Liquid apple extract, liquid apple sweetener and process for their preparation

Abstract

Process for producing a liquid apple extract by subjecting a raw apple extract to a pectinase enzyme activity in the presence of organic fining agents, followed by clarification and concentration, the raw apple extract being a distillation residue of an alcohol-rich supernatant during the precipitation of apple pectin from apple pomace.

Description

[0001] The present invention relates to a liquid apple extract and a process for its production. The invention also relates to a liquid apple sweetener and a process for its production. Background of the invention: Apple extract

[0002] In Germany, 400 to 750 million liters of apple juice are produced annually. This generates between 100,000 and 200,000 tons of apple pomace.

[0003] Apple pomace is the more or less solid residue (press cake) left over after pressing the juice during apple juice production. The range of possible uses for apple pomace as a byproduct of the fruit processing industry is broad and extends across both the food and non-food sectors. For years, efforts have been made to process this residue with minimal residue for the purpose of resource recovery. Depending on the objective, material and / or energy recovery options are considered, taking into account numerous influencing factors such as transport options and costs, the time period in which the pomace is generated, processing capacity, preservation methods, and the amount of remaining residue and its disposal.Traditionally, apple pomace is used for composting or as animal feed (cattle / pigs) in fresh, dried, or ensiled form. Disposing of pomace in landfills is increasingly costly and therefore considered impractical. Instead, methods for recovering valuable materials from apple pomace are now the focus. The most important of these is pectin, a cell wall polysaccharide that, depending on the technology used, largely remains in the pomace after juice extraction and can be recovered through suitable extraction processes.

[0004] From an industrial perspective, pectin is arguably the most important component of apple pomace. Along with cellulose and hemicelluloses, pectins are among the most important polysaccharides in plant cell walls. They are preferably extracted from the pomace in an aqueous environment under acidic conditions (pH 1–3, usually nitric, sulfuric, or hydrochloric acid) and elevated temperatures (50–90 °C). The pectin is then precipitated from the filtrates using high-proof alcohol (e.g., isopropanol). After several washing steps, the pectin is gently dried, milled, and standardized. Only dried pomace is used for the industrial production of pectin. The extraction conditions depend primarily on the desired quality of the pectin to be produced. Suitable chemical and enzymatic processes allow for the production of pectins with varying degrees of esterification, gelling properties, and viscosity ranges.

[0005] Another way to put apple processing residues to good use is the production of fiber-rich dietary fiber preparations, often referred to in the literature as cell wall materials, which represent a form of alcohol-insoluble substance. They consist primarily of cellulose, hemicellulose, and pectin. Their physicochemical properties are strongly influenced by the key processing steps (physical, chemical, and enzymatic pretreatments). Targeted extraction methods allow for the production of preparations that, after rehydration, exhibit high water-binding capacity and viscoelastic properties, making them attractive for use as swelling and thickening agents in food products.

[0006] In order to achieve complete utilization of all intermediate products generated during pectin production, it is recommended to use the depectinized apple pomace for the production of fiber-rich dietary fiber.

[0007] Starting with the pectin extract (liquid pectin), a liquid apple extract can also be produced as a byproduct. In this process, the pectin is precipitated from the liquid pectin using alcohol and washed, and the pectin obtained during precipitation is pressed out. The resulting alcohol-rich supernatant is distilled, and the alcohol distillate is returned to the precipitation cycle. The remaining aqueous liquid represents a raw, liquid fruit extract (hereinafter referred to as raw apple extract), which, after concentration and possible dearomatization, is used in the food industry as a clear, syrupy apple extract.

[0008] Apple extracts (e.g., HERBAROMO from Herbstreith & Fox) have been used and valued for years in numerous applications, both for their excellent coloring properties and their pleasant aroma. The coloring is due to the formation of brown pigments, partly through a natural enzymatic reaction during the crushing of the apples for juice extraction. Because of the carefully selected raw materials and the manufacturing process, which is designed to preserve the natural properties of the apple extracts, these extracts represent a fruit-based alternative to caramel coloring. Depending on the dosage, the resulting color in the final product ranges from golden yellow to dark brown. Furthermore, other ingredients such as naturally occurring fruit sugars, minerals, and fruit acids contribute to a well-rounded flavor in many applications.

[0009] Studies on food coloring have shown that natural colors are now preferred over synthetic dyes. Their increasing market share corresponds to a declining market share of synthetic dyes. The reason for this boom in natural colors is the growing demand and strong consumer interest in using natural ingredients.

[0010] Following the publication of the IARC (International Agency for Research on Cancer, USA, 2011) study on the levels of potentially harmful substances (so-called imidazoles) in foods colored with caramel colors E 150c and E 150d, the demand for products for natural brown coloring has recently increased again.

[0011] From a food law perspective, apple extracts fall into the group of coloring foods and can therefore be declared as "apple extract" or "coloring apple extract." This also meets consumer demands for natural ingredients and additionally lends the final product the positive image of the raw material, the apple.

[0012] Through additional processing steps, in which the fruit acids and minerals are removed from the apple extract using activated charcoal and ion exchangers, a special apple extract, known as apple syrup, is obtained after concentration. Apple syrup is an alternative to sugar and other sweeteners. It consists of 100 percent apples and is a light-colored syrup with a low acidity. Because acids and flavor compounds are filtered out, apple syrup has a neutral to slightly fruity taste. It can be used to sweeten beverages as well as for cooking and baking. Its sweetness is roughly equivalent to that of sugar. While 100 grams of sugar contain 400 kilocalories (kcal), apple syrup contains around 300 kcal. Due to its polyphenol content, apple syrup becomes more deeply brown with increasing oxidation and can therefore also be used as a sweet coloring agent.The liquid apple syrup can therefore also be referred to synonymously as coloring liquid apple syrup.

[0013] Furthermore, the manufacturing process described above results in low yields of apple extract, which are only between 30 and 60%.

[0014] The publication by Singh et al., 2004 (“Apple juice clarification using fungal pectinolytic enzyme and gelatine”, Indian J. Biotechnol. 3: 573-576) describes the clarification of apple juice using pectinolytic enzymes from fungi and gelatin. Apple juice is used as the starting material, which, after the addition of gelatin and polygalacturonase from A. niger, is incubated under different conditions.

[0015] CN 109371075 A relates to a separation process for separating proteins, apple polyphenols, apple starch and pigments from apple juice. Apple juice is used as the starting material.

[0016] The publication by Yates et al., 2017 (“Multivalorization of apple pomace towards materials and chemicals. Waste to Wealth.” In: Journal of Cleaner Production, 143: 847-853) concerns the production of a biocompatible scaffold material by heating a deesterified apple pomace to 500°C.

[0017] The publication by O'Shea et al., 2015 (“Physicochemical assessment of two fruit byproducts as functional ingredients: Apple and orange pomace. In: Journal of Food Engineering 153: 89-95”) concerns the physicochemical determination of apple pomace and also describes the isolation of pectin by acid extraction and precipitation with ethanol. The use of the alcoholic supernatant after pectin precipitation is not addressed.

[0018] The publication by Fertonani et al., 2009 (“Extraction of low methoxyl pectin from pomace: effects of acid concentration and time on the process and the product,” in: Braz. Arch. Biol. Technol., 52(1): 177–185) concerns the isolation of pectin from apple pomace by acid extraction and precipitation using ethanol. The use of the alcoholic supernatant after pectin precipitation is not addressed.

[0019] Therefore, there is a need for new processes for the production of apple extracts and the apple extracts produced by them.

[0020] The present invention is based on the objective of improving the state of the art or offering an alternative to it. Summary of the invention

[0021] According to a first aspect of the present invention, the stated problem is solved by a process for producing a liquid apple extract by the action of a pectinase enzyme activity on a crude apple extract in the presence of organic fining agents with subsequent clarification and concentration, wherein the crude apple extract represents a distillation residue of an alcohol-rich supernatant from the precipitation of apple pectin from apple pomace.

[0022] The process according to the invention results in a significant increase in yield from the previous 30 to 60% to 85%. This brings us a big step closer to the complete utilization of all intermediate products generated during pectin production.

[0023] Furthermore, the inventive method allows for targeted control of the amounts of apple extract versus apple sweetness, thus enabling a targeted response to market requirements.

[0024] In the manufacturing process according to the invention, apple pomace, a processing residue from pectin production, is used as a raw material. This processing residue is inexpensive, available in sufficient quantities, and offers a sustainable and ecologically sound source for the products according to the invention, namely a liquid apple extract or a liquid apple sweetener.

[0025] Apple extracts are established and accepted in the food industry, so that corresponding compositions can be used immediately and internationally without lengthy approval procedures. The invention in detail

[0026] The inventive process for producing a liquid apple extract advantageously comprises the following steps: (a) Providing a crude apple extract; (b) Optional adjustment of pH and / or soluble solids content; (c) Contacting the raw apple extract with an organic fining agent; (d) Enzymatic treatment of the raw apple extract containing the fining agent with a pectinase; (e) Preliminary clarification of the extract from step (d); (f) Clarification of the extract from step (e); (g) Concentration to obtain a liquid apple extract.

[0027] In step (a) of the process, a crude apple extract is provided. This is a residue that arises as a distillation residue in the corresponding distillation apparatus during the production of apple pectin (see Fig. 2).

[0028] In the optional step (b), the crude apple extract is adjusted to predefined values ​​with respect to pH and soluble solids content (measured in degrees Brix) in order to establish the optimal reaction conditions for subsequent fining with organic fining agents and enzyme action. If the crude apple extract already exhibits the optimal pH and solids content values, this adjustment in step (b) is unnecessary.

[0029] In step (c), an organic fining agent is brought into contact with the raw apple extract. This is expediently done by adding the organic fining agent to the raw apple extract, preferably while stirring to ensure homogeneous mixing.

[0030] In step (d), the crude apple extract undergoes enzymatic treatment with a pectinase. For this purpose, a pectinase or a mixture of pectinases is added to the crude apple extract, and this reaction mixture is incubated for a specific time at a predetermined temperature. The pectinase breaks down the short-chain pectins or pectin fragments present in the crude apple extract, thereby facilitating clarification and releasing valuable constituents such as oligosaccharides or monosaccharides, which then enrich the apple extract. Consequently, the proportion of unprocessable apple extract (the molasses typically used as animal feed) is reduced, leading to a significant increase in yield.

[0031] Step (d) is carried out with respect to pH, temperature and TS value in such a way that the pectinase can exert its enzymatic activity.

[0032] In this process, the pectinase is preferably used in an amount of 0.01 to 0.05 wt% and particularly preferably in an amount of 0.02 to 0.03 wt% based on the total batch.

[0033] It has been shown that the combination of organic fining agent and pectinase has a synergistic effect on clarification efficiency and yield. If only the organic fining agent or only the pectinase is used, significantly increased amounts (> a factor of 10) of the respective components are required to achieve a comparable effect. Such high quantities are uneconomical and contaminate the apple extract.

[0034] In step (e), the extract from step (d) undergoes preliminary clarification. This involves removing the flocs formed during fining, which are preferably suspended, from the crude extract. Methods for preliminary clarification are known to those skilled in the art from wine and juice production. These methods involve the use of a separator, a sedimentation unit, or a decanter.

[0035] In step (f), the extract from step (e) undergoes fine clarification. This involves filtering out the small particulate suspended solids from the extract. Methods for fine clarification are known to those skilled in the art from wine and juice production. These primarily involve the use of a depth filter.

[0036] As a result of steps (e) and (f), a clear apple extract with very low turbidity is obtained.

[0037] In step (g), the apple extract is concentrated to obtain the liquid apple extract according to the invention. The appropriate concentration results in a storage-stable apple extract that can be diluted again as needed (i.e., primarily for marketing).

[0038] In a second aspect, the invention provides a method for producing a liquid apple sweetener, wherein in the method, in addition, between step (f) and step (g), in a further step (f1), the fruit acids and minerals are removed with the help of activated charcoal and ion exchangers, and a liquid apple sweetener is obtained as an apple extract by subsequent concentration in step (g).

[0039] In one embodiment, steps (c) and (d) of the process for producing a liquid apple extract can be carried out simultaneously.

[0040] The crude apple extract used as a starting material in the process may have one or more of the following properties: (a) a pH value of 4.0 - 5.0; (b) a dry matter (DM) content of 15 - 20 °Bx; (c) a turbidity of more than 1000 FNU; (d) a mineral content of 1 to 2 wt%, preferably 1.25 to 1.75 wt%; (e) a sugar content of 5 - 15% by weight; (f) a protein content of 0.1 to 0.5 wt%, preferably 0.2 to 0.4 wt% and particularly preferably 0.3 wt%.

[0041] The pH value can range from 4.0 to 5.0, for example 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8 or 4.9.

[0042] The dry matter content of raw apple extract and the apple extract or apple sweetener derived from it can be specified in degrees Brix (°BX). A value in degrees Brix means that the density of the measured liquid corresponds to the density of a sucrose solution in water containing the number of grams of sucrose per 100 g of solution indicated by the degree value. The dry matter content can be, for example, 16, 17, 18, or 19 °BX.

[0043] Turbidity is determined optically, but measured electronically. The wavelength of the measurement radiation is typically in the infrared range at 860 nm. FNU stands for "Formazine Nephelometric Units" and is a common unit of turbidity. A formazin solution is used as the turbidity standard, and the turbidity units refer to dilutions of this solution. The FNU determination involves a scattered light measurement (90° angle) and is performed according to the specifications of ISO 7027.

[0044] The mineral content can be, for example, 1.3, 1.4, 1.5, 1.6, or 1.7.

[0045] Raw apple extract can have a sugar content of 5-15% by weight, and for example, a sugar content of 6, 7, 8, 9, 10, 11, 12, 13, or 14% by weight. The sugars present are primarily fructose, glucose, and sucrose, with fructose making up the largest proportion, followed by glucose. Thus, raw apple extract can contain 4% glucose and 6% fructose.

[0046] The protein content can be, for example, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40 or 0.45 wt%.

[0047] In a preferred embodiment, the organic brightening agent is an animal protein, a vegetable protein, a yeast protein extract or a chitin derivative or a combination thereof.

[0048] The chitin derivative is preferably chitosan or chitin-glucan. These are preferably obtained from the mycelium of Aspergillus niger.

[0049] Chitosan is also known as soluble or deacetylated chitin, chitan, or polyglucosamine. It consists of β-1,4-glycosidically linked 2-amino-2-deoxy-β-glucose (glucosamine) units. It is typically obtained from chitin through chemical or enzymatic deacetylation. Due to its free amino groups, chitosan is classified as a cationic polyelectrolyte with ion-exchange properties and can therefore selectively bind anionic food components such as dyes, cholesterol, or heavy metals. It can also bind alginates, pectins, proteins, inorganic phosphates (polyphosphates), and polyelectrolytes, including minor electrolytes such as NaCl, calcium salts, sodium phosphates, and ionic emulsifiers. Furthermore, it possesses both fungicidal and bactericidal properties. In general, chitosan reduces the microbial count of the product.

[0050] In a preferred embodiment, the protein used as an organic fining agent is selected from the group consisting of gelatin, casein, ovalbumin, potato protein, pea protein, broad bean protein, sunflower protein, or wheat protein. Potato protein, pea protein, or sunflower protein is particularly preferred as the organic fining agent.

[0051] To achieve a cosmetic effect comparable to gelatin using plant-based treatments, a protein content of at least 80% is required. This limits their use to so-called protein isolates, which contain no or minimal amounts of lipid or fiber components. Most plant proteins are characterized by a wide range of molecular weights. In pea protein, the legume group (35 to 60 kDa) predominates, while potato protein consists mainly of patatin (35 kDa).

[0052] In this process, the protein is preferably used in an amount of 0.075 to 0.20 wt% and particularly preferably in an amount of 0.1 to 0.15 wt%.

[0053] In one embodiment, the protein used as an organic brightening agent is a hydrated protein, which is preferably hydrated as a solution or suspension in water or an aqueous buffer prior to addition in step (c).

[0054] With regard to the pectinase, it is preferred that the pectinase is selected from the group consisting of pectin lyase, pectin methyl esterase, pectin acetylesterase, endo-polygalacturonase, exo-polygalacturonase, arabinogalactanase, exo-1,5-α-arabinanase, endo-1,5-α-arabinanase, α-L-arabinofuranosidosis, rhamnogalacturonan acetylesterase, rhamnogalacturonanase, rhamnogalacturonan lyase, endo-xylogalacturonan hydrolase, endo-mannanase, endo-β-1,6-galactanase, endo-β-1,4-galactanase, β-glucuronidase, β-galactosidase and feruloylesterase, or a combination thereof.

[0055] In the context of the invention, a pectinolytic enzyme is understood to be an enzyme that cleaves pectin or pectin fragments, i.e., hydrolyzes the glycosidic bonds or deesterifies the pectin. In a preferred embodiment, the enzyme in the invention is one that cleaves pectin or pectin fragments, i.e., hydrolyzes the glycosidic bonds and thus degrades the pectin to form oligosaccharides or monosaccharides. This pectin degradation can be facilitated by pectinases that deesterify the pectin.

[0056] The pectinolytic enzyme can be synonymously called pectinase. Examples of pectinases include pectin lyase, pectin acetylesterase, pectin methylesterase, endo- and exo-polygalacturonase, pectate lyase, and rhamnogalacturonase. The following table lists selected pectinases, their EC numbers (Enzyme Commission numbers), possible substrates and their action towards these, their pH optimum, and their temperature optimum: Pectinase EC No. . substrate action pH Optim . Temp.Opt . Pectin lyase 4.2.2.10(PL1) Highly esterified pectin Endo-α-1,4-β elimination 5 - 5,5 50°C Pectin methyl esterase 3.1.1.11(CE8,CE12) Highly esterified pectin Randomized methyl ester hydrolysis 4 - 4,5 55°C Pectin acetylesterase 3.1.1.6 Highly esterified pectin Acetyl ester hydrolysis at the O-2 or O-3 group of HG or RG-I 8,0 50°C EndoPolygalacturonase 3.2.1.15(GH28) Low esterified pectin Endo-α-1,4-depolymerization 4 - 4,5 45-50°C ExoPolygalacturonase 3.2.1.67 Low esterified pectin Exo-α-1,4-hydrolysis 5 55°C Arabinogalactanase(endo-arabinase) (3.2.1.90) Pectin in "hairy" regions Endo-β-1,3 1,6 Hydrolysis 4 50°C Exo-1,5-α-arabinanase 3.2.1.-(GH93) Pectin in "hairy" regions Exo-α-1,5 hydrolysis 4 50°C Endo-1,5-α-arabinanase 3.2.1.99(GH43) Pectin in "hairy" regions Endo-α-1,5 hydrolysis 4 50°C Endo-xylogalacturonanhydrolase 3.2.1.-(GH28) Pectin in "hairy" regions XGA EndoHydrolysis - - Mannanase (Endo-Mannanase) 3.2.1.78 Pectin in "hairy" regions Manann-endo-β-1,4 hydrolysis 3-6 80°C RG-I: rhamnogalacturonan I, HG: homogalacturonan, XGA xylogalacturonan (Carbohydrate active enzyme (CAZy) family information with GH = glycosyl hydrolases, PL = polysaccharide lyases)

[0057] The following table gives some examples of commercially available enzymes with their reaction optima: Product name Manufacturer Optima Rapidase PEP DSM pH = 4 - 5; T = 50 °C Pectinase 872 L Biocatalysts pH = 4 - 5; T = 30 - 50°C Fructozym Flot Erbslöh pH = 3 - 5; T > 15 °C

[0058] Pectin methyl esterase (abbreviation: PME, EC 3.1.1.11, also: pectin demethoxylase, pectin methoxylase) is a widespread enzyme in the cell wall of all higher plants as well as some bacteria and fungi. It cleaves the methyl esters of pectins, forming polygalacturonic acid and releasing methanol. PME has been isolated in many isoforms, all of which, according to the invention, can be used for enzymatic deesterification. Pectin methyl esterases have a pH optimum between 2 and 5 and a temperature optimum between 30 and 50°C, although, depending on the specific enzyme, significant enzyme activity can be observed even at temperatures as low as 15°C.

[0059] Pectin lyase (EC 4.2.2.10), also known as pectolyase, is a naturally occurring pectinase that breaks down pectin. It is commercially produced from fungi in industry.

[0060] Pectin lyase catalyzes the following process: Eliminative cleavage of (1→4)-α-D-galacturonan methyl ester to yield oligosaccharides with 4-deoxy-6-O-methyl-α,-D-galact-4-enuronosyl groups at their reducing end. This enzyme belongs to the class of lyases, specifically to the carbon-oxygen lyases that act on polysaccharides.

[0061] The systematic name of this enzyme is (1→4)-6-O-methyl-αD-galacturonan lyase. Other common names include endo-pectin lyase, pectin methyl trans-eliminase, pectin trans-eliminase, pectolyase, PL, PMGL, and PNL.

[0062] Endo-polygalacturonase (EC 3.2.1.15, pectin depolymerase, pectolase, pectin hydrolase, and poly-α-1,4-galacturonide glyanohydrolase; systematic name (1→4)-α-D-galacturonan glyanohydrolase (endo-cleaving)) is an enzyme that cleaves the α-1,4-glycosidic bonds between galacturonic acid units: (1,4-α-D-galacturonosyl)n+m + H2O => (1,4-α-D-galacturonosyl)n + (1,4-α-D-galacturonosyl)m.

[0063] Endoarabinanases (EC 3.2.1.99) are endoactive hemicellulases that catalyze the endohydrolysis of (1,5)-alpha-arabinofuranoside bonds in (1,5)-arabinanes. They are also known as arabinan endo-1,5-alpha-L-arabinosidase or endo-1,5-alpha-L-arabinanase. The activity of arabinanase is activated by the substrate azurin-crosslinked unbranched arabinan (AZCL-arabinan), commercially available as Arabinazyme1™ tablets (available from Megazyme International, Ireland Ltd, Wicklow, Ireland). One unit of endoarabinanase activity is defined as the amount of enzyme required to release 1 micromole of arabinose reducing sugar equivalents from carboxymethyl (CM) linear arabinan per minute under defined test conditions (40°C, pH 4.0).

[0064] Exoarabinanases (EC 3.2.1._) are exo-active hemicellulases that catalyze the hydrolysis of terminal, non-reducing alpha-L-arabinofuranoside groups in alpha-L-arabinosides. There are various types of exoarabinanases, for example, but not limited to, EC 3.2.1.55. In one embodiment, the arabinanase is obtained from Aspergillus. In a preferred embodiment, the arabinanase is isolated from Aspergillus aculeatus.

[0065] Rhamnogalacturonan acetylesterase (RGAE; EC 3.1.1.6) is an accessory hemicellulase that catalyzes the deacetylation of rhamnogalacturonan I, one of the most complex pectinate polysaccharides of the cell wall of higher plants. The polysaccharide rhamnogalacturonan I is composed of alternating rhamnose and galacturonic acid units. The latter can be acetylated at the C-2 and C-3 positions, and the removal of such acetyl groups facilitates the action of lyases and hydrolases, since acetylation sterically hinders the cleavage of the glycoside bonds.

[0066] Pectinolytic enzymes belong to the class of carbohydrate-active enzymes (CAZymes). They are involved in the breakdown of complex hydrocarbons and glycoconjugates and are classified into different classes based on their amino acid sequence and functional domains. As a highly cross-linked superstructure, pectin hydrolysis requires a potent set of complementary hydrolytic CAZymes. Glycosyl hydrolases (GH family) and polysaccharide lyases (PL family) are required for the backbone of homogalacturonan (HG). Specifically, the interaction of exo- and endo-polygalacturonases (GH 28 family) releases monomeric GalA by hydrolyzing the -1,4-glycosidic bond. Pectin and pectate lyases (PL family), on the other hand, form 4,5-unsaturated (methyl)-galacturonic acid oligomers via an elimination reaction and show substrate specificity to more or less methyl-esterified HG.Methyl esterification and O-acetylation of HG require the hydrolytic activity of pectin methylesterases and pectin acetylesterases (CE family) to produce polygalacturonic acid (PolyGalA) from HG. The complete enzymatic hydrolysis of the more complex pectin structures (RG-I, RG-II, and XG) requires a variety of additional hydrolytic enzymes. Thus, the use of so-called accessory enzymes such as arabinofuranosidases, arabinases, galactases, galactosidases, xylosidases, rhamnosidases, and glucuronyl hydrolases can make further fermentable monosaccharides available.

[0067] For enzymatic treatment, it is advantageous if the pectinase exhibits primary activity with pectin lyase, pectin acetylesterase, or endo-polygalacturonase, with secondary activities with arabinogalactanase and / or endo-xylogalacturonan hydrolase. Since the chemical composition of pectin is complex and various neutral sugars are attached to it, diverse secondary activities are available to promote degradation and flocculation during enzymatic treatment.

[0068] In one embodiment, the apple crude extract in step (d) has a soluble dry substance of 9 to 28 °Brix, preferably of 11 to 24 °Brix, and particularly preferably of 15 to 20 °Brix.

[0069] The measure of soluble dry matter in a liquid (and thus approximately the sugar content) is usually given in degrees Brix (°Brix). This indirectly provides an objective value for the ripeness of a fruit. A liquid has a Brix value of 1 degree (=1% Brix) if it has the same density as a solution of 1 g of sucrose in 100 g of sucrose / water; it has a Brix value of 10 degrees (=10% Brix) if its density is that of a solution of 10 g of sucrose in 100 g of sucrose / water (corresponding to a ten percent solution).

[0070] Depending on the dry matter content of the raw apple extract obtained during pectin production, this raw apple extract must be diluted to obtain the Brix grades mentioned above.

[0071] In the process according to the invention, the crude apple extract in step (d) can have a pH value of 3.8 to 4.7, preferably 3.9 to 4.6, and particularly preferably 4.0 to 4.5. The enzymatic treatment can be carried out, for example, at a pH value of 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, or 4.6.

[0072] Depending on the pH value of the raw apple extract obtained during pectin production, this raw apple extract must be adjusted to the above-mentioned pH values ​​by adding acids, bases or buffers.

[0073] In the process according to the invention, the enzymatic treatment of the crude apple extract in step (d) can be carried out at a temperature of 40 to 75°C, preferably 45 to 70°C and particularly preferably 50 to 65°C. It can, for example, be carried out at a temperature of 45°C, 50°C, 55°C, 60°C, 65°C or 70°C.

[0074] The enzymatic treatment of the crude apple extract in step (d) can be carried out for a duration of 1 to 6 hours, preferably 1.5 to 5 hours, and particularly preferably 2 to 4 hours. For example, the enzymatic treatment can be carried out for a duration of 1.5 h, 2.0 h, 2.5 h, 3.0 h, 3.5 h, 4.0 h, 4.5 h, or 5.0 h.

[0075] The progress of the enzymatic treatment and the determination of the end point can be monitored by measuring the turbidity of the mixture. For this purpose, the sample material is centrifuged, and the turbidity of the supernatant is measured. This should be less than 50 FNU. Additionally, the formation of flocs is visually assessed, with a good enzymatic reaction being associated with the formation of "large" flocs.

[0076] In the process according to the invention, the crude apple extract can be stirred or shaken during the enzymatic treatment in step (d). Preferably, the stirring or shaking is carried out in such a way that the flocs formed by the clarifying components are kept in suspension.

[0077] In the process according to the invention, the coarse clarification in step (e) can be carried out by a separator, a decanter or a sedimenter, preferably a separator being used.

[0078] In the production of liquid apple sweetener, the coarsely or finely clarified apple extract can also be subjected to ultrafiltration in order to separate the sugar.

[0079] In the process according to the invention, the fine clarification in step (f) can be carried out by depth filtration. A depth filter serves to separate particles from flowing fluids. The separation effect occurs at the depth of the filter medium. In contrast to surface filtration, the formation of a filter cake is expressly undesirable in depth filtration. Depth filters with a separation efficiency of 15 µm are preferably used. For example, the BECO depth filters from Eaton (Bonn, Germany) can be used. These are filters with filtration-active mineral components for clarifying liquids with a coarser crystalline, amorphous, or gel-like turbidity structure; suitable for highly viscous liquids. However, finer filters can also be used.

[0080] The concentration of the apple extract or apple sweetener in step (g) can be achieved by reducing the concentrate under heat. The concentration should be carried out as gently as possible. Accordingly, it is performed in a single pass and / or using a falling film evaporator operating under vacuum.

[0081] The ion exchanger used in step (f1) to remove the fruit acids is preferably selected from the group consisting of anion exchangers or cation exchangers. The use of cation exchange resins with a uniform particle size distribution based on a styrene-divinyl copolymer is particularly preferred. The monodisperse beads are chemically and mechanically very stable and are especially effective for disinfection in food preparation. The favorable kinetics result in a significantly better operating capacity than comparable ion exchangers with a heterodisperse particle size distribution. Examples of suitable cation exchange resins are the products of the Lewatit-S family (Lanxess, Cologne, Germany).

[0082] In one embodiment, the activated carbon used in step (f1) to remove the organic and inorganic acids is a granular activated carbon that allows the liquid to be treated in percolation.

[0083] In one embodiment, the liquid apple extract of the invention has a turbidity of less than 50 FNU, preferably less than 15 FNU, particularly preferably less than 10 FNU, and especially less than 2 FNU. By combining the organic fining agents and applying pectinolysis to a crude apple extract, a particularly clear extract with correspondingly reduced turbidity can be produced. A clear extract exhibits higher consumer acceptance and typically possesses greater stability.

[0084] The apple extract according to the invention is preferably produced or manufactured using the method according to the invention.

[0085] The liquid apple extract can have an aW value of 0.800 to 0.866. The aW value (also known as water activity or activity of water) of a food product is a measure of the "available" or "active" water, as opposed to simply stating the water content. The significance of this value stems from the fact that the shelf life of food depends not only on the pure water content but also on the degree to which the water is bound by the substrate. Water activity influences the growth of microorganisms, the course of chemical processes such as non-enzymatic browning, enzyme activity, and the physical properties of the food. The aW value is an important measure regarding the shelf life of food and influences the presence of microorganisms (spoilage organisms), which have varying requirements for freely available water.In the absence of free water, the growth processes of some water-loving microorganisms are slowed down; sensitive organisms can even be killed. For most microorganisms, the optimum growth temperature is between 0.98 and 1.

[0086] In a preferred embodiment of the invention, the liquid apple extract in concentrate has a soluble dry matter content of 62 to 76 °Brix, preferably 65 to 73 °Brix, and particularly preferably 68 to 70 °Brix. The aforementioned high Brix values ​​stabilize the apple extract, allowing it to be stored and used for extended periods without preservatives.

[0087] The liquid apple extract produced by the process according to the invention can have an extinction value of between 0.3 and 1.2. These extinction values ​​correspond to different color intensities of the apple extract. Typically, the intensification of the brown color is induced by a heating step, preferably carried out at approximately 70°C.

[0088] The liquid apple extract produced using the inventive method can also have a pH value between 4.0 and 4.3.

[0089] The liquid apple extract produced using the inventive method can furthermore have a mineral content of between 6 and 8 wt%.

[0090] In a preferred embodiment, the liquid apple extract according to the invention exhibits the three properties described above: extinction value, pH value, and mineral content in a cumulative manner.

[0091] In a particularly preferred embodiment, the liquid apple extract according to the invention exhibits the six properties described above (FNU, aW value, TS, extinction value, pH value, mineral content) in a cumulative manner.

[0092] In a third aspect, the invention provides a liquid apple sweetener characterized by having an aW value of 0.605 to 0.733.

[0093] In a preferred embodiment, the liquid apple sweetener is produced using the previously described method according to the invention. Definitions

[0094] An apple crude extract, as defined in the application, is the residue from the distillation of the alcohol-rich supernatant (precipitated alcohol) that remains after the precipitation of apple pectin and pectin separation. The apple crude extract is obtained as stillage or sludge in the distillation apparatus after the distillation of the precipitated alcohol (see Fig. 2 and character description here).

[0095] Within the scope of the invention, an organic fining agent is understood to be a fining agent that is an organic compound. Examples include proteins, protein extracts, yeast extracts, or polysaccharides such as chitosan. This distinguishes the fining agents according to the invention from inorganic fining agents such as bentonite, copper sulfate, or copper citrate.

[0096] A pectin according to the application is defined as a plant polysaccharide consisting essentially of α-1,4-glycosidically linked D-galacturonic acid units as a polyuronide. The galacturonic acid units are partially esterified with methanol. The degree of esterification describes the percentage of carboxyl groups in the galacturonic acid units of the pectin that are present in esterified form, e.g., as methyl esters.

[0097] It should be explicitly noted at this point that features of the solutions described above or in the claims and / or figures can also be combined, if necessary, in order to implement or achieve the explained features, effects and advantages in a cumulative manner.

[0098] It should be expressly noted that, within the context of this patent application, indefinite articles and numerical indications such as "one", "two", etc., are generally to be understood as "at least" indications, 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.

[0099] Further advantages, special features and expedient further developments of the invention will become apparent from the dependent claims and the following presentation of preferred embodiments with reference to the illustrations. Examples of implementation

[0100] The embodiments shown here are merely examples of the present invention and should therefore not be interpreted as limiting. Alternative embodiments considered by a person skilled in the art are likewise covered by the scope of protection of the present invention. 1. Description of the manufacturing process

[0101] In the first step, the crude apple extract is adjusted to a dry matter content (TS) of 20 °Bx and a pH of 4.0, and heated to 50 °C. Hydrated sunflower protein and the pectinolytic enzyme SEBClear UFL (Advanced Enzymes, evoxx technologies GmbH, Monheim, Germany) are then added. The suspension is incubated for three hours at 50 °C with stirring and subsequently centrifuged to separate the flocs (coarse clarification). In the subsequent fine clarification, the resulting extract, which has a turbidity of 20 FNU, is finely filtered using a depth filter, resulting in an apple extract with a turbidity of less than 2 FNU. Finally, it is gently concentrated by vacuum heating. This yields a clear apple extract with a dry matter content of 70 °Bx. The process flow is also shown schematically in the flowchart of the Fig. Figure 1 shows. In an alternative embodiment, a liquid coloring apple sweetener can be produced from the finely clarified apple extract by subsequent treatment with activated carbon and ion exchanger, followed by a final concentration step.

[0102] The Fig.Figure 2 shows the integration of the apple crude extract into the general process flow of apple pomace processing. Starting with apple pomace, the pectin is extracted from this pomace by incubation in an acidic environment (alternatively, alkaline incubation or enzymatic pectinolysis can be used), and the pectin contained in the liquid phase is removed from the solid pomace residue. Functionalized apple fibers can be produced from the solid residue if required. By adding an alcohol (e.g., isopropanol), the pectin from the pectin extract is precipitated and, in the following step (e.g., by pressing), separated from the alcohol-containing phase (here called the alcohol supernatant). By distilling off the alcohol, it can be recycled back into the process, and the remaining residue in the distillation apparatus represents the apple crude extract, which is used as the starting material in the process according to the invention.

Claims

[1] Method for producing a liquid apple extract by the action of a pectinase enzyme activity on a crude apple extract in the presence of organic fining agents with subsequent clarification and concentration, wherein the crude apple extract is a distillation residue of an alcohol-rich supernatant from the precipitation of apple pectin from apple pomace. [2] A method for producing a liquid apple extract according to claim 1 comprising the following steps: (a) Providing a crude apple extract; (b) Optional adjustment of pH and / or soluble solids content; (c) Contacting the raw apple extract with organic fining agents; (d) Enzymatic treatment of the raw apple extract containing the fining agent with a pectinase; (e) Preliminary clarification of the extract from step (d); (f) Clarification of the extract from step (e); (g) Concentration to obtain a liquid apple extract. [3] Method for producing a liquid apple extract according to claim 2, characterized by , that in addition, between step (f) and step (g) in a further step (f1) the fruit acids and minerals are removed with the help of activated charcoal and ion exchanger and a liquid apple sweetener is obtained as apple extract through subsequent concentration in step (g). [4] Method for producing a liquid apple extract according to claim 2 or 3, characterized by that steps (c) and (d) are performed simultaneously. [5] Method according to any one of claims 2 to 4, characterized by that the crude apple extract provided according to step (a) has one or more of the following properties: (a) a pH value of 4.0 - 5.0; (b) a dry matter (DM) content of 15 - 20 °Bx; (c) a turbidity of more than 1000 FNU; (d) a mineral content of 1 to 2 wt%, preferably 1.25 to 1.75 wt%; (e) a sugar content of 5 - 15% by weight; (f) a protein content of 0.1 to 0.5 wt%, preferably 0.2 to 0.4 wt% and particularly preferably 0.3 wt%. [6] Method according to any one of the preceding claims, characterized by that the organic brightening agent is an animal protein, a plant protein, a yeast protein extract or a chitin derivative, or a combination thereof. [7] Method according to claim 6, characterized by that the organic brightening agent is a protein selected from the group consisting of gelatin, casein, ovalbumin, potato protein, pea protein, broad bean protein, potato protein or sunflower protein. [8] Method according to claim 6 or 7, characterized bythat the protein is a hydrated protein, preferably hydrated as a solution or suspension in water or an aqueous buffer prior to addition in step (c). [9] Method according to any of the preceding claims, characterized by , that the pectinase is selected from the group consisting of pectin lyase, pectin methylesterase, pectin acetylesterase, endo-polygalacturonase, exo-polygalacturonase, arabinogalactanase, exo-1,5-α-arabinanase, endo-1,5-α-arabinanase, α-L-arabinofuranosidosis, rhamnogalacturonan acetylesterase, rhamnogalacturonanase, rhamnogalacturonan lyase, endo-xylogalacturonan hydrolase, endo-mannanase, endo-β-1,6-galactanase, endo-β-1,4-galactanase, β-glucuronidase, β-galactosidase and feruloylesterase, or a combination thereof. [10] Method according to any one of the preceding claims, characterized bythat the pectinase exhibits a primary activity with respect to pectinlyase, pectinacetylesterase or endo-polygalacturonase with secondary activities with respect to arabinogalactanase, and / or endo-xylogalacturonanhydrolase. [11] Method according to any one of claims 2 to 10, characterized by , that the apple crude extract in step (d) has a soluble dry substance of 9 to 28 °Brix, preferably of 11 to 24 °Brix, and particularly preferably of 10 to 20 °Brix. [12] Method according to any one of claims 2 to 11, characterized by , that the apple crude extract in step (d) has a pH of 3.8 to 4.7, preferably of 3.9 to 4.6, and particularly preferably of 4.0 to 4.

5. [13] Method according to any one of claims 2 to 12, characterized by , that the enzymatic treatment of the apple crude extract in step (d) is carried out at a temperature of 40 to 75°C, preferably 45 to 70°C and particularly preferably 50 to 65°C. [14] Method according to any one of claims 2 to 13, characterized by , that the enzymatic treatment of the crude apple extract in step (d) is carried out for a period of 1 to 6 hours, preferably 1.5 to 5 hours and particularly preferably 2 to 4 hours. [15] Method according to any one of claims 2 to 14, characterized by , that the apple crude extract is stirred or shaken during the enzymatic treatment in step (d), preferably the stirring or shaking being carried out in such a way that the flocs formed by the clarifying components are kept in suspension. [16] Method according to any one of claims 2 to 15, characterized by , that the coarse clarification in step (e) is carried out by a separator, a decanter or a sedimenter, preferably a separator being used. [17] Method according to any one of claims 2 to 16, characterized by , that the fine clarification in step (f) is carried out by depth filtration. [18] Method according to any one of claims 2 to 17, characterized by , that the concentration in step (g) is carried out by concentrating the concentrate under heating, preferably by vacuum evaporation in a falling stream. [19] Method according to any one of claims 3 to 18, characterized by , that the ion exchanger used in step (f1) to remove the fruit acids is selected from the group consisting of anion or cation exchangers. [20] Method according to any one of claims 3 to 19, characterized by , that the activated carbon used in step (f1) is a granular activated carbon which allows the treatment of the liquid to be percolated. [21] Liquid apple extract produced by a process according to claims 2, 4-20, characterized bythat the extract has a turbidity of less than 50 FNU, preferably less than 15 FNU, particularly preferably less than 10 FNU, and especially a turbidity of less than 2 FNU. [22] Liquid apple extract according to claim 21, characterized by that the extract has an aW value of 0.800 to 0.

866. [23] Liquid apple extract according to claim 21 or 22, characterized by that the extract has a soluble dry substance of 62 to 76°Brix, preferably of 65 to 73°Brix, and particularly preferably of 68 to 70°Brix. [24] Liquid apple extract according to claims 21 to 23, characterized by that the extract exhibits one or more of the following properties: (a) pH value between 4.0 and 4.3; (b) Mineral content of between 6 and 8 wt%; (c) Extinction between 0.3 and 1.

2. [25] Liquid apple sweetener produced by a process according to any one of claims 3 to 20, characterized by, that the apple's sweetness has an aW value of 0.605 to 0.

733. [26] Liquid apple sweetener according to claim 25, characterized by that the apple sweetness has one or more of the following properties: (a) A turbidity of less than 1 FNU, preferably less than 0.5 FNU; (b) A soluble dry substance of between 62 and 76°Brix, preferably of 65 to 73°Brix, and particularly preferably of 68 to 70°Brix; (c) A pH value between 3.2 and 3.8.

Images