Abstract: This invention relates to a process for the manufacture of crystal sugar from an aqueous sugar juice containing sugars and organic and mineral impurities, including Ca.sup.2+ and/or Mg.sup.2+ ions, such as a sugar cane or sugar beet juice, comprising the following operations:(a) concentration of said sugar juice to give a syrup, and(b) crystallization of said syrup to give a crystal sugar and a molasses,characterized in that it also comprises an operation:(c) of tangential microfiltration, tangential ultrafiltration or tangential nanofiltration, this operation being effected before operation (a).It also relates to a process for the production of crystal white sugar from a sugar juice of the sugar cane juice type, comprising the above-mentioned process for the production of crystal sugar, completed by re-melt, decolorization and crystallization operations.

Abstract: A process for decolorizing and demineralizing a sugar solution without the need for using cation exchange resins or activated carbon. The process includes the steps of contacting the sugar solution with a macroporous polymeric adsorbent having cationic functional sites to decolorize and demineralize the sugar solution, and contacting the sugar solution with an anion exchange resin to further demineralize the sugar solution.

Abstract: A method and an apparatus for making a simple sugar solution from a liquid solution including at least one compound sugar by performing hydrolysis in the presence of a heterogeneous catalyst. The method comprises contacting the hydrolysis reaction medium with at least one microporous solid adsorbent compound selected for compatibility with the hydrolysis and . catalysis conditions and for selectively adsorbing by-products other than simple sugars under the hydrolysis reaction conditions. A pure, colourless, food-grade simple sugar solution is achieved.

Abstract: A process to produce solid glucose from a hydrolyzate consisting of a mixture of glucose, water, and an acid used in the hydrolysis of a biomass material is covered herein. In the process, the hydrolyzate is concentrated, as required, to form two phases: a solid glucose phase and an acidic liquid phase. The phases are formed in a vessel where they are separated for recovery of the acidic liquid phase. The solid glucose phase, containing residual acidic liquid phase, is then extracted to remove most of the residual acid to produce solid glucose mostly free of acid. The recovered acid may then be recycled. The solid glucose may be further processed including purification and also drying.

Abstract: A process for refining a raw sugar, particularly raw sugar from the sugar cane sugar industry, characterized in that it comprises the steps of:(a) remelting of the raw sugar for obtaining a raw sugar syrup,(b) carbonatation or phosphatation of said raw sugar syrup, and(c) tangential microfiltration and/or tangential ultrafiltration of the raw sugar syrup, which has been subjected to carbonatation or phosphatation.The process is completed by the steps of:(d) decolorization of the sugar syrup resulting from step (c), and(e) crystallization and/or demineralization of the sugar syrup resulting from step (d).

Abstract: A pulp of milled agave plant heads are liquified during centrifugation and a polyfructose solution is removed and then concentrated to produce a polyfructose concentrate. Small particulates are removed by centrifugation and/or filtration and colloids are removed using termic coagulation techniques to produce a partially purified polyfructose extract substantially free of suspended solids. The polyfructose extract is treated with activated charcoal and cationic and anionic resins to produce a demineralized, partially hydrolyzed polyfructose extract. This partially hydrolyzed polyfructose extract is then hydrolyzed with inulin enzymes to produce a hydrolyzed fructose extract. Concentration of the fructose extract yields a fructose syrup.

Abstract: The invention relates to a process for the manufacture of a starch hydrolysate of low polymolecularity index which may be used in particular in continuous ambulatory peritoneal dialysis. This process consists essentially in acid and enzymatic hydrolysis of a waxy starch milk and then chromatography on macroporous strong cationic resins of the hydrolysate obtained. The starch hydrolysate is essentially characterized by a polymolecularity index of less than 2.8, a weight-average molecular weight between 5,000 and 22,500 daltons and a number-average molecular weight below 8,000 daltons.

Abstract: Plasticized liquid membranes and processes for separating monosaccharides from disaccharides and from other monosaccharides employing the membranes are provided. Fructose is separated from glucose via the membrane process to provide fructose in concentrations sufficient for HFS (high fructose syrup) and sucrose, glucose and fructose are separated from crude sources such as molasses, sugar cane juice and beet sugar juice. The plasticized membranes are prepared by dissolving a lipophilic polymer such as cellulose triacetate, an organic liquid plasticizer such as a hydrophobic ether compound e.g. 2-nitrophenyloctyl ether and, a carrier compound such as a quaternary ammonium salt or a boronic acid compound with lipophilic substitution in a suitable solvent which upon evaporation provides the plasticized membrane. The membrane produced is homogeneous having all three components equally dispersed in the membrane.

Abstract: An efficient method for manufacturing a purified juice product from sugar beets. Untreated beet juice is initially prelimed using lime and CaCO.sub.3 to produce a prelimed juice product. Instead of subjecting the prelimed product to main liming and dual carbonation stages, the product is delivered to a porous filtration membrane which allows sugar molecules to pass therethrough which preventing the passage of solid matter and dissolved impurities. Optimum results are achieved if the prelimed product flows across the membrane from end to end. The membrane permeate is thereafter combined with CO.sub.2(g) in a single carbonation stage to remove dissolved lime. This step generates a purified juice product which can be processed to manufacture pure crystalline sugar. The membrane retentate can be combined with water and refiltered to collect residual sugar materials. The foregoing process uses less energy and raw materials (e.g. lime) compared with conventional methods.

Abstract: A process for manufacturing a high molecular weight molasses product having improved drying properties, which includes: feeding starting material molasses having a RT value of 8-45% and a color of at least 100,000 ICUMSA units to a membrane filtering plant (apparatus) having an inert membrane having a nominal cut off value of at least 2,000 dalton; and filtering a low molecular weight fraction as a permeate from a high molecular weight fraction as a retentate, and collecting the high molecular weight fraction having a color of at least two times the color of the starting molasses or at least 200,000 ICUMSA units.

Abstract: A multi-step membrane separation process whereby the natural polymer .alpha.-chitosan extracted from the shell of crustaceans, etc. can be simply separated and purified into low molecular weight chitosan or oligosaccharide chitosan in a high yield. A chitosan mixture of various molecular weights is reacted with an acid in the presence of enzyme while applying an ultrasonic treatment to the mixture and then, added with pure water to give an aqueous solution having a chitosan concentration of 1 to 50%. It is subjected to a continuous membrane filtration under a pressure and further to a second fractionation and separation technique employing a proper membrane according to a desired molecular weight cut-off, at least one time.

Abstract: A method for purifying non-branched beta cyclodextrin from aqueous solutions is disclosed. The process entails a plurality of independent crystallization steps.

Abstract: A syrup of natural carob sugars having 55-75% sucrose, 7-15% fructose, 7-16% glucose, 0.5-3% other sugars, 4-14% cyclitols and 0.5-2% organic and inorganic impurities. Sugars are extracted from carob pulp and the juice thus obtained is subjected to chromatographic separation to separate the sugars from the non-sugars. The product obtained may be used in applications similar to those of other sugars.

Abstract: A novel starch-based texturizing agent, methods of manufacture and food formulations containing the texturizing agent. The texturizing agent comprises an insoluble microparticle (e.g., titanium dioxide), a gum (e.g., xanthan gum) and starch (e.g., pregelatinized starch) in the form of a complex in which the insoluble microparticle has been stabilized or entrapped therein. The texturizing agent can be used in low fat and fat-free foods, including mayonnaise, edible spreads such as margarines, salad dressing, mousse, cottage cheese dressing, sour cream, ice cream, yogurt and cream cheese.

Abstract: This invention relates to a process for the manufacture of crystal sugar from an aqueous sugar juice containing sugars and organic and mineral impurities, including Ca.sup.2+ and/or Mg.sup.2+ ions, such as a sugar cane or sugar beet juice, comprising the following operations:(a) concentration of said sugar juice to give a syrup, and(b) crystallization of said syrup to give a crystal sugar and a molasses,characterized in that it also comprises an operation:(c) of tangential microfiltration, tangential ultrafiltration or tangential nanofiltration, this operation being effected before operation (a).It also relates to a process for the production of crystal white sugar from a sugar juice of the sugar cane juice type, comprising the above-mentioned process for the production of crystal sugar, completed by re-melt, decolorization and crystallization operations.

Abstract: The method of making a stabilized starch includes mixing an aqueous starch suspension having a starch concentration of from 5 to 50 % by weight with an aqueous metal salt solution which contains from 10 to 50 % by weight of at least one metal salt selected from the group consisting of TiOSO.sub.4, TiOCl.sub.2, Al.sub.2 (SO.sub.4).sub.3, NaAlO.sub.2, Fe(NO.sub.3).sub.3, FeSO.sub.4, ZnCl.sub.2, Na.sub.2SiO.sub.3, SbCl.sub.3, ZrOSO.sub.4, ZrOCl.sub.2, MgCl.sub.2 and SnCl.sub.4 with a starch-suspension-to-metal-salt-solution ratio of from 1:5 to 10:1, to form a mixture having a pH of from 3 to 10 and containing the stabilized starch; and after the mixing of step a), separating the stabilized starch from the mixture and washing and drying it. The starch suspension preferably contains starch particles having a particle size of from 1 to 150 microns.

Abstract: When a strong base anion exchange resin, such as a chloride-form strong base anion exchange resin, is conditioned with a low concentration of hydroxyl (for example, an NaOH solution with a concentration between 1 and 10 mM), the conditioned resin separates in, sit, Is from sugars and sugar alcohols, while still allowing ready desorption of the sugars from the resin. The feedstock is first passed over a column containing this conditioned resin, followed by a mobile phase solvent, preferably water. The inositols have a lower affinity for the treated resin than do the sugars and sugar alcohols in the feedstock, and therefore pass through the column more quickly. The process may economically be performed on industrial-scale inositol separations, particularly when used in a preferred simulated moving bed chromatographic system.

Abstract: A beet juice treatment method in which reaction products are recycled. Beet juice is first prelimed with lime and CaCO.sub.3 to produce first and second juice fractions. The second fraction contains flocculated materials, and is combined with CO.sub.2. Solid flocs and calcium carbonate reaction products are removed from the second fraction. The second fraction and first fraction are then recombined to produce a third juice fraction which is combined with lime in a main liming stage for additional purification. The third fraction is then supplied with additional CO.sub.2 to generate a CaCO.sub.3 sludge product. The sludge product is divided into first and second portions. The first portion is reused in the preliming stage. The second portion is converted to regenerated lime for reuse in the main liming stage and possibly the preliming stage. These steps reduce waste production and provide economic benefits.

Abstract: The following description sets forth a new process for the preparation of .gtoreq.98.5% pure crystalline lactulose from commercially available aqueous syrups having the following composition: 50-70% by weight of lactulose, 3-9% by weight of lactose, 3-14% by weight of galactose, 4-7% by weight of other carbohydrates, the total content of carbohydrates different from lactulose being of from 10% to 30%.

Abstract: A novel starch-based texturizing agent is disclosed. The texturizing agent is produced from high amylose (>40%) starch under specific conditions of temperature, pressure and shear. The texturizing agent functions to provide several fat-like attributes such as structure, viscosity, smoothness and opacity to reduce and/or essentially replace the fat content in foods. Additionally the texturizing agent can be used in full fat foods as a stabilizer. Foods containing the novel texturizing agents include mayonnaise, spoonable and pourable salad dressings, yogurt, cottage cheese, sour cream, cream cheese, peanut butter, frosting, cheesecake, mousse and several sauces, among others. The texturizing agent can also be incorporated into drug and cosmetic formulations.

Abstract: Refined sugar is produced without using conventional refining processes. Clarification of melted raw cane sugar is obtained either by ultra-centrifugation or ultra-filtration, and removal of certain compounds responsible for adverse color quality and viscosity is effected through a set of packed columns filled with an absorbent for these compounds. After evaporation and crystallization, refined cane sugar is produced.

Abstract: Refined sugar is produced directly from sugarcane without using conventional refining processes. Clarification of extracted cane juice is obtained either by ultra-centrifugation or ultra-filtration, and removal of certain compounds responsible for adverse color quality and viscosity is effected through a set of packed columns filled with an absorbent for these compounds. After evaporation and crystallization, refined cane sugar is produced.

Abstract: A method is disclosed for softening and purifying molasses or syrup to obtain a clarified syrup that can then easily be handled by conventional ion-exclusion or other techniques for recovery of sugar. The process comprises steps that can be performed at ambient temperature. The molasses or syrup is carbonated at high pH, followed by adding organic solvent(s) such as ethanol. The sludge and liquid phases are separated. The solvent is then recovered, leaving a liquid phase comprising a soft and very clear sugar-containing liquid. The liquid phase may then be used in known systems for sugar recovery such as ion-exclusion chromatographic systems. Organic acids such as aconitic acid may be recovered from the sludge residue.

Abstract: A syrup of natural carob sugars having 55-75% sucrose, 7-15% fructose, 7-16% glucose, 0.5-3% other sugars, 4-14% cyclitols and 0.5-2% organic and inorganic impurities. Sugars are extracted from carob pulp and the juice thus obtained is subjected to chromatographic separation to separate the sugars from the non-sugars. The product obtained may be used in applications similar to those of other sugars.

Abstract: A method for isolating and purifying trehalose from trehalose-containing solutions is described. Using ultrafiltration and selective concentration, highly pure crystals of trehalose dihydrate are obtained from aqueous solution.

Abstract: The object of the present invention is to chromatographically separate the higher and lower molecular weight components of juices, liquors, syrups and/or molasses (e.g., inorganic-organic complexes and organic non-sugars), thereby permitting the lower molecular weight sugar and soluble salt-containing fraction(s) to be further processed into natural sweetener products.

Abstract: Disclosed is a method of separating .beta.-amylase from a solution containing .beta.-amylase, in which the solution is treated with an .alpha.-cyclodextrin fixed water-insoluble high polymer compound in the presence of ammonium sulfate to form an adsorbed composite of the high polymer compound and .beta.-amylase and soluble impurities not adsorbed to the high polymer compound are separated and removed. By the method, a high-purity .beta.-amylase, which is highly useful in the starch saccharification industry, may specifically and efficiently be isolated from a .beta.-amylase-containing mixture solution.

Abstract: A process for producing refined sugar directly from plants of cane or beet raw juices which bypasses the traditional manufacturing of an intermediate product called "raw sugar". After treatment of the sugar juice with a flocculant, the juice has pressurized air dissolved in it, followed by rapid lowering of the pressure to ambient in a dissolved air flotation cell to separate impurities by aeration. Further amounts of flocculant are added, and the juice is passed through a serpentine flocculator comprising a pipe containing a plurality of relatively straight section interrupted by sharp bends to expose the juice sequentially to different turbulent regimes defined by different ranges of Reynolds numbers to form flocs containing undissolved solids. Flocs and other undissolved solids are separated from the juice by flotation and settling. The sugar juice or liquor is partially evaporated to a concentration between about 45.degree. and 50.degree.

Abstract: A method for separating and purifying cyclodextrins is disclosed. This method is also able to sequentially separate alpha, beta and gamma cyclodextrins. The method entails forming a matrix with an inclusion compound bound thereto and passing an aqueous solution containing cyclodextrin through the matrix and eluting the cyclodextrins in a sequential order. The inclusion compound bound to the matrix determines the order in which the cyclodextrins are eluted.

Abstract: A method for preparing a mixture of fructose, glucose and compounds of the general formula GF.sub.n, wherein G is glucose and F is fructose and n is an integer. The mixture is recovered from plant tubers or roots by means of a method which does not involve any chemical modification of the components of the mixture. A juice or syrup comprising fructose, glucose, sucrose and oligosaccharides is subjected at one or more suitable steps to a physical separation process to reduce the amount of fructose, glucose and sucrose. The physical separation may be carried out by chromatography or nanofiltration or both. The mixture is suitable for use in foodstuffs and beverages for human beings and animals.

Abstract: A method as provided wherein betaine is separated eluted from beet molasses using a chromatographic simulated moving bed system having at least three chromatographic columns connected in series. The betaine is eluted during the same cycle as sucrose and rest molasses feeding and substantially simultaneous water feeding step, at least one water feeding step, a circulation step, and elution of sucrose, betaine and rest molasses fractions from selected columns.

Abstract: A method for preparing a mixture of fructose, glucose and oligosaccharides prepared from tubers or roots, and the use of the mixtures as a filler bulking agent with a sweet taste.

Abstract: There is provided a method of metering monocalcium saccharate into a sugared juice. The process includes taking a sample of the juice to be analyzed, diluting the sample with alcohol in order to form a precipitate, separating the precipitate by filtration, dissolving the precipitate in deionized water, acidifying the solution obtained by the addition of phosphoric acid and metering the saccharose into the said solution. The method is usable, in particular, in sugar refining in the production of sugared juices by the alkaline diffusion process.

Abstract: A first activating material with pores having alkali-ionization promoting function and a process for the preparation thereof, the material comprises animal bone material which is calcined so that the water content is below several wt. percent and is pulverized or powdered into a chipped, granular or powdery state. A second activating material and a process for the preparation thereof, the second activating material comprises the first activating material as well as a magnetic clay powder, both being kneaded, solidified and calcined. A first flocculating agent comprises a solution of the first activating material in sulfuric acid or hydrochloric acid. A second flocculating agent and a process for the preparation of the second flocculating agent which comprises a homogeneous composition comprising the second flocculating agent and a metal solution of a mixture of copper with iron or zinc in sulfuric acid or hydrochloric acid.

Abstract: Regeneration of an ion exchange resin used as a sugar decolorizer by passing a low sodium chloride concentration aqueous solution followed by passing higher sodium chloride concentration aqueous solution through the ion exchange resin and recycling at least a part of the effluent from the higher sodium chloride concentration aqueous solution.

Abstract: Membrane separation of monosaccharides from an aqueous solution containing higher saccharides and saccharifying enzyme is considerably improved when the separation is performed under conditions where the polarization modulus for the enzyme is between 10 and 1,000, especially when the latter is between 50 and 500. A process utilizing this constraint affords a considerable savings in enzyme residence time and enzyme usage, and permits glucose of at least 94% purity to be prepared using membranes with a molecular weight cutoff as high as 70,000 with partial saccharification of thinned starch to give glucose levels in the range of 65-90%.

Abstract: Branched beta cyclodextrins are purified and separated sequentially from solution by passing a solution containing branched beta cyclodextrins through a column containing a matrix on which an inclusion compound has been bound. The process is carried out under ambient conditions at a neutral pH.

Abstract: Glucose is separated from mixtures with mannose and other saccharides by adsorption on low aluminum Y-type zeolites, i.e., having up to about 50 atoms of aluminum per unit cell and desorbing the adsorbate with water. Glucose is removed from the adsorption process in the raffinate.

Abstract: The invention relates to a process for recovering sugar, sugar alcohol and organic acids comprising citric, malic and quinic acids from a juice extracted from almond hulls. Residues from the extraction is also recovered.

Abstract: A process for recovering unreacted sucrose from a reaction mixture of sucrose and a fatty acid alkyl ester in an organic solvent as reaction medium in the presence of a catalyst in the production of a sucrose fatty acid ester which comprises adjusting the reaction mixture from which a part of the organic solvent as reaction medium may be previously removed and to which water is added, to a neutral pH region, adding a neutral salt and sucrose to the reaction mixture to precipitate the sucrose fatty acid ester, filtering off the precipitate, and bringing the filtrate into contact with a reverse osmosis membrane to recover the unreacted sucrose. According to the invention, unreacted sucrose can be easily recovered, while the sucrose fatty acid ester not contaminated with the organic solvent as reaction medium can be obtained from the reaction mixture without using an organic solvent for purification.

Abstract: A process for preparing high-purity lactulose by the following stages:(a) diluting with water to a concentration of 15-25% a syrup containing 45-55% of lactulose and having a lactulose content on a dry substance basis of between 74 and 82% w/w;(b) pretreating the diluted syrup with bromine or bifunctional boron resins;(c) treating the pretreated syrup from stage (b) with ion exchange resins of strong anion type under conditions such that the pH of the percolated syrup is between 8 and 10.

Abstract: A method for refining a sugar liquor by cristobalite and an ion exchange resin, and a method for refining the sugar liquor by a novel ion exchange resin refining system, are disclosed. Cristobalite exhibits specific adsorbant properties for various colloidal or suspended substances, while the ion exchange resin exhibits superior decoloring and desalting properties with respect to colorants and salts. By combining refining by cristobalite and refining by the ion exchange resin, there is provided a sugar refining system whereby even non-washed sugar liquor may be refined. The ion exchange resin refining system of the present invention includes three series of adsorption towers.

Abstract: A method of recovering lactose from milk whey or cheese whey with a high yield, wherein the whey is concentrated, part of the lactose is crystallized, and the crystals are separated and dried; the mother liquor is purified by heating it to about 60.degree. to 70.degree. C. at a pH of about 5.8 to 7.0 and by removing the resultant precipitate by centrifugation; the purified mother liquor is fractionated chromatographically, using sulphonated polystyrene resin which is in sodium ion form and cross-linked by a 3-6% per weight divinylbenzene and which is even-grained, the flow rate is about 0.4 to 1.5 m.sup.3 /h, the temperature about 50.degree. to 75.degree. C., and the pH about 5.5 to 7; whereafter elution is carried out with water, and the following fractions are recovered: a protein fraction which may also contain salts, an intermediate fraction which is recirculated to the fractionating step, and a lactose fraction which is passed to the crystallization step.

Abstract: A process for decolorizing an aqueous sugar solution by contacting the solution with an absorbent resin, wherein the adsorbent resin is a macroporous copolymer being post-crosslinked in a swollen state in the presence of a Friedel-Crafts catalyst and functionalized with hydrophilic groups prior to contact with the aqueous sugar solution.

Abstract: Improved process for decolorizing aqueous sugar solutions by contacting solution with an adsorbent anion exchange resin prepared by aminating a macroporous, chloromethylated copolymer with a polyamine under conditions sufficient to promote crosslinking of unreacted amine sites with chloromethyl groups on the copolymer.

Abstract: The invention concerns a process for production of L-arabionose in crystalline form. Starting material are extracted sugar beet pulp or other L-araban containing plant materials. These are heated in an autoclave as an aqueous suspension in the presence of Ca(OH).sub.2. The so obtained solution is chromatographed on a cationic exchanger in the Ca-form. The araban containing fraction is hydrolyzed after adding H.sub.2 SO.sub.4, neutralized and rechromatographed on a cationic exchanger in Ca-form. After concentrating the arabinose containing fractions L-arabinose is obtained in form of crystals by cooling crystallization.

Abstract: A method for separating and purifying cyclodextrins is disclosed. This method is also able to sequentially separate alpha, beta and gamma cyclodextrins. The method entails forming a matrix with an inclusion compound bound thereto and passing an aqueous solution containing cyclodextrin through the matrix and eluting the cyclodextrins in a sequential order. The inclusion compound bound to the matrix determines the order in which the cyclodextrins are eluted.

Abstract: A process for the removal of non-sugar impurities from beet diffusion juice having essentially no beet tissue particles therein and comprising water, sugar, and dissolved and colloidal non-sugar impurities. The diffusion juice is subjected to a progressive preliming procedure to thereby produce a limed first juice fraction containing non-sugar flocs and a limed, floc-free second juice fraction. The fractions are separated and the floc-free fraction is subjected to cold and hot main liming. Subsequently, and without substantial mechanical or chemical degradation, at least a portion of the first juice fraction containing at least a portion of the non-sugar flocs is united with the main-limed second juice fraction in a first carbonation procedure wherein carbon dioxide reacts with the lime present to produce calcium carbonate precipitate which, in addition to being an adsorption filter aid, forms protective scales around the floc particles.

Abstract: A method for processing aqueous sugar juice containing a mixture of aldehyde-function saccharides and ketonic-function saccharides for separating and selecting ketonic-function saccharides, comprising (a) producing a hydro-organic medium by mixing the juice with an active methylene ketonic compound, a calcium-based catalyst and preferably ethanol, (b) mixing the medium until furanic polyalcohol is formed by condensation of the ketonic compound and the aldehyde-function saccharides and (c) allowing the furanic polyalcohol to precipitate and separating it by physical means from the liquid medium.

Abstract: Pentoses and hexoses are epimerized by heating sugar dissolved in a solvent in the presence of a molybdenum(VI) compound, by an improved process in which, for the preparation of a sugar having cis OH groups in the 2- or 3-position, of the formula Ia or Ib ##STR1## where R is one of the radicals ##STR2## a homogeneous solution of the corresponding sugar of the formula IIa or IIb ##STR3## is heated to 75.degree.-100.degree. C. in the presence of from 30 to 200 mol %, based on sugar used, of a metal salt of the formula (III)MeX.sub.2 (III)where Me is Mg, Ca, Sr, Ba or Zn and X is Cl or Br, which may or may not contain water of crystallization, and in the presence of from 2 to 20 mol %, based on the sugar used, of a molybdenum(VI) compound.The process is particularly important for the preparation of D-ribose, which is required as an intermediate for vitamin B.sub.2.