Low sugar food products with high fiber content

Abstract

To provide a process for producing a food product, particularly a juice beverage with reduced sugar content and enriched with dietary fibers, and to provide a food product produced by the process.SOLUTION: Provided is a processed juice beverage with reduced sugar content and elevated levels of at least one oligosaccharide and / or polysaccharide selected from the group consisting of fructans and fructooligosaccharides (FOS), as compared to the corresponding unprocessed natural juice, the beverage having a palatable taste and further comprising at least one of sorbitol and gluconic acid.SELECTED DRAWING: None

Description

[Technical field]

[0001] FIELD OF THEINVENTION The present invention provides a process for producing food products, particularly reduced sugar and fiber-rich juice beverages, and the resulting food products, which are low in calories and contain beneficial amounts of fiber, while complying with starting material preference tests. [Background technology]

[0002] 2. Background of the Invention Increased dietary energy intake from beverages is a major factor involved in the obesity epidemic seen in North America over the past few decades. Today, Americans consume 150-300 more calories per day than 30 years ago, and caloric beverages account for 50% of this increase. Energy intake from beverages currently represents 21% of the total daily energy intake of the general American population. Evidence from short-term human studies suggests that calories consumed in liquid form lead to less satiety and poorer energy compensation compared to calories from solid foods. These findings suggest that increased consumption of liquid calories may result in weight gain, and conversely, decreased liquid calorie intake may lead to weight loss. Even without added sugars, fruit juice contains approximately the same amount of sugar as soft drinks. The primary contributors to the caloric content of fruit juice are the monosaccharides glucose and fructose. In beverages defined as containing "100% fruit juice", sugar is primarily derived from fructose. Glucose ingestion is known to stimulate the release of chemicals in the body that regulate food intake (e.g., insulin). Fructose, on the other hand, does little to suppress appetite and appears to be preferentially associated with the formation of new fat cells.

[0003] Microorganisms can reduce the calorie content of juice through two main processes: biomineralization and bioconversion.

[0004] The complete conversion of mono- and disaccharides (glucose, fructose and sucrose) to carbon dioxide and water (biomineralization by aerobic respiration) can be achieved under aerobic conditions by many organisms. The metabolism of these sugars is most efficiently achieved by yeast species. Yeasts can be classified into several groups depending on their mode of energy production, which utilizes respiration or fermentation. The best known yeast species, baker's yeast and wine yeast Saccharomyces cerevisiae, easily adapts to a variety of growth conditions. For example, glucose can be utilized by S. cerevisiae in several different pathways, depending on the presence of oxygen and other carbon sources. On the other hand, yeasts of the genera Kluyveromyces, Rhodotorula and Cryptococcus are obligate respirators (they neither ferment nor grow in limited oxygen environments).

[0005] The yeast Kluyveromyces, unlike S. cerevisiae, is not sensitive to glucose concentrations. When glucose concentrations are high, Saccharomyces utilizes sugars to convert them to ethanol even under aerobic conditions (Crabtree effect). Kluyveromyces is Crabtree negative and therefore does not increase biomass, CO2 production, or the like under aerobic conditions, even with high glucose / fructose concentrations. 2 and water, and no ethanol. Besides E. coli and Aspergillus niger var awamori, K. lactis is one of the main organisms grown in the fermentation industry to produce chymosin on a large scale, which is used in cheese production.

[0006] Plants, fungi, and some bacteria can convert simple sugars into polysaccharides. Polysaccharides such as cellulose, hemicellulose, pectin, gums, mucilages, and lignin are dietary fibers. Although these fibers are chemically unrelated, all of them are resistant to breakdown by the human digestive system.

[0007] The glucose polymer cellulose is produced by all plants as the main component of the cell wall. Cellulose is a structural component of the primary cell wall of many forms of green plants, algae and oomycetes (a superfamily of fungi). Some species of bacteria can synthesize cellulose, which they then secrete and form biofilms. Cellulose is a polysaccharide consisting of hundreds to over ten thousand linear β(1→4)-linked D-glucose units and is the most common organic compound on Earth. Cellulose is tasteless and odorless. In vascular plants, cellulose is synthesized at the plasma membrane by rosette terminal complexes (RTCs). RTCs are hexameric protein structures, approximately 25 nm in diameter, that contain the cellulose synthases that synthesize the individual cellulose chains. RTCs contain at least three different cellulose synthases. Cellulose synthesis requires two distinctly separate processes in which chain initiation is followed by chain elongation. The synthase protein isoform (CesA) glucosyltransferase enzyme initiates cellulose polymerization using a steroid primer, sitosterol-β-glucoside, and uridine diphosphate (UDP)-glucose. Cellulose synthase utilizes the UDP-D-glucose precursor to extend the growing cellulose chain.

[0008] Bacteria from the genera Aerobacter, Acetobacter, Achromobacter, Agrobacterium, Alcaligenes, Azotobacter, Pseudomonas, Rhizobium and Sarcina synthesize cellulose. The most extensively studied member of the Acetobacter species is the species A. xylinum, which extrudes glucan chains from pores into the growth medium. These chains aggregate and bundle into microfibrils, forming microbial cellulose ribbons. Various types of sugars are used as substrates. Production occurs mainly at the liquid-air interface. Acetobacter xylinum is the most prolific cellulose producer in nature. A typical single cell can convert up to 108 glucose molecules into cellulose in an hour. This rate of cellulose production is impressive considering that as many as a million cells can be packed into a single droplet, and each of these "factories" can convert up to 108 glucose molecules into cellulose per hour.

[0009] Fructans are fructose polymers produced by plants, yeast, fungi and bacteria. Fructans with short chain lengths are known as fructooligosaccharides (FOS), while longer chain fructans are called inulins or levan. FOS can be prepared by the transfructosylation action of the β-fructosidase enzyme on sucrose. The resulting mixture is a glucose-fructose mixture with n ranging from 1 to 5. nFOS contain oligosaccharides with the general formula (GFn): FOS are derived from Aureobasidium pullulans, Aureobasidium spp., Arthrobacter spp., Aspergillus japonicus, Aspergillus niger, Aspergillus oryzae, Aspergillus phoenicis, Aspergillus sydowii, Claviceps purpurea, Fusarium oxysporum, Penicillium frequentans, Penicillium spinulosum, Phytophthora parasitica, and other fungi. It is produced naturally by a wide variety of microorganisms, including Bacillus parasitica, Scopulariopsis brevicaulis, and Saccharomyces cerevisiae.

[0010] The longer fructans are composed of inulins, which contain mainly β(2→1) glycosidic bonds between adjacent fructose units, and levans, which contain mainly β(2→6) glycosidic bonds. Among the FOS, levan is naturally produced by microorganisms including several Gram-negative species such as Pantoea agglomerans, Erwinia amylovora, Acetobacter suboxydans, Gluconobacter oxydans, and Aerobacter levanicum, as well as several Gram-positive bacteria such as Bacillus subtilis, Paenibacillus polymyxa, Bacillus amyloliquefaciens, Streptococcus mutans, Actinomyces viscosus, and some members of the Corynebacterium genus.

[0011] Levans form non-structural carbohydrates that can link together to form supramolecules composed of hundreds of thousands of units. Zymomonas mobilis and members of Acetobacter are the bacteria most investigated for levan production. Fructans, including levan, are soluble dietary fibers that act by modifying the nature of the microflora content of the digestive tract and by modifying the absorbance of other nutrients and chemicals. Soluble fibers absorb water into a gelatinous viscous substance that is fermented by bacteria in the digestive tract. The presence of fructans helps control weight by filling the stomach and providing a feeling of satiety. Due to their viscosity, soluble fibers have been suggested to change the composition of the bile acid pool, resulting in lower cholesterol levels and reducing dietary fat absorption (Queenan KM et al., 2007.Nutr.6:6-14). They have also been suggested to slow the absorption of glucose into the bloodstream and prevent large swings in blood sugar levels. Soluble dietary fibers can have the additional beneficial effect of reducing constipation and improving bowel movements.

[0012] Various approaches have been taken to reduce the sugar content in fruit juices, aiming at different goals. For example, US Patent No. 4,579,739 discloses a process for the production of natural carbonated beverages, which comprises fermenting must with a combination of at least one yeast and at least one lactic acid bacterium selected for their symbiotic ability and their ability to produce a synergistic organoleptic effect that eliminates all yeast aftertaste, the former selected from the group of Saccharomyces cerevisiae and Kluyveromyces lactis, and the latter selected from the group of Lactobacillus casei and Lactobacillus hilgardii. The must is inoculated so that the number of yeast and lactobacillus bacteria per ml, respectively, has a ratio of 1:10 to 1:500. The must is an aqueous solution of fermentable sugars that also contains natural elements, in particular assimilable nitrogen necessary for the growth and activity of yeast. The must may therefore be a fruit juice, a vegetable juice, an extract from a plant seed, root or leaf.

[0013] US Patent No. 4,971,813 discloses a process for separating and recovering aroma and flavor volatiles from fruit or vegetable juices and for reducing the amount of sugar in the juice. The process involves spraying juices of a specific temperature range into a vacuum chamber at a lower temperature to form a microaerosol, and then treating the recovered juice fraction with yeast to remove the aroma / flavor volatiles from the juice. The alcohol formed during the fermentation reaction is removed by distillation, preferably by the same aerosolization process in which the volatiles are removed. The aroma and flavor volatiles are added back into the juice to provide a superior tasting, reduced calorie fruit juice.

[0014] Japanese Patent Application JP1983198117 discloses a process for obtaining a fermented beverage with a low alcohol content and improved flavor for drinking. The process includes adding a pre-cultured yeast of the species Kluyveromyces lactis or Kluyveromyces fragilis to a fruit or vegetable juice so that alcoholic fermentation takes place. The microbial cells are then separated to obtain a fermentation liquid, which can be concentrated and / or dried and adjusted to obtain a desired alcohol concentration, preferably an ethanol concentration of less than 1% (w / v).

[0015] European patent EP0440975 discloses a fermentation product with reduced ethanol content produced from sugar-containing fruit juice or other sugar-containing substrate, which is obtained by adding 0.01-5% by weight of yeast (calculated as dry matter), if necessary assimilable nitrogen compounds and / or phosphorus compounds, to a first portion of substrate having a fermentable sugar content of 5-30% by weight, in order to induce fermentation, and treating the mixture with 0.1-2 parts by volume of air or with an amount of oxygen equal to air per volume part of substrate and minute ventilation, until an ethanol content of 1-10% by volume, in particular up to 7.5% by volume, of the substrate is obtained; at this point, a second portion of substrate is added with continued aeration together with air or oxygen.

[0016] European patent EP0554488 discloses a process for selectively reducing the sugar content of sugar-containing foods while maintaining the original sensory properties, except for "sweetness". The original food material is subjected to controlled fermentation with microbial species and the species most suitable for the particular food material is selected based on sensory analysis according to ISO guideline 8587 from various species of microorganisms suitable for sugar degradation. The resulting food material has a reduced sugar content while having comparable properties compared to the original starting product.

[0017] US 2004 / 0234658 A1 discloses a process for controlling the reduction of sugar content in fruit juices, in particular grape juice, which comprises subjecting the original fruit juice, if necessary previously clarified, to a selective ultrafiltration substantially permeable to sugars and then to a selective nanofiltration substantially impermeable to sugars. The two retentates obtained are then mixed with the remainder of the ultrafiltration permeate or concentrate and, if necessary, with a portion of the untreated original fruit juice, and the ultrafiltration permeate is treated in order to eliminate or limit the phenomenon of crystallization or the formation of troublesome substances in the nanofiltration retentate or concentrate.

[0018] US Patent Application Publication No. 2008 / 0044531 discloses a method for treating sugar-containing (e.g., sucrose, fructose, glucose) beverages (e.g., fruit juice, vegetable juice), comprising passing a stream of the beverage in contact with a packed bed of ion-adsorbing material capable of selectively removing sugar from the beverage, and separating a reduced-sugar beverage from the packed bed. High-intensity natural and / or artificial sweeteners can be added to the reduced-sugar beverage to produce a beverage product with the same flavor and nutritional content as the original beverage, but with a lower calorie content. The reduced-sugar beverage can also be used as a flavoring for the beverage and food industry, or as an ingredient component of reduced- and full-calorie foods (e.g., jellies, candies, etc.). The reduced-sugar beverage can be concentrated to a higher level using less energy compared to standard juices. The resulting concentrate also realizes significant refrigeration and shipping costs compared to standard juice concentrates.

[0019] No. 9,375,027 discloses fruit juices, purees, and other foods in which a portion of the available sugars in the fruit products are converted into non-digestible polymers, thereby lowering the energy content and at the same time increasing the nutritional value by forming prebiotic components in the product that are stable in the juice. Also disclosed is a method for producing juices and purees that allows for the preservation of all components naturally occurring in the fruit except for the sugars.

[0020] US Published Application No. 2013 / 0216652 discloses a method for reducing the inherent sugar content in a food or sugar-based ready-to-drink product, such as juice, by contacting the food with a sufficient amount of at least one transglycosidase under conditions sufficient to enzymatically convert the inherent sugars in the food to non-digestible carbohydrates and non-digestible oligosaccharides, such as fructo-oligosaccharides and gluco-oligosaccharides, thus forming a more nutritious product. The present invention also relates to the nutritional food products produced by the methods of the present invention.

[0021] However, there is a recognized need and it would be highly advantageous to have a low cost process for reducing the sugar content of fruit or vegetable juice drinks while increasing the dietary fiber of the juice, and the resulting juice drinks. Summary of the Invention [Problem to be solved by the invention]

[0022] The present invention provides a process for reducing the sugar content in foods, particularly juices derived from fruits or vegetables, and fortifying the foods with dietary fiber, sugar alcohols (natural low-calorie sweeteners) and acidity regulators. Additionally, the present invention provides reduced calorie, high fiber foods, particularly juice beverages that are non-carbonated and essentially devoid of alcohol. [Means for solving the problem]

[0023] The present invention is based in part on the unexpected discovery that contacting fruit juice, particularly apple juice, with certain microorganisms in dead or live form or with certain combinations of yeasts and bacteria or fungi not only reduces the sugar content of the juice (including sucrose, fructose, and glucose), but also converts the mono- or disaccharide sugars to oligosaccharides and / or polysaccharides, sugar alcohols, and gluconic acid. The resulting juice has a low sugar content and calories and contains beneficial nutritional oligosaccharides and / or polysaccharides that contribute to the consumer's digestion and satiety. The addition of dead or live microorganism(s) does not negatively affect the taste of the juice, retaining its palatability properties, but with a reduced sweetness. When dead microorganism(s) are used, they are killed in a specific manner that preserves the enzymatic activity within the cells of the dead microorganism(s).

[0024] The process and products of the present invention are more advantageous than previously known processes for producing low sugar, high oligosaccharide and / or polysaccharide foods in that at least: (1) intact microbial cells (dead or live) are used, so that no expensive isolated enzymes or genetically modified microorganisms or enzymes need to be used, and the microbial cells are active in reducing the amount of monosaccharides and disaccharides present in the juice and converting sugars into oligosaccharide and / or polysaccharide(s); (2) the cells, especially the dead cells, can be immobilized and, if necessary, further packed into columns or beds for easy handling; (3) the reduction in sugar content results from the reduction in the content of saccharin, glucose, fructose and sucrose, all major sugars typically present in sweet foods; and (4) additional beneficial products are produced, including sorbitol and gluconic acid. Effect of the Invention

[0025] According to a particular aspect, the present invention provides a process for preparing a low-sugar, high-fiber food product, the process comprising contacting a starting food product containing sugars or a composition comprising sugars with at least one microbial cell active for reducing the sugar content of the starting food product and converting mono- or disaccharides into at least one oligosaccharide and / or polysaccharide, thereby obtaining a processed food product having a reduced sugar content and an increased content of at least one oligosaccharide and / or polysaccharide compared to the starting food product.

[0026] According to certain embodiments, the microbial cells are selected from the group consisting of dead cells, live cells, and combinations thereof. According to certain exemplary embodiments, the microbial cells are dead cells.

[0027] Any method known in the art for obtaining non-growing, non-viable, dead microbial cells that retain the activity of converting mono- or disaccharides to oligosaccharides and / or polysaccharides can be used in accordance with the teachings of the present invention.

[0028] According to certain exemplary embodiments, the dead microbial cells are obtained by exposing the live cells to about 50% to about 90% ethanol. According to further certain exemplary embodiments, the microbial cells are obtained by exposing the live cells to 50% to 90% ethanol for about 30 minutes.

[0029] It is expressly understood that, where applicable, dead microbial cells retain the integrity and / or functionality of the cell wall. The presence of a cell wall may aid in the use of dead microbial cells in suspension as well as in immobilized form according to certain embodiments of the invention. According to certain embodiments, the cell membrane (also called plasma membrane or plasmalemma) is at least partially disrupted.

[0030] According to certain embodiments, the dead microbial cells are immobilized in or on the matrix.

[0031] According to certain embodiments, the starting food or the composition comprising the starting food has a pH of less than 7.0. According to some embodiments, the pH of the starting food material or the composition comprising the starting food material is from about 2.5 to about 6.5.

[0032] According to a particular embodiment, the starting food product is a liquid.

[0033] According to a particular embodiment, the starting food product is a natural juice or ready-to-drink product containing sugar. According to a particular embodiment, the pH of the natural juice or ready-to-drink product is from about 2.5 to about 4.5.

[0034] According to certain embodiments, the resulting processed food further comprises at least one sugar alcohol. According to certain exemplary embodiments, the sugar alcohol is sorbitol. According to certain embodiments, the resulting processed food further comprises gluconic acid. According to certain exemplary embodiments, the resulting processed food further comprises sorbitol and gluconic acid.

[0035] According to certain embodiments, the resulting processed food contains reduced fructose, sucrose and glucose contents compared to the contents in the starting sugar-containing food.

[0036] According to certain embodiments, the processed food obtained by the process of the present invention has a taste and aroma similar to that of the starting food, and is less sweet.

[0037] According to certain embodiments, the conversion of mono- or disaccharides (glucose / fructose / sucrose) to oligosaccharides and / or polysaccharides is not associated with the production of harmful by-products that are not suitable for human consumption.

[0038] According to certain exemplary embodiments, the oligosaccharides or polysaccharides produced are polymers of fructose. According to some embodiments, the polymers of fructose are fructans, including short chain length oligosaccharides (fructooligosaccharides, FOS) and long chain length fructan polysaccharides. According to some exemplary embodiments, the fructan polysaccharide is a levan.

[0039] According to certain exemplary embodiments, the food product obtained by the process of the present invention comprises polysaccharide(s) at a concentration of about 1 mg to about 15 g per 100 ml of juice (0.001% to 15% w / v).

[0040] The starting food is contacted with the dead or live microbial cells for a time and under suitable conditions sufficient to reduce the sugar content of the starting food and convert the mono- or disaccharides, particularly fructose, glucose and sucrose, into polysaccharide(s). The exact incubation time and conditions depend on the type of starting food and the type of microbial cells used.

[0041] According to certain embodiments, when the starting food is a natural juice, the natural juice can be a clear juice, a juice suspension, or even a puree.

[0042] According to certain embodiments, contacting the microbial cells with the starting food or the composition comprising the starting food comprises adding dead or live microbial cells to the starting food or the composition comprising the starting food. According to these embodiments, the method further comprises, optionally after a required incubation time, separating the microbial cells from the processed food or the composition.

[0043] According to certain exemplary embodiments, the microbial cells are dead and the dead microbial cells are immobilized on or within the matrix.

[0044] According to some embodiments, contacting the microbial cells with the starting food or the composition comprising the starting food comprises adding a matrix containing dead immobilized microbial cells to the starting food or the composition comprising the starting food. According to these embodiments, the method further comprises separating the matrix from the food or the composition after the required incubation time. According to some embodiments, the matrix is ​​in the form of beads.

[0045] According to certain exemplary embodiments, the matrix is ​​packed in a bed or a column. According to these embodiments, contacting the microbial cells with the starting food or the composition comprising the starting food comprises passing the starting food or the composition comprising the starting food through a column. According to certain exemplary embodiments, the starting food or the composition comprising the starting food is passed through a column at a rate of 0.01 to 10 column volumes per hour.

[0046] According to certain embodiments, the microbial cells are selected from the group consisting of yeast, bacteria, and combinations thereof.

[0047] According to certain embodiments, the yeast is selected from the group consisting of Xanthophyllomyces dendrorhous, Kluyveromyces lactis, Ogataea polymorpha, Metschnikowia fructicola, Saccharomyces cerevisiae, yeast isolated from olives, and any combination thereof, with each possibility representing a separate embodiment of the present invention.

[0048] According to some embodiments, the yeast is Xanthophyllomyces dendrorhous.

[0049] In some embodiments, the yeast is a Crabtree negative species. As used herein, the term "Crabtree negative" refers to yeast that is characterized by little or no ethanol production under aerobic conditions and is characterized by a low rate of conversion of sugars to biomass, CO 2 and the ability of the yeast to convert water into yeast extract. According to these embodiments, the yeast is selected from the group consisting of Kluyveromyces lactis, Ogataea polymorpha, Metschnikowia fructicola, yeast isolated from olives, and any combination thereof.

[0050] According to certain embodiments, the bacterium is selected from the group consisting of Zymomonas mobilis, Acetobacter xylinum, Sarcina ventriculi, Gluconobacter xylinus, Pseudomonas sp. #142 (also known as Capriavidus sp. ATTC 55702), Microbacterium laevaniformans, Paenibacillus polymyxa, Bacillus licheniformis, Bacillus subtilis (formerly known as Bacillus subtilis natto), Bacillus macerans, Streptococcus salivarius, and the like. Salivarius, Leuconostoc mesenteroides, Aerobacter levanicum (also known as Herbicola), and any combination thereof. Each possibility represents a separate embodiment of the present invention.

[0051] According to certain exemplary embodiments, the microbial cells are dead cells of the bacterium Zymomonas mobilis.

[0052] According to additional exemplary embodiments, the microbial cells are dead cells of the bacterium Bacillus licheniformis.

[0053] According to certain embodiments, the process comprises contacting the starting food with a combination of dead or live cells of at least one yeast species and at least one bacterial or fungal species. The cells can be dead or viable. According to certain embodiments, a combination of dead and live cells is used.

[0054] According to certain exemplary embodiments, when a combination of yeast and bacterial or fungal cells is used, the yeast is selected from the group consisting of Xanthophyllomyces dendrorhous, Kluyveromyces lactis, Ogataea polymorpha, Metschnikowia fructicola, Saccharomyces cerevisiae, and yeast isolated from olives. Each possibility represents a separate embodiment of the invention. According to certain exemplary embodiments, the yeast is Kluyveromyces lactis. According to other exemplary embodiments, the yeast is Metschnikowia fructicola.

[0055] According to certain exemplary embodiments, when a combination of at least one yeast species and at least one bacterial species is used, the bacteria is selected from the group consisting of Zymomonas mobilis, Acetobacter xylinum, Sarcina ventriculi, Gluconobacter xylinus, Pseudomonas sp. #142 (also known as Capriavidus sp. ATTC 55702), Microbacterium labanifonans, Paenibacillus polymyxa, Bacillus licheniformis, Bacillus subtilis (formerly known as Bacillus subtilis natto), Bacillus macerans, Streptococcus salivarius, Leuconostoc mesenteroides, and Aerobacter labanicum (also known as Herbicola). Each possibility represents a separate embodiment of the present invention.

[0056] According to certain additional exemplary embodiments, when a combination of dead or live yeast cells and dead or live bacterial cells is used, the bacterial cells are cells of the bacterium Zymomonas mobilis. According to further exemplary embodiments, the bacterial cells are cells of the bacterium Bacillus licheniformis.

[0057] According to other exemplary embodiments, when the dead or live cells are fungal or yeast-fungal combination cells, the fungus is selected from the group consisting of Aureobasidium pullulans, Aspergillus japonicus, Aspergillus niger, Aspergillus foetidus, Aspergillus oryza, Sclerotinia sclerotiorum, and Scopulariopsis brevicaulis. Each possibility represents a separate embodiment of the invention. According to certain embodiments, the dead or live microbial cells are the fungus Aspergillus japonicus.

[0058] According to certain embodiments, a combination of dead yeast cells and dead bacterial or fungal cells is used, while according to other embodiments, a combination of live yeast cells and live bacterial or fungal cells is used.

[0059] According to certain embodiments, contacting the starting food with dead or live microbial cells comprises suspending the microbial cells in the starting food or a composition comprising the starting food, and the process further comprises isolating the microbial cells from the processed food or a composition comprising the processed food. According to certain currently exemplary embodiments, if the microbial cells are dead cells, contacting the starting food with dead microbial cells comprises passing a stream of the starting food or a composition comprising the starting food in contact with the dead, immobilized microbial cells, and the process further comprises collecting the processed food or a composition comprising the processed food.

[0060] The conditions under which the dead or live microbial cells are in contact with the starting food, including temperature, pH, oxygen concentration and duration, depend on the microbial cell species (including yeast, bacteria and fungi), combinations thereof and the type of starting food. Unexpectedly, the present invention now shows the conversion of fructose, glucose and sucrose into oligosaccharides and / or polysaccharides under acidic pH conditions. Acidic pH is the typical pH of natural juices.

[0061] According to some embodiments, the process further comprises repeating the step of contacting the starting food with dead or live microbial cells at least once.

[0062] According to certain embodiments, the process is run as a batch process, a semi-continuous process, a continuous process, or a combination thereof, with each possibility representing a separate embodiment of the present invention.

[0063] According to certain embodiments, the process further comprises an ethanol removal step. Ethanol removal can be carried out by any method known in the art. According to certain embodiments, the ethanol content in the obtained food product is less than 0.5% v / v. According to additional embodiments, the ethanol concentration is less than 0.1% (v / v).

[0064] According to some embodiments, the process further comprises adding an artificial sweetener to the resulting processed food having reduced sugar content and high oligosaccharide and / or polysaccharide(s) content.

[0065] According to some embodiments, sterilization conditions are maintained throughout the process. According to additional or alternative embodiments, the process further comprises pasteurizing the resulting processed food with reduced sugar content and increased oligosaccharide and / or polysaccharide(s) content.

[0066] According to yet additional embodiments, when the starting food is a juice or ready-to-drink liquid, the process further comprises concentrating the resulting processed beverage, with or without prior pasteurization, having a reduced sugar content and a high content of oligosaccharides and / or polysaccharide(s).

[0067] According to yet a further aspect, the present invention provides a processed food product having reduced sugar and calorie content and increased content of at least one oligosaccharide and / or polysaccharide selected from the group consisting of fructans and fructooligosaccharides (FOS), and further comprising at least one of sorbitol and gluconic acid, as compared to a corresponding starting unprocessed food product.

[0068] According to certain embodiments, processed foods having reduced sugar content, high polysaccharide content, and containing sorbitol and / or gluconic acid are produced by the process of the present invention.

[0069] According to certain embodiments, the processed food has at least one of fructose, glucose and sucrose content reduced compared to the corresponding starting unprocessed food.According to other embodiments, the at least one polysaccharide in the processed food is a polymer of fructose, including but not limited to fructan and fructooligosaccharide.According to some embodiments, the fructan is levan.

[0070] According to some embodiments, the processed foods having reduced sugar content, high polysaccharide content, and containing sorbitol and / or gluconic acid have comparable taste and aroma compared to the corresponding starting unprocessed foods with reduced sweetness.

[0071] According to additional embodiments, the processed food contains less than 0.5% ethanol. According to other embodiments, the processed food is essentially CO 2 Does not include.

[0072] According to certain embodiments, the processed food is essentially devoid of microbial cells. According to certain exemplary embodiments, the processed food is essentially devoid of microbial cells. According to certain embodiments, the processed food is essentially devoid of free enzymes. According to certain exemplary embodiments, the processed food is devoid of free enzymes.

[0073] According to certain exemplary embodiments, the starting raw food product is a natural juice or ready-to-drink product that contains sugar.

[0074] According to certain additional aspects, the present invention provides a process for reducing the sugar content of a starting food and converting mono- and disaccharides to at least one oligosaccharide and / or polysaccharide, comprising contacting the starting food or a composition comprising the starting food with at least one dead microbial cell active for reducing the sugar content of the food and converting mono- or disaccharides to at least one oligosaccharide and / or polysaccharide.

[0075] The at least one type of dead microbial cell is as described above. According to some exemplary embodiments, the at least one type of dead microbial cell is the bacterium Zymomonas mobilis.

[0076] According to some exemplary embodiments, the at least one dead microbial cell is the yeast Aureobasidium pullulans.

[0077] According to additional exemplary embodiments, the starting food product is contacted with a combination of Aureobasidium pullulans and Zymomonas mobilis.

[0078] According to certain embodiments, the at least one type of dead cell is immobilized in beads. According to some embodiments, the beads are packed in a column. According to these embodiments, the process comprises passing the starting food through a column to contact the starting food with at least one type of microbial cell.

[0079] Other objects, features and advantages of the present invention will become apparent from the following description and drawings. [Brief description of the drawings]

[0080] [Figure 1] Glucose and fructose levels in processed apple juice after passing through a column containing dead Zymomonas mobilis cells compared to the levels in the starting untreated juice. [Diagram 2] Demonstrate the reduction in sucrose concentration as a function of time. Using the yeast Aureobasidium pullulans, a 29% reduction is demonstrated after 18.5 hours. [Figure 3-1] Demonstrating the reduction of sugar content and the production of sorbitol and gluconic acid in apple juice after incubation with dead and fixed Zymomonas mobilis cells. Figure 3A: Sucrose content, Figure 3B: Sorbitol, Figure 3C: Gluconic acid. Control - starting apple juice. 2h - Content after 2 hours of incubation. 22h - Content after 22 hours of incubation. [Figure 3-2] Demonstrating the reduction of sugar content and the production of sorbitol and gluconic acid in apple juice after incubation with dead and fixed Zymomonas mobilis cells. Figure 3A: Sucrose content, Figure 3B: Sorbitol, Figure 3C: Gluconic acid. Control - starting apple juice. 2h - Content after 2 hours of incubation. 22h - Content after 22 hours of incubation. [Figure 4]The sugar content of apple juice changes during incubation with different microorganisms. Figure 4A: Kluyveromyces lactis. Figure 4B: Zymomonas mobilis. Figure 4C: Gluconobacter xylinus. [Figure 5-1] Figure 2 shows the change in BRIX of apple juice during incubation with different microorganisms. [Figure 5-2] Figure 2 shows the change in BRIX of apple juice during incubation with different microorganisms. [Figure 6] Showing a decrease in BRIX due to repeated contact with Bacillus licheniformis. [Figure 7-1] The effect of different growth conditions on the change in BRIX of apple juice incubated with Aspergillus japonicus is shown in Figure 7A: Effect of aeration and growth temperature, Figure 7B: Effect of juice pH, Figure 7C: Effect of yeast extract addition, Figure 7D: Effect of ammonium nitrate addition, Figure 7E: Effect of peptone or sucrose addition. [Figure 7-2] The effect of different growth conditions on the change in BRIX of apple juice incubated with Aspergillus japonicus is shown in Figure 7A: Effect of aeration and growth temperature, Figure 7B: Effect of juice pH, Figure 7C: Effect of yeast extract addition, Figure 7D: Effect of ammonium nitrate addition, Figure 7E: Effect of peptone or sucrose addition. [Figure 7-3] The effect of different growth conditions on the change in BRIX of apple juice incubated with Aspergillus japonicus is shown in Figure 7A: Effect of aeration and growth temperature, Figure 7B: Effect of juice pH, Figure 7C: Effect of yeast extract addition, Figure 7D: Effect of ammonium nitrate addition, Figure 7E: Effect of peptone or sucrose addition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0081] Detailed Description of the Invention The present invention provides a process for reducing the sugar content of sugar-containing foods, particularly natural juice drinks, while at the same time increasing the content of dietary fiber in the food, without negatively affecting other properties of the food, in particular only reducing sweetness, but not aroma and taste. The unique process of the present invention does not require the use of expensive and / or genetically engineered isolated enzymes, and is more advantageous than previously known processes at least in terms of the simplicity of engineering and employing intact microbial cells, particularly dead cells, which can be immobilized while retaining enzymatic function. The resulting processed food is low in calories while providing a feeling of satiety to the consumer, and retains the aroma and taste of the starting, particularly natural, food. The processed food does not contain large amounts of microbial cells or any enzymes. If the food is a juice, the juice obtained by the process of the present invention is not carbonated and is essentially devoid of alcohol.

[0082] The present invention now discloses contacting a sugar-containing food product with a particular type or types of microbial cells, particularly dead microbial cells that retain the sugar-lowering capacity and ability to convert mono- and disaccharides to oligosaccharides and / or polysaccharides that the corresponding live microbial cells have. In a particular embodiment, the present invention discloses a combination of cells (dead, alive or a combination thereof) of yeast and bacterial or fungal species that provide this dual activity.

[0083] definition The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0084] Unless the context clearly requires otherwise, throughout the specification, the words "include", "including", and the like, are to be construed in their inclusive sense, i.e., "including but not limited to," as opposed to their exclusive or exhaustive sense.

[0085] The word "about" as used herein should generally be understood to refer to both numbers in a numerical range and to refer to the numerical value ±5%. Furthermore, all numerical ranges herein should be understood to include each whole integer within the range.

[0086] As used herein, the term "monosaccharide" refers to a simple sugar such as glucose or fructose that is not hydrolyzed to obtain other sugars.

[0087] The term "disaccharide" as used herein refers to any compound containing two covalently linked monosaccharide units. This term includes, but is not limited to, compounds such as sucrose, lactose, and maltose. The term "sucrose" refers to a disaccharide composed of one mole of D-glucose and one mole of D-fructose, in which the C-1 carbon atom of glucose and the C-2 carbon atom of fructose are involved in a glycosidic bond.

[0088] The term "oligosaccharide" as used herein refers to a compound having 2-10 monosaccharide units linked by glycosidic bonds. The term "fructooligosaccharide" (FOS) refers to a short chain oligosaccharide composed of D-fructose and D-glucose units. For example, some FOS are composed of one molecule of D-glucose at the terminal position and 2-6 D-fructose units. The bond between the fructose residues in FOS is a β-(2-1) glycosidic bond.

[0089] The term "polysaccharide" as used herein refers to a polymeric carbohydrate molecule composed of long chains of monosaccharide units linked together by glycosidic bonds, which upon hydrolysis result in constituent monosaccharides or oligosaccharides. They range from linear to highly branched structures. According to certain embodiments, the polysaccharides of the invention are fructans. Fructans are usually constructed of sucrose units and fructose residues, (i.e. glucose-fructose disaccharides), at what is otherwise the reducing end. The position of the bond of the fructose residue determines the type of fructan. The bond usually occurs at one of the two main hydroxyl groups (OH-1 or OH-6), and there are two basic types of simple fructans: 1-bonds: in inulin, fructosyl residues are linked by β-2,1 bonds, 6-bonds: In levan (or phlein), the fructosyl residues are joined by β-2,6 bonds.

[0090] The third type of fructan, the graminan type, contains both β-2,1 and β-2,6 linkages.

[0091] The term "dietary fiber" refers to the indigestible portion of food of plant origin.Dietary fiber includes (1) soluble fiber that dissolves in water, can be easily fermented into gas and bioactive by-products in the colon, and can be prebiotic and viscous (which can delay gastric emptying and thus cause a prolonged feeling of satiety), and (2) insoluble fiber that does not dissolve in water, is metabolically inactive, and can provide bulk or is prebiotic and can be metabolically fermented in the large intestine (bulking fiber absorbs water as it moves through the digestive system and eases bowel movements).According to certain exemplary embodiments, the term "dietary fiber" is used herein to refer to soluble fiber.

[0092] As used herein, the terms "living cell", "viable cell" and "viable cell" in relation to microbial cells are used interchangeably herein and refer to cells that proliferate when grown on a compatible medium and are found to be viable when examined by a viability test (e.g., propidium iodide staining).

[0093] As used herein, the term "dead cells" refers to cells that do not proliferate when grown on a compatible medium and are found to be non-viable when examined by viability tests (e.g., propidium iodide staining), while retaining, at least to some extent, the ability of the corresponding viable cells to reduce sugar levels in foods and convert mono- or disaccharides to oligosaccharides and / or polysaccharides.

[0094] As used herein, the term "free enzyme" or "free enzymes" refers to an enzyme or enzymes that are not associated with a microbial cell (dead or living) or isolated enzymes. According to certain embodiments, the term refers to isolated enzyme(s) that are intentionally added to the starting food product.

[0095] As used herein, the terms "column volume / hour", "bed volume / hour" and "matrix volume / hour" are used interchangeably herein and refer to one unit volume of a variable passing through the same unit volume of matrix / bed / column within one hour.

[0096] According to one aspect, the present invention provides a process for preparing a low sugar, high fiber food product, comprising contacting a starting food product containing sugars or a composition comprising sugars with at least one type of dead or living microbial cells capable of reducing the sugar content of the food product and converting mono- or disaccharides into oligosaccharides and / or polysaccharides, thereby obtaining a food product with reduced sugar content and high oligosaccharide and / or polysaccharide content.

[0097] According to certain exemplary embodiments, the microbial cells are dead cells.

[0098] Methods for killing microbial cells while retaining the ability of dead microbial cells to convert mono- or disaccharides to oligosaccharides and / or polysaccharides are known in the art. Methods commonly used in the art include incubating live cells in solutions containing ethanol; bile salts or bile salt-like compounds (e.g., sodium cholate); detergents (e.g., Tween 20, SDS, Triton X100); aldehydes such as glutaraldehyde; or formaldehyde. As known to those skilled in the art, the solution concentration and microbial density of cells are determined depending on the type of solution and microbial cells.

[0099] According to certain exemplary embodiments, the dead cells are obtained by isolating the living microbial cells from the growth medium by centrifugation and incubating the pellet with 70% ethanol at a concentration of 1 g of cells in 1 liter of 70% ethanol for 1 hour. According to certain embodiments, at the end of the incubation, the cells are separated from the solution and fixed. According to some exemplary embodiments, the immobilization matrix is ​​alginate. The matrix containing the dead microbial cells can be further sterilized by circulation of 70% ethanol within the matrix.

[0100] According to a particular embodiment, the starting food product is a ready-to-drink product containing natural juice or sugar.

[0101] Any method known in the art for extruding juice from a raw material and, if necessary, pre-treating the resulting juice prior to subjecting it to the process of the present invention can be used with the teachings of the present invention.

[0102] According to certain embodiments, the juice is forced out of the raw material by squeezing or grinding. As used herein, the terms "squeezing" and "grinding" are intended to include any disintegration procedure that provides a fluid, paste, or suspension of any consistency or coarseness from the edible portion of the raw material. The squeezing or grinding provides the natural juice from which the juice product of the present invention is produced, which may have the consistency of a liquid, a suspended pulp, a mash, a slurry, or a puree. According to certain exemplary embodiments, the raw material is a fruit.

[0103] Any fruit or vegetable juice containing sugar can be processed according to the teachings of the present invention.Thus, the process is equally applicable to apple, cranberry, pear, peach, plum, apricot, nectarine, grape, cherry, currant, raspberry, gooseberry, blackberry, blueberry, strawberry, lemon, orange, grapefruit, potato, tomato, celery, rhubarb, carrot, radish, cucumber, pineapple, custard apple, coconut, pomegranate, kiwi, mango, papaya, banana, watermelon and cantaloupe.Each possibility represents a separate embodiment of the present invention.According to some exemplary embodiments, the juice is apple, pear, cranberry, orange, strawberry, grape or cherry.Each possibility represents a separate embodiment of the present invention.

[0104] The process of the present invention combines the production of dietary fiber in foods, particularly juices, and the reduction of sugar content of natural juices in an efficient and cost-effective manner. The use of microorganisms as producers of the enzymes necessary for such conversion of monosaccharides to dietary fiber eliminates the need to separate and purify the enzymes. The use of dead microbial cells is even more convenient as dead cells, once produced, are not affected by environmental conditions, and furthermore, the enzyme activity is not subject to rate-limiting conditions, such as substrate feedback inhibition. Unexpectedly, the conversion of monosaccharides to oligosaccharides and / or polysaccharides according to the teachings of the present invention also occurred at acidic pH. Previously, enzymes active in such conversions were shown to be active only at approximately natural pH. According to certain exemplary embodiments, the dead microbial cells are immobilized in a matrix, typically in beads. The microbial cell-containing matrix can be added directly to the natural juice or a composition comprising the natural juice, such that contact between the natural juice and the microbial cells occurs during incubation. Alternatively, the microbial cell-containing matrix is ​​packed to form a bed or column, and the natural juice is contacted with the microbial cells by passing the natural juice through the bed or column.

[0105] As used herein, the term "reduced sugar content" or "reduced sugar content" refers to a concentration level of sugars, particularly glucose, fructose and sucrose, in a food product, particularly a natural juice, that is less than the concentration level of sugars in a corresponding food product that has not been contacted with microbial cells according to the teachings of the present invention.

[0106] According to certain embodiments, the total sugar content in the processed food obtained by the process of the present invention is reduced by at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, and 95% or more compared to the total sugar content in the starting food. According to some embodiments, the fructose content in the processed food is reduced by at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, and 95% or more compared to the content in the starting food. According to some embodiments, the sucrose content in the processed food is reduced by at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, and 95% or more compared to the content in the starting food. According to some embodiments, the glucose content in the processed food is reduced by at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, and 95% or more compared to the content in the starting food.

[0107] According to certain embodiments, the process of the present invention provides a stable production of oligosaccharides and / or polysaccharides, i.e. no or only a small reduction in the content of oligosaccharides and / or polysaccharides in the processed food.

[0108] According to certain exemplary embodiments, when the processed food obtained by the process of the present invention is a juice, the juice comprises oligosaccharides and / or polysaccharides in a concentration of 1 mg to 15 g per 100 ml juice (0.001% to 15% w / v).

[0109] According to certain embodiments, the process comprises contacting the starting food with a combination of dead or live cells of at least one yeast species and at least one bacterial or fungal species.

[0110] According to certain embodiments, the starting food is contacted simultaneously with a combination of cells of at least one yeast species and cells of at least one bacterial or fungal species. According to other embodiments, the starting food is contacted with cells of at least one yeast species and sequentially with cells of at least one bacterial or fungal species. According to certain exemplary embodiments, the starting food is first contacted with at least one yeast species and then with at least one bacterial or fungal species.

[0111] The resulting low-calorie, high-fiber food, especially beverage, essentially contains the same nutritional benefits as the original food, fruit or vegetable juice, but is significantly lower in calories due to the removal of sugar and its conversion to dietary fiber and sugar alcohols. Advantageously, the resulting processed food may further contain gluconic acid, which is known in the food industry as an acidity regulator and may thus contribute to the stability of the resulting product. Moreover, gluconic acid adds no calories to the resulting food (its caloric value is 0) and may act as a carrier for iron, calcium and other ions that may be present in the food, based on its ability to form gluconate salts with such ions. Gluconate salts provide better bioavailability of these essential trace elements.

[0112] However, it should be understood that not all sugars must be removed / converted to obtain the reduced calorie, high dietary fiber processed food of the present invention.

[0113] According to certain embodiments, the food products of the present invention may have 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10% or less of the calorie content of the food product from which it is derived, while at the same time, the reduced calorie food product may have a taste profile and mouth feel comparable to the starting food product.

[0114] In some foods, the reduction in inherent sugar content may affect the taste of the product as consumers expect it to be. In some cases, natural or artificial sweeteners can be added to add sweetness. The sweetener(s) may be selected according to the desired nutritional characteristics, taste profile, and other factors. In certain embodiments, the sweetener is selected from the group consisting of, but not limited to, erythritol, tagatose, sorbitol, mannitol, xylitol, rhamnose, trehalose, aspartame, cyclamate, saccharin, sucralose, glycyrrhizin, malitol, lactose, Lo Han Guo, rebaudioside, steviol glycoside, xylose, arabinose, isomalt, lactitol, maltitol, and any combination thereof. Each possibility represents a separate embodiment of the present invention.

[0115] When the food product of the present invention is a juice drink, it can also be used as a flavoring agent or as a dietary fiber supplement in the drink or food. The sugar-reduced drink can further be used as an ingredient for low-calorie products (e.g., jellies, fillings, fruit preparations, candies, or cakes, etc.).

[0116] The reduced calorie, high dietary fiber beverages of the present invention can be concentrated from 10% to 90% or more, if desired. The concentrate has a significantly reduced volume compared to standard juice concentrations due to the reduction in sugar. Processing costs for concentrated juice are significantly reduced due to the absence of sugar in the juice stream. The reduced sugar concentrate, due to its lower volume, has significantly lower refrigerated shipping and storage costs compared to standard concentrates. Thermal, aromatic, and nutritional degradation of the juice is also reduced because the concentration process requires less heat and time.

[0117] The following examples are presented to more fully illustrate some embodiments of the present invention. However, they should in no way be construed as limiting the broad scope of the present invention. Those skilled in the art can easily devise many variations and modifications of the principles disclosed herein without departing from the scope of the present invention.

[0118] Working Example Materials and Methods Microbial growth conditions The bacterium Zymomonas mobilis was cultured under anaerobic conditions at 30 °C in growth medium containing 2% yeast extract and 2% glucose for 48 h (or up to 10 9 The cells were grown to a concentration of 1000 cells / ml.

[0119] The yeast Aureobasidium pullulans was grown for 48 h in a growth medium of 2.4% potato dextrose broth under aerobic conditions at 30°C.

[0120] The yeasts Kluyveromyces lactis, Ogataea polymorpha, Metschnikowia fructicola, Xanthophyllomyces dendrorhous or yeasts isolated from olives; the bacteria Gluconobacter xylinus, Pseudomonas sp. #142, Microbacterium levaniformans, Paenibacillus polymyxa, or Bacillus licheniformis; or the fungus Aspergillus japonicus were each grown for 48 h in their specific growth media. X. dendrorhous was incubated at 20°C. K. lactis, Pseudomonas sp. #142, yeasts isolated from olives, P. polymyxa, A. japonicus, and G. xylinus were incubated at 30°C. O. polymorpha and M. fructicola were grown at room temperature, and B. licheniformis and M. levaniformans were grown at 37°C. All cultures were rotated at 200 RPM in 500 ml flasks while Z. mobilis was incubated anaerobically at 30°C.

[0121] Acquisition of dead microbial cells Bacteria, yeast or fungi were grown as described above. After the culture reached the desired cell density, the cells were centrifuged and immediately suspended in 70% ethanol for 1 hour. The suspension was then centrifuged to form a cell pellet. To confirm the growth potential of the cells, a sample of cells from the pellet was placed on growth medium. If no growth was observed, the cells in the pellet were designated "dead microbial cells". If necessary, a viability test is performed using propidium iodide staining or other known viability staining procedures before the cells are designated "dead cells".

[0122] Sugar determination: Sugars (disaccharides, monosaccharides, and sugar alcohols) were separated on an analytical HPLC system (Pump System 320, Kontron, Switzerland) equipped with a SugarPak I column (6.5 × 300 mm, Waters, Milford, MA) using a refractive index detector (LDC Analytical, Riviera Beach, FL). Water was used as the solvent at a flow rate of 0.5 ml / min.

[0123] FOS / Levan Quantification FOS / levan was precipitated from treated and untreated juice samples with 1.5 volumes of isopropanol. The precipitate was air-dried and further dried at 37° C. for 48 h and weighed or resuspended in 0.1 M HCl and hydrolyzed at 100° C. for 1 h. The monosaccharides produced were quantified by HPLC.

[0124] Acetic acid analysis Quantitative analysis of acetate ions in the samples was performed using an ion chromatograph equipped with an ion conductivity detector (Dionex ICS 3000). Anions were separated on a hydroxide-selective anion-exchange analytical column (AS11, 250 × 4 mm, Dionex).

[0125] Ethanol Analysis Qualitative and quantitative analysis of ethanol was made using an Agilent model 5973N MSD mass spectrometer (MS) with a 7683 autosampler and a model 6890 gas chromatograph (GC) (Agilent, Palo Alto, CA) equipped with a 30 m x 0.25 μm id HP-5 (crosslinked phenylmethylsiloxane) column with a film thickness of 0.25 μm id. The initial oven temperature was maintained at 40°C for 6 minutes. The temperature was then increased to 150°C at a rate of 2.5°C / min and finally to 250°C at a rate of 90°C / min. The injector and ion source were maintained at 250°C and 280°C, respectively. The split ratio was 10:1, and 2 μL of sample was injected. There was a 2 minute solvent delay, after which mass spectra were collected from m / z 35 to 300 at 5.27 scans / sec. Compound identification was performed by comparing mass spectra and retention times with those of the corresponding reference standards (Aldrich Chemical Co., St. Louis, MO; Bedoukian Research, Danbury, CT). For the purpose of quantifying the identified components, a linear regression model was determined using a standard dilution method with cyclohexanone as the internal standard. Target ions were used to identify and quantify each component by the mass spectrometry system.

[0126] BRIX decision BRIX (or Degrees Brix, symbol Bx) is the sugar content of an aqueous solution. One degree of BRIX is 1 gram of sucrose in 100 grams of solution. BRIX was determined using a ref-85 digital refractometer.

[0127] Immobilization of dead microbial cells within and / or on the beads A matrix of immobilized beads and dead microbial cells was prepared as follows: A 1000 ml composite solution was prepared as follows: Solution A: 100 mg / l Na 2 -10 g sodium alginate (SIGMA) in 500 ml of EDTA solution Solution B: 100 mg / l Na 2-10 g of Gelrite (SIGMA) in 500 ml of EDTA solution Solutions A and B were sterilized separately at 120° C. for 20 minutes and then mixed while still warm.

[0128] The composite solution was then cooled to room temperature and the dead microbial cell pellet prepared as described above was resuspended in the solution. The cell concentration was at least 4% wet weight per volume (wet w / v). Typically, the cell concentration was 6% wet w / v.

[0129] Cell capture Prior to the entrapment procedure, the complex solution-cell mixture was homogenized. Any debris remaining in the homogenate was removed by filtration from the homogenate.

[0130] The mixed complex cell solution was then diluted with 1% CaCl2 at pH 6.2-6.8 containing 0.005% chitosan (high molecular weight, FLUKA). 2 The solution was added dropwise to the beads. The preferred average diameter of the resulting beads should be 2 mm or less to enlarge the ratio between the surface area of ​​the beads and their mass. After the beads were formed, the solution was stirred at 25° C. for 4 hours. The solution containing the microbial dead cell beads was then transferred to 4° C. for 24 hours. The beads were transferred to a column using a wide open funnel, and the bottom valve was opened to ensure the removal of access liquid and to keep all the beads in the column. The column was washed with 10 bed volumes at a flow rate of 1 bed volume / hour to remove the remaining calcium chloride.

[0131] Example 1: Changes in sugar content of apple juice in contact with immobilized dead cells of Zymomonas mobilis Dead cells of Zymomonas mobilis were immobilized and packed into the column as described above. Commercial apple juice was passed through the column at a rate of 0.2 bed volumes (BV) / h. Glucose and fructose levels were determined as described in the Materials and Methods section above. Figure 1 clearly shows the reduction in the content of both sugars in the treated juice.

[0132] Example 2: Time course of sugar content in apple juice exposed to immobilized dead cells of Aureobasidium pullulans Commercial apple juice was incubated with chitosan beads containing dead immobilized Aureobasidium pullulans yeast cells for 18.5 h at 30°C. Samples were collected at 0, 7 and 18.5 h. Sucrose concentrations were measured by HPLC at the Volcani center, Agriculture Research Organization.

[0133] Figure 2 shows that the sugar content in the juice decreased continuously. After 18.5 h of incubation with the immobilized yeast Aureobasidium pullulans, the sugar content decreased by 29%.

[0134] Example 3: Polysaccharide production in apple juice in contact with immobilized dead cells of Zymomonas mobilis FOS and / or levan production was investigated in apple juice contacted with dead, immobilized Zymomonas mobilis cells at various temperatures. The juice was passed through a column containing dead, immobilized bacteria at a rate of 0.2 BV / hr. 10 ml of treated juice, and the source untreated starting juice product, were taken for FOS / levan analysis as described in the "Materials and Methods" section above. The results are shown in Table 1 below.

[0135] Table 1: Levan / FOS production in apple juice passed through immobilized dead cells of Z. mobilis at different temperatures. [Table 1]

[0136] As can be seen from Table 1, the highest levan / FOS content was obtained when the juice was contacted with immobilized dead Z. mobilis cells at a temperature of 55°C.

[0137] The possibility that higher levan / FOS levels could be obtained by re-incubating the juice from the first run (1 BV / hr) with immobilized dead Z. mobilis cells for a longer period was investigated. Therefore, the juice was incubated with immobilized dead Z. mobilis cells for 11 or 23 days. The results are shown in Table 2 herein below (day "0" represents the juice after the first run).

[0138] Table 2: Levan and / or FOS production in apple juice incubated with immobilized dead cells of Z. mobilis as a function of incubation time. [Table 2] As can be seen from Table 2, there is no advantage to further incubation of the juice obtained after the first run.

[0139] Example 4: Changes in sugar content of apple juice in contact with immobilized dead cells of Zymomonas mobilis Beads with immobilized dead cells of the bacterium Zymomonas mobilis were prepared as described above. Commercial apple juice was incubated with the dead immobilized bacterial cells for 18.5 h. Samples were taken at 0, 7 and 18 h. Sugar content was measured using GC-MS at the Interdepartmental Unit of the Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem.

[0140] The sucrose content was significantly reduced as fast as after 2 hours of incubation. At the end of the experiment, the sucrose content was about 18% of its initial concentration (Table 3). Unexpectedly, under these conditions, sorbitol (Figure 3, Table 3) and gluconic acid (Figure 3) were produced. As is evident from Figures 1 and 3, using the process of the present invention, the concentrations of all the major sugars in apple juice (sucrose, glucose and fructose) were significantly reduced. As shown in Table 2 above, sugars were converted to fructooligosaccharides (FOS) and fructopolysaccharides (levan).

[0141] Table 3: Sugar reduction and sorbitol accumulation in apple juice incubated with immobilized Zymomonas mobilis dead cells. [Table 3]

[0142] Example 5: Effect of culture conditions of live microbial cells on sugar content of juice The microbial cells first incubated with diluted apple juice were harvested, washed, and then resuspended in apple juice to test their ability to reduce sugar content.

[0143] K. lactis, O. polymorpha, M. fructicola, Z. mobilis, G. xylinus, Pseudomonas sp. #142, yeast isolated from olives, B. licheniformis, P. polymyxa, X. dendrorhous or M. levaniformans were grown for 48 h in their specific growth media diluted 1:200 in 100 ml of apple juice adjusted to pH 7.0 with KOH (except for X. dendrorhous which was diluted in fresh apple juice) and grown for a further 48 h. The cells were centrifuged and the pellet washed twice with distilled water (DW). The pellet was resuspended in 10 ml of apple juice and 1.8 × 10 for yeasts and bacteria, respectively. 9 or 1.8 x 10 10 The concentration was adjusted to CFU / ml.

[0144] The cells were then incubated with rotation as described above. Samples were taken at the indicated times and OD 600 The samples were tested for sugar content, sugar content, and FOS content. BRIX values ​​were also determined. Designated samples were analyzed for ethanol or acetic acid content.

[0145] All microorganisms tested (except Pseudomonas sp. #142) were able to reduce the sugar content, albeit at different rates. Representative data is shown in FIG. 4. K. lactis reduced the sucrose content from 2.8% to 0.065% in only about 0.5 hours, the glucose content from 3% to 0.005% in 2.5 hours, and the fructose content from 7% to 0.33% in 3 hours. Z. mobilis reduced all sugars to nearly zero after 25.5 hours. G. xylinus was able to reduce only the glucose content, and only after 105.5 hours of incubation. Analysis of acetate production revealed that G. xylinus produced acetate under these experimental conditions. It was therefore concluded that G. xylinus was not suitable for use in the process of the present invention.

[0146] Example 6: Changes in BRIX of apple juice during incubation with different live microbial cells As shown in Figure 5, yeast isolated from olives reduced the BRIX of apple juice in the fastest manner, resulting in a BRIX of about 6 within about 2 hours of incubation. It took 2.5 hours of incubation with M. fructicola, 3.5 hours with K. lactis, 5.5 hours with Z. mobilis and 19.5 hours with O. polymorpha to reduce the apple juice BRIX to the same value (about 6). M. labanniformans and P. polymyxa were also found to have a minor effect, reducing the BRIX to about 10 after 23 hours. B. licheniformis was found to be ineffective in reducing the BRIX value maintained during the 24 hour incubation.

[0147] Samples for ethanol analysis were taken when the samples reached a BRIX of about 9 and about 6. Ethanol content analysis revealed that K. lactis, Z. mobilis and M. fructicola produced ethanol under the experimental conditions tested, as listed in Tables 4-8. O. polymorpha produced the least amount of ethanol when the samples reached a BRIX of about 9. M. fructicola produced the least amount of ethanol when the samples reached a BRIX of about 6. B. licheniformis produced no ethanol. It is noted that when baker's yeast S. cerevisiae was tested under the same conditions, the amount of ethanol was similar to that obtained with Z. mobilis.

[0148] Table 4: BRIX values ​​and ethanol content in apple juice incubated with K. lactis [Table 4]

[0149] Table 5: Ethanol content in apple juice incubated with Z. mobilis [Table 5]

[0150] Table 6: Ethanol content in apple juice incubated with M. fructicola [Table 6]

[0151] Table 7: Ethanol content in apple juice incubated with O. polymorpha [Table 7]

[0152] Table 8: Ethanol content in apple juice incubated with yeasts isolated from olives. [Table 8]

[0153] Because B. licheniformis did not produce ethanol, we investigated whether incubating apple juice with two different batches of the bacteria would help reduce BRIX levels. 10 It was found that soaking CFU / ml of B. licheniformis for 30 minutes reduced the BRIX to 10.1, while soaking an additional batch of bacteria in the same juice reduced the BRIX to 8.8 (Figure 6). Advantageously, no ethanol or acetic acid was produced.

[0154] Example 7: Polysaccharide Production FOS production by live Z. mobilis was investigated as follows: bacteria were soaked in apple juice for 22 hours. FOS were then precipitated and hydrolyzed from the treated juice or from untreated samples. Monosaccharide content was then analyzed, revealing a 1.6-fold increase in glucose content and a 1.4-fold increase in fructose content in the bacteria-treated juice. This result indicates the formation of FOS by Z. mobilis in this experimental system.

[0155] FOS content was further assessed during the incubation period using Z. mobilis, P. polymyxa, or X. dendrorhous. Samples were taken at the indicated times and FOS was precipitated and weighed. The results are shown in Table 9 below.

[0156] Table 9: FOS content (mg / 100ml juice) [Table 9]

[0157] As can be seen from Table 9, the highest FOS contents were obtained for different microorganisms at different incubation times. An incubation time of 5.5 hours proved to be the most effective for Z. mobilis and P. polymyxa, whereas an incubation time of 12 hours was the most effective for X. dendrorhous. M. labanifonans formed only a small amount of FOS under the experimental conditions.

[0158] The possibility of obtaining higher FOS levels was investigated by re-incubating apple juice once treated with FOS-forming microorganisms for 5.5 hours with a second batch of the microorganisms for 5 hours. After the second incubation time, the FOS content in apple juice incubated with P. polymyxa was 70 mg / 100 ml of juice, the FOS content in apple juice incubated with Z. mobilis was 110 mg / 100 ml, and the FOS content in apple juice incubated with X. dendrorhous was 190 mg / 100 ml. Thus, only for X. dendrorhous, the second incubation time was significant for the further production of FOS.

[0159] Example 8: Examination of the effect of different growth conditions on the BRIX-reducing activity of live A. japonicus To investigate the effect on BRIX reduction and FOS yield, the growth experiment with A. japonicus was repeated using different growth conditions. The control conditions were as described above (aerobic, 30 °C) but with more aeration. The following conditions were investigated: aeration and growth temperature (Figure 7A); juice pH of 5.6 or juice pH titrated daily to pH = 7 (Figure 7B); addition of 0.1% or 1% yeast extract (Figure 7C); addition of 0.1% or 1% ammonium nitrate (Figure 7D); addition of 1% peptone or 1% sucrose (Figure 7E). BRIX was checked at the indicated times.

[0160] As can be seen from Figure 7, the BRIX values ​​were most significantly decreased when the fungus was grown in apple juice containing 1% yeast extract under aerobic conditions at 30°C. Under all the specified growth conditions, FOS production by A. japonicus was negligible.

[0161] The above description of the specific embodiments fully reveals the general nature of the present invention, so that such specific embodiments can be easily modified and / or adapted to various applications by applying current knowledge without undue experimentation and without departing from the general concept, and such adaptations and modifications should and are intended to be understood within the meaning and range of equivalents of the disclosed embodiments. It should be understood that the expressions or terminology used herein are for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention.

[0162] This application may include the following inventions. (1) 1. A process for preparing a low sugar, high fiber food product, comprising the steps of: reducing the sugar content of a starting food product; contacting a starting food product containing sugars or a composition comprising sugars with at least one type of microbial cell active for converting monosaccharides or disaccharides into at least one type of oligosaccharide and / or polysaccharide; thereby obtaining a processed food product having a reduced sugar content and an increased content of at least one type of oligosaccharide and / or polysaccharide compared to the starting food product. (2) 2. The process of claim 1, wherein the microbial cells are selected from the group consisting of dead cells, live cells, and combinations thereof. (3) The process according to any one of (1) to (2), wherein the microbial cells are dead microbial cells. (4) The process according to (3), wherein the dead microbial cells are fixed. (5) The process according to any one of (1) to (4), wherein the microbial cells are selected from the group consisting of yeast cells, bacterial cells, and combinations thereof. (6) 6. The process according to claim 5, wherein the microbial cells are cells of a yeast selected from the group consisting of Xanthophyllomyces dendrorhous, Kluyveromyces lactis, Ogataea polymorpha, Metschnikowia fructicola, Saccharomyces cerevisiae, yeast isolated from olives, and any combination thereof. (7) The process according to any one of (5) to (6), wherein the bacterial cell is selected from the group consisting of Zymomonas mobilis, Bacillus licheniformis, Paenibacillus polymyxa, and any combination thereof. (8) The process described in (7) above, wherein the microbial cells are Zymomonas mobilis cells. (9) The process according to any one of (1) to (8), wherein the process comprises contacting the starting food or a composition comprising the starting food with a combination of microbial cells of at least one yeast species and at least one bacterial or fungal species. (10) 10. The process according to claim 9, wherein the yeast cell species is selected from the group consisting of Kluyveromyces lactis, Ogataea polymorpha, Metschnikowia fructicola, Saccharomyces cerevisiae, Xanthophyllomyces dendrorhous and yeast isolated from olive. (11) The species of bacterial cells include Acetobacter xylinum, Sarcina ventriculi, Zymomonas mobilis, Gluconobacter xylinus, Pseudomonas species #142, Microbacterium laevaniformans, Paenibacillus polymyxa, Bacillus licheniformis, Bacillus subtilis, Bacillus macerans, Streptococcus salivarius, Leuconostoc mesenteroides, and the like. The process according to any one of (9) to (10), wherein the bacterium is selected from the group consisting of Aerobacter mesenteroides and Aerobacter levanicum. (12) 11. The process according to any one of (9) to (10), wherein the species of the fungal cell is selected from the group consisting of Aspergillus japonicus, Aspergillus niger, Aspergillus foetidus, Aspergillus oryzae, Aureobasidium pullulans, Sclerotinia sclerotiorum and Scopulariopsis brevicaulis. (13) The process according to any one of (1) to (12), wherein the starting food or a composition comprising the starting food has a pH of less than 7.0. (14) The process according to any one of (1) to (13), wherein the starting food product is selected from the group consisting of natural juices and ready-to-drink products containing sugar. (15) 15. The process according to (14), wherein the starting food product is a natural juice obtained from a fruit or vegetable selected from the group consisting of apple, cranberry, pear, peach, plum, apricot, nectarine, grape, cherry, currant, raspberry, gooseberry, blackberry, blueberry, strawberry, lemon, orange, grapefruit, potato, tomato, celery, rhubarb, carrot, radish, cucumber, pineapple, custard apple, coconut, pomegranate, kiwi, mango, papaya, banana, watermelon and cantaloupe. (16) The process according to any one of (1) to (15), wherein the starting food contains a sugar selected from the group consisting of glucose, fructose, sucrose, and any combination thereof. (17) The process according to any one of (1) to (16), wherein contacting the starting food or a composition comprising the starting food with the microbial cells comprises adding the microbial cells to the food or a composition comprising the food. (18) 18. The process according to (17), further comprising separating the microbial cells from the food or a composition comprising the food after an incubation period. (19) 5. The process of claim 4, wherein the dead immobilized microbial cells are packed in a bed or column. (20) 20. The process of claim 19, wherein contacting the starting food with the dead immobilized microbial cells comprises passing a flow of the starting food or a composition comprising the starting food through the bed or column and collecting the processed food or a composition comprising the processed food. (twenty one) 20. The process of claim 19, wherein the flow of food or food-containing composition passes through the bed or column at a rate of 1 bed volume per hour. (twenty two) The process according to any one of (1) to (21), further comprising an ethanol removal step. (twenty three) The process according to (22), wherein the ethanol concentration in the processed food is less than 0.5% (v / v). (twenty four) The process according to any one of (1) to (23), wherein the processed food contains a reduced amount of sugar selected from the group consisting of glucose, fructose, sucrose, and any combination thereof, compared to the sugar content in the starting food. (twenty five) The process according to any one of (1) to (24), wherein the processed food contains an increased amount of at least one of a sugar alcohol and gluconic acid compared to the amount in the starting food. (26) 26. The process according to claim 25, wherein the sugar alcohol is sorbitol. (27) The process according to any one of (1) to (26), wherein the processed food contains an increased amount of at least one oligosaccharide and / or polysaccharide compared to the amount in the starting food. (28) 28. The process according to claim 27, wherein the oligosaccharide is a fructooligosaccharide (FOS). (29) The process according to any one of (27) to (28), wherein the polysaccharide is a fructan. (30) The process according to (29), wherein the fructan is levan. (31) The processed food is basically CO 2 The process according to any one of (1) to (30), which does not include (32) The process according to any one of (1) to (31), wherein the processed food has a taste and aroma equivalent to that of the starting food with reduced sweetness. (33) A processed food produced by the process according to any one of (1) to (32), having a reduced sugar content and an increased oligosaccharide and / or polysaccharide content compared to the starting unprocessed food. (34) 34. The processed food of claim 33, wherein the processed food is essentially devoid of microbial cells. (35) The processed food according to any one of (33) to (34), wherein the processed food essentially lacks a free enzyme or a plurality of free enzymes. (36) A processed food having reduced sugar and calorie content, increased oligosaccharide and / or polysaccharide content, and a pleasant taste compared to a corresponding unprocessed food, wherein the polysaccharides are selected from the group consisting of fructans and fructooligosaccharides (FOS), and further comprising at least one of sorbitol and gluconic acid. (37) The processed food according to (36), having a reduced content of at least one of fructose, glucose and sucrose, as compared to a corresponding unprocessed food. (38) The processed food according to any one of (36) to (37), wherein the processed food contains less than 0.5% (v / v) ethanol. (39) The processed food is essentially CO 2 The processed food according to any one of (36) to (38), which does not contain. (40) The processed food according to any one of (36) to (39), wherein the processed food essentially lacks a free enzyme or a plurality of free enzymes. (41) The processed food according to any one of (36) to (40), wherein the processed food is a juice drink.

Claims

[Claim 1] A processed juice beverage having a reduced sugar content, an increased content of at least one oligosaccharide and / or polysaccharide selected from the group consisting of fructans and fructooligosaccharides (FOS), and a pleasant taste compared to a corresponding unprocessed natural juice, the processed juice beverage further comprising at least one of sorbitol and gluconic acid.

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