, sticky gluten-like protein isolate mass, termed “protein micellar mass” or PMM, which is separated from residual aqueous phase and dried.

[0004] The protein isolate has a protein content (as determined by Kjeldahl Nx 6.25) of at least about 90 wi%, is substantially undenatured (as determined by , differential scanning calorimetry) and has a low residual fat content of less than about 1 wit%. The yield of protein isolate obtained using this procedure, in terms of the proportion of protein extracted from the oil seed meal which is recovered as dried protein isolate was generally less than 40 wt%, typically around 20 wt%.

[0005] The procedure described in the aforementioned patents was developed as a modification to and improvement on the procedure for forming a protein isolate from a variety of protein source materials, including oil seeds, as described in USP 4,208,323 (Murray IB). The oil seed meals available in 1980, when USP 4,208,323 issued, did not have the fat contamination levels of canola oil seed meals available at the time of the

Murray II patents, and, as a consequence, the procedure of US Patent No. 4,208,323 cannot produce from oil seed meals processed according to the Murray II process, proteinaceous materials which have more than 90 wt% protein content. There is no description of any specific experiments in USP 4,208,323 carried out using rapeseed (canola) meal as the starting material.

[0006] USP 4,208,323 itself was designed to be an improvement on the process described in US Patents Nos. 4,169,090 and 4,285,862 (Murray IA) by the introduction of the concentration step prior to dilution to form the PMM. The latter step served to improve the yield of protein isolate from around 20 wt% for the Murray IA process.

[0007] In copending United States Patent Applications Nos. 60/288,415 filed

May 4, 2001, 60/326,987 filed October 5, 2001, 60/331,066 filed November 7, 2001, 60/333,494 filed November 28, 2001, 60/374,801 filed April 24, 2002 and US

Publication No. 2003125526, filed May 3, 2002, also published as WO 02/089597 assigned to the assignee hereof and the disclosures of which are incorporated herein by reference, there are described further improvements on these prior art protein isolation procedures as they apply to oil seeds to obtain improved yields of dried product protein isolate in terms of the proportion of the protein extracted from the oil seeds which is recovered as protein isolate and to obtain protein isolate of high purity, usually at least about 100 wt% at a Kjeldahl nitrogen (N) conversion rate of Nx 6.25. The procedure is employed particularly to produce a canola protein isolate.

[0008] In the procedure described in the aforementioned US Patent Applications, the oil seed meal is extracted with an aqueous food grade salt solution. The resulting protein extract solution, after an initial treatment with pigment adsorbing agent, if desired, is reduced in volume using ultrafiltration membranes to provide a concentrated protein solution having a protein content in excess of about 200 g/L. The concentrated protein solution then is diluted into chilled water having a temperature below about 15 °C, resulting in the formation of a white cloud of protein micelles which are allowed to

Amended sheet 15/04/2005

. WO0.03/034836 PCT/CA02/01590 separate. Following removal of the supematant, the precipitated, viscous sticky mass (PMM) is dried.

[0009] In one embodiment of the process described in the aforementioned US

Patent Application No. 60/288,415 as it is applied to canola protein isolate and as described in pending United States Patent Applications Nos. 60/326,987, 60/331,066 60/333,494, 60/374,801 and US Publication No. 2003125526, the supernatant from the

PMM settling step is processed to recover a protein isolate comprising dried protein from the wet PMM and supernatant. This may be effected by initially concentrating the supernatant using ultrafiltration membranes, mixing the concentrated supernatant with the wet PMM and drying the mixture. The resulting canola protein isolate has a high purity of at least about 90 wt% protein, preferably at least about 100 wt%, at a Kjeldahl ‘conversion rate Nx 6.25. This latter product is termed "Puratein" by the applicants.

[0010] In pending United States Patent Applications No. 60/331,646 filed

November 20, 2001 and 60/383,809 filed May 30, 2002, from which US Publication No. 2004039174 and WO 03/043439 claim priority assigned to the assignee hereof and the disclosure of which are incorporated herein by reference, there is described a continuous process for making canola protein isolates. In accordance therewith, canola oil seed meal is continuously mixed with a food grade salt solution, the mixture is conveyed through a pipe while extracting protein from the canola oil seed meal to form an aqueous protein solution, the aqueous protein solution is continuously separated from residual canola oil seed meal, the aqueous protein solution is continuously conveyed through a selective membrane operation to increase the protein content of the aqueous protein solution to at least about 200 g/L while maintaining the ionic strength substantially constant, the resulting concentrated protein solution is continuously mixed with chilled water to cause the formation of protein micelles, and the protein micelles are continuously permitted to settle while the supernatant is continuously overflowed until the desired amount of protein micellar mass has accumulated in the settling vessel. The protein micellar mass is removed from the settling vessel and may be dried. The protein micellar mass has a protein content of at least about 100 wt% as determined by Kjeldahl nitrogen (Nx 6.25).

As in the case of the aforementioned pending United States patent applications, the overflowed supernatant may be proceeded to recover a protein isolate comprising dried ) protein from the wet PMM and supernatant. This procedure also may be effected on a semi-continuous basis.

Amended sheet 15/04/2005

[0011] As described in copending United States Application No. 60/332,165 filed April 15, 2002, assigned to the assignee hereof and the disclosure of which is . incorporated herein by reference, the settled PMM and protein derived from the supernatant have different relative proportions of the 12S, 7S and 2S proteins of canola ' protein. The PMM derived protein isolate, having a protein content of at least about 90 wt%, preferably at least about 100 wt%, has a protein component content of about 60 to about 98 wt% of 7S protein, about 1 to about 15 wt% of 12S protein and 0 to about 25 wt% of 2S protein. The supematant-derived canola protein isolate having a protein content of at least about 90 wt%, preferably at least about 100 wt%, has a protein component content of 0 to about 5 wt% of 12S protein, about 5 to about 40 wt% of 7S protein and about 60 to about 95 wt% of 2S protein.

[0012] The processing of the supernatant from the PMM settling step to remove a protein isolate comprising dried protein from the wet PMM and supematant then is a blend of the isolates derived from the respective sources and exhibits a composite protein component content.

[0013] Canola is also termed rapeseed or oil seed rape.

SUMMARY OF INVENTION

[0014] It has now been found that the high purity blended canola protein isolate produced by the procedure -of the aforementioned pending patent applications (“Puratein”) has broadly based functionality in food products, unique among proteinaceous materials. The ability to utilize a protein which is vegetable in origin in food products enables truly vegetarian food products to be provided in instances where egg white and/or animal-derived protein have been used in the absence of any available substitute.

[0015] In one aspect, the present invention provides, in a food composition comprising a foodstuff and at least one component providing functionality in said food composition, the improvement which comprises at least partially replacing said at least one component by a substantially undenatured canola protein isolate having a protein content of at least about 90 wt%, as determined by Kjeldahl nitrogen x6.25, on a dry , weight basis. The canola protein isolate comprises a blend of:

Claims (7)

i WO 03/034836 PCT/CA02/01590 CLAIMS ‘What we claim is:

1. A food composition including a foodstuff and at least one component providing functionality in said food composition, wherein said at least one component is at least partially replaced by a substantially undenatured canola protein isolate having a protein content of at least about 90 wt%, as determined by Kjeldahl nitrogen x6.25 (N x 6.25) on a dry weight basis, said canola protein isolate comprising a blend of: (1) a first canola protein isolate having a protein content of at least 90 wt% on a dry weight basis (N x 6.25) and which exhibits a protein profile which is: about 60 to about 98 wt% of 7S protein about 1 to about 15 wt% of 12S protein 0 to about 25 wt% of 2S protein, and 2) a second canola protein isolate having a protein content of at least about 90 wt% on a dry weight basis (N x 6.25) and which exhibits a protein profile which is: about 60 to about 95 wt% of 2S protein about 5 to about 40 wt% of 7S protein 0 to about 5 wt% of 12S protein.

2. A composition as claimed in claim 1, in which said first canola protein isolate and said second canola protein isolate are present in said blend in a weight ratio of about 5:95 to about 95:5.

3. A composition as claimed in claim 1 or 2, in which said first canola protein isolate is a dried amorphous protein mass formed by settling the solid phase from an aqueous dispersion of canola protein micelles and said second protein isolate is a dried concentrated supernatant from said settling step.

4. A food composition including a foodstuff and at least one component providing functionality in said food composition, wherein said at least one component is at least partially replaced by a substantially undenatured canola protein isolate having a protein content of at least about 90 wt% as determined by Kjeldahl nitrogen x 6.25 on a dry weight basis, said canola protein isolate being a blend of an amorphous protein mass formed by settling the solid phase from an aqueous dispersion of canola protein miscelles Amended sheet 15/04/2005

. WO .03/034836 PCT/CA02/01590 and mixing said amorphous protein mass with concentrated supernatant from the settling step.

5. A composition as claimed in claim 4, in which said blend is processed in a dried form.

6. A food composition as claimed in claim 1 substantially as hereinbefore described with reference to the Examples.

7. A food composition as claimed in claim 4 substantially as hereinbefore described with reference to the Examples. Amended sheet 15/04/2005