Pomace removal

Interior Valley wineries primarily designed to produce dessert wine used pomace removal methods which were not acceptable for table wine production both from the quality and sanitary viewpoints. Pomace removal meant... 

The epicarp contains a number of components of relatively high polarity that are not removed by mechanical extraction and remain in the pomace. Removal of these components along with the oil by solvent extraction of the pomace accounts for the higher unsaponifiable content of olive-pomace oil. 

Another piece of equipment in high demand is an automatic pomace removal system which evacuates the skins from the tank toward the press, replacing the arduous task of manually emptying the tank. 

Hydrauhc pressure is apphed to the mash first at 2750—3440 kPa (400—500 psi) and then at 17,200—20,600 kPa (2500—3000 psi) for preset times the pomace is removed after each cycle. One person can operate several presses at once, each with a 4—5 t/h throughput. 

Prompt removal of stems from crusher and pomace from presses... 

Removing Stems from Crusher and Pomace from Presses. See Equipment Cleaning. Prompt removal of all waste from the fermentation area minimizes fruit fly buildup. 

Citrus peel, apple pomace from juice manufacture, and beet pulp left over from the manufacture of sucrose are common commercial sources of pectins. After some preliminary purification of the raw material, the extraction is usually performed with hot dilute acid (pH —1.0-3.5 in a temperalure range of 70-90°Ci. The pectin is then precipitated from the extract with ethanol or isopropanol, or with metal salts (copper or aluminum). The metal ions have to be subsequently removed by washing... 

For white wine production, the grapes usually were not stemmed. The crushed grapes were left for six to ten hours before the free-run (separated) juice was drawn off. The pomace was then pressed and the pressed pomace was washed as with red pomace. The fermentation of white musts was done in 2/3-full oak casks. The fermentation was watched daily. The yeast foam was removed. By the sixth day, the fermentation had slowed down sufficiently to then use a fermenting bung. The Italians often use a bag of sand, which they place over the bung-hole. He recommended fermenting room temperatures of 21°-27° C and cellar temperatures of 15.6°-21° C, preferring 15.6° C after the first year. 

It is of interest to note the amount of hand labor required in pre-Prohibition wineries. Crushers often were placed at the highest point in the winery, the fermentors were on the top floor, and storage tanks were on lower floors. It was not until the 1890s that machine-operated pumps and filters were used commonly. Grapes, of course, were still delivered in boxes and unloaded by hand and the pomace was removed from the fermentors by hand labor, in a few cases until recently. 

Must and Wine Yield. The wine gallon yield per ton varies with type of grape, whether white or black. Total wine gallon yield is composed of three fractions. The main volume is the free-run juice that flows from the crushed grape second is the drain screen juice that separates from the pomace, which already has had the free-run juice removed and third is the press juice from the tight squeezing of the screen-drained pomace that was conveyed to the grape press. 

After free draining, the pomace is removed and pressed. The press wine, which yields 30-45 gallons per ton, is dark red, high in tannin, and heavy bodied. This press wine generally is segregated from the free-run fraction and, after separate clarification to reduce the astringency caused by polyphenolic compounds, may be blended in with the main free-run volume. 

Removal of the red pomace from the fermentor is accomplished by a number of different methods. In some wineries, it is shoveled directly to a portable press located in front of the tank. In other cases, the pomace is... 

Liquidification of starches for free flow Recovery of sugar from candy scraps Remove starches to increase sparkling properties Remove starches to increase sparkling properties An aid in preparation of pectin from apple pomace Conversion of starches to low molecular weight dextrins (corn syrup)... 

PagnaneUi, R, Sara, M., Veglio, R, and Lnigi, T. 2003. Heavy metal removal by olive pomace Biosorbent characterization and eqnUibrinm modeling. Chemical Engineering Science, 58 4709-17. 

Monopotassium tartrate may be recovered from pomace, from lees, or from the virtually pure material obtained from tartrate removal processes [36]. Monopotassium tartrate from this source provides most of the commercially marketed material used in such diverse products as baking powder and cream of tartar. 

This product is usually obtained by leaching the pomace of various fruits. The dark, cloudy appearance and characteristic odor are removed by treating a 1 % solution with activated carbon for 1 hour at 50° C. 

Procedure. The method of acid extraction and demethylation of pectin from apple pomace at 60 C. was essentially that previously described (17), up to the point of clarification of the pectin extract. Prior to clarification, the temperature of the extract was raised to about 50 C. in order to aid dispersion of the pectinates. Following the clarification and removal of starch, the pectin was precipitated as calcium pectinate by adding 20% calcium chloride solution to the extract at room temperature. The quantity of calcium chloride was such that any excess of the salt did not give a further precipitate after the precipitated material had stood from 1 hour to overnight as a practical handling procedure. After the calcium pectinate had been filtered off through muslin by hand, the relative completeness of precipitation was estimated by determining the relative viscosity (Ostwald at 26 C.) of the liquid pressed out. A relative viscosity of 1.2 or less indicated practically complete precipitation. 

The above trends are also substantiated by the results shown in T le V for the extraction of black raqrberty pomace sub-H20. The pomace is the substance left over after the removal of the jitice from black raspberries. Here, extraction with ethanol yields an approximately equivalent result to that obtained on dried eldeibeny seeds (Ts le FV). The results for extraction with sub-H20 and 90%+ Sub-H20 yield less total ANC than in the case of the whole dried eldeibeny seeds, but this is due to the reduced levels of ANCs found in all pomaces after Ae juice is etqiressed. 

Pectin is widely distributed in plants. It is produced commercially from peels of citrus fruits and from apple pomace (crushed and pressed residue). It is 20-40% of the dry matter content in citrus fruit peel and 10-20% in apple pomace. Extraction is achieved at pH 1.5-3 at 60-100 °C. The process is carefully controlled to avoid hydrolysis of glycosidic and ester linkages. The extract is concentrated to a liquid pectin product or is dried by spray- or drum-drying into a powered product. Purified preparations are obtained by precipitation of pectin with ions which form insoluble pectin salts (e. g. AI +), followed by washing with acidified alcohol to remove the added ions, or by alcoholic precipitation using isopropanol and ethanol. 

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