Protein GELS rich in vegetable content

Abstract

A vegetable protein gel, wherein said gel comprises vegetable puree or re-hydrated vegetable powder; between 10 to 25 wt% of one or more plant protein isolate or plant protein concentrate; optionally 2 to 15 wt% of one or more vegetable oil; optionally 0.1 to 1 wt% of sodium bicarbonate; and optionally 0.1 to 1 wt% salt and spices; wherein the water content of the gel is at least 55 wt%, and wherein the water to plant protein wt% ratio is 6 or less.

Description

[0001] PROTEIN GELS RICH IN VEGETABLE CONTENT

[0002] Introduction

[0003] Tofu is a traditional component of East Asian and Southeast Asian cuisines and has been consumed in China for over 2,000 years. In modern Western cooking, it is most often treated as a meat substitute. Some commercial products such as VegBlock claim to be a Tofu-like product. According to the manufacturer, it is made from vegetables, beans and seeds, and high in fibre and protein. It claims to be versatile and works in curries, pasta, buns, wraps, bowls and salads and pizza toppings. VegBlock is rich in cereals (quinoa) and pulses (lentils, pea) but vegetables is not the first ingredient on the product label and it is not a fresh product.

[0004] There are currently no Tofu-like products with vegetable as the most prominent and therefore first ingredient on the product label available on the market. There is a clear need for new products which encourage vegetable consumption amongst consumers of Tofu-like products and that are easy to cook, appealing, fresh, and healthy.

[0005] Summary of the invention

[0006] The present invention relates to the manufacture of a tofu like protein gel with vegetable as the most prominent ingredient. The technical hurdle that has been overcome is the creation of a protein gel network in a vegetable matrix. Aside water, vegetables are mainly composed of carbohydrates which are thermodynamically incompatible with proteins. The protein phase maintains the gel network and is diluted in the vegetable carbohydrate phase. The inventors have surprisingly been able to obtain a gel with a protein continuous phase which includes a discontinuous vegetable polysaccharide phase.

[0007] Embodiments of the invention

[0008] The present invention relates to a vegetable protein gel, said gel comprising a. Vegetable puree or re-hydrated vegetable powder; b. Between 10 to 25 wt% of one or more plant protein isolate or plant protein concentrate; c. Optionally 2 to 15 wt% of one or more vegetable oil; d. Optionally 0.1 to 1 wt% of sodium bicarbonate; and e. Optionally 0.1 to 1 wt% salt and spices; wherein the water content of the gel is at least 55 wt%, and wherein the water to plant protein wt% ratio is 6 or less.

[0009] In said vegetable protein gel the wt% in points b), c), d) and e) are meant in addition to the amount of these constituents that may naturally already be present in the vegetable puree or re-hydrated vegetable powder. Thus the 10 to 25 wt% one or more plant protein isolate or plant protein concentrate is meant in addition to the plant protein that may be present in the puree. Similarly, the 2 to 15 wt% of one or more vegetable oil; the 0.1 to 1 wt% of sodium bicarbonate and the 0.1 to 1 wt% salt and spices are meant in addition to what is already in naturally in the vegetable puree or re-hydrated vegetable powder.

[0010] In some embodiments the amount of vegetable puree or re-hydrated vegetable powder in the vegetable protein gel is from 30 to 90 wt%, preferably from 40 to 80 wt%, more preferably from 50 to 75 wt% and still more preferably from 55 to 65 wt%.

[0011] In some embodiments, the water to plant protein wt% ratio is between 3.5 to 6.

[0012] In some embodiments, the vegetable puree comprises between 80 to 98% water.

[0013] In some embodiments, the vegetable puree is made from a vegetable selected from one or more of carrot, bell pepper, spinach, tomato, broccoli, pumpkin, butternut, beetroot, green pea, and radish.

[0014] In some embodiments, the vegetable puree is made from a vegetable selected from carrot, bell pepper, broccoli and spinach.

[0015] In some embodiments, the vegetable puree is made from a green vegetable.

[0016] In some embodiments, plant protein isolate or plant protein concentrate is used as a gelling agent. In some embodiments, the protein isolate or protein concentrate is able to gel under heating.

[0017] In some embodiments, the protein isolate or protein concentrate is able to gel under freezing.

[0018] In some embodiments, the protein isolate or protein concentrate is derived from soy, gluten, pea, mung bean, faba, or canola.

[0019] In some embodiments, the vegetable puree or re-hydrated vegetable powder is prepared from carrot, spinach, broccoli, red bell pepper, white radish, or pumpkins.

[0020] In some embodiments, the vegetable puree or re-hydrated vegetable powder is prepared from spinach.

[0021] In some embodiments, the vegetable puree or re-hydrated vegetable powder is prepared from carrot.

[0022] In some embodiments, the vegetable puree or re-hydrated vegetable powder is prepared from red bell pepper.

[0023] In some embodiments, the vegetable puree or re-hydrated vegetable powder is prepared from spinach and the plant protein isolate or plant protein concentrate is prepared from soy.

[0024] In some embodiments, the vegetable puree or re-hydrated vegetable powder is prepared from carrot and the plant protein isolate or plant protein concentrate is prepared from soy.

[0025] In some embodiments, the vegetable oil is rapeseed oil or sunflower oil, or a blend thereof. Vegetable oil can be added to improve sensory characteristic of the vegetable gel. It can also bring ideal fatty acid composition for nutritional claims. Preferably, the vegetable oil is from a different vegetable source than the vegetable puree.

[0026] Typically, a vegetable protein gel of the invention comprises 12 to 16% of protein isolate or protein concentrate; 55 to 65 % of a vegetable puree; and wherein the water to protein ratio is or is adjusted to between 3.5 and 5.

[0027] In some embodiments, the vegetable protein gel comprises between 0.3 to 0.7 wt% sodium bicarbonate, or between 0.4 to 0.6 wt% sodium bicarbonate.

[0028] Typically, a vegetable protein gel of the invention comprises 12 to 16% of protein isolate or protein concentrate; 55 to 65 % of a vegetable puree, for example comprising carrot, pepper bell, tomato, broccoli, pumpkin, butternut, beetroot, green pea, and / or radish; 0.1 to 1% of sodium bicarbonate; 5 to 15% of vegetable oil or mixture thereof; 0.1 to 1% salt and spices; and wherein the water to protein ratio is or is adjusted to between 3.5 and 5.

[0029] For example, a vegetable protein gel of the invention comprises about 0.8 wt% salt; about 10 wt% sunflower oil; about 15 wt% soy protein isolate; about 58 wt% spinach puree; and about 16.2 wt% water.

[0030] For example, a vegetable protein gel of the invention comprises about 0.8 wt% salt; about 0.5 wt% baking soda; about 10 wt% sunflower oil; about 15 wt% soy protein isolate; about 58.6 wt% spinach puree; and about 15.1 wt% water.

[0031] The vegetable protein gel may be combined with vegetable pieces and / or grains.

[0032] In one embodiment, the vegetable protein gel comprises one or more of spinach puree, shitake mushrooms, chopped chives, and spices, for example black pepper and cumin powder.

[0033] In one embodiment, the vegetable protein gel comprises one or more of carrot puree, pistachios, cranberries, and spices, for example garam masala.

[0034] In one embodiment, the vegetable protein gel comprises one or more of red bell pepper puree, roasted bell pepper, parsley, black sesame seeds, and spices, for example smoked paprika.

[0035] A typical vegetable protein gel of the invention has the following formulation: 12 to 16% of protein isolate or concentrate which is able to gel under heating for hot set gelation or under freezing for cold set gelation.; 55 to 65 % of a vegetable puree made of carrot, pepper bell, tomato, broccoli, pumpkin, butternut, beetroot, green pea, and / or radish; 0.1 to 1% of sodium bicarbonate can be added to increase the pH and obtain a firmer gel; 5 to 15% of vegetable oil or mixture of vegetable oils can be added to improve the sensory characteristics of the vegetable gel. It can also provide an optimal fatty acid composition for nutritional claims; and salt and spices at 0.1 to 1% can be added to adjust the taste of the gel. The water to protein ratio should be adjusted to values between 3.5 and 5 to be above the minimum gelling concentration of the protein. In one embodiment, the vegetable protein gel is made according to a method as described herein.

[0036] The invention further relates to a method of making a vegetable gel, said method comprising a. Mixing (i) vegetable puree or re-hydrated vegetable powder; (ii) one or more of plant protein isolate or plant protein concentrate; b. Adjusting if necessary the water to plant protein ratio; c. Molding; and d. Cooking.

[0037] In some embodiments, in said method the amount of vegetable puree or re-hydrated vegetable powder in the vegetable protein gel is from 1 to 90 wt%, preferably from 40 to 80 wt%, more preferably from 50 to 75 wt% and still more preferably from 55 to 65 wt%.

[0038] In some embodiments, said method comprises a. Shear mixing (i) vegetable puree or re-hydrated vegetable powder; (ii) between 10 to 25 wt% of one or more of plant protein isolate or plant protein concentrate; (iii) optionally 2 to 15 wt% vegetable oil; (iv) optionally 0.1 to 1 wt% sodium bicarbonate; and (v) optionally 0.1 to 1 wt% salt and spices. b. Adjusting if necessary the water to plant protein ratio to between 3.5 to 6; c. Molding in a mold or directly in packaging; and d. Cooking, for example steam cooking and / or retorting.

[0039] In some embodiments, the vegetable puree comprises between 85 to 95% water.

[0040] In some embodiments, the temperature in step a) is maintained at 60°C or lower.

[0041] In some embodiments, the cooking step is performed at 90°C or higher.

[0042] In some embodiments, the vegetable is blanched in boiling water, drained before being subjected to high shear. In some embodiments, the puree is cooled to less than 5°C. The puree may then be mixed with additional water, for example about 15% of the final recipe, for example for about 1 minute to avoid increasing the puree temperature but still obtain a homogeneous mixture.

[0043] Preferably, the temperature of the mixture does not raise above the protein denaturation temperature.

[0044] Preferably, the dough is cooked at about 90°C for about 30 minutes. The time and temperature of the cooking depended on the size and shape of the produced gel block.

[0045] Preferably, the mixing step is performed at less than 60°C. Preferably, the cooking step is performed at about 90°C, for example for about 30 minutes. Preferably, the cooling step is performed at about 4°C.

[0046] Cooking can be performed in a sealed packaging during pasteurization or retorting. In another embodiment, cooking can be performed in a heated die after extrusion. It may then be cut, packaged, which includes pasteurization, and then frozen. In another embodiment, the packaging can be filled with the dough, sealed and retorted. Gelification occurs during retorting.

[0047] In some embodiments, the pH of the puree is between 4.3 to 7.0. In some embodiments, the pH of the puree is between 4.3 to 4.9. In some embodiments, the pH of the puree is about 4.7. In some embodiments, the pH of the puree is between 5.9 to 7.0. In some embodiments, the pH of the puree is between 6.3 to 6.5. In some embodiments, the pH of the puree is between 4.9 to 5.5. In some embodiments, the pH of the puree is about 7.0.

[0048] Definitions

[0049] The compositions disclosed herein may lack any element that is not specifically disclosed herein. Thus, a disclosure of an embodiment using the term "comprising" includes a disclosure of embodiments "consisting essentially of" and "consisting of" and "containing" the components identified. Similarly, the methods disclosed herein may lack any step that is not specifically disclosed herein. Thus, a disclosure of an embodiment using the term "comprising" includes a disclosure of embodiments "consisting essentially of" and "consisting of" and "containing" the steps identified. Any embodiment disclosed herein can be combined with any other embodiment disclosed herein unless explicitly and directly stated otherwise. Unless defined otherwise, all technical and scientific terms and any acronyms used herein have the same meanings as commonly understood by one of ordinary skill in the art in the field of the invention. Although any compositions, methods, articles of manufacture, or other means or materials similar or equivalent to those described herein can be used in the practice of the present invention, the preferred compositions, methods, articles of manufacture, or other means or materials are described herein.

[0050] The term "wt%" used herein refers to weight % of the total vegetable protein gel composition.

[0051] The vegetable protein gel according to the invention as main ingredient comprises vegetable puree or re-hydrated vegetable powder. According to the invention the vegetable puree or re-hydrated vegetable powder may be made from for example carrot, bell pepper, spinach, tomato, broccoli, pumpkin, butternut, beetroot, green pea, and radish or any combinations thereof. However, the vegetable puree or re-hydrated vegetable powder as main ingredient does not comprise grains, for example soy, wheat and rice grains. Furthermore, the vegetable puree or re-hydrated vegetable powder does not comprise edible seaweeds.

[0052] As used herein, "about," is understood to refer to numbers in a range of numerals, for example the range of -40% to +40% of the referenced number, more preferably the range of -20% to +20% of the referenced number, more preferably the range of -10% to +10% of the referenced number, more preferably -5% to +5% of the referenced number, more preferably -1% to +1% of the referenced number, most preferably -0.1% to +0.1% of the referenced number.

[0053] All numerical ranges herein should be understood to include all integers, whole or fractions, within the range. Moreover, these numerical ranges should be construed as providing support for a claim directed to any number or subset of numbers in that range. For example, a disclosure of from 1 to 10 should be construed as supporting a range of from 1 to 8, from 3 to 7, from 1 to 9, from 3.6 to 4.6, from 3.5 to 9.9, and so forth.

[0054] Examples

[0055] Example 1

[0056] Vegetable protein gel recipes A vegetable protein gel was prepared with a Tofu like texture by using protein isolate or concentrate as gelling agent. Firstly, a vegetable puree consisting of carrot, spinach, broccoli, bell pepper, or pumpkins was prepared. The vegetable was blanched in boiling water, drained and subjected to high shear to produce a fine puree. The puree was then cooled to 5°C. The puree was then mixed with some additional water, usually around 15% of the final recipe, and for only 1 minute to avoid increasing the puree temperature but still obtain a homogeneous mixture.

[0057] Protein powder was then added to the vegetable puree and mixed to obtain a homogeneous mass. The mixing should not raise the temperature of the mass to above the protein denaturation temperature. Salts were then added and mixed into the vegetable / protein mass. The obtained dough could be molded in different shapes such as cylindrical, parallelepipedal cubic, or irregular shapes. The dough was then cooked at 90°C for approximately 30 minutes. The time and temperature of the cooking depended on the size and shape of the produced gel block. The process flow sheet is shown in Figure 1. A typical process flow includes mixing at less than 60°C to avoid gelation, cooking 90°C for 30 minutes, and cooling at 4°C.

[0058] Examples of vegetable protein gels of the invention are given in the following tables.

[0059]

[0060] Vegetable gels according to the invention were successfully obtained with red bell pepper, white radish, spinach, and carrot. The gel can be combined with vegetable pieces and grains. The following protein gels based on spinach puree, carrot puree, and red bell pepper puree were made:

[0061] - Spinach puree in cylinder shape with inclusions (tasted pan fried) with pieces of shitake mushrooms pan fried with olive oil, chopped chives, and spices (black pepper, cumin powder);

[0062] - Carrot puree in cylinder shape with inclusions (tasted pan fried) with pieces of pistachios, pieces of cranberries, and spices (garam masala); and

[0063] - Red bell pepper puree in cylinder shape with inclusions (tasted pan fried) with pieces of roasted bell pepper, chopped parsley, black sesame seeds (only on the outside of the cylinder), and spices (smoked paprika).

[0064] Example 2

[0065] Vegetable gel characterization

[0066] Figure 2 shows the rheological properties of soy gel and soy-vegetable gels under heating and cooling in a plate-plate geometry. The same gelation behavior was observed for the different samples and a higher final elastic modulus, G', for the spinach-soy gel and carrot-soy gel. It can be seen that the inclusion of vegetables increases elastic modulus, and that the carrotsoy gel gives a stronger texture.

[0067] Example 3

[0068] Texture measurement of gels Figure 3 shows TAxT+ texture measurement of soy gel and soy gel with spinach, carrot and bell pepper. Texture measurement of the gel firmness shows clearly that spinach provides a firmer gel compared to soy gel, carrot-soy gel and red bell pepper-soy gels. The red bell pepper shows a lower hardness value. Other texture parameters such as chewiness, cohesiveness, and gumminess for vegetable-based gels are consistently lower when compared to the soy gel. The figures clearly illustrate that the spinach-soy, carrot-soy, and red bell pepper-soy gels exhibit reduced chewiness and cohesiveness, which confirms the influence of vegetable puree on the protein network.

[0069] Example 4

[0070] Vegetable protein gel pH

[0071] One of main challenges that has been overcome is the obtaining of a firm and cohesive gel in spite of the physical-chemical properties of the vegetables. The initial acidity of the vegetable was found to be quite influential. The cohesiveness and texture properties of the protein gel may be dependent on weak bonds (mainly H-bonds, electrostatic interactions) and especially on covalent di-sulphide bonds. It was thus hypothesized that the pH of gelation is a key parameter to adjust. The results showed that a cohesive gel with good sensory texture properties could surprisingly be obtained. Higher pH may be promoting the presence of RS- radicals and final proportion of intermolecular disulphide bonds which build the gel network. The pH of the matrix may also modify the ratio of cationic or anionic charges of the protein molecules.

[0072] For manufacturing the gel, vegetables were cooked and reduced to a fine puree. The puree has a pH which varies depending on the vegetable used. The pH of some of the purees are as follows: tomato (4.3 - 4.9); red bell pepper (4.7); carrot (5.9 - 7); broccoli (6.3 - 6.5); pumpkin (4.9 - 5.5); and spinach (7.0).

[0073] The initial pH of each vegetable puree was found to have an impact on the protein gelation. One objective was to control the gel texture whatever vegetable is used for making the gel. The protein content of the vegetable was also found to have an impact on gel cohesiveness and texture. Vegetable do not typically contain high amounts of protein (less than 1%). An exception are green vegetables which contain Rubisco and enzymatic protein associated to chloroplasts involved in carbon fixation. Rubisco protein represents approximately 3% of the leaf mass. The protein content of spinach and broccoli is around 2.8 to 3% while carrot and bell pepper have a protein content of around 0.8 to 0.9% due to the presence of Rubisco associated with green chlorophyll.

[0074] One problem to solve was how to overcome texture differences due to vegetable puree pH, content in pectin, content in fibers or content in protein. It was surprisingly found that the problem could be solved by adjusting the pH to a higher value nearer to the isoelectric point of the protein (for soy, it is 4.5) with calcium bicarbonate. Other alkaline or buffering agents also worked. The addition of 0.5 or 1% sodium bicarbonate increases the pH of the spinach, carrot or bell pepper puree and gel. The increase is more significant for pH of the solid gel. The final solid gel pH is between 7.5 and 8 for all gels with 0.5% sodium bicarbonate and pH 8 for all gels with 1% sodium bicarbonate.

[0075] The impact of this pH adjustment on the gel texture showed that there is a texture improvement for carrot and bell pepper gel at 0.5% sodium bicarbonate addition and a weaker improvement for 1% addition. Therefore 0.5% sodium bicarbonate addition resulted in the best texture for carrot and red bell pepper which have no rubisco, relatively high pectin level and lowest initial puree pH. Addition of 0.5% sodium bicarbonate provides a cohesive and firm gel for all range of the tested vegetable even if the firmness of carrot and bell pepper is lower than the one of spinach.

[0076] Example 5

[0077] Effect of fibers

[0078] The presence of fibers, for example pectin, in the vegetable was also found to interfere with the protein gelation. Moreover, pectin content and fiber composition of vegetable are also variable. Examples are provided in the following table.

[0079] The fiber composition and soluble fiber to insoluble fiber ratio was found to impact on the protein gelation. To assess the impact of pectins on protein gelation, a citrus pectin with a degree of methoxylation of 60% was combined with soy protein at increasing ratios and at various pH.

[0080] The addition of pectin was found to decrease the gel strength of the soy protein isolate at pH 6. When the pH was lowered to pH 5 or pH 4, the soy protein lost its gelling ability, aggregated, and precipitated. Upon addition of pectin a thin paste was obtained instead.

[0081] Phase separation was observed using microscopy. Upon acidification, protein aggregates were visible. Following pectin addition, the aggregates were more round and smaller at pH 4.

[0082] At low pectin content, the protein gel was found to weaken which could explain why high pectin content vegetables like carrot provide softer gels than vegetables without pectin like spinach.

Claims

Claims1. A vegetable protein gel, said gel comprising a. Vegetable puree or re-hydrated vegetable powder; b. Between 10 to 25 wt% of one or more plant protein isolate or plant protein concentrate; c. Optionally 2 to 15 wt% of one or more vegetable oil; d. Optionally 0.1 to 1 wt% of sodium bicarbonate; and e. Optionally 0.1 to 1 wt% salt and spices; wherein the water content of the gel is at least 55 wt%, and wherein the water to plant protein wt% ratio is 6 or less.

2. The vegetable protein gel according to claim 1, wherein the water to plant protein wt% ratio is between 3.5 to 6.

3. The vegetable protein gel according to any one of claims 1 and 2, wherein the vegetable puree comprises between 80 to 98% water.

4. The vegetable protein gel according to any one of claims 1 to 3, wherein the vegetable puree is made from a vegetable selected from one or more of carrot, bell pepper, spinach, tomato, broccoli, pumpkin, butternut, beetroot, green pea, and radish.

5. The vegetable protein gel according to any one of claims 1 to 4, wherein the vegetable puree is made from a vegetable selected from carrot, bell pepper, broccoli and spinach.

6. The vegetable protein gel according to any one of claims 1 to 5, wherein the vegetable puree is made from a green vegetable.

7. The vegetable protein gel according to any one of claims 1 to 6, wherein the protein isolate or protein concentrate is able to gel under heating.

8. The vegetable protein gel according to any one of claims 1 to 6, wherein the protein isolate or protein concentrate is able to gel under freezing.

9. The vegetable protein gel according to any one of claims 1 to 8, wherein the protein isolate or protein concentrate is derived from soy, gluten, pea, mung bean, faba, or canola.

10. The vegetable protein gel according to any one of claims 1 to 9, wherein the vegetable oil is rapeseed oil or sunflower oil, or a blend thereof.

11. A method of making a vegetable protein gel, said method comprising a. Shear mixing (i) vegetable puree or re-hydrated vegetable powder; (ii) between 10 to 25 wt% of one or more of plant protein isolate or plant protein concentrate; (iii) optionally 2 to 15 wt% vegetable oil; (iv) optionally 0.1 to 1 wt% sodium bicarbonate; and (v) optionally 0.1 to 1 wt% salt and spices. b. Adjusting if necessary the water to plant protein ratio to between 3.5 to 6; c. Molding in a mold or directly in packaging; and d. Cooking, for example steam cooking and / or retorting, wherein the water content of the gel is at least 55 wt%, and wherein the water to plant protein wt% ratio is 6 or less.

12. The method according to claim 11, wherein the vegetable puree comprises between 85 to 95% water.

13. The method according to any one of claims 11 and 12, wherein the vegetable puree or re-hydrated vegetable powder is prepared from spinach and the plant protein isolate or plant protein concentrate is prepared from soy.

14. The method according to any one of claims 11 to 13, wherein the temperature in step a) is maintained at 60°C or lower.

15. The method according to any one of claims 11 to 14, wherein the cooking step is performed at 90°C or higher.

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