IN FOOD PRODUCTS

FIELD OF THE INVENTION

The present invention pertains to the field of food technology. More particularly, the invention relates to the use of biomass from citric acid or gluconic acid production in food products.

BACKGROUND OF THE INVENTION

Citric acid is a weak organic acid consisting of three carboxyl (R-COOH) groups with the formula C ₆ HsO. At room temperature, citric acid appears as a white crystalline powder. It can exist either in an anhydrous (water-free) form or as a monohydrate.

Citric acid is widely used as a flavoring and preservative in food and beverages, especially soft drinks. Citrate salts of various metals are used to deliver those minerals in a biologically available form in many dietary supplements. The buffering properties of citrates are used to control pH in foods, household cleaners and pharmaceuticals.

Over million tons of citric acid are produced annually worldwide, traditionally by fermentation of various carbohydrates using the microorganism Aspergillus niger.

Gluconic acid is an organic compound with the molecular formula C ₆ Hi ₂ 0 ₇ and structural formula HOCH ₂ (CHOH) ₄ COOH. The salts of gluconic acid are known as "gluconates". Gluconic acid and gluconate salts, occur widely in nature arising from the oxidation of glucose. Gluconic acid is industrially prepared by fermentation of Aspergillus niger. Salts of gluconic acid such as calcium gluconate are used as mineral supplements. Sodium gluconate is used as sequestering agent.

Aspergillus niger is one of the most important microorganisms used in biotechnology. It is a filamentous fungus, used in various industrial fermentation processes, producing enzymes and organic acids such as citric acid or gluconic acid for the food industry. Chitosan and glucans are produced from the mycelium of this strain and used in the food, cosmetic and pharmaceutical industries. Aspergillus niger is also used in fermenting tea leaves. The safety of Aspergillus niger was described in the literature and it is considered as safe microorganism for use in food applications.

The fermentation broth of Aspergillus niger in citric acid and gluconic acid production contains various metabolites, cellular fragments and various other substances, which result from the fermentation of the fungus. The mycelial biomass from the submerged fermentation process is separated from the fermentation broth, which is used afterwards in the citric acid and gluconic acid purification process, enabling isolation of the wet spongy mycelium, which is washed with water in order to remove residual acid.

M. Roehr et al. in the article named "Kinetics of biomass formation and citric acid production by Aspergillus niger on pilot plant scale" published in Biotechnology and Bioengineering, Vol. XXIII, pp 2433-2445, 1981, describe the optimization of citric acid production on pilot scale with respect to the citric acid formation and minimization of the formation of waste products including said fermentation biomass.

Industrial waste is the by-product produced by industrial activity, which includes any material that is rendered useless during a manufacturing process of an industrial product such as that of citric acid biomass. In cases where the manufacturing plant has no practical use for the biomass, it should be discarded from the factory premises at a substantial cost.

The use of fermentation biomass from processes for preparing citric acid as feed product or as a raw material for isolation of chitin-glucan has been described in the literature in, e.g., International Patent Publication WO03/06882. This application describes, inter alia, a method of isolating cell wall derivatives from fungal or yeast biomass, e.g., chitin polymers or chitin-glucan copolymers. In another aspect, the invention relates to a method of preparing chitosan from chitin. This application further recites using chitin polymers, chitin -glucan copolymers or chitosan polymers for various applications. However, the application "as such" of Aspergillus niger whole biomass from various fermentation processes of citric acid or gluconic acid as a food ingredient for direct human consumption has never been described in the literature.

There is a need in the art for a method of using the whole biomass from fermentation processes of citric acid or gluconic acid "as such" for direct human consumption or as a functional food ingredient, which will enable improving food formulations with said biomass while serving as a low-fat and fiber-rich food supplement.

SUMMARY OF THE INVENTION

The present invention provides the direct use of whole bulk biomass of Aspergillus niger for human consumption in various food applications, e.g., the use of whole bulk biomass of Aspergillus niger from fermentation processes of citric acid or gluconic acid production as a food ingredient for human consumption in various food applications.

Said bulk biomass, which is the biomass formed during the fermentation of citric acid or gluconic acid by Aspergillus niger, is named herein "the biomass of the present invention".

According to a preferred embodiment, the biomass of the present invention, which consists of the mycelium of Aspergillus niger, is a novel food ingredient that is beneficial and safe for human consumption.

According to the present invention, the biomass produced during fermentation of carbohydrates by Aspergillus niger in the manufacture of citric acid or gluconic acid is subject to washing with water, e.g., to washing with hot water.

According to the present invention, the wet biomass produced during fermentation of various carbohydrates by Aspergillus niger in the manufacture of citric acid or gluconic acid includes non-soluble nutritional fibers consisting of glucoseamine polymer having chitin-glucan structure, which is a long-chain polymer of N- acetylglucosamine and long-chain polymer of d-glucose units to perform 1,3 beta glue an. According to another preferred embodiment of the present invention, said bulk biomass of Aspergillus niger can be used as it is without any chemical or physical pre- treatment, except for drying in certain cases, and without addition of additives or preservatives.

According to an aspect of the present invention, the use of said biomass in food formulations significantly improves the texture and viscosity such as thixotropy of the formulation. The biomass of the present invention can act as a thickening agent; it improves the texture and the stability of the formulation and therefore it assists in reducing the content of expensive stabilizers and thickening agents added to the formulation while enriching the formulation's content of non-soluble fibers, preventing water syneresis and improving the shelf life of certain foods.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides the direct use of whole bulk biomass of Aspergillus niger for human consumption in various food applications, e.g., the use of whole bulk biomass of Aspergillus niger from fermentation processes of citric acid or gluconic acid production for human consumption in various food applications.

Said bulk biomass, which is the biomass formed during the fermentation of citric acid or gluconic acid by Aspergillus niger, is named herein "the biomass of the present invention".

According to a preferred embodiment, the biomass of the present invention, which consists of the mycelium of Aspergillus niger, is a novel food ingredient that is beneficial and safe for human consumption.

According to the present invention, the biomass produced during fermentation of carbohydrates by Aspergillus niger in the manufacture of citric acid or gluconic acid is subject to washing with water, e.g., to washing with hot water.

According to the present invention, the wet biomass produced during fermentation of carbohydrates by Aspergillus niger in the manufacture of citric acid or gluconic acid includes non-soluble nutritional fibers consisting of glucoseamine polymer having chitin- glucan structure, which is a long-chain polymer of a N-acetylglucos amine and long-chain polymer of d- glucose units to perform 1,3 beta glucan.

According to another preferred embodiment of the present invention, said bulk biomass of Aspergillus niger can be used as it is without any chemical or physical pre- treatment, except for drying in certain cases, and without addition of additives or preservatives.

According to an aspect of the present invention, said wet biomass contains at least 5% of non-soluble nutritional fibers, preferably between 10% and 20% of non-soluble nutritional fibers.

According to another aspect of the present invention, said wet or dry biomass has low fat content and therefore it has low caloric value and in addition it includes high content of non-digestible nutritional fibers.

According to another aspect of the present invention, said biomass can absorb water easily and therefore application of additional shear force is not needed either before or after applying the biomass of the present invention into the food formulation.

According to another aspect of the present invention, said wet biomass contains between 1% and 4% of proteins, preferably between 1% and 2.5% of proteins.

According to another aspect of the present invention, said wet biomass can absorb water in a ratio of at least 1 ml water per 1 g of biomass, preferably, 9 ml of water per 1 g of biomass.

According to another aspect of the present invention, the use of said biomass in food formulations significantly improves the texture and thixotropy/viscosity of the formulation. The biomass of the present invention can act as a thickening agent; it improves the stability of the formulation even with higher water content, and therefore it assists in reducing the content of expensive ingredients such as stabilizers and thickening agents added to the formulation while enhancing the formulation's content of non-soluble fibers, preventing water syneresis and improving the shelf life of foods.

A fiber-rich food formulation has health benefits that include, inter alia, normalizing the bowel movements because dietary fibers increase the weight and si/e of the stool and decrease the chance of constipation. In addition, fiber-rich food formulations may assist in maintaining bowel health and may lower the risk of developing hemorrhoids and small pouches in the colon (diverticular disease). Furthermore, fiber-rich food formulations may assist in lowering cholesterol levels by lowering low-density lipoprotein, or "bad," cholesterol levels and may help also in controlling blood sugar levels by slowing the absorption of sugar and thus assisting in improving blood sugar levels. Furthermore, fiber-rich food formulations may assist in lowering the risk of intestinal inflammations.

Without wishing to be bound by any particular theory, it is assumed herein that maintaining stable formulation having constant and stable texture with adequate rheological properties is desirable in the field of food technology. The need to keep a stable formulation is specially needed in processed foods such as sauces, dressings and spreads. Relatively expensive ingredients, thickening agents and stabilizers such as hydrocolloids must be added to these product formulations to ensure constant stability and smooth texture of the formulation. Among these colloidal gums are included, e.g., guar gum, locust bean gum, carrageenan, Xanthan gum and the like. However, using gums to increase viscosity may result in poor texture and in addition, the safety of using some food additives that are used as stabilizers may be questionable.

The biomass of the present invention has high fibers content and it is therefore a good, natural and clean label solution to help reducing the costs of food formulations that need relatively large amounts of stabilizers. The biomass of the present invention has relatively large capability of absorbing water and therefore it may increase the formulation stability, e.g., stabilize emulsions and prevent syneresis (the extraction or expulsion of a liquid from a gel) without the additional use of stabilizers. Thus, by adding the biomass of the present invention to a food formulation, the thixotropic viscosity properties of the formulation are increased. By adding additional volume of water to the formulation and/or by using reduced quantity of relatively expensive ingredients such as stabilizers and thickening agents as well as other raw materials, a significant cost saving may be achieved.

According to some embodiments of the present invention, said biomass can be used to produce processed meat analogs selected from vegetarian hamburger, vegetarian sausage, vegetarian hot dog, vegetarian schnitzel, vegetarian chicken breast substitute, vegetarian meatloaf and the like.

According to another embodiment of the present invention, said biomass can be used as a filler and a source of dietary fibers to the food formulation in addition to adding substantial increase in bulkiness of the formulation and thus to a decrease in the overall cost of the food formulation.

The biomass of the present invention has high water absorbing and holding capacity that makes it most suitable for food products, which are solutions or emulsions having high content of water such as tomato based products including pizza sauce and ketchup, salad spreads such as humus, tahini spread, eggplant salad, cabbage salt, regular mayonnaise and light mayonnaise, thousand Island sauce, mustard and the like.

According to some embodiments of the present invention, said biomass can be used to produce vegetable dips or spreads such as vegetable sandwich spread, vegetable salad spread, cocktail spread and the like.

According to some embodiments of the present invention, said biomass can be used to produce bakery or baking products such as breads, biscuits, cakes, cookies, crackers, pastries, pies, rolls, savories and the like.

According to some embodiments of the present invention, said biomass can be used in the production of many types of sauces such as Thousand Island Sauce, French, Ranch or Italian Sauce, Caesar Salad Sauce, horseradish sauce and the like. According to some embodiments of the present invention, said biomass can be used to produce fruit preparations for dairy products such as yogurts, creams, processed cheeses, ice creams, toppings and the like.

According to some embodiments of the present invention, said biomass can be used to produce liquid soups and gravies, dried soups and gravies and the like.

EXAMPLES

The following examples further illustrate the invention but should not be construed as in any way limiting its scope.

EXAMPLE 1

This example demonstrates the preparation of low-cost ketchup sauce using the biomass of the present invention.

Sugar (20%), salt (2%) and onion powder (0.4%) were mixed together. Tomato concentrate 28-30° Bx (29%) and warm water (34.6%) at 70-80°C were added to a Thermomix blender and blended at law speed. The dry mixture of sugar, salt and onion powder was added while mixing. Then, the biomass of the present invention was added (10%) until a stable and homogenous texture was obtained. Mixing was continued and the temperature was raised to 85°C. The product was packed in a plastic bottle and cooled to ambient temperature. Same procedure was repeated without adding the biomass of the present invention but with higher amount of tomato concentrate 28-30° Bx (39%) and water was added to adjusted formulation to 100%, as "control".

EXAMPLE 2

This example demonstrates the preparation of low-cost pizza sauce using the biomass of the present invention.

Sugar (1.5%), salt (1.1%), citric acid (0.1%), onion powder (0.4%), garlic powder (0.3%), dry oregano (0.15%), black pepper (0.1%) and dry basil (0.1%) were mixed together. Water (63.75%) at 70-80°C was added to a Thermomix blender and blended at law speed. Tomato concentrate 28-30° Bx (22.5%) was added to the blender and blending was set to high speed followed by addition of the dry mixture of sugar, salt, onion powder, garlic powder, oregano, black pepper and basil while mixing. Then, the biomass of the present invention was added (10%) until a stable and homogenous texture was obtained. Mixing was continued and the temperature was raised to 85°C. The product was packed in a plastic bottle and cooled to ambient temperature. Same procedure was repeated with higher amount of tomato concentrate 28-30°Bx (30%) and water was adjusted to 100%, without adding the biomass of the present invention as "control".

EXAMPLE 3

This example demonstrates the preparation of low-cost "Thousand Island Sauce" using the biomass of the present invention.

Sugar (15%), salt (1.5%), potassium sorbate (0.1%) and onion powder (0.15 %) were mixed together. Water at ambient temperature (7.85%) was added to a Thermomix blender and blended at law speed. Then, the biomass of the present invention was added (15 %) until a stable and smooth texture was obtained. The mixture of sugar, salt, potassium sorbate and onion powder was then added. Tomato concentrate 28-30 ^Q Bx (5%) was added to the blender followed by addition of mustard (1.7%) and pasteurized egg yolk (1.2%) and blending was set to medium speed followed by addition of vinegar 5% (10.5%) while mixing. Canola oil (32%) was added until uniform texture was obtained. Mixing was continued at low speed and crashed pickled cucumber slices were added (10%) until good dispersion of the cucumbers was achieved. The product was packed in a plastic bottle. Same procedure was repeated without the biomass of the present invention but with addition of Xanthan gum (0.2 %), guar gum (0.1%), modified starch (3%) and water was added to adjust formulation to 100 % as "control".

EXAMPLE 4

This example demonstrates the preparation of low-cost tahini salad dressing using the biomass of the present invention.

Sodium benzoate (0.1%), potassium sorbate (0.1%), salt (0.9%), garlic powder (1%) were mixed together. Warm water (7.8 %) at 30°C was added to a Thermomix blender and blended at medium to high speed. Then, crude tahini paste was added (36%) and the biomass of the present invention was added (10%) until a stable and smooth texture was obtained. The dry mixture of sodium benzoate, potassium sorbate, salt and garlic powder was then added under constant mixing. Concentrated lemon juice (2.5 %) was added to the blender and mixing was continued to allow formation of smooth texture. The product was packed in a plastic bottle. Same procedure was repeated without the biomass of the present invention but with addition of higher amount of crude tahini (46%) Xanthan gum (0.3 %), guar gum (0.1%) and water was added to adjust formulation to 100% as "control".

EXAMPLE 5

This example demonstrates the preparation of low-cost humus salad dressing using the biomass of the present invention.

Sodium benzoate (0.1%), potassium sorbate (0.1%), salt (0.9%), garlic powder (0.5%) and citric acid (0.5%) were mixed on dry basis in a blender. Water (23.9%) at ambient temperature was added to a Thermomix blender and blended at medium to high speed. Then, the dry mixture of sodium benzoate, potassium sorbate, salt, garlic powder and citric acid was added while mixing and the biomass of the present invention was added (10%) until a stable and smooth texture was obtained. Then, cooked humus (50%) was added under constant high-speed stirring followed by addition of crude tahini paste (14%) and mixing was continued at high speed to allow formation of smooth texture. The product was packed in a plastic bottle. Same procedure was repeated without the biomass of the present invention but with addition of higher amount of cooked humus (68%) and tahini sauce (16%) and water was added to adjust formulation to 100 % as "control".

EXAMPLE 6

This example demonstrates the preparation of white bread containing 6% of the biomass of the present invention on dry basis.

Flour (1325 g), wet yeast (60 g), margarine (20 g), baking enhancer (19 g), sugar (20 g), gluten (18 g), biomass of the present invention (530 g) were mixed on dry basis in a mixer. Water (666 ml) was added to the mixer followed by adding salt (30 g), until the dough was well developed. Portions of 550g of dough were shaped to form pieces of bread. Then, the formed dough was proofed in a proofing room at a temperature of 28°C and humidity of 80% for about 60 minutes. The proofed pieces of dough were baked in rotating oven at 240-250°C for about 35 minutes. Same procedure was repeated without the biomass of the present invention as "control" using the following quantities: flour (1325 g), wet yeast (55 g), margarine (20 g), baking enhancer (19 g), sugar (18 g), salt (26 g), gluten (8.5 g) and water (725 ml). The following Table 1 summarizes the differences between the white bread containing the biomass of the present invention and the "control" bread that does not include the biomass of the present invention.

Table 1

EXAMPLE 7

This example demonstrates the preparation of light mayonnaise using the biomass of the present invention.

Xanthan gum (0.2%), sodium benzoate (0.1%), potassium sorbate (0.1%), salt (1.5%) and sugar (3%) were mixed on dry basis in a blender. Water (59.1%) at ambient temperature was added to a Thermomix blender and blended at low speed. Then, the dry mixture of Xanthan gum, sodium benzoate, potassium sorbate, salt and sugar was added while mixing and the biomass of the present invention was added (10%) until a stable and smooth texture was obtained. Then, pasteurized egg yolk (4%) was added under constant medium speed stirring followed by addition of 5% vinegar (7%) and vegetable oil (5%) and mixing was continued at medium speed to allow formation of smooth texture. The product was packed in plastic bottle. Same procedure was repeated without the biomass of the present invention using guar gum (0.3 %), Xanthan gum (0.5%) modified starch (3-6%) and water, which was added to adjust formulation to 100 % as "control".

EXAMPLE 9

This example demonstrates the differences in properties between humus salad dressing produced with and without adding the biomass of the present invention.

Humus salad dressing formulation (with addition of the biomass of the present invention) and "control" (without addition of the biomass of the present invention), were prepared as described in Example 5. The formulation containing said biomass and the control were monitored for 4 weeks and the results are detailed in Table 3 below.

Table 3

All references, including publications, patent applications and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety

All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein.

Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above- described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.