PROCESS FOR PRODUCING A LOW ISOFLAVONE-CONTENT PLANT PROTEIN INGREDIENT

Abstract

The invention relates to the field of protein ingredients for human and animal consumption. More particularly, the invention concerns a process for producing a plant-based protein ingredient with a reduced isoflavone content, obtained from textured proteins derived from protein, oil, or oleaginous plants. The resulting product has a texture and consistency similar to that of a meat product. Abstract figure: 1

Description

Title of the invention: METHOD FOR PRODUCING A PLANT PROTEIN INGREDIENT LOW ISOFLAVONE CONTENT

[0001] The invention relates to the field of protein ingredients intended for human and animal nutrition. More particularly, the invention relates to a method for producing a plant protein ingredient with a reduced isoflavone content, from textured proteins derived from protein, oil-proteaginous or oleaginous plants. The product obtained has a texture and consistency close to that of a meat product. Field of invention

[0002] Many seeds, pods or beans of protein, oil-protein or even oil-producing plants are used as a source of protein for human or animal nutrition. Some, such as soybeans, hops, clover, alfalfa, lentils, chickpeas, flax or sunflower seeds, naturally contain isoflavones such as, for example, genistein, daidzein and glycetein. These isoflavones, which are polyphenols, are also called phytoestrogens or plant estrogens because they have a biochemical structure comparable to female estrogenic hormones.

[0003] The massive increase in the consumption of plant-based products, particularly those derived from soybeans, raises the question of the accumulation of phytoestrogens in the organisms that consume them. This question has led public health organizations to recommend maximum daily amounts of isoflavones, particularly in products intended for children and pregnant women, as well as better consumer information. Studies also report the harmful effects of a diet rich in soy on the fertility of farm animals.

[0004] The food industry processes some of these legumes, particularly soybeans, using a standard industrial texturizing process to produce protein compounds with a texture that favors their use in animal or human food. The products thus obtained have a higher protein concentration and are more easily assimilated by the body. These products are of great interest due to their texture, digestibility and reduced bitterness, particularly for human food. They are commonly used by the food industry, directly or as ingredients in preparations and products intended for humans but also for farm animals and pets.

[0005] However, current methods of preparing textured proteins, particularly from soybeans, and of assembling them into processed products, result in the production of products intended for consumers, comprising high concentrations of isoflavones.

[0006] Many techniques have been implemented in the past to seek to extract Isoflavones in order to enhance their value, or to improve the taste quality of foods, particularly those based on soybeans, from the point of view in particular of the absence of plant flavors specific to soybeans and / or from the point of view of their texture.

[0007] Methods for reducing the amount of isoflavones are described for example in document EP0943245 and consist of alcohol extractions.

[0008] Other methods use extractions on absorption resins such as document EPI 166643 which describes a method for separating and recovering isoflavones and plant proteins from a plant material containing proteins and isoflavones; this method comprises contacting a clarified plant protein extract containing isoflavones with a polar ion exchange resin, the protein extract is thus depleted of said isoflavones, by separating on the one hand a protein depleted in isoflavones and on the other hand the isoflavones thanks to the ion exchange resin.

[0009] Document US3970805 describes a process for preparing shredded protein products having an improved meat-like texture from hydrated protein extrudates. This process comprises the following steps:

[0010] a) providing a plurality of pieces of hydrated extrudates,

[0011] b) subjecting the hydrated extrudate pieces to a shredding force sufficient to break and split the hydrated extrudate pieces primarily along the longitudinal axis of said hydrated extrudate pieces and thereby provide a plurality of fragments of substantially smaller cross-sectional diameter than the hydrated extrudate pieces.

[0012] Document WO2016 / 150834 discloses a method for preparing a meat-like food product, the method comprising the following steps:

[0013] a) feeding an extruder barrel with 40 to 70% by weight of water and 15 to 35% by weight of vegetable proteins;

[0014] b) injecting 2 to 15% by weight, preferably 2 to 10% by weight, of liquid oil, fat or a combination thereof into the extruder barrel at a location downstream of the feed location of step a);

[0015] c) extruding the mixture through a cooling die.

[0016] The first two examples of processes of the state of the art have as their objective the recovery of isoflavones with a view to their valorization, and not the preparation of a product depleted in isoflavones, while the third concerns a process for texturizing vegetable proteins.

[0017] There is a need for protein products of plant origin with a reduced isoflavone content so that the consumer can control the quantity of isoflavones that he ingests per day or that is administered to animals. Statement of the invention

[0018] The objective of the invention is to produce a food rich in proteins of plant origin, having improved nutritional and taste qualities compared to the state of the art and having reduced isoflavone contents compared to plant sources commonly used as raw material.

[0019] Thus, the invention relates to a process for producing a plant protein ingredient from textured proteins, intended for human and animal food and whose isoflavone content is reduced by at least 50% compared to the quantity present in the textured proteins from protein, oil-proteaginous or oil-producing plants and, comprising the steps of:

[0020] - Initial rinse using a first aqueous solution

[0021] - Carrying out at least two cycles comprising: • A decoction in a second aqueous solution • A cooling rinse using a third aqueous solution

[0022] - Spin Advantages of the invention

[0023] The process according to the invention has the advantage of allowing the preparation of a 100% plant-based ingredient whose isoflavone content is significantly reduced compared to the textured proteins used as raw materials.

[0024] This ingredient has other advantages such as improved digestibility and improved taste qualities compared to the state of the art, in particular less bitterness and neutral taste (by reducing plant aromas). The texture and consistency are close to those of a meat product.

[0025] Compared to the state of the art, the invention simultaneously addresses three objectives which have until now only been partially or separately achieved, namely: a. Reducing the isoflavone content in foods for health reasons; b. Improvement of texture and more generally of structural sensations of consistency, visual appearance, hold and sensation of touch in the hand and physical sensation in the mouth when chewing in order to obtain a compound as close as possible to the texture of a chosen meat (beef, pork, chicken or other); c. Improving taste and digestibility to, on the one hand, eliminate antinutritional factors and the bitterness of legumes and, on the other hand, obtain a compound as close as possible to the taste of a chosen meat (beef, pork, chicken or others). Until now, no technique had been proposed to simultaneously improve these three characteristics of meat analogue products based on soybeans or other legumes and more generally for foods derived from soybeans intended for humans or animals.

[0026] This ingredient thus responds to a new mode of consumption, reflecting the transition from a diet traditionally based on meat-based dishes to dishes incorporating proteins of plant origin. DETAILED DESCRIPTION OF THE INVENTION

[0027] The invention relates to a process for producing a plant protein ingredient for human and animal food, the isoflavone content of which is reduced, from textured proteins derived from protein, oil-proteaginous or oil-producing plants, in which the reduction in isoflavones is at least 50% relative to the quantity present in said textured proteins, this process comprising the steps of: - Initial rinse using a first aqueous solution - Completion of at least two cycles including: • A decoction in a second aqueous solution • A cooling rinse using a third aqueous solution - Spin.

[0028] By "ingredient" is meant both a product used as a basic material for the production of processed products or elaborate recipes, and a product which can be consumed as a food in its own right.

[0029] By "textured protein" we mainly mean a protein obtained by extrusion of seeds (soy, peas, cotton, etc.) cold-deoiled. By extension, this term also covers all new methods of preparing textured proteins from seeds or other forms of plant sources.

[0030] By "protein, oilseed or oil-producing plants" is meant plants called legumes such as soybeans, hops, clover, alfalfa, lentils, chickpeas, flax, peanut and sunflower seeds. These plants have in common the fact that they contain isoflavones in significant quantities.

[0031] By "isoflavone(s)" is meant a subfamily of flavonoids present in significant quantities in legumes. These isoflavones are also called phytoestrogens. Isoflavones include in particular genistein, daidzein and glycetein.

[0032] By "decoction" is meant a method of extracting the active ingredients and / or aromas from a generally plant-based preparation in a heated, or even boiling, solution.

[0033] It is understood that the method according to the invention consists of transforming a textured protein into a product with a low isoflavone content. The prior steps of preparing the textured protein from protein, oil-proteaginous or oil-producing plants are not part of the present invention.

[0034] The method according to the invention typically comprises three steps: an initial rinse, a decoction / rinse step and a final spin.

[0035] The isoflavones contained in textured proteins have a hydrophilic character and can be extracted by a natural treatment involving the action of an aqueous solution with or without the addition of hydrophilic solvents or catalysts, and / or modification of the pH, via a sequence of several steps as described below. Step One: Initial Rinse

[0036] The initial rinse serves to clean the proteins of residual particles and flours highly titrated in isoflavones and to hydrate the textured proteins.

[0037] Rinsing consists of pouring a stream of solution onto the product or soaking it; it is carried out using an aqueous solution.

[0038] Rinsing can for example be carried out using (i) any device allowing a more or less continuous flow of the aqueous solution over the product, so as to promote contact of the entire product with the aqueous solution and allowing rapid evacuation of the solution having been in contact with the product, or (ii) a flow formed by one or more jets, or by spraying in more or less fine droplets, flow preferably carried out at low pressure so as not to impose excessive mechanical stresses on the product so that it does not lose its texture and its grains are not disintegrated, or (iii) by soaking in an aqueous solution.

[0039] The aqueous solutions used during the different stages of the process consist of: • exclusively made up of water at a pH between 6 and 8 • water enriched with acidic or alkaline compounds, such as citric acid, acetic acid, sodium bicarbonate, etc., • water enriched with ethanol, • any other aqueous solution, particularly saline.

[0040] For the sake of clarity, it is specified that the aqueous solutions used at the different stages of this process may be identical or different. Step Two: Decoction / Rinse Cycles

[0041] This second step consists of a decoction of the proteins in a heated aqueous solution then a cooling rinse using a new aqueous solution.

[0042] The inventors have determined that a 50% reduction in the initial isoflavone content can be achieved when the process comprises at least two decoction-rinse cycles. In an advantageous embodiment, three decoction-rinse cycles allow for further reduction of the isoflavone content.

[0043] Thus, the step of reducing the isoflavone content comprises at least two decoction-rinse cycles. In a preferred embodiment, the method comprises 3 decoction / rinse cycles.

[0044] The number of cycles to be carried out depends on the conditions applied and the level of isoflavones that one wishes to obtain in the final product.

[0045] The process allows a reduction of at least 50% of the initial quantity of isoflavones. The quantity in the final product can be reduced by 50% or more, in particular by 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98%, or until only traces are obtained in the scientific sense of the term (detection limit) by adapting the process parameters.

[0046] Decoction consists of immersing the treated product in a bath of heated aqueous solution. The aqueous solution is as described above.

[0047] The volume ratio of aqueous solution to product in the decoction bath is at least 2 to 1. To ensure that the product is always immersed in the aqueous solution bath, and to promote natural convection movements, a ratio of 4 to 1 is preferred, more preferably a ratio of 10 to 1.

[0048] The decoction bath is carried out in an open or closed container, allowing mixing by natural convection and possibly slow and moderate mechanical mixing of the material.

[0049] The temperature of the decoction bath is between 75°C and 100°C, preferably between 85°C and 100°C, at atmospheric pressure.

[0050] The duration of the decoction is between 1 and 30 minutes and preferably 4 to 10 minutes, for example 5 min.

[0051] The objectives of the decoction are to continue the extraction of isoflavones, to hydrate the product, to improve the digestibility of the products by cooking and the bioavailability of their constituents, to eliminate certain antinutritional factors (phytic acid) when the bath has an acidic pH (pH < 7) and the inhibitors of proteases (thermal action) and to extract other products generating bitter taste and their precursors.

[0052] The rinsing that follows the decoction is carried out in the same way as the initial rinsing, by sprinkling or soaking, using an aqueous solution. The objective of this rinsing is to eliminate the isoflavones still present on the material, the constituents generating bitterness or vegetal notes and certain antinutritional factors.

[0053] The temperature and flow rate of the aqueous solution during rinsing must allow rapid cooling of the material. During this cooling, the core temperature of the product at the end of rinsing must be less than 30°C, preferably less than 20°C, and ideally less than 10°C.

[0054] During the decoction / rinse cycles, the purpose of rinsing with cooling is to restore firmness and texture to the product by renaturing the proteins and to stimulate the vacuolar structure of the product before a new decoction step in order to further optimize the extraction of isoflavones and off-flavor precursors, with cooling also limiting the development of bacteria and flora.

[0055] In all cases, the aqueous solution is removed after each step of the process. Third step: final spin

[0056] Spinning can be carried out using various methods: - by means of a device carrying out centrifugation, pressing, or vacuum action, in order to extract the leaching juice still retained in the vacuoles of the material. The wringing pressure must be strong enough to extract the juice but moderate enough not to damage the texture of the product. It must not go beyond the plasticity limit of the texture of the product. - passively by gravity draining into a pierced container for a few hours, and preferably in 24 hours.

[0057] In all cases the leaching juice is removed before moving on to the next step. The purpose of spinning is to mechanically remove the isoflavones in solution in the water which is still retained in the vacuoles of the material and to give the product a hydration level such that the material is supple and has a texture similar to meat and such that the product does not release water under the effect of slight pressure, in its packaging.

[0058] Generally speaking, each of the steps of the process must be carried out at least once and the steps of decoction, rinsing and possibly spinning can be repeated several times, according to a sequence appropriate to the desired objective.

[0059] Preferably, a spinning step will be carried out after each rinsing and / or decoction step.

[0060] The characteristics of each step and in particular the durations, temperatures, volume ratio between aqueous solution and product, the number of steps and the sequences of the steps are determined according to the desired performance and in particular the final isoflavone content but also the texture, firmness, appearance, taste of the product. The aim is to reproduce the organoleptic parameters of a meat product (beef, pork, poultry, etc.).

[0061] The hydration rate of the products thus produced is variable depending on the characteristics of the starting proteins, the texturing and the characteristics of the aqueous solutions and the parameters of the decoction, rinsing and spinning operations. Hydration gains of a factor of 2 to 4 are generally observed between the initial weight of textured proteins and the final weight after treatment; preferably this factor is 2.8.

[0062] A general diagram illustrating an embodiment of the method according to the invention is presented in [Fig.l]. DESCRIPTION OF FIGURES

[0063] [Fig.l] [Fig.l]: General diagram of an embodiment of the process according to the invention allowing the obtaining of the ingredient with reduced isoflavone content, a) initial rinsing, b) decoction, c) rinsing, d) spinning.

Claims

Claims

1. Process for transforming textured proteins for human and animal consumption, the isoflavone content of which is reduced, from protein, oil-proteaginous or oil-producing plants, in which the reduction in isoflavones is at least 50% compared to the quantity present in said textured proteins, this process comprising the steps of: - Initial rinsing using a first aqueous solution - Carrying out at least two cycles comprising: • A decoction lasting between 1 and 10 minutes in a second aqueous solution • A cooling rinse using a third aqueous solution - Spin-drying.

2. Method according to claim 1 characterized in that three decoction / rinsing cycles are carried out.

3. Method according to one of claims 1 or 2 characterized in that said aqueous solutions are evacuated after each step.

4. Method according to one of the preceding claims, characterized in that the isoflavone content of said ingredient is reduced by at least 80% compared to the quantity present in said textured proteins.

5. Method according to one of the preceding claims, characterized in that said first, second and third aqueous solutions may be identical and different and chosen from (i) a solution consisting exclusively of water and having a pH between 6 and 8, (ii) an aqueous solution enriched with acidic or alkaline compounds, (iii) an aqueous solution enriched with ethanol, (iv) a saline solution.

6. Method according to one of the preceding claims, characterized in that said textured proteins are derived from soy.

7. Method according to one of the preceding claims, characterized in that said aqueous solution used for the decoction is heated between 85°C and 100°C at atmospheric pressure.

8. Method according to one of the preceding claims, characterized in that the temperature of the product at the end of rinsing is less than 30°C.

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