Method for processing wet pomace

Abstract

The invention relates to a method for processing depectinised or non-depectinised wet pomace with the aim of microbially stabilising the wet pomace and thus enabling storage or transport for further processing. The invention also relates to the use of microbially stabilised wet pomace for the production of plant fibres, preferably citrus fibres or apple fibres.

Description

[0001] Process for processing wet pomace

[0002] The present invention relates to a method for processing wet pomace with the aim of microbially stabilizing the wet pomace and thus enabling storage or transport for further processing. The invention also relates to the use of a microbially stabilized wet pomace for the production of pectin and / or plant fibers, preferably citrus fibers or apple fibers.

[0003] Background of the invention

[0004] Dietary fiber is a largely indigestible food component, usually carbohydrates, found primarily in plant-based foods. For simplicity, dietary fiber is divided into water-soluble fiber, such as pectin, and water-insoluble fiber, such as cellulose. Dietary fiber is considered an important component of the human diet.

[0005] The consumption of fiber is considered beneficial to health. The water-soluble fiber in food increases the volume of food without significantly increasing its energy content. If it is not sufficiently swollen before ingestion, it absorbs additional water in the stomach. The resulting increase in volume leads to an increased feeling of satiety. Furthermore, fiber prolongs the time the food stays in the intestine or stomach. Water-soluble fiber such as pectin binds bile acids from cholesterol metabolism in the intestine, thus leading to a lowering of cholesterol levels.

[0006] Soluble fiber, in particular, is thought to reduce glucose absorption, slow glucose adsorption and starch processing, and control postprandial glucose levels in serum. People who consume high amounts of fiber have a reduced risk of numerous lifestyle diseases, particularly obesity, high blood pressure, coronary heart disease (CHD), stroke, diabetes, and various gastrointestinal diseases. Accordingly, the German Nutrition Society (DGE) recommends a minimum of 30 g of fiber as a guideline for daily intake.

[0007] The use of functionalized plant fibers as dietary fiber in food production is becoming increasingly important. Apple and citrus fibers are particularly popular in this context. These plant fibers have the advantage of being a mixture of insoluble fibers such as cellulose and soluble fibers such as pectin, thus ideally providing the health-promoting spectrum of effects listed above. Through the use of these fibers, the functional properties of food products, for example, with regard to viscosity, emulsion formation, gel formation, dimensional stability, or texture, can be specifically optimized and adjusted. Accordingly, they can replace other less accepted or even harmful additives in food. As non-E-classified substances, they lead to simpler product labeling and thus increased product acceptance.

[0008] The starting material for the production of these functionalized plant fibers is non-depectinized pomace, and especially depectinized pomace. Pomace refers to the press residues from juice extraction, with particular use being made of the press residues from apple and citrus juice extraction. During pectin production, these pomace are digested, and the pectin they contain is extracted via acidic or alkaline hydrolysis. It is then precipitated from the extract by adding alcohol. The pomace that remains as a solid residue after this pectin extraction is called depectinized pomace.

[0009] This depectinized pomace is an advantageous starting material for the production of functionalized fibers for several reasons:

[0010] • Due to pectin extraction, the material is already broken down and is in fibrous form.

[0011] • Through depectinization, the very high pectin content in apple and citrus pulp is reduced to such an extent that the desired texturizing and stabilizing properties take precedence over the gelling properties.

[0012] • The residual pectin content of the depectinized pomace allows, with appropriate modification of the fiber production process, a targeted adjustment of physicochemical properties such as texturization, emulsifiability, stabilization or water binding.

[0013] • The depectinized pomace is actually a "waste material" from pectin production and can now be recycled through fiber production to produce a fiber-rich and therefore healthy food. This explains why depectinized pomace has become an important starting material for fiber production and has led to a corresponding industrial link between pectin production and fiber production.

[0014] This process coupling presents the industry with new challenges, as the depectinized pomace usually results in unstable wet pomace, which can no longer be further processed due to the relatively rapid onset of fermentation and / or mold infestation.

[0015] This problem is solved in the current state of the art by processing the pomace as quickly as possible. The disadvantage of this approach is that the production processes of pectin extraction and fiber production must be precisely coordinated. Due to its instability, long-distance transport of the depectinized pomace to other production sites is not possible.

[0016] Another solution is to dry the depectinized pomace. However, this is energy-intensive and therefore expensive, and it also requires hydration of the pomace during fiber production.

[0017] Numerous dried pomace products are known in the state of the art, which are mainly used as animal feed or for the production of ingredients such as pectin or functional plant fibers.

[0018] For example, agroFood Solution GmbH (Werder, Germany) markets a dried, finely ground apple pomace under the name “Herbavital AF Fein”, which is made from freshly harvested, juiced and gently dried apples.

[0019] Likewise, agroFood Solution GmbH (Werder, Germany) markets a dried, finely ground citrus pulp under the name “Herbavital CF Fein”, which is made from freshly harvested, de-oiled and gently dried citrus fruits.

[0020] There is therefore a need for processes that stabilize depectinized pomace and thus enable longer-term storage or transport.

[0021] The present invention is based on the object of improving the state of the art or offering an alternative to it. Summary of the invention

[0022] According to a first aspect of the present invention, the stated object is achieved by a method for processing pomace comprising the following steps: a) providing a pomace; b) microbial stabilization of the pomace by acidifying and / or sulfurizing the pomace; c) filling the microbially stabilized pomace into a container.

[0023] The process according to the invention results in a pomace that is sufficiently stable during storage and transport to enable subsequent processing for fiber production.

[0024] The process according to the invention can also be carried out in accordance with food law regulations, so that further processing into functionalized plant fibers is possible without any problems.

[0025] Furthermore, the pomace treated with the method according to the invention can be processed into functionalized plant fibers without impairing the functional properties of the final fiber product.

[0026] Even after application of the process according to the invention, the pomace is to be regarded as a natural ingredient with its known positive properties.

[0027] The process according to the invention can be easily integrated into existing industrial processes and can be widely used for all depectinized or non-depectinized pomace, i.e., independent of the plant starting material and the respective method for pectin extraction.

[0028] It can therefore be used for both apple and citrus pomace.

[0029] The invention in detail

[0030] In the process according to the invention, a pomace is provided in step a).

[0031] According to the invention, the term pomace encompasses both non-depectinized and depectinized pomace. For the purposes of the application, "non-depectinized pomace" refers to the residue resulting from the pressing of fruit, vegetables, or plant components whose pectin has not yet been specifically reduced by an industrial process. This particularly applies to the press residue from the production of apple juice, citrus juice, or carrot juice, whereby this press residue has not yet been used to extract pectin. The non-depectinized pomace of the invention is considered wet pomace, meaning it has not been subjected to a drying process.

[0032] In a special embodiment, the pomace is depectinized pomace.

[0033] For the purposes of this application, "depectinized pomace" refers to pomace whose pectin content has been deliberately reduced through an industrial process. This refers in particular to the solid, undried residue from pectin production, which is based on pomace as the starting material. The depectinized pomace of the invention is considered wet pomace, meaning it has not been subjected to a drying process.

[0034] In a preferred embodiment, the depectinized wet pomace is fresh pomace, meaning that the depectinized wet pomace is provided within one day or 12 hours, 6 hours, 3 hours, or 2 hours after separation of the liquid pectin extract. Alternatively, the depectinized wet pomace can also be provided within 2 days after separation of the liquid pectin extract.

[0035] In step b), the pomace prepared in step a) is then microbially stabilized, preferably depectinized. This ensures that the pomace does not ferment or mold. The availability of water, carbohydrates, and proteins makes the pomace an attractive substrate for microorganisms, which can colonize it and impair or even prevent its further use in the food sector. Microbially induced spoilage is associated with several problems: the risk of growth of pathogenic microorganisms, the depletion of important ingredients, and ultimately the production of toxic substances due to fungal infestation.

[0036] After microbial stabilization in step b), the microbially stabilized pomace is filled into a container according to step c). This filling process reduces the risk of contamination and makes the pomace suitable for storage and transport. It should be clarified that microbially stabilized pomace is microbially stabilized wet pomace. Starting with a depectinized or non-depectinized wet pomace as the starting material, which is provided in step a) of the process, the wet pomace is microbially stabilized using the measures from step b) and filled as wet pomace in step c).

[0037] The process according to the invention therefore produces microbially stabilized wet pomace. This arises solely from the underlying technical problem, which only arises for wet pomace, not for dried pomace.

[0038] The process according to the invention is based on chemical methods for microbial stabilization (optionally combined with surface post-treatment) and thus does not require a drying step for pomace stabilization. As previously described, the chemical microbial stabilization according to the invention has proven to be an advantageous alternative to energy-intensive drying, which also requires hydration for further processing. Furthermore, it has been shown that the functional properties of a fiber are significantly worse when using dried pomace instead of wet pomace as the starting material.

[0039] In a preferred embodiment, the pomace provided in step a) is selected from the group consisting of citrus pomace, apple pomace, sugar beet pomace, carrot pomace, and pea pomace. This pomace can be either a non-depectinized pomace or a depectinized pomace. Preference is given to using a depectinized pomace selected from the group consisting of citrus pomace, apple pomace, sugar beet pomace, carrot pomace, and pea pomace.

[0040] Citrus fruits and preferably citrus processing residues are used as raw materials for the citrus pomace. Accordingly, citrus peel—and here preferably citrus albedo and / or citrus flavedo—can be used as raw materials in the process according to the invention. The raw material used is preferably citrus pomace, i.e., the press residues of citrus fruits, which typically also contain the pulp in addition to the peel, or citrus pulp, i.e., the residues from the juice production industry, which contain the pectin and cellulose material of the inner, juice-containing part of the respective citrus fruit. All citrus fruits known to the person skilled in the art can be used as citrus fruits.The following are examples, not limited to: Mandarin (Citrus reticulata), Clementine (Citrus x aurantium Clementine group, syn.: Citrus Clementina), Satsuma (Citrus x aurantium Satsuma group, syn.: Citrus unshiü), Mangshan (Citrus mangshanensis), Orange (Citrus x aurantium Orange group, syn.: Citrus sinensis), Bitter orange (Citrus x aurantium Bitter orange group), Bergamot (Citrus x limon Bergamot group, syn.: Citrus bergamiä), Pomelo (Citrus maxima), Grapefruit (Citrus *aurantium Grapefruit group, syn.: Citrus paradisi), Pomelo (Citrus x aurantium Pomelo group), True lime (Citrus x aurantii folia), Common lime (Citrus x aurantiifolia, syn.: Citrus latifoliä), kaffir lime (Citrus hystrix), Rangpur lime (Citrus x jambhiri), lemon (Citrus x limon, lemon group), citron (Citrus medicä), and kumquats (Citrus japonica, syn.: Fortunellä). Preferred are oranges (Citrus x aurantium, orange group, syn.: Citrus sinensis) and the lemon (Citrus x limon lemon group).

[0041] Apple pomace can be obtained from all cultivated apples (Malus domesticus) known to the expert. Apple processing residues can advantageously be used as the starting material. Accordingly, apple peel, core, seeds, or pulp, or a combination thereof, can be used as the starting material. The preferred starting material is apple pomace, i.e., the pressing residues of apples, which typically contain the above-mentioned components in addition to the peel.

[0042] Sugar beet pomace is made from sugar beet (Beta vulgaris subsp. vulgaris) as the raw material. During sugar production, the raw juice from sugar beet pulp is leached by hot water in an extraction tower using a countercurrent process and the diffusion process, thus extracting 99% of the sucrose. The diffusion process produces the leached pulp as a byproduct, which is mechanically pressed in pulp presses to approximately 30-34% dry matter, thus forming sugar beet pomace.

[0043] Carrot pomace is produced during the production of carrot juice. It is a press residue from juice production and is a nutrient-rich and vitamin-rich biomaterial with high carotene content. The carrot (Daucus carota) is a plant species in the carrot family (Apiaceae). Several subspecies are distinguished. The carrot (Daucus carota subsp. sativus), also called garden carrot, turnip, yellow turnip, or root, is a cultivated form of the wild carrot (Daucus carota subsp. carota).

[0044] Pea pomace is pomace made from pea shells. Pea shells have a high pectin content of approximately 16% and are also suitable for the production of functional fibers. Since shell components make up to 10% of peas, depending on the variety, the use of this byproduct can increase resource efficiency and the market value of peas. For the purposes of this invention, the term "pea" refers to the pea (Pisum sativum), also known as the garden pea or table pea.

[0045] In a preferred embodiment, the pomace provided according to step a), which is preferably depectinized pomace, is a wet pomace. The wet pomace preferably has a dry matter content of 5 to 25% dry substance (DS). The pomace can have a dry matter content of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24% DS. A pomace with such a dry matter content has an advantageous consistency with regard to microbial stabilization, insofar as the chemicals used for acidification or sulfurization can be easily stirred in.

[0046] The depectinized pomace preferably used in the process according to the invention can be produced by any method known to the person skilled in the art. Thus, the pomace provided in step a) can be the result of depectinization by enzymatic treatment, by digestion in an alkaline medium, or by digestion in an acidic medium. Digestion in an acidic medium is preferred.

[0047] The depectinized wet pomace has a reduced pectin content due to the depectinization process. This is preferably measured as the water-soluble pectin content of the total dry matter of the wet pomace. The depectinized wet pomace can have a water-soluble pectin content of 2 wt% to 14 wt%, preferably of 2 wt% to 10 wt%, and particularly preferably of 2 to 8 wt%. The content of water-soluble pectin in the depectinized wet pomace can be, for example, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 8 wt%, 8 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, or 12 wt%.

[0048] Based on the total mass of the depectinized wet pomace, this results in a water-soluble pectin content of approximately 0.9 to 1.6 wt.%. In one embodiment of the invention, the microbial stabilization of the pomace in step b) is achieved by sulfurizing the pomace. Sulfurizing is a preservation method used particularly for wine. Sulfurizing (also known as sulfurization) is a method in which sulfur dioxide, or the sulfite formed in an aqueous solution, acts as a preservative. The SO2 physically dissolved in the water has an antimicrobial and enzyme-deactivating effect, and the bisulfite ion can reduce previously oxidized components of the pomace and can also be oxidized itself by free oxygen, thus protecting the pomace from oxidation.

[0049] The sulphurisation carried out in step b) in the process according to the invention can be carried out by all sulphurisation processes known to the person skilled in the art.

[0050] In a preferred embodiment of the invention, the sulphurization of the pomace, which is preferably a depectinized pomace, is carried out in step b) by adding a sulphur compound to the pomace, wherein the sulphur compound is selected from the group consisting of potassium disulphite, liquefied SO2, sulphurous acid, sodium sulphite, and sodium hydrogen sulphite.

[0051] The use of a sulfite salt is particularly preferred, and in this case, sodium sulfite is particularly preferred. Sodium sulfite serves as a preservative and antioxidant for food (additive number E221).

[0052] In a preferred embodiment, the sulphurization of the pomace, which is preferably a depectinized pomace, is carried out in step b) either by adding an aqueous sodium sulphite solution to the pomace in step b) while mixing with the pomace or by adding solid sodium sulphite to the pomace.

[0053] The aqueous sodium sulfite solution preferably contains between 10 and 20 wt% sodium sulfite. The sodium sulfite solution can accordingly contain 11, 12, 13, 14, 15, 16, 17, 18, or 19 wt% sodium sulfite.

[0054] The solid sodium sulfite is preferably used in powder form to enable fine distribution in the pomace to achieve a homogeneous sulfite content.

[0055] The pomace, which is preferably depectinized pomace, preferably has a sulfite content of between 50 and 5000 ppm, preferably between 100 and 2500 ppm, and particularly preferably between 200 and 1000 ppm, due to the sulfurization in step b). A sulfite content in this range is capable of sufficiently microbially stabilizing the pomace without compromising its subsequent use in the food sector.

[0056] In a preferred embodiment, the microbial stabilization of the pomace, which is preferably a depectinized pomace, is carried out in step b) by acidifying the pomace to a pH of between 1.0 and 4.0, preferably between 1.0 and 3.0, particularly preferably between 1.1 and 2.5, and especially preferably between 1.2 and 2.0. The pH value of the acidified pomace can therefore be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.8 or 3.9.

[0057] Acidification can be achieved with an organic acid, a mineral acid, or a buffer solution. The depectinized pomace is preferably acidified with an organic acid, preferably selected from the group consisting of formic acid, acetic acid, and citric acid. Organic acids not only preserve the wine through pH adjustment, but the anion itself also exhibits bacteriostatic properties. Among mineral acids, hydrochloric acid, sulfuric acid, or nitric acid are preferred.

[0058] If citric acid is used, it can also be used in powder form to prevent dilution of the wet pomace. The microbial stabilization of the pomace, which is preferably depectinized pomace, in step b), whether by sulfurization or acidification, can take place at a temperature of between 20°C and 85°C, preferably between 40°C and 80°C, and particularly preferably between 50°C and 75°C. The temperature can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, or 75°C, respectively. At such elevated temperatures, sulfurization or acidification is particularly effective.

[0059] The pomace microbially stabilized in step b), which is preferably depectinized pomace, is filled into a container in the subsequent step b). Filling in step c) can take place at a temperature of between 20°C and 85°C, preferably between 40°C and 80°C, and particularly preferably between 50°C and 75°C. The temperature can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, or 75°C, respectively. Filling with appropriately heated pomace reduces the risk of recontamination, and the pomace has a lower viscosity and is therefore easier to fill. Preferably, both the microbial stabilisation of the pomace, which is preferably a depectinised pomace, in step b) and the bottling according to step c) take place in the temperature ranges described above.

[0060] During microbial stabilization by sulfurization or acidification, an antioxidant can also be added. This is particularly beneficial for colored pomace, such as carrot pomace, to counteract discoloration caused by oxidation. Examples of antioxidants are: Lactic acid (E 270), Ascorbic acid (E 300), Sodium L-ascorbate (E 301), Calcium L-ascorbate (E 302), Ascorbic acid esters (E 304), Tocopherol (E 306), Alpha-tocopherol (E 307), Gamma-tocopherol (E 308), Delta-tocopherol (E 309), Propyl gallate (E 310), Octyl gallate (E 311), Dodecyl gallate (E 312), Isoascorbic acid (E 315), Sodium isoascorbate (E 316), Tertiary butylhydroquinone (TBHQ) (E 319), Butylhydroxyanisole (E 320), Butylhydroxytoluene (E 321), Lecithin (E 322), Citric acid (E 330), sodium citrate (E 331), potassium citrate (E 332), calcium disodium EDTA (E 385), diphosphates (E 450), disodium diphosphate (E 450a), trisodium diphosphate (E 450b),Tetrasodium diphosphate (E 450c), dipotassium diphosphate (E 450d), tripotassium diphosphate (E 450e), dicalcium diphosphate (E 450f), calcium dihydrogen diphosphate (E 450g), triphosphates (E 451), pentasodium triphosphate (E 451a), pentapotassium triphosphate (E 451b), polyphosphate (E 452), sodium polyphosphate (E 452a), potassium polyphosphate (E 452b), sodium calcium polyphosphate (E 452c), calcium polyphosphate (E 452d) and combinations thereof.

[0061] Ascorbic acid and its salts are particularly preferred as antioxidants.

[0062] The container used for filling in step c) is suitably suitable for acidic and hot foods and preferably has one or more of the following properties:

[0063] • It can be closed with a lid, which reduces the risk of contamination.

[0064] • It is stackable, allowing easy storage and efficient transport.

[0065] • It has a volume of 0.5 to 2 m 3 With such a volume, the pomace is still easy to transport (e.g., on a Euro pallet) and is also suitable for large-scale industrial processing.

[0066] • The container can also be designed as a dump truck, allowing for easy emptying (e.g., into a reaction vessel for subsequent fiber production). The container can be designed so that it can be picked up from all four sides using industrial trucks. This facilitates transport and storage. Pallet trucks or forklifts are preferred industrial trucks.

[0067] The microbially stabilized pomace, which is preferably depectinized pomace, filled into a container according to step c), can also be subjected to a post-treatment for further microbial stabilization. This post-treatment is intended, in particular, to further microbially stabilize the surface of the filled pomace, as this compartment is particularly susceptible to colonization by microorganisms.

[0068] According to one embodiment, this post-treatment can be carried out by smoothing the surface of the freshly bottled depectinized pomace. This simple method reduces the surface area of ​​the pomace and thus also the risk of contamination.

[0069] According to a further embodiment, the post-treatment can be carried out by treating the surface of the freshly bottled pomace, which is preferably depectinized pomace, with a preservative. This allows the surface, as the particularly vulnerable compartment, to be specifically treated without introducing large amounts of preservative into the pomace. As a result, the pomace is only minimally altered, and the preservative is also used sparingly.

[0070] In a preferred embodiment, both post-treatment methods are used together—that is, smoothing the surface and treating it with a preservative. This can conveniently be achieved by simultaneously applying the preservative to the surface using the tool used to smooth the surface, for example, a squeegee or a bristle.

[0071] Numerous preservatives are known to the person skilled in the art, and they can select them accordingly, taking into account the pomace, which is preferably depectinized pomace, and its further processing. The preservative is preferably a food additive, which is particularly preferably selected from the group consisting of ethanol, isopropanol, sorbic acid (E200), sodium sorbate, potassium sorbate (E202), calcium sorbate (E203), 4-

[0072] Heptyl hydroxybenzoate, benzoic acid (E210), sodium benzoate (E211), potassium benzoate (E212), calcium benzoate (E213), ethyl 4-hydroxybenzoate (E214), ethyl 4-hydroxybenzoate sodium (E215), propyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate sodium, methyl 4-hydroxybenzoate (E218), methyl 4-hydroxybenzoate sodium (E219), sodium sulfite (E211), sodium hydrogen sulfite (E222), sodium metabisulfite (E223), potassium metabisulfite (E224), calcium metabisulfite, calcium hydrogen sulfite (E227), potassium hydrogen sulfite (E228), biphenyl, orthophenylphenol, sodium orthophenylphenol, thiabendazole, nisin (E234), natamycin (E235), formic acid, sodium formate, potassium formate, hexamethylenetetramine (E239), formaldehyde, gum guaicum, dimethyl carbonate (E242), ethyl lauroyl arginate (E243), acetic acid (E260), potassium acetate (E261), sodium acetate (E262), ammonium acetate, dehydroacetic acid, sodium dehydroacetate, lactic acid (E270), propionic acid (E280), sodium propionate (E281),Calcium propionate (E282) and potassium propionate (E283) or any combination thereof.

[0073] Preferred preservatives are isopropanol and ethanol. These are highly antimicrobial and inexpensive, and can be easily sprayed on as liquids (preferably as aqueous ethanol or isopropanol solutions). They are also often used in the subsequent pectin or fiber production process, so their presence is not disruptive in subsequent processes.

[0074] The preservative can be used as a solution or dispersion, with water, an aqueous solution or an alcohol being preferred as the solvent or dispersant.

[0075] The preservative can also be used in its pure form, and depending on its physical state, in liquid or solid form. For liquid preservatives (such as alcohols), application by spraying is preferred; for solid preservatives, sprinkling with a powdered preservative is recommended.

[0076] In an advantageous embodiment, the preservative is sprayed as a solution or dispersion onto the surface of the bottled depectinized pomace during the treatment.

[0077] In a further aspect, the invention relates to the use of the microbially stabilized depectinized pomace produced according to one of the preceding claims for the production of plant fibers. Preference is given to the production of citrus fibers or apple fibers. In a further aspect, the invention relates to the use of the microbially stabilized non-depectinized pomace produced according to one of the preceding claims for the production of pectin or for the production of plant fibers. Preference is given to the production of citrus pectin or apple pectin, or the production of citrus fibers or apple fibers.

[0078] Definitions

[0079] Citrus fiber, according to the application, is a predominantly fiber component isolated from a non-woody plant cell wall of a citrus fruit and consisting primarily of cellulose. The term "fiber" is somewhat misnomer because citrus fibers do not appear macroscopically as fibers, but rather as a powdered product. Other components of citrus fiber include hemicellulose and pectin.

[0080] According to the application, "wet pomace" is defined as pomace that has not been subjected to any drying process and therefore still contains a high proportion of watery liquid. The wet pomace therefore has a low dry matter content, preferably corresponding to a dry matter content of 5 to 25% dry matter (DM). Therefore, the wet pomace is not dried pomace.

[0081] A pectin according to the application is defined as a plant polysaccharide which, as a polyuronide, consists essentially of α-1,4-glycosidically linked D-galacturonic acid units. The galacturonic acid units are partially esterified with methanol. The degree of esterification describes the proportion of carboxyl groups in the galacturonic acid units of the pectin that are present in esterified form, e.g., as methyl esters.

[0082] At this point, it should be explicitly pointed out that features of the solutions described above or in the claims and / or figures can also be combined if necessary in order to be able to implement or achieve the explained features, effects and advantages accordingly in a cumulative manner.

[0083] It should also be expressly pointed out that, in the context of this patent application, indefinite articles and numerical expressions such as “one”, “two”, etc. are generally to be understood as “at least” expressions, i.e. as “at least one...”, “at least two...”, etc., unless it is expressly clear from the respective context or it is obvious or technically necessary for the person skilled in the art that only “exactly one...”, “exactly two...”, etc. can be meant.

[0084] Further advantages, special features and expedient developments of the invention emerge from the subclaims and the following representation of preferred embodiments with reference to the figures.

[0085] Examples of implementation

[0086] The embodiments shown here are merely examples of the present invention and should therefore not be considered limiting. Alternative embodiments contemplated by those skilled in the art are equally encompassed within the scope of the present invention.

[0087] 1. Determination of the properties of functional carrot fibers depending on the preservation method

[0088] In the present experiment, a non-depectinized carrot pomace was comparatively microbially stabilized as follows:

[0089] Batch 1 : Potassium sorbate with 0.2 wt% final concentration (pH = 4.25)

[0090] Preparation 2: Acetic acid with 1% w / w final concentration (pH = 3.85)

[0091] Approach 3: Sodium sulfite with 1800 ppm final concentration (pH= 5.93)

[0092] The pomace was preserved as described above and then stored in an air-filled bag at room temperature for 5 days. The pomace was pressed. Subsequently, 100 g of the pomace (approx. 12% dry matter) was diluted 1:1 with water. The suspension was mixed with twice the amount of IPA, and the pH was adjusted to less than 4.0 with HNO3. The mixture was then incubated overnight at 60°C and washed twice with one liter of 70% IPA and once with one liter of 90% IPA. The sample was then dried in a drying cabinet at 60°C and ground using a Retsch mill with a 500 μm insert. The resulting fibers were analyzed for taste, odor, color, and water binding. Results and Discussion:

[0093] The results are shown in the following table:

[0094] Table 1 : Properties of carrot fibers produced from differently preserved non-depectinized carrot pomace.

[0095] Of the three substances tested, sodium sulfite is the most suitable for preserving non-depectinized carrot pomace, as it preserves the pomace's color (visual inspection, results not shown here). Potassium sorbate and acetic acid produce a noticeable darkening of the pomace color, which also persists into the final product (visual inspection, results not shown here). With an additional dose of ascorbic acid (0.1% based on wet pomace), the browning can be reduced but not completely prevented.

[0096] After five days, all of the preserved pomace smelled more or less like old carrot salad. None of the pomace smelled spoiled. The functional carrot fibers produced from them were all sensorially sound.

[0097] The functional properties of fibers made from pomace preserved with potassium sorbate are noticeably weaker than those made with acetic acid and sodium sulfite. These fibers exhibit poorer water binding and lower viscosity.

[0098] If carrot pomace is microbially contaminated, the functional properties of the carrot fibers produced from it also decrease very quickly. In a laboratory experiment, microbially contaminated dry carrot pomace was treated with 3 x 10 6 Germs per g of pomace were processed into functional fibers using conventional methods. The resulting carrot fiber had a water binding capacity of only 16 g / g (experiment: LB 159 / 2014-W by Herbstreith & Fox; detailed results not shown here).

[0099] Summary:

[0100] Acetic acid (possibly with added ascorbic acid) is a possible alternative to sodium sulfite. However, disadvantages such as a lower L value in the finished carrot fiber must be considered. Potassium sorbate, on the other hand, cannot be recommended, as it also reduces the functional properties of the carrot fiber.

[0101] 2. Determination of the storage stability of depectinized citrus pulp (CNT) in transport boxes

[0102] Implementation:

[0103] The depectinized citrus pulp (CNT) is packaged in plastic boxes, each containing approximately 600 kg of CNT with a dry matter content of 15%. The depectinized citrus pulp (CNT) was acidified to a pH of 1.5 during production, and the surface was smoothed after filling.

[0104] Three boxes were tested comparatively, with the surface of box 3 also being sprayed with IPA. The boxes were then stored in an unheated warehouse at an outside temperature of approximately 12°C. The first visible appearance of mold clusters serves as detection of microbial spoilage.

[0105] Results and discussion:

[0106] The results are shown in the following table:

[0107] Table 1: Storage stability of depectinized CNT depending on pH acidification, surface structure and application of IPA.

[0108] The combination of smoothing the surface and maintaining a pH value of 1.5 allows for mold-free storage for up to 5 days. An additional spray of the surface with isopropanol increases stability by an additional 2 days. Overall, the growth rate and spread of the mold was noticeably slow, so that even after almost 2 weeks of storage, the surface was only affected by isolated pockets of mold.

[0109] 3. Determination of the storage stability of depectinized citrus pulp (CNT) in transport boxes under the influence of the surface texture

[0110] Implementation:

[0111] The depectinized citrus wet pomace (CNT) is packaged in plastic boxes, each containing approximately 500 kg of CNT with a dry matter content of 14%. The packaging process results in a crumbly pomace surface, which was not treated in control experiment 1. Experiments 2 to 4 were treated as follows, with the treatment taking place 3 days after filling the boxes:

[0112] VA2: Smoothing the surface A3: Spraying the surface with isopropanol (1 liter per box using a horticultural sprayer)

[0113] VA4: Smooth the surface and spray with isopropanol (= combination of VA2 and VA3).

[0114] The boxes were then stored in an unheated warehouse at an outside temperature of approximately 12 °C.

[0115] The visible appearance of mold nests serves as a detectable endpoint of microbial spoilage.

[0116] Results and discussion:

[0117] The results are shown in the following table: Table 1 : Storage stability of depectinized CNT depending on the surface structure and application of IPA.

[0118] Smoothing the surface leads to a 50% increase in stability from 6 to 9 days until the first mold growth. Spraying with isopropanol protects the CNT from mold for up to 10 days, and combining it with smoothing increases stability by an additional day.

[0119] 4. Preparation of a 2.5 wt% fiber dispersion

[0120] Recipe:

[0121] 2.50 g carrot fiber

[0122] 97.5 g demineralized water (room temperature) Littering time: 15 seconds

[0123] The required amount of demineralized water (room temperature) is placed in a 250 ml beaker. The precisely weighed amount of fiber is slowly sprinkled directly into the agitator's suction while the stirrer (Ultra Turrax) is running at 8000 rpm (speed 1). The sprinkling time depends on the amount of fiber; it should last 15 seconds per 2.5 g of sample. The dispersion is then stirred for exactly 60 seconds at 8000 rpm (speed 1). If the sample is to be used for viscosity determination, it is placed in a temperature-controlled water bath at 20°C.

[0124] To measure viscosity, the sample is carefully poured into the rheometer's measuring system after exactly 1 hour, and the respective measurement is started. If the sample settles, it is gently stirred with a spoon immediately before filling. 5. Test method for determining water-binding capacity

[0125] The sample is allowed to swell with excess water for 24 hours at room temperature. After centrifugation and subsequent decantation of the supernatant, the water binding capacity can be determined gravimetrically in g H2O per g sample. The pH value of the suspension must be measured and recorded.

[0126] The following parameters must be observed:

[0127] Sample weight:

[0128] Carrot fiber: 1.0 g (in centrifuge tube)

[0129] - Added water: 60 ml

[0130] - Centrifugation: 4000 xg

[0131] - Centrifugation time 10 min

[0132] 20 minutes after centrifugation begins (or 10 minutes after centrifugation ends), separate the supernatant water from the swollen sample. The sample with the bound water is weighed.

[0133] The water binding capacity (WBV) in g H2O / g sample can now be calculated using the following formula:

[0134] Sample with bound water (g) - 1.0 g

[0135] WBV (g H2O / g sample) = -

[0136] 1.0 g

[0137] 6. Test method for determining viscosity

[0138] A 2.5 wt% fiber dispersion prepared according to method 4 is used as the test sample.

[0139] Measuring device: Physica MCR series (e.g. MCR 301, MCR 101)

[0140] Measuring system: Z3 DIN or CC25

[0141] (Note: The Z3 DIN and CC25 measuring systems are identical measuring systems)

[0142] Number of sections: 4 Measurement parameters:

[0143] Section 1:

[0144] Section settings: - Default size: Shear rate [s -1

[0145] - Profile: constant

[0146] - Value: 0 s' 1

[0147] - Section duration: 60 s

[0148] - Temperature: 20 °C

[0149] 2. Section: Section settings: - Default size: Shear rate [s -1

[0150] - Profile: Ramp lin

[0151] - Value: 0.1 - 100 s' 1

[0152] - Section duration: 120 s

[0153] - Temperature: 20 °C

[0154] Section 3:

[0155] Section settings: - Default size: Shear rate [s -1

[0156] - Profile: constant

[0157] - Value: 100 s' 1

[0158] - Section duration: 10 s

[0159] - Temperature: 20 °C

[0160] Section 4:

[0161] Section settings: - Default size: Shear rate [s -1

[0162] - Profile: Ramp lin

[0163] - Value: 100 - 0.1 s' 1

[0164] - Section duration: 120 s

[0165] - Temperature: 20 °C Evaluation:

[0166] The viscosity (unit [mPas]) is read as follows: 4th section at = 50 s 1 7. Test method for determining color and brightness

[0167] The color and brightness measurements are performed using the Minolta Chromameter CR 300 or CR 400. The spectral properties of a sample are determined using standard color values. The color of a sample is described by its hue, brightness, and saturation. These three basic properties allow the color to be represented three-dimensionally:

[0168] The hues lie on the outer surface of the color solid, brightness varies along the vertical axis, and saturation levels run horizontally. When using the L*a*b* measurement system (pronounced L-star, a-star, b-star), L* represents brightness, while a* and b* indicate both hue and saturation. a* and b* indicate positions on two color axes, with a* representing the red-green axis and b* the blue-yellow axis. For color measurement displays, the device converts the standard tristimulus values ​​into L*a*b* coordinates.

[0169] Carrying out the measurement:

[0170] The sample is sprinkled onto a white sheet of paper and leveled with a glass stopper. For measurement, the chromameter's measuring head is placed directly on the sample and the trigger is pressed. Triplicate measurements are taken for each sample, and the average is calculated. The L*, a*, and b* values ​​are displayed by the instrument to two decimal places.

[0171] 8. Test method for the determination of water-soluble pectin in pomace samples

[0172] Through aqueous extraction, the pectin contained in pomace samples is transferred to the liquid phase. By adding alcohol, the pectin is precipitated from the extract as an alcohol-insoluble substance (AIS).

[0173] Extraction:

[0174] Weigh 10.0 g of the sample to be tested into a glass dish. 390 g of boiling distilled water are placed in a beaker, and the previously weighed sample is stirred for 1 minute at the highest speed using an Ultra-Turrax.

[0175] The sample suspension, cooled to room temperature, is divided into four 150 ml centrifuge beakers and centrifuged for 10 min at 4000 x g. The supernatant is collected. The sediment from each beaker is resuspended with 50 g of distilled water and centrifuged again for 10 min at 4000 x g. The supernatant is collected, and the sediment is discarded.

[0176] The combined centrifuges are placed in approximately 4 l of isopropanol (98%) to precipitate the alcohol-insoluble substance (AIS). After 1 h, the solution is filtered through a filter cloth and the AIS is manually pressed. The AIS is then placed in approximately 3 l of isopropanol (98%) in the filter cloth and loosened manually while wearing gloves.

[0177] The pressing process is repeated, the AIS is quantitatively removed from the filter cloth, loosened and dried at 60 °C for 1 hour in a drying cabinet.

[0178] The pressed, dried substance is weighed to 0.1 g to calculate the alcohol-insoluble substance (AIS).

[0179] Calculation:

[0180] The calculation of the water-soluble pectin based on the fiber-containing sample is carried out using the following formula, where the water-soluble pectin is obtained as an alcohol-insoluble substance (AIS): AIS fal x 100 scale in g

Claims

Patent claims 1 . A method for processing pomace, comprising the following steps: a) providing a pomace; b) microbially stabilizing the pomace by acidifying and / or sulfurizing the pomace; c) filling the microbially stabilized pomace into a container.

2. Process according to claim 1, characterized in that the pomace in step a) is selected from the group consisting of citrus pomace, apple pomace, sugar beet pomace, carrot pomace and pea pomace.

3. Process according to claim 1 or 2, characterized in that the pomace in step a) is a wet pomace which preferably has a dry matter content of between 5 and 25% TS.

4. A process according to any one of the preceding claims, characterized in that the pomace provided in step a) is a non-depectinized pomace or a depectinized pomace.

5. A process according to claim 4, characterized in that the depectinized pomace in step a) is the result of depectinization by enzymatic treatment, by digestion in an alkaline medium or by digestion in an acidic medium.

6. Process according to one of the preceding claims, characterized in that the microbial stabilization of the pomace in step b) is carried out by sulfurizing the pomace.

7. A process according to claim 6, characterized in that the sulfurization is carried out by adding a sulfur compound to the pomace, wherein the sulfur compound is selected from the group consisting of potassium disulfite, liquefied SO2, sulfurous acid, sodium sulfite, and sodium hydrogen sulfite.

8. Process according to claim 7, characterized in that the sulphurization of the pomace in step b) is carried out by: i. Adding an aqueous sodium sulfite solution to the pomace in step b) while mixing with the pomace, preferably by means of an aqueous sodium sulfite solution containing between 10 and 20 wt% sodium sulfite; or ii. Adding solid sodium sulfite to the pomace.

9. Process according to claims 6 to 8, characterized in that the sulfurization in step b) produces a pomace having a sulfite content of between 50 and 5000 ppm, preferably between 100 and 2500 ppm, and particularly preferably between 200 and 1000 ppm.

10. Process according to one of the preceding claims, characterized in that the microbial stabilization of the pomace in step b) is carried out by acidifying the pomace to a pH of between 1.0 and 3.0, preferably between 1.1 and 2.5, and particularly preferably between 1.2 and 2.

0.

11. A method according to claim 10, characterized in that an acid selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, formic acid, acetic acid and citric acid is used to acidify the pomace.

12. Process according to one of the preceding claims, characterized in that the microbial stabilization in step b) and / or the filling in step c) takes place at a temperature of between 20°C and 85°C, preferably between 40°C and 80°C, and particularly preferably between 50°C and 75°C.

13. Method according to one of the preceding claims, characterized in that the container is suitable for acidic and hot foods, and preferably has one or more of the following properties: i. Closable with a lid; ii. Stackable; iii. Volume of 0.5 to 2 m 3 ; iv. Represents a dump truck; v. Can be picked up from all four sides by industrial trucks.

14. Method according to one of the preceding claims, characterized in that the microbially stabilized product filled into a container according to step c) Pomace is subjected to post-treatment for further microbial stabilization.

15. A method according to claim 14, characterized in that the after-treatment is carried out by smoothing the surface of the freshly filled pomace.

16. A method according to claim 14 or 15, characterized in that the after-treatment is carried out by treating the surface of the freshly filled pomace with a preservative.

17. The method according to claim 16, characterized in that the preservative is preferably a food additive, which is particularly preferably selected from the group consisting of ethanol, sorbic acid (E200), sodium sorbate, potassium sorbate (E202), calcium sorbate (E203), 4-hydroxybenzoic acid heptyl ester, benzoic acid (E210), sodium benzoate (E211), potassium benzoate (E212), calcium benzoate (E213), 4-hydroxybenzoic acid ethyl ester (E214), sodium 4-hydroxybenzoic acid ethyl ester (E215), 4-hydroxybenzoic acid propyl ester, sodium 4-hydroxybenzoic acid propyl ester, 4-hydroxybenzoic acid methyl ester (E218), sodium 4-hydroxybenzoic acid methyl ester (E219), sodium sulfite (E211), sodium hydrogen sulfite (E222), sodium disulfite (E223), potassium bisulfite (E224), calcium bisulfite, calcium hydrogen sulfite (E227), potassium hydrogen sulfite (E228), biphenyl, orthophenylphenol, sodium orthophenylphenol, thiabendazole, nisin (E234), natamycin (E235), formic acid, sodium formate, potassium formate,Hexamethylenetetramine (E239), formaldehyde, gum guaicum, dimethyl carbonate (E242), ethyl laureth arginate (E243), acetic acid (E260), potassium acetate (E261), sodium acetate (E262), ammonium acetate, dehydroacetic acid, sodium dehydroacetate, lactic acid (E270), propionic acid (E280), sodium propionate (E281), calcium propionate (E282), and potassium propionate (E283), or any combination thereof.

18. A method according to claim 16 or 17, characterized in that the preservative is sprayed as a solution or dispersion onto the surface of the bottled pomace during the treatment.

19. Use of the microbially stabilized depectinized pomace according to one of the preceding claims for the production of plant fibers, preferably citrus fibers or apple fibers.

20. Use of the non-depectinized pomace microbially stabilized according to any one of claims 1 to 18 for the production of pectin, preferably citrus pectin or apple pectin or functional fruit fibers.

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