CA1094869A

CA1094869A - Acidic proteinaceous beverage

Info

Publication number: CA1094869A
Application number: CA299,364A
Authority: CA
Inventors: E. Donald Murray; Chester D. Myers; Terrence J. Maurice
Original assignee: General Foods Inc
Current assignee: General Foods Inc
Priority date: 1978-03-21
Filing date: 1978-03-21
Publication date: 1981-02-03
Also published as: GB2017146B; GB2017146A

Abstract

ABSTRACT OF THE DISCLOSURE
Protein fortification of acidic beverages in significant quantities is achieved without an excessive increase in viscosity and without the necessity of stabilizing additives and emulsifiers. The compositions in ready-to-drink dilute form have a pH of less than about 3.7 and exhibit a stability against protein separation at room and refrigeration temperatures, preferably with con-centration of dispersed protein of up to about 7% w/v.
The protein fortification is achieved using protein micellar masses obtained from a suitable protein source, such as, a plant protein. The fortified composition may be formulated in dry form, for later dispersement in water to form the dilute ready-to-drink composition.

Description

9~ Y~ G~f - The present invention relates to proteinaceous beverages and dehydrated forms thereof.
Acidic beverages from natural and synthetic sources are well known in both carbonated and non-carbonated varieties. Examples o~ such beverages include natural citrus fruit juices and citrus-imitative beverages.
Attempts have been made to incorporate various protein materials into acidic beverages to increase their rather limited nutritional value.
The prior art attempts to produce protein-fortified acidic beverages have been frustrated by stability problems which do not permit the inclusion of more than minor quantities, i.e. up to about 1 to 1 1/2%
w/v, of the protein without causing protein separation in only a short standing period.
Conventional protein materials~ such as, soy, ; whey or fish protein concentrates and isolates, have been ^
used. Procedures, such as agglomeration and partial hydrolysis in combination with emulsifiers and stabilizers have been used in attempts to increase the concentration of protein in the beverage. However, large viscosity in-; creases are o~ten experienced at other than minor concen-~ trations o~ protein which provide the product with an , objectionable mouth-~eel.
In accordance with the present invention, there is provided a novel protein-fortified acidic beverage composition which does not exhibit the prior art problems, including those of low protein levels; high viscosity and poor dispersibilit~.
The compositions of this invention utilize a unique protein isolate, known as protein micellar mass.
The production of this protein micellar mass is described in our copending Canadian Application Serial No.262,397.
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~ s outlined in our prior application, the protein isolate is formed using a controlled two-step operation. In the first step, the protein source material is treated with an aqueous food grade salt solution at a temperature of about 15 to about 35C, a salt concen-tration of at least 0.2 ionic strength, generally about 0.2 to about 0.8, and a pH of about 5.5 to about 6.5 to cause solubilization (or salting-in) of the protein, usually in about 10 to about 60 minutes. In the second step, the aqueous protein solution is diluted to decrease its ionic strength to a value less than about 0.1.
The dilution of the aqueous protein solution which may have a protein concentration, ~or example up to about 10~ w/v, causes association of protein molecules to form highly proteinaceous micelles which settle in the form of an amorphous highly viscous, sticky, gluten-li~e micellar mass of protein having a moisture content of about 60 to about 75% by weight. The protein micellar mass so produced is referred to herein as PMM. The PMM exhibits a unc-tionality not exhibited by the source material nor by an isoelectric isolate of that material. The wet PMM may be dried to a powder for use in that form. Any convènient drying technique may be used, for example, spray drying, freeze drying or vacuum drum drying.
In view of the prior art difficulty in forming stable dispersions from conventional proteins, it is surprising that stable dispersions of P~ are readily i formed at acid pH values below about 3.7 without the necessity to use emulsifiers and suspending aids or chemical modi~ications of the protein~ such as, by partial hydrolysisjand that high concentrations of protein may be present in such dispersions, without an attendant large viscosity increase.

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The compositions of this invention are provided in "dilute" form, "concentrate" form, or in "dry" form.
By the term "dilute" i5 meant an aqueous composition which is ready to drink, by the term "concentrate" is meant a concentrated aqueous composition requiring dilution prior to drinking, and by the term "dry" is meant, a solid mixture of components which, when dissolved and dispersed in a suitable volume of water, provides a dilute ready-to-drink composition.

The ability to incorporate large quantities of protein into acidic beverage compositions enables bever-ages of significant nutritional value to be provided. By "significant nutritional value" is meant a significant proportion of the daily allowance of protein recommended by governmental health authorities. For example, the compositions of the present invention may be formulated to provide 10% of the daily intake of protein in a 6-oz. serving recommended by the U.S. government or in a 6-oz. serving to provide Ua good source of protein" as recommended by the Canadian government~
In the compositions of this invention, the PMM conveniently is incorporated in its dry form although the wet PMM also may be used, if desired. While a PMM from one protein source only usually is employed, it also is possible to use mixtures of PMM' 5 from diferent protein sources, thereby achieving amino acid complementation, which is of considerable nutritional importance.

The dilute beverage compositions of this inven-tion have a pH value up to about 3.7, generally in the - 30 range of about 2.9 to about 3.4.
If the pH is above about 3.7, precipitation of the protein occurs, while pH values below about 2.7 are ~;119~8~

usually too acidic in taste to be acceptable. A pH of about 3.0 to about 3.2 is most preferred for the dilute compositions o~ this invention.
The acidic aqueous compositions of this inven-tion exhibit stability against separation of protein from the aqueous phase in the absence of added emulsifiers and surfactants. By the term "stable" as used herein is meant an aqueous composition which resists separation of solid phase from aqueous phase upon standing at refrigeration temperatures tabout 5 to 10C) for several days, typically 2 to 3 days,and which also resists separation by centrifuging at room temperature (about 20 to 25C) and at refrigeration temperature.
The concentration of PMM present in the composi-tion may be quite high, even as high as 30 % w/v, and remain stable. However, since the PMM is present as a buffered combination with acidifying agents, the taste effect of the acidifying agents is a significant factor in limiting the practical concentration of protein to less than about 7% w/v, usually in the range of about 2 to about 6.5% w~v, preferably about 3.5 to about 6.5% w/v.
For comparison, milk has a protein concentration of about 3.5 to 4~ w/v but is not stable at acidic pH levels.
Since high concentrations of PMM can be tolerated and still retain stability, the compositions may be readily formulated in a concentrate form for dilution to the dilute form for drinking.
The novelty of this invention resides in the high levels of protein that remain dispersed in the acidic environment. This environment is provided by a buffer system comprising the PMM itself and a suitable food grade acidifying agent, preferably, citric acid, malic acid or tartaric acid. The acidiEying agent may be mixed with S

8~9 the dry PMM to form the buffer system or the acidifying agent may be mixed with the wet PMM and the mixture then is dried.
The buffered dry composition formed by either of these techniques may be stored for considerable periods without degradation and forms one embodiment of this inven-tion. The dxy composition rapidly disperses in water, even at high protein concentrations, often in less than 60 seconds to provide an aqueous acid beverage.
The compositions of this invention, therefore, are formed by simple and gentle processing steps which do not result in any significant denaturing of the protein, as determined by calorimetry.
The compositions of this invention may be formulated from a variety of acidic beverage materials, including carbonated and non-carbonated materials. One group of non-carbonated materials is the commercial citrus-imitatiYe compositions, which include sweeteners, coloring agents and ~lavorings, and are usually available in dry or zo dehydrated orm for dissolving in water, or in aqueous concentrate form. The relative proportions of the com-ponents depend on the taste and color of the product - desired.
The PMM may be included with the other com-ponen~s of the beverage compositions of this invention in a variety of ways. For example, in the case of the dilute composition, the P~M, in dry or wet form, may be dispersed in the desired quantity directly into the dllute composition.
Alternatively, the PMM in dry or wet form, may be dry mixed with the other components and the resulting mixture dissolved and dispersed in water.

48~9 The protein source from which the P~ is formed for incorporation into the compositions of this invention may vary widely and includes the plant proteins, for example, starchy cereals, such as, wheat, corn, oats, rye, barley and triticale, starchy legumes, such as, field peas, chickpeas, fababeans, navy beans and pinto beans, and oil seeds, such as, sunflower seed, rapeseed and soy beans;
animal proteins, for example, serum protein; and microbial proteins, i.e. single cell proteins. Preferably the protein source is a plant protein, owing to the readily available nature of this material.
The invention is illustrated urther by the follo~ing Example:
Example PMM ~rom fababeans was prepared following the procedure outlined in the a~orementioned Canadian patent application Serlal No. 262,397 and spray dried. The spray dried PMM was dry mixed with the other components of citrus-imitative beverage compositions, to provide two different formulations as set forth in the following Table I:
TAB~E I

Component Formulation A B
% by weiaht Sugar 67.31 57.66 Citric acid 5.52 5.62 Color premix 1.26 1.03 Flavor and enhancers1.69 1.45 Dry PMM 24.22 34.24 1~94~

Each of the Formulations A and B was mixed in lOOg of cold water in the amounts of 18.38g for Formulation A and 21.47g for Formulation B. The resulting dilute com-positions contained protein at 4% w/v in the case of .
Formulation A and 6.5% w/v in the case of Formulation B.
The compositions exhibited stability against protein separa-tion after standing at refrigeration temperature (5 to 10C) for several days.
The dilute compositions had the properties set forth in the following Table II:
TABLE II

Viscosity tBrookfield units)*
20C 7.5C
Dilute Composition A 38.445.7 Dilute Composition B 45Ø 50.4 Dilute Composition A
without PMM 240928.7 Water 18.819.1 - Cow's Milk twhole milk) 30.4. 36.7 * As determined on Brookfield Viscometer Model LVT using Spindle No. 1 at 30 rpm.
It will be seen from the results of Table II that while the viscosity of the dilute compositions is increased with respect to the PMM-free material, the :increase in viscosity is not significant and the resulting viscosity has an order of magnitude of the viscosity of milkO

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for the formation of a dry protein composition capable of rapid dispersion in water to provide a stable dispersion having a pH of about 2.7 to about 3.7, said process comprising (a) extracting protein from protein source material with an aqueous food grade salt solution at a temperature of about 15° to about 35°C, a salt concentration of at least about 0.2 ionic strength and a pH of about 5.5 to about 6.5, (b) diluting the resulting protein solution to an ionic strength of less than about 0.1 to form an aqueous dispersion of protein micelles, (c) settling the solid phase from said aqueous dispersion to form a protein micellar mass, (d) separating said settled protein micellar mass from the residual aqueous phase, and (e) providing said separated protein micellar mass in dry form in admixture with sufficient at least one food grade acidifying agent to provide on dispersing in water said stable aqueous protein composition having a pH
of about 2.7 to about 3.7 by either:
(i) homogeneously mixing said protein micellar mass and said at least one acidifying agent and drying the homogeneous mixture, or (ii) drying said protein micellar mass and mixing said at least one acidifying agent with the dried micellar mass.

2. The process of claim 1 wherein said stable dispersion has a pH of about 2.9. to about 3.4.

3. The process of claim 1 wherein said stable dispersion has a pH of about 3.0 to about 3.2.

4. The process of claim 1, 2 or 3, wherein said food grade salt solution has an ionic strength of about 0.2 to about 0.8 and said extraction is effected for about 10 to about 60 minutes.

5. The process of claim 1, 2 or 3, wherein said protein is selected from the group consisting of plant proteins, animal proteins and microbial proteins.

6. The process of claim 1, 2 or 3, wherein said protein is selected from the group consisting of starchy cereals, starchy legumes and oil seeds.

7. The process of claim 1, 2 or 3 including incorporating sweeteners, colouring agents and flavouring agents with said dry admixture suitable to provide a composition capable of dispersion and dissolving in water to provide a citrus-imitative beverage.

8. The process of claim 1 t 2 or 3 wherein said acidifying agent is selected from citric acid, malic acid and tartaric acid.

9. A dry protein composition capable of rapid dispersion in water to provide a stable dispersion having a pH of about 2.7 to about 3.7 whenever produced by the process of claim 1 or by any obvious chemical equivalent thereof.

10. A dry protein composition capable of rapid dispersion in water to provide a stable dispersion having a pH of about 2.9 to about 3.4 whenever produced by the process of claim 2 or by any obvious chemical equivalent thereof.

11. A dry protein composition capable of rapid dispersion in water to provide a stable dispersion having a pH of about 3.0 to about 3.2 whenever produced by the process of claim 3 or by any obvious chemical equivalent thereof.

12. A dry protein composition capable of rapid dispersion in water to provide a stable dispersion having a pH of about 2.7 to about 3.7 and consisting of a homogeneous mixture of a dried protein micellar mass and an acidifying agent selected from citric acid, malic acid and tartaric acid, whenever produced by the process of claim 8 or by any obvious chemical equivalent thereof.

13. A process for the formation of an aqueous protein beverage, which comprises dispersing the composition of claim 9 in water in sufficient quantity to provide a dispersed concentration of protein in said water of up to about 7% w/v.

14. The process of claim 13 wherein sufficient compo-sition is dispersed to provide a dispersed concentration of protein of about 2 to about 6.5% w/v.