PREMIX COMPOSITION FOR CLARIFYING BEER

Abstract: A premix composition for clarifying beverages like beer includes, by weight, (a) about 40 to 90 %, preferably 60-85 %, of silica xerogel having less than 10 % water therein, preferably 5 % or less, and a particle size, as defined by its mean volume average diameter MV, in both the dry state and as a 10 % aqueous slurry, of less than 50 mu , preferably about 5-30 mu , and (b) about 10 to 60 %, preferably 15-40 %, of crosslinked polyvinylpyrrolidone having a particle size as defined, in the dry state, of about 10 to 50 mu , and about 30-60 mu in a 10 % aqueous slurry, and a process of obtaining, chill-haze stabilized beer with substantial reduction in high molecular weight proteins, as well as polyphenols, flavanoids and tannins, in an efficient and effective single-step process at a rapid filter-flow rate, with undetectable residual soluble polyvinylpyrrolidone thereafter, and no microbiological growth in the premix, effective haze stability after time, and advantageous redispersibility of the premix used in the process.

Description: PREMIX COMPOSITION FOR CLARIFYING BEER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to clarification of beverages such as beer and wine, and, more particularly, to a premix composition and process for effecting such clarification in an efficient and advantageous single-step process. 2. Description of the Prior Art Non-biological haze in unstabilized beer arises from complexation of haze-sensitive proteins and haze-producing polyphenols and tannoids. Accordingly, silica gels such as hydrogel or xerogel have been used for effecting clarification of beer by adsorbing haze-sensitive proteins. However, silica hydrogel contains greater than 30% water and is therefore prone to microbial growth on storage. Silica xerogel contains only 5% water but becomes compacted upon hydration. Crosslinked polyvinylpyrrolidone (PVPP) also has been effective for treating unstabilized beer by specific adsorption of condensed and polymeric polyphenols and tannoids present in beer. Sequential treatments with silica gels and PVPP have been used with some measure of success. Combinations of silica hydrogel and PVPP for a single treatment process have been considered but when hydrated such an admixture becomes voluminous and clumpy making it difficult to pump homogeneously. Similarly, the industry has warned that xerogel and PVP should never be present simultaneously, as they may neutralize each other's effects. The prior art is represented by the following U.S. Patents: 2,316,241 ; 3,117,004; 3,163,538; 3,413,120; 3,512,987; 3,554,759; 3,617,301 ; 3,818,111 ; 3,903,316; 4,166,141 ; 4,820,420; 4,910,182; and by the following foreign patents and technical publications: (1) Gorinstein, S et al, J of Food Biochemistry 14, 161-172 (1990). (2) Boschet, G. Brauindustrie 70 (16) 1441-4 (1985). (3) McMurrough, I. et al J. Am. Soc. Brewing Chemists 50 (2) 67-76 (1992). (4) GB 1 ,151 ,476 ('69) Deutsche Gold (silica + PVP). (5) Weyh, H. Inst. Chem. Tech. Anal. Chem. 8050 (1987). (6) Boschet, G. Bios (Nancy) 17 (8-9) 49-52 (1986). (7) Birkner, F. EPA 183162 A2 06/04/1986 EP 85114640 (11/18/85). (8) Hums, N. DE 3509892A1 09/25/1986. (9) Buchvarov, V. Monatsschr. Brauwiss 39 (5) 188-92 (1986) (10) Wackerbauer, K. Monatsschr. Brauwiss 37 (5) 201-7 (1984). (11) Chi, C.W. DE 3302258A1 01/25/83. (12) Jaeger, P. Mitt. Versuchsstn Gaerungsgewerke Wien 34 (9-10) 83-9 (1980). (13) Sfat, M.R. Tech. Q, Master Brew Assn Am 12 (4) 243-8 (1975) (14) Silbereisen, K. Monatsschr. Brauwiss 21 (8) 221-35 (1968). (15) Schafft, H. Brauwelt 117 (36) 3-7 (1977). (16) Blecher, L. Brew. Dig, 51 (7) 33-5, 44 (1976). (17) Grace, DE 3302258A1 (1983). (18) Chi, C.W. Can. Pat. 1 ,178,222. (19) Suhner, Ger. Pat. Publicn. 1907610, CA. 75, 10/1972 (p. 2/6) QD 1A5. However, none of these references disclose a composition for clarifying beer or wine in an efficient and advantageous manner with a premix composition of a silica xerogel having defined characteristics present in a predetermined amount with a crosslinked polyvinyl lactam polymer. Accordingly, it is an object of the present invention to provide a new and improved premix composition of a siliceous material and crosslinked polyvinylpyrrolidone for use in clarification of beer or wine. Another object herein is to provide a stable premix composition for clarification of beer or wine which has a long shelf life and is not prone to microbiological contamination. Still another object of the invention is to provide a stable premix composition of a siliceous material and a crosslinked polyvinyl lactam which is effective for colloidal stabilization of beer. Among the other objects herein is to provide such a premix composition which can efficiently remove sensitive proteins, polyphenols, flavanoids and tannoids from beer, and to effect a substantially complete reduction in chill haze in the beer. Yet another object herein is to provide a process for colloidal stabilization of beer in a single dosing and a single filtration operation. A specific object herein is to provide a stable premix composition which is selective to removal of high molecular weight proteins while leaving the desirable low molecular weight proteins remaining in the clarified beer. A feature of the present invention is the provision of a stable premix of predetermined composition which is a siliceous xerogel material having less than about 10% by weight of water therein, and a particle size as defined by its mean volume average diamter, Mv, of less than 50 μ, both in the dry state and as a 10% aqueous slurry, and a crosslinked polyvinyl lactam, preferably crosslinked polyvinylpyrrolidone (PVPP), in a weight ratio of about 40 to 90% of the xerogel to about 10 to 60% of PVPP, for effective clarification of beer. These and other objects and features of the invention will be made apparent from the following description of the invention. SUMMARY OF THE INVENTION What is described herein is a premix composition for clarifying beer in an effective manner which comprises, by weight, (a) 40 to 90% silica xerogel having less than 10% water therein, preferably 5% or less, and (b) 10 to 60% by weight of crosslinked polyvinylpyrrolidone (PVPP). Preferably, (a) is 60 to 85% and (b) is 15 to 40%; most preferably, (a) is 70 to 80% and (b) is 20 to 30%. In this invention, (a) has a particle size as defined by its mean volume average diameter, Mv, in both the dry state and as a 10% aqueous slurry, of less than 50 μ, preferably about 5-30 μ, component (b) has a defined particle size in the dry state of about 20 to 50 μ, and, in a 10% aqueous slurry, of about 30 to 90 μ. A premix composition wherein prior to admixture, the ratio between particle sizes of (a) in a 10% aqueous slurry to its dry state is about 0.6 to about 2.0. A premix composition wherein prior to admixture, the ratio between the particle sizes of (b) in a 10% aqueous slurry to the dry state is about 1.0 to about 2.0. A premix composition wherein the particle size, as defined by its mean volume average diameter, Mv, of (a) is less than the correspondingly defined particle size of (b). A feature of the invention is the provision of a flocculated aqueous slurry of the defined premix composition, preferably including about 5 to about 20% by wt. of the premix composition and about 80 to about 95% water, for example, which is prepared by admixing silica xerogel and PVPP in defined proportions, and slowly adding water thereto with agitation. Another feature of the invention is the provision of a process for clarifying beer which includes treating beer with such an agitated flocculated aqueous slurry of the defined premix, and filtering the thus-treated beer, wherein both proteins and polyphenols are removed in one step from the treated beer in a contact time of about 3 hours or less. Such a process requires only a dose of about 10 lbs. of the premix composition for each 100 barrels of beer. The process also features a step of conveniently pumping both the clarified beer and the spent premix composition out of the treatment tank into a filter tank after carrying out the clarification step. The clarified beer or wine is obtained herein in a process which is conducted at an advantageous filter flow rate, with undetectable residual soluble polyvinylpyrrolidone therein, and no biological growth in the premix, with effective haze stability after time, and easy redispersibility of the used premix. IN THE DRAWING The FIGURE is a graphical representation of dispersibility of premix compositions of silica xerogel and PVPP as a function of composition. DETAILED DESCRIPTION OF THE INVENTION Silica gel is produced by reacting sodium silicate with sulfuric acid. The gel then is broken up, washed and sized. This product is known as silica "hydrogel". Sodium sulfate is a by-product of the process of formation of silica hydrogel. When sodium sulfate is removed from silica hydrogel and the residue is dried to less than 10% water therein, a silica product known as "xerogel" is obtained. In this invention, a stable premix composition is provided which includes a predetermined composition of xerogel having less than 10% water therein, preferably 5% or less. Suitable xerogels for use herein include SIL- Proof® BG-5 and BG-6 (SCM Chemicals); Britesorb® D-300 (PQ Corp.), and Lucilite XLC (Crossfield Corp.). The other component of the premix composition is crosslinked polyvinylpyrrolidone (PVPP), such as Polyclar® PC-10, which is available from International Specialty Products (ISP). In accordance with the present invention, the premix composition for colloidal stabilization of beer is prepared by admixing xerogel and crosslinked polyvinylpyrrolidone (PVPP) solids. Suitable premix compositions in accordance with the invention contain about 40 to 90%) by weight of xerogel, preferably 60 to 85%, and most preferably about 70-80%; and about 10 to 60% of PVPP, preferably about 15 to 40%, and most preferably about 20 to 30%. In the premix composition, the xerogel component provides the larger surface area to receive the PVPP component in a predetermined ratio without causing compactation of the resultant admixture. Accordingly, suitable xerogel: PVPP wt. ratios in the premix composition generally will depend upon the particle size of the xerogel used therein. Suitable specific premix compositions herein include, for example, 83% xerogel and 17% PVPP (a 15:3 wt. ratio); 70% xerogel and 30% PVPP (a 7:3 wt. ratio); and 63% xerogel with 37%> PVPP (a 1:7 wt. ratio). In the preferred forms of the invention, the xerogel component of the premix should have a smaller particle size than the PVPP so that it can be complexed between the PVPP particles. The premixed composition can be stored in a stable condition for prolonged periods of time with minimal chance of microbial contamination. Before use, the premix composition must be hydrated with water with agitation to form an aqueous dispersion or slurry having a premix concentration of about 5-20 wt. %. In this aqueous dispersion, PVPP stabilizes the xerogel by flocculating the xerogel without affecting the requisite adsorbing characteristics of each material. This flocculated, aqueous dispersion then is used in a single-step treatment of unstabilized beer. During this treatment, the flocculated premix in the dispersion remains in the slurry state without any significant compaction. This stable, flocculated aqueous premix slurry is achieved herein because its PVPP component quickly hydrates upon addition of water thereto to form a swelled system. The swelled PVPP system then immediately complexes the xerogel component to prevent premature compaction of the system while the xerogel becomes fully hydrated. Then, in this complexed condition, the xerogel can become fully hydrated by addition of water to the premix over a long period of time without causing compaction of the system. Suitably, the solid premix composition of the invention usually is hydrated with water for about 3 hours to form a thick, flocculated aqueous slurry containing about 5-20 wt. % of the premix. This flocculated composition can be kept in a holding tank for long periods without affecting the clarifying properties of either component, and with advantageous microbiological stability. The flocculated hydrated premix slurry thus-prepared then is pumped into the beer treatment tank where it can perform its clarifying and chill haze stability functions. After treatment, the clarified beer is pumped into a filter tank then the stabilized beer is passed through a cake of diatomaceous earth to remove any traces of the premix remaining in the beer. Alternate filtration systems like ceramic candles, membrane filtration or centrifugation can be used in the place of diatomaceous earth filtration. In a typical run, 18 lbs. of the premix composition of the invention at a 15:3 wt. ratio of xerogel to PVPP is used for each 100 barrels of unstabilized beer. This single step treatment produced stabilized beer with a prolonged shelf life showing an efficacy removal of sensitive proteins and haze-making polyphenols. While the mechanism of action of the xerogel and PVPP components of the premix upon each other is not completely understood at present, it is believed that the water-insoluble polymeric PVPP component is a microcrystalline system which can hydrogen bond or complex to the xerogel via water bridges without penetration to prevent the xerogel from settling out. The PVPP also provides the matrix for simultaneous adsorption of polyphenols and high molecular weight proteins onto the xerogel by a process of diffusion, attachment and penetration. The advantageous clarification results are achieved herein in a single dosing step with about a 2-30 minute contact time with the two component premix composition of the invention and a single filtration step, operating with an efficient Filter Index, i.e. less pressure build-up across the filter, less diatomaceous earth in the filtration step and a greater beer volume throughput through the filter. The stabilized and filtered beer obtained herein had a shelf- life of greater than 3 months, which was over 3 times that of beer treated with either single component of the premix, and equal to sequential single treatments with each component. The FIGURE shows the effective dispersibility of xerogel and PVPP premix systems as a function of its composition. The degree of dispersibility in an aqueous premix at a 10-20 wt. % concentration is inversely related to the number of inversions required to redisperse a slurry of given composition which has stood for 24 hours. Suitable premix compositions require less than 1000 inversions, preferably less than 500 inversions, and, most preferably less than 100 inversions. As is seen therein, these properties are achieved in premix compositions which contain about 10-60% by weight PVPP (Polyclar 10), preferably 15-40%, and, most preferably, about 20-30%, the rest being the defined silica xerogel component. EXAMPLES Methods of Analysis Tannoid Content (Tannometer) Tannoids are defined as those fractions of the polyphenolic compounds that can be precipitated by the addition of PVP K90 to the beer sample. They include the low and medium molecular weight polyphenols. The haze in beer is fundamentally a complex between the condensed polyphenols, referred to as TANNOIDS (T), and the SENSITIVE PROTEINS (P), in an equilibrium governed by the law of mass action as shown in equation (1) and equation (2): P + T ≠ PT (1) so that [P] X [T] = k [Pη (2) where [P] is the concentration of polypeptides and proteins (Sensitive Proteins defined as substances giving haze when tannin is added) and [T] is the concentration of tannoids that form precipitate with PVP K 90 (molecular weight 350,000). For the analysis of Tannoids, a solution of PVP K90 was injected into a beer sample. The Tannoids in the beer form a precipitate with PVP K90 through hydrogen bonding. The addition of PVP K90 is plotted against the formation of haze and the maxima of the peak gives the Tannoid Content expressed as mg PVP/L beer. A lower value of tannoids in the treated beer indicates a reduction in haze. Sensitive proteins (Tannometer) The sensitive protein test via the Tannometer provides insight to the levels of haze forming proteins present in beer. In this test, a solution of tannic acid was dosed into a beer sample. Proteins in the beer complex with tannin to form an insoluble PT complex giving rise to haze. The result is expressed in EBC units of haze corresponding to the addition of 10mg of tannin per liter of beer. A lower value of sensitive proteins in the treated beer indicates a reduction in haze. Flavanoids and Polyphenols The flavanoid content in beer samples was analyzed by Analytica EBC, method 9.9.2. Total polyphenols in beer is analyzed using Methods of Analysis of ASBC, method BEER - 35. Both methods give an absorbance value measured by a spectrometer and the results are expressed in ppm. HPLC with dual-electrode offers a precise qualitative and quantitative method for the determination of haze producing flavanols in beer. The flavanoid/polyphenols in beer are of two-fold interest, owing to their proven involvement in haze formation and their potential impact on flavor. Malt and hops provide beer with its share of the polyphenols. The absence of protective groups on the hydroxylated flavanoid matrix is the reason why these polyphenols can react with proteins thereby causing colloidal instability in beer. Also, associated with polyphenols is the characteristic astringent flavors in beer. The anthocyanogens which are part of the polyphenols can easily be hydrolyzed to anthocyanidin. These anthocyanidins give beer harsh and astringent flavors. Polyclar adsorbs these anthocyanogens thereby reducing the formation of astringency in beer. Total Haze and Aging Test The total haze is read directly from the bottle, using an Lg automatic haze meter. The haze meter is calibrated with certified haze standards obtained from Advanced Polymer Systems. All readings are taken with distilled water in the measuring chamber to prevent the formation of condensation on the outside surface of cold samples. Haze readings are taken on fresh beer samples at 22°C and at 0°C. Aging tests are performed by incubating samples in a dry oven at 37°C for one week and then transferring to storage at 0°C for one day before taking total haze readings on the cold samples. Samples are put through this cycle for several weeks or until an excessive value for haze is obtained. The end of useful shelf life is generally taken to be 2.0 EBC haze units and one week storage at 37°C is taken as being equal to one-month storage at ambient temperature. RUNS 1-8 (EXAMPLES 1-8) Runs 1-8 are Lab Runs. Runs 1 , 2, 3, 4 are Comparative Runs. Runs 5 and 6 are Invention Runs. Runs 7 and 8 are Control Runs. Double Filtration - Filtration After Sequential Addition of Each Component RUN NO. 1 Unstabilized beer was used for Examples 1 through 7. This beer sample was not treated with any form of stabilizer and was centrifuged to decrease yeast cell count to approximately 1 million cells per ml by the brewery. In a 1500-ml glass jar equipped with a lid was added 1000-ml of unstabilized beer, 0.571g (equivalent to a dosing rate of 15-lbs/100bbl) of Xerogel (Britesorb D-300, PQ Corporation) and a magnetic stir bar. This mixture was placed on a magnetic stir plate within a refrigerator, set at 0°C. After 3 hours of stirring, 1.90g of diatomaceous earth (DE) was added (equivalent to 50-lbs/100bbl) and mixed into the solution by swirling the jar. This mixture was then vacuum filtered through a 2.5-μm glass fiber filter using a Bϋchner funnel and vacuum flask. To the filtrate was added 0.114g of Polyclar ® 10 (equivalent to 3-lbs/100bbl) and mechanically stirred at 0°C for 15 minutes. 1.90g of DE was again added and mixed into solution and filtered as previously described. The clear filtered beer was analyzed for tannoid content, sensitive proteins, total polyphenols, flavanoids, and also subjected to heat forcing tests to determine colloidal stability, described under "Methods of Analysis". Results can be found in Tables 1 , 2 and 3. RUN NO. 2 Run 1 was repeated except that 0.267g of Polyclar ® 10 (equivalent to 7-lbs/100bbl) was added in place of 0.114g of Polyclar ® 10 after the first filtration process. Results can be found in Tables 1 , 2 and 3. Single Filtration - Sequential Addition of Components RUN NO. 3 In an experiment similar to that performed in Example 1 , a 1000-ml sample of unstabilized beer was dosed with 0.571g of Xerogel (Britesorb D-300, equivalent to 15-lbs/100bbl) and mechanically stirred for 2-3/4 hours. Then, 0.114g of Polyclar ® 10 (equivalent to 3-lbs/1 OObbl) was added to the mixture and stirred for an additional 15 minutes. DE was dosed into the sample and the mixture was filtered as described in Example 1. Results can be found in Tables 1 , 2 and 3. RUN NO. 4 Example 3 was repeated except that 0.267g Polyclar ® 10 (equivalent to 7-lbs/100bbl) was used in the place of 0.114g of Polyclar ® 10. Results can be found in Tables 1 , 2 and 3. Premix of Components - Single Filtration RUN NO. 5 In an experiment similar to that performed in Example 1 , Xerogel (Britesorb D-300) and Polyclar ® 10 were premixed in the ratio of 15:3 by weight. A 1000-ml sample of unstabilized beer was dosed with 0.685g of the 15:3 ratio premix (equivalent to 18-lbs/100bbl). The sample was placed on a magnetic stir plate within a refrigerator, set at 0°C. After 3 hours of stirring, 1.90g of diatomaceous earth (DE, equivalent to 50-lbs/100bbl) was added and mixed into the solution by swirling the jar. This mixture was then vacuum filtered through a 2.5-μm glass fiber filter using a Bϋchner funnel and vacuum flask. The filtered beer was then analyzed as described in Example 1. Results can be found in Tables 1 , 2 and 3. RUN NO. 6 Example 5 was repeated except that Xerogel (Britesorb D-300) and Polyclar ® 10 were premixed in the ratio of 15:7 by weight. A 1000-ml sample of beer was dosed with 0.838g of the 15:7 ratio premix (equivalent to 22- lbs/1 OObbl) and processed as described in Example 5. Results can be found in Tables 1 , 2 and 3. Control Sample (Treated with Xerogel Alone or Untreated) for Examples 1 Through 6 RUN NO. 7 A control experiment was performed by dosing 1000-ml of unstabilized beer with 0.157g of Xerogel (Britesorb D-300, equivalent to 15-lbs/1 OObbl). The mixture was mechanically stirred for 3 hours in a refrigerator, set at 0°C. 1.90g of diatomaceous earth (DE) was added to the mixture (equivalent to 50- lbs/1 OObbl) and mixed into the solution by swirling the jar. This mixture was then vacuum filtered through a 2.5-μm glass fiber filter using a Bϋchner funnel and vacuum flask. The filtered beer was then analyzed as described in Example 1. Results can be found in Tables 1 , 2 and 3. RUN NO. 8 A second control experiment was performed using 1000-ml of unstabilized beer with no form of beer stabilizer added. The beer was mechanically stirred for 3 hours in a refrigerator, set at 0°C. 1.90g of diatomaceous earth (DE) was added to the beer (equivalent to 50-lbs/1 OObbl) and mixed into solution by swirling the jar. This mixture was then vacuum filtered through a 2.5-μm glass fiber filter using a Bϋchner funnel and vacuum flask. The filtered beer was then analyzed as described in Example 1. Results can be found in Tables 1 , 2 and 3. TABLES 1-3 TABLE 2 TABLE 3 * Haze measurements, samples heat forced at 37°C, measurements taken at 0°C. EXAMPLE 9 - Large Scale Trial (Runs 9a and 9b) Beer stabilized with an admixture of 70% by weight silica xerogel (Millenium BG6) and 30% by weight Polyclar® 10 (Run 9a) produced superior shelf life compared to treatment with silica hydrogel and a combination of silica hydrogel and Polyclar® 10. A brewery trial for a German Pilsner was carried out by stabilizing 500hl of beer with silica hydrogel alone (a prior art treatment), silica hydrogel plus Polyclar® 10 and the admixture of this invention. All stabilizers were added to the beer prior to filtration with DE (kieselguhr), with an estimated contact time with beer of 10 minutes. Forced haze development was measured by the number of 60°C/0°C cycles (24 hours at each temperature) required to reach 2.0 EBC haze. 8 cycles by the above method is taken as equivalent to 10 months of predicted shelf life. Forced haze development results in packaged beer from brewery stabilization trials follow in Tables 4 and 5. TABLE 4 (Comparative Examples) TABLE 5 (Invention) Run 9a (80g/hl) 8 In a commercial plant trial, 200 barrels of an American Lager microbrewery beer was treated at 40g/hl (10 lbs/1 OObbl) with the admixture of this invention described in Run 9a above. The results of treated beer were compared with untreated beer by the heat forcing test method. Beer samples were stored at 37°C for 6 days. After that, the same samples were cooled to 0°C for 24 hours. Total haze was read at 0°C. This cycle was repeated until a total haze of 2.0 EBC was reached indicating the end of useful shelf life. One week of this cycle is taken as equivalent to 1 month of predicted shelf life at ambient temperature. The results are summarized in Table 6 below. TABLE 6 EXAMPLE 10 - Premix of Components Xerogel (Millennium BG5) and Polyclar ® 10 were premixed in the ratio of 7:3 by weight. A 1000-ml sample of a new unstabilized beer was dosed with 0.381 g of the 7:3 ratio premix (equivalent to 10-lbs/1 OObbl). The sample was mechanically stirred using a magnetic stir plate within a refrigerator, set at 0°C. After 3 hours of stirring, 1.90g of diatomaceous earth (DE, equivalent to 50-lbs/1 OObbl) was added and mixed into the solution by swirling the jar. This mixture was then vacuum filtered through a 2.5-μm glass fiber filter using a Bϋchner funnel and vacuum flask. The filtered beer was then analyzed as described in Example 1. Results can be found in Tables 7 and 8 below. EXAMPLE 11 - Premix of Components Example 10 was repeated except that the 7:3 premix was dosed at 0.571 g (equivalent to 15-lbs/1 OObbl). Results can be found in Tables 7 and 8. EXAMPLE 12 - Polvclar ® 10 Treatment In an experiment similar to Example 11 , a 1000-ml sample of unstabilized beer was dosed with 0.114g of Polyclar ® 10 (equivalent to 3-lbs/1 OObbl) in place of the premix. Results can be found in Tables 7 and 8. Example 13 - Xerogel Treatment Example 12 was repeated except that 0.762g of Xerogel (Millennium BG5, equivalent to 20-lbs/1 OObbl) was used in place of Polyclar ® 10. Results can be found in Tables 7 and 8. EXAMPLE 14 - Xerogel Treatment - Control for Examples 10 Through 13 Example 12 was repeated except that 0.571 g of Xerogel (Millennium BG5, equivalent to 15-lbs/1 OObbl) was used in place of Polyclar ® 10. Results can be found in Tables 7 and 8. TABLE 7 TABLE 8 Invention Example 11 produced distinctly superior haze stability. EXAMPLE 15 - Premix of Components Example 10 was repeated except that Xerogel, Lucilite XLC (Crossfield Corp.) was used in place of Xerogel, Millennium BG5. Results can be found in Tables 9 and 10. EXAMPLE 16 - Premix of Components Example 11 was repeated except that Xerogel, Lucilite XLC (Crossfield Corp.) was used in place of Xerogel, Millennium BG5. Results can be found in Tables 9 and 10. EXAMPLE 17 - Polyclar ® 10 Treatment Example 12 was repeated. Results can be found in Tables 9 and 10. EXAMPLE 18 - Xerogel Treatment Example 13 was repeated except that Xerogel, Lucilite XLC (Crossfield Corp.) was used in place of Xerogel, Millennium BG5. Results can be found in Tables 9 and 10. EXAMPLE 19 - Xerogel Treatment - Control for Examples 15 Through 18 Example 14 was repeated except that Xerogel, Lucilite XLC (Crossfield Corp.) was used in place of Xerogel, Millennium BG5. Results can be found in Tables 9 and 10. TABLE 9 TABLE 10 Example 16 produced far superior stabilization (lower total EBC value) than Comparative Runs 17-19. EXAMPLE 20 - Sedimentation Properties of Polvclar ® 10 To a 100 ml stoppered graduated cylinder was added 10g of Polyclar ® 10 and a quantity of distilled water to bring the total volume of the mixture to 100 ml. The sample was thoroughly mixed to disperse the solids and allowed to stand overnight to fully hydrate. The mixture was then remixed by vigorous inversion of the cylinder to fully disperse the solids. The volume of settled solids was noted after 15 min., 30 min., 1 hour, 3 hours, 6 hours, and 24 hours of settling time. Results are found in Table 11. EXAMPLE 21 - Sedimentation Properties of Xerogel (Millennium BG6) Example 20 was repeated except that 10g of Xerogel (Millennium BG6) was used in place of Polyclar ® 10. Results are tabulated in Table 11. EXAMPLE 22 - Sedimentation Properties of Xerogel (Millennium BG5) Example 20 was repeated except that 10g of Xerogel (Millennium BG5) was used in place of Polyclar ® 10. Results are tabulated in Table 11. EXAMPLE 23 - Sedimentation Properties of Xerogel (Crossfield, Lucilite XLC) Example 20 was repeated except that 10g of Xerogel (Crossfield, Lucilite XLC) was used in place of Polyclar ® 10. Results are tabulated in Table 11. Example 24 - Sedimentation Properties of Polyclar 10/Xerogel (Millennium BG6) Mixture Example 20 was repeated except that 10g of Polyclar ® 10 was replaced with a solid premix containing 7g of Xerogel (Millennium BG6) and 3g Polyclar ® 10. Results are tabulated in Table 11. EXAMPLE 25 - Sedimentation Properties of Pol velar ® 10/Xerogel (Millennium BG5) Mixture Example 20 was repeated except that 10g of Polyclar ® 10 was replaced with a solid premix containing 7g of Xerogel (Millennium BG5) and 3g Polyclar ® 10. Results are tabulated in Table 11. EXAMPLE 26 - Sedimentation Properties of Poivclar ® 10/Xerogel (Crossfield. Lucilite XLC) Mixture Example 20 was repeated except that 10g of Polyclar ® 10 was replaced with a solid premix containing 7g of Xerogel (Crossfield, Lucilite XLC) and 3g Polyclar ® 10. Results are tabulated in Table 11. EXAMPLE 27 - Sedimentation Properties of Polvclar 10/Xerogel (Millennium BG6) Mixture Example 20 was repeated except that 8g of Xerogel (Millennium BG6) and 2g of Polyclar ® 10 were used. Results are tabulated in Table 11. EXAMPLE 28 - Sedimentation Properties of Polvclar 10/Xerogel (Millennium BG5) Mixture Example 20 was repeated except that 8g of Xerogel (Millennium BG5) and 2g of Polyclar ® 10 were used. Results are tabulated in Table 11. EXAMPLE 29 - Sedimentation Properties of Polvclar ® 10/Xerogel (Crossfield. Lucilite XLC) Mixture Example 20 was repeated except that 8g of Xerogel (Crossfield, Lucilite XLC) and 2g of Polyclar ® 10 were used. Results are tabulated in Table 11. TABLE 11 The results established a reduced level of compacted solids for invention runs. Example 30 - Dispersion Properties of Polvclar ® 10 The sample from Example 20, after settling for 24 hours, was inverted up and down at the rate of about 60 inversions per minute. The number of inversions to re-disperse the solids was noted (each 180 degree rotation constitutes one inversion). Results are tabulated in Table 12. EXAMPLE 31 - Sedimentation Properties of Xerogel (Millennium BG6) The sample from Example 21 , after settling for 24 hours, was inverted up and down and the number of inversions to re-disperse the solids is noted. Results are tabulated in Table 12. EXAMPLE 32 - Sedimentation Properties of Xerogel (Millennium BG5) The sample from Example 22, after settling for 24 hours, was inverted up and down and the number of inversions to re-disperse the solids is noted. Results are tabulated in Table 12. EXAMPLE 33 - Sedimentation Properties of Xerogel (Crossfield. Lucilite XLC) The sample from Example 23, after settling for 24 hours, was inverted up and down and the number of inversions to re-disperse the solids is noted. Results are tabulated in Table 12. EXAMPLE 34 - Sedimentation Properties of Polvclar 10/Xerogel (Millennium BG6) Mixture The sample from Example 24, after settling for 24 hours, was inverted up and down and the number of inversions to re-disperse the solids is noted. Results are tabulated in Table 12. EXAMPLE 35 - Sedimentation Properties of Polvclar 10/Xerogel (Millennium BG5) Mixture The sample from Example 25, after settling for 24 hours, was inverted up and down and the number of inversions to re-disperse the solids is noted. Results are tabulated in Table 12. EXAMPLE 36 - Sedimentation Properties of Polvclar ® 10/Xerogel (Crossfield. Lucilite XLC) Mixture The sample from Example 26, after settling for 24 hours, was inverted up and down and the number of inversions to re-disperse the solids is noted. Results are tabulated in Table 12. EXAMPLE 37 - Sedimentation Properties of Polvclar 10/Xerogel (Millennium BG6) Mixture The sample from Example 27, after settling for 24 hours, was inverted up and down and the number of inversions to re-disperse the solids is noted. Results are tabulated in Table 12. EXAMPLE 38 - Sedimentation Properties of Polvclar 10/Xerogel (Millennium BG5) Mixture The sample from Example 28, after settling for 24 hours, was inverted up and down and the number of inversions to re-disperse the solids is noted. Results are tabulated in Table 12. EXAMPLE 39 - Sedimentation Properties of Polvclar ® 10/Xerogel (Crossfield. Lucilite XLC) Mixture The sample from Example 29, after settling for 24 hours, was inverted up and down and the number of inversions to re-disperse the solids is noted. Results are tabulated in Table 12. TABLE 12 The above data shows that the premix considerably reduced the number of inversions necessary to flocculate the sample, as compared to a single component. EXAMPLE 40 - Filter Flow Rate Properties of Polvclar ® 10/Xerogel The following twelve admixtures were prepared by blending xerogel (Britesorb D-300) and increasing quantities of Polyclar 10 containing the following weight % of Polyclar 10. 0%, 8%, 16%o, 25%, 30%, 32%, 42%, 50%, 65%, 75%, 85% and 100%. This was carried out by mixing the components in a V-blender for a period of 60 minutes. The filter flow rates for the flow of water over a filter bed prepared from the above admixtures were determined as follows. 4.00 g of different admixtures (premix in samples) were separately mixed (hydrated) in 200ml of distilled water for 24 hours and then the Filter Flow Rate Index determined using Schenk pressure filter apparatus. Filter bed was established with the experimental premix in test, and then the time required for 100 ml of water to pass through the bed was measured with the a stop watch in seconds (at 20°C, pressure of 0.2 bar, filter diameter 60mm, type of filter Schenk D filter Mat). The Filter Flow Rate Index (FFRI) is then calculated as Filter Flow Rate Index = 1000/t where t is time in seconds for 100ml of filtrate to be collected. The results are shown in Table 13. TABLE 13 Filter Flow Rate Index as function of Polyclar 10 concentration in Premix of Polyclar 10 and Britesorb D- 300 (Xerogel from PQ Corporation) Filter Flow Rate maximizes at Polyclar 10 concentration of between 30% and 42 %; (premix with Britesorb D-300) EXAMPLE 41 - Filter Flow Rate Properties of Polvclar ® 10/Xerogel The experiment in Example 40 was repeated replacing Britesorb D-300 with BG6. The following weight % Polyclar 10 were used in this case, 0%, 17%, 25%, 30%), 32%, 41%, 50%, 65%, 75%, 85%, 90% and 100%. The results are tabulated in Table 14. TABLE 14 Filter Flow Rate Index as function of Polyclar 10 concentration in Premix of Polyclar 10 and BG 6 (Xerogel from Millenium) In this case, Filter Flow Rate maximizes at Polyclar 10 concentration of between 41% and 65 % (premix with BG6.) EXAMPLE 42 -Effect of Complete Hvdration on the Particle Size Distribution of Xerogel. Polvclar 10 and the Premix of Xerogel and Polyclar 10 The descriptions for various sample preparation are shown below and the results are summarized in Table 15. EXAMPLE 42-A1 Particle size distribution was determined on DRY powder of BG6 by Microtrac SRA 9200 (see results under DRY in Table 15). Later, 10g of BG6 was added to a stoppered graduated cylinder. Distilled water was added to bring the volume to the 100ml mark and mixed with the powder to disperse the solids. It was then allowed to stand overnight to fully hydrate the contents in the cylinder. The sample was then re-mixed by vigorous inversions of the cylinder to fully disperse the solid. The sample was then tested for particle size distribution, similar to the DRY sample, results are shown under Column IV in Table 15. EXAMPLE 42-A2 Particle size distribution was determined on DRY powder of Polyclar 10 by Microtrac 9200 (see results under DRY in Table 1). Later, 10g of Polyclar 10 was added to a stoppered graduated cylinder. Distilled water was added to bring the volume to the 100 ml mark and mixed with the powder to disperse the solids. It was then allowed to stand overnight to fully hydrate the contents in the cylinder. The sample was then re-mixed by vigorous inversions of the cylinder to fully disperse the solid. The sample was then tested for particle size distribution, similar to the DRY sample, results are shown under Column IV in Table 15. EXAMPLE 42-A3 Polyclar 10/Xerogel (BG6) premix was prepared by mixing 70g of BG6 and 30g of Polyclar 10 in a V-blender for a period of 60 minutes. Particle size distribution of the premix was determined and recorded under Column III in Table 15. Later, 10g of this premix was added to a stoppered graduated cylinder. Distilled water was added to bring the volume to the 100ml mark and mixed with the powder to disperse the solids. It was then allowed to stand overnight to fully hydrate the contents in the cylinder. The samples were then re-mixed by vigorous inversions of the cylinder to fully disperse the solids. The samples was then tested for particle size distribution, similar to the DRY sample, by Microtarc - SRA 9200, results are shown under HYDRATED in Table 15. EXAMPLE 42-B1 Example A1 was repeated, except in this case the Xerogel BG5 was used instead of Xerogel BG6. EXAMPLE 42-B2 Example 42-A3 was repeated, except in this case the 7:3 premix was made with Xerogel BG5 and Polyclar 10. EXAMPLE 42-C1 Example 42-A1 was repeated, except in this case the Xerogel Britesorb D-300 was used instead of Xerogel BG6. EXAMPLE 42-C2 Example 42-A3 was repeated, except in this case the 7:3 premix was made with Xerogel Britesorb D-300 and Polyclar 10. EXAMPLE 42-D1 Example 42- A1 was repeated, except in this case the Xerogel Lucilite XLC was used instead of Xerogel BG6. EXAMPLE 42-D2 Example 42-A3 was repeated, except in this case the 7:3 premix was made with Xerogel Lucilite XLC and Polyclar 10. EXAMPLE 42-E1 Example 42-A1 was repeated, except in this case the Xerogel Stabifix was used instead of Xerogel BG6. EXAMPLE 42-E2 Example 42-A3 was repeated, except in this case the 7:3 premix was made with Xerogel Stabifix and Polyclar 10. EXAMPLE 42-F1 Example 42-A1 was repeated, except in this case the Hydrogel Chillgarde was used instead of Xerogel BG6. EXAMPLE 42-F2 Example 42-A3 was repeated, except in this case the 7:3 premix was made with Hydrogel Chillgarde and Polyclar 10. EXAMPLE 42-G1 Example 42-A1 was repeated, except in this case the Hydrogel Britesorb A-100 was used instead of Xerogel BG6. EXAMPLE 42-G2 Example 42-A3 was repeated, except in this case the 7:3 premix was made with Hydrogel Britesorb A-100 and Polyclar 10. TABLE 15 The mean volume diameter of the hydrated premix of Xerogel and Polyclar 10 shows a marked increase compared to the individual components. This increase in the particle size under wet conditions is indicative of the flocculent effect of Polyclar 10. EXAMPLE 43 - Effect of different modes of filtration on the Residual PVP (polyvinylpyrrolidone) in beer Unstabilized beer samples were treated with different doses of Polyclar 10 and Xerogel (Britesorb D-300) and the premix of Britesorb D-300 and Polyclar 10, and then subjected to different modes of filtration as per procedure outlined in earlier examples and listed below. Residual PVP in beer was analyzed (by the method described in "Confirmation by Pyrolysis- Gas Chromatography of the Absence of Polyvinylpyrrolidone in Beer Treated with Cross-linked Polyvinylpyrrolidone" by T.M.H. Cheng and E.G. Malawer published in J. Am.Soc.Brew.Chem. 54(2):85-90,1990). Results are shown in Table 16. Procedure for Preparation of Beer Samples Double Filtration- Filtration After Addition of each Component, 15:3 ratio Britesorb D-300 : Polyclar 10 This was carried out as per procedure in Run No. 1 as shown in A in Table 16. Double Filtration - Filtration After Addition of each Component, 15:7 ratio Britesorb D- 300 : Polyclar 10 This was carried out as per procedure in Run No. 2 as shown in B in Table 16. Premix of Components - Single Filtration, 15:3 ratio Britesorb D- 300 : Polyclar 10 This was carried out as per procedure in Run No. 5 as shown in C in Table 16. Premix of Components - Single Filtration, 15:7 ratio Britesorb D-300 : Polyclar 10 This was carried out as per procedure in Run No. 6 as shown in D in Table 16. TABLE 16 It can be seen from the results in Table 16 that the presence of silica gel when mixed with crosslinked PVP facilitates the adsorption of any trace residual soluble PVP. EXAMPLE 44 - Microbiological Stability of Premix of Xerogel/Polvclar 10 System and Comparison with other Premix and Single Components Polyclar 10/Xerogel (Britesorb D-300) premix was prepared by mixing 150g of Xerogel (Britesorb D-300) and 30g of Polyclar 10 in a V blender for a period of 60 minutes. Similarly, a premix of 150 g of Xerogel (Chillgarde) and 30g of Polyclar 10 was prepared by mixing in a V blender for a period of 60 minutes. These two premixes together with single components of Polyclar 10, Chillgarde and Britesorb D-300 were also, used in the experiment. All the samples were assessed for microbiological stability using the test "Adequacy of Preservation (Challenge) Test" from Sutton Laboratories, Method MLM 100-9. The challenge test protocol is designed to assess effective antimicrobial activity over storage time, thus simulating shelf life of the product. TABLE 17 The results in Table 17 above demonstrate that the premix of Xerogel (Britesorb D-300) and Polyclar 10 gave a higher microbiological stability than the premix of Hydrogel (Chillgarde) and Polyclar 10. The premix of Xerogel (Britesorb D-300) and Polyclar 10 also has an acceptable microbiological stability. On the other hand, the premix of Hydrogel (Chillgarde) and Polyclar 10 had a "not acceptable" result with considerably higher mold growth. While the invention has been described with particular reference to certain embodiments thereof, it will be understood that changes and modifications may be made which are within the skill of the art. Accordingly, it is intended to be bound only by the following claims.

Claims: WHAT IS CLAIMED IS: 1. A premix composition for clarifying beer effectively in a single-step process, comprising, by weight, (a) about 40%) to about 90% of silica xerogel having less than 10% water therein, and (b) about 10% to about 60% of crosslinked polyvinylpyrrolidone. 2. A premix composition according to claim 1 wherein (a) is 60 to 85%, and (b) is 15%) to 40%). 3. A premix composition according to claim 1 wherein (a) is 70 to 80% > , and (b) is 20 to 30%. 4. A premix composition according to claim 1 wherein, prior to admixture (a) has a particle size, as defined by its mean volume average diameter, Mv, of less than 50 μ both in the dry state and in a 10% aqueous slurry. 5. A premix composition according to claim 4 wherein (a) has a particle size of about 5-30 μ. 6. A premix composition according to claim 1 wherein, prior to admixture, the ratio between particle sizes of (a) in a 10%) aqueous slurry to its dry state is about 0.6 to about 2.0 7. A premix composition according to claim 14 wherein, prior to admixture, (b) has a particle size as defined by its mean volume average diameter, Mv, of about 20 to 50 μ in the dry state. 8. A premix composition according to claim 1 wherein, prior to admixture, (b) has a particle size of about 30-90 μ in a 10%> aqueous slurry. 9. A premix composition according to claims 7 and 8 wherein, prior to admixture, the ratio between the particle sizes of (b) in a 10% aqueous slurry to the dry state is about 1.0 to about 2.0. 10. A premix composition according to claim 1 wherein (a) has a particle size as defined in claims 4, 5 and 6, and (b) has a particle size as defined in claims 7, 8 and 9. 11. A premix composition according to claim 1 wherein the particle size, as defined by its mean volume average diameter, Mv, of (a) is less than the correspondingly defined particle size of (b). 12. A process of stabilizing beer or wine beverages which comprises (a) treating said beverage with an agitated aqueous flocculated slurry of the composition of claim 1 , and (b) filtering the thus-treated beverage. 13. A process according to claim 12 wherein both proteins and polyphenols are removed in one step from said beverage. 14. A process according to claim 12 wherein (a) in the contact time is about 3 hours or less than 3 hours. 15. A process according to claim 12 wherein a dose of about 5-20 lbs of said premix composition is used for each 100 barrels of said beverage. 16. A process according to claim 12 including the step of pumping both the stabilized beverage and the used premix composition from the treatment tank into a filter tank. 17. A process according to claim 12 which is characterized by an advantageous filter flow rate, undetectable residual soluble polyvinylpyrrolidone in the treated beverage, no biological growth in the premix, effective haze stability, and advantageous redispersibility of used premix. 18. A flocculated aqueous slurry of the premix composition of claim 1. 19. A flocculated aqueous slurry of claim 17 having about 5-20 wt. %> of the premix composition and about 80 to 95%> water. 20. A process of preparing the flocculated aqueous slurry of claim 18 which comprises admixing solid xerogel and crosslinked polyvinylpyrrolidone and slowly adding water with agitation thereto. 21. A premix composition according to claim 1 wherein, in the dry state, its particle size as defined by its mean volume average diameter, Mv, is between the average particle sizes of both components (a) and (b) therein. 22. A premix composition according to claim 1 wherein in a 10% aqueous slurry its particle size, as defined by the mean volume average diameter, Mv, is higher than the particle sizes of both components (a) and (b) therein. 23. A premix composition according to claim 1 wherein the ratio of its particle size as defined by the mean volume average diameter, Mv, of a 10% aqueous slurry to the corresponding particle size in the dry state is about 2 to about 6. 24. A premix composition according to claim 1 wherein (a) has 5% or less water therein.

Inventors: CHENG TOM, IANNIELLO ROBERT, MOLA ANDREW, NARAYANAN KOLAZI S, REHMANJI MUSTAFA, CHENG, TOM, IANNIELLO, ROBERT, MOLA, ANDREW, NARAYANAN, KOLAZI, S., REHMANJI, MUSTAFA
Applicants: CHENG TOM, IANNIELLO ROBERT, ISP INVESTMENTS INC, MOLA ANDREW, NARAYANAN KOLAZI S, REHMANJI MUSTAFA, CHENG, TOM, IANNIELLO, ROBERT, ISP INVESTMENTS INC., MOLA, ANDREW, NARAYANAN, KOLAZI, S., REHMANJI, MUSTAFA
Application year: 1999
Main classification: C12H1
IPC codes: B01J20, C12H1