Extraction juice

Most of the technical procedures employed are based on the same pressing process that has always been used. The overriding concern in juice extraction is to avoid oxidation - which makes rapid extraction essential. The juice extraction equipment must therefore satisfy the following criteria. 

From the point of view of maintaining quality, the extraction process must be rapid and exclude air, so as to prevent changes in quality. To this end the plant should be technically efficient, if possible continuously operable, and highly reliable, with few breakdowns. It should also require few staff to operate it. The plant should provide a maximum yield, run economically and be easy to clean. 

The pressure, degree of crushing, etc., will of course vary from case to case and depend on the quality of the fruit and the experience and skill of the operator. 

The rack and frame press is a further development of the basket press. Rack and frame presses are commonly used on farms that process apples and pears. They are particularly suitable for mashes that are difficult to press. They give high yields and good juice quality with little suspended 

In terms of their design they are fairly small in size, but the output is high. The biggest disadvantage of the rack and frame press is the high labour requirements. Other disadvantages are the severe oxidation of the juice produced and the irregular flow of juice. 

The designer of a blending/filling system must have a full understanding of the process its limitations, the raw materials, the packaging materials and their levels of contamination and the means of controlling the contamination to enable wholesome product with adequate shelf life to be produced. 

The details of the juice extraction process will depend on the fruit, but this section outlines a typical method. Some processors size the extraction plant to handle all the juice they will require for the year within the harvesting period others will freeze or otherwise store the fruit and extract juice as it is required on a much smaller plant. 

There are three main blending routes, which can be used individually or in combination to form a product. Traditionally this is carried out in the syrup room as it used to be normal to produce the drink as a syrup and dilute it prior 

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In another extractor (Automatic Machinery and Electronics Inc. (AMC)) the individual fmits are cut in half as they pass a stationary knife. The halves are oriented in a vertical plane, picked up by synthetic mbber cups, and positioned across plastic serrated reamers revolving in a synchronized carrier in a vertical plane. As the fmit halves progress around the extractor turntable, the rotating reamers exert increasing pressure and express the juice. The oil and pulp contents in the juice increase with greater reaming pressure. The recoverable oil is removed in a separate step prior to juice extraction. Needle-sharp spikes prick the peel of the whole fmit, releasing oil that is washed away with water and recovered from the oil—water emulsion. 

Screw presses have been used extensively in North America, but are not popular in Europe. The mash is added at the top of a vertical rotating screw. As the mash moves down it is compressed in the taper and juice flows out through slatted conical walls. Compression of the pomace blocks channels for juice flow and iuhibits juice extraction. Extensive use of press aids is necessary for efficient operation. 

Cranberry juice, too acidic to be consumed as a 100% juice drink, has been sold since 1929 as cranberry juice cocktail. Juice extraction usually involves pressing the juice from thawed cranberries in a tapered screw press, which affords a 60—64% juice yield. The juice is diluted with two volumes of water and sugar is added to raise the °Brix to 15 to produce a juice cocktail. Under the Federal Food, Dmg and Cosmetic Act, cranberry juice cocktail must contain not less than 25% single-strength cranberry juice with soluble soHds content of 14—16 °Brix, vitamin C content of 30—60 mg/177 mL (6 02), and... 

In production of sugar, the juice extracted from the sugar cane or sugar beets is treated with a suspension of Ca(OH)2, which neutralizes the symp acidity and precipitates calcium sucrate, leaving impurities ia the solution. This is filtered and the calcium sucrate is converted to sugar and CaCO by reaction with CO2. 

Fleisch-saft, m. meat juice, extract of meat, -seite, /. flesh side, -tee, m. beef tea. -ver-giftung, /. meat poisoning, -waren, f.pl. meats, esp. dried meats, -wasser, n. meat broth, -zucker, m. inositol, inosite. 

Pectin degradation requires fee combined action of various enzymatic activities. However, evaluation of fee contribution of individual pectinases in Suit juice extraction and clarification is rather complicated. Most commercial pectinolytic enzyme preparations are produced by fermentation wife filamentous fungi, mostly strains belonging to fee genus Aspergillus,. plication studies with mixtures of isolat enzymes obtained by fermentation or by means of fractionation of commercial enzyme preparations can be used to assess the importance of fee various individual enzymes. Subsequently, molecular biology and fermentation technology can be used to enhance specific desirable enzymatic activities. 

Since many years, pectolytic enzymes have been widely used in industrial beverage processing to improve either the quality and the yields in fruit juice extraction or the characteristics of the final product [1,2]. To this purpose, complex enzymatic mixtures, containing several pectolytic enzymes and often also cellulose, hemicellulose and ligninolytic activities, are usually employed in the free form. The interactions among enzymes, substrates and other components of fruit juice make the system very difficult to be investigated and only few publications are devoted to the study of enzymatic pools [3-5], An effective alternative way to carry out the depectinisation process is represented by the use of immobilized enzymes. This approach allows for a facile and efficient enzymatic reaction control to be achieved. In fact, it is possible to avoid or at least to reduce the level of extraneous substances originating from the raw pectinases in the final product. In addition, continuous processes can be set up. 

The authors thank Charles Stafford, Elizabeth Kolbe, Paul Golden (US EPA OPP, Analytical Chemistry Branch) and Elizabeth Flynt (US EPA OPP, Environmental Chemistry Branch) for gathering information on the validation work performed by both branches Lynda V. Podhorniak, US EPA, for providing the grapefmit juice extracts and the HPLC/fiuorescence chromatogram of the grapefruit juice control ... 

Percival SS, Talcott ST, Chin ST, Mallak AC, Lound-Singleton A and Pettit-Moore J. 2006. Neoplastic transformation of BALB/3T3 cells and cell cycle of HL-60 cells are inhibited by mango (Mangifera indicaL.) juice and mango juice extract. J Nutr 136 1300-1304. 

The effect of temperature on the RP-HPLC behaviour of /(-carotene isomers has been extensively investigated and the results were employed for the separation of carotenoids of tomato juice extract. Carotenoids were extracted from food samples of 2g by adding magnesium carbonate to the sample and then extracted with methanol-THF (1 1, v/v) in a homogenizer for 5min. The extraction step was repeated twice. The collected supernatants were evaporated to dryness (30°C) and redissolved in methanol-THF (1 1, v/v). Separations were performed on a polymeric ODS column (250 X 4.6 mm i.d. particle size 5/.an). The isocratic mobile phase consisted of methanol-ACN-isopropanol (54 44 2, m/m). The flow-rate was 0.8 or 2.0 ml/min. The effect of temperature on the retention times of lycopene and four /(-carotene isomers is shown in Table 2.11. The data indicated that the temperature exerts a considerable influence on the retention time and separation of /(-carotene isomers. Low temperature enhances the efficacy of separation. 

The chromatoraphic profile of a tomato juice extract at a column temperature of 7°C, flow rate 2.0 ml/min and further chromatographic conditions (see caption) is shown in... 

Fig. 2.15. Chromatographic profile of a tomato juice extract at a column temperature of 7°C. Peak identification 4 =/0-apo-8 -carotenal 9 = (E)-/0-carotene 11 = 13(Z)-/0-carotene 10 = 9(Z)-/0-carotene 7 = lycopene 7a = 9(Z)-lycopene 7b = 15(Z)-lycopene. Reprinted with permission from V. Bohm [39],...

A CC chromatogram of a mixture of known VFAs, lactic acid and pivalic acid (internal standard) is shown in Fig. 8.3, and a chromatogram of a silage juice extract with pivalic acid internal standard is shown in Fig. 8.4. 

Juices extracts (liquorize), spirits (orange, lemon), syrups (black currant), tinctures (ginger), and aromatic waters Mineral pigments (iron oxides), natural colorants, anthocyanins, carotenoids, chlorophylls riboflavine, red beetroot extract, and caramel synthetic organic dyes azo compounds... 

CF HPLC-UV and GC with FID and MS detection. HPLC column Nucleosil C-18 mobile phase of 10% MeOH (pH = 3.2). GC column 1% of OV-17 on Supelco-port. Orange, citrus, lemon. No CF found in orange juice. Extraction of frozen samples in 80% EtOH, filtration, adjustment to pH = 2.0, centrifugation. Adjustment of the supernatant solution to pH = 9.0, BuOH extraction, azeotropic distillation of the combined butanolic phases. 313... 

For orange juices and vegetables juice extraction using Ana-lytichem Cl 8 solid phase (SPE). For milk samples protein precipitation with HCL, vortex mixing, centrifugation, 1-octanesulfonic acid extraction. For cola MeOH addition, vortex mixing, filtration. 

Quality can be regarded as a measure of the suitability of a fruit juice, fruit juice concentrate or fruit juice extract for an intended application. In general, whatever the application, it will be the consistency in performance of the product, from batch to batch and season to season, that is the prime concern. In order to meet quality targets, therefore, it becomes critical that processing is carried out in the correct manner using fruit of an optimum level of maturity, and that the product is stored under suitable conditions to limit effects of degradation during a required shelf-life. 

Juice extracted from cane or beet undergoes further purification steps, including precipitation, absorption, crystallisation and evaporation, which remove nonsugars and progressively concentrate the sucrose solution. The final step is crystallisation of sucrose from the syrup. This mixture of sucrose and liquor, known as the massecuite , is then centrifuged, and the crystals are washed and dried to a moisture content of 0.02% w/w and stored (Beesley, 1990). 

Hesperidin Solubility. Hesperidin, a tasteless flavanone glycoside, is the least soluble of all citrus flavonoids. It is found in practically every variety of citrus (5) and is the major flavonoid in sweet oranges and lemons. In fruit or leaves, hesperidin is found as a soluble complex which can be extracted with water or alcohol (5). During juice extraction, the complex is destroyed and hesperTdin slowly precipitates as fine, white, needle-shaped crystals. Once in the solid form, hesperidin can be redissolved in formamide, pyridine or in dilute alkali. 

Citrus fruits, especially certain of their component parts, constitute one of the richest sources of pectin. On a dry weight basis, as much as 30% of orange fruit albedo may be pectin (8). The rag, comprising the fruit core and segment membranes after juice extraction, is also a rich source. Since pectin is a cell wall component, it follows that comparatively little would be present in juice expressed from fruit. For example, concentrations ranging from 0.01 to 0.13% in orange juice have been reported (15). Much of this would be present as cell wall fragments and particulate material in juice pulp and cloud. 

Bruemmer, J. H. Roe, B. Enzymic oxidation of simple diphenols and flavonoids by orange juice extracts. J. Food Sci., 1970, 35, 116-119. 

The peel, internal membranes, ruptured juice vesicles and seed residue remaining after juice extraction represent the raw material for production of dried citrus pulp. This residue, in its wet state, contains 75-85% water and ferments or sours readily because of the presence of soluble sugars. The difficulty of handling this wet material necessitates dehydration to a moisture content in the range of 107. water. Once dried, if proper precautions are taken to maintain dry conditions, the product may be handled, stored, and shipped in a manner similar to other dry feed stuffs. 

The juice vesicles, or "sacs," remaining after juice extraction and pulp-washing may be included in the portion of peel residue dried as cattle feed. However, it is feasible to recover and utilize this material as either frozen (3) or drum-dried juice sacs (44). 

Another method of ingesting khat is by chewing a paste made of khat leaves, water, and sugar or honey, sometimes flavored with herbs. A tea made from the flowers of the khat plant— flower of paradise in Yemen—is considered restorative. In addition, the leaves are sometimes added to plain tea, or smoked in combination with tobacco. Ethiopians often drink a juice extract made from khat leaves. 

Pomegranate juice was shown to possess an antioxidant activity that was three times higher than the antioxidant activity of green tea.19 The antioxidant activity was higher in juice extracted from whole pomegranate than in juice obtained from arils only, suggesting that the processing extracts some of the hydrolyzable tannins present in the fruit rind into the juice. 

To make juice extraction easier, a cold pressing (cryoextraction) technology has been developed (Chauvet et ah, 1986). Cooling the grapes below 0 °C (potentially as low as —16 °C) freezes berries with lower sugar contents, while the juice of berries with the highest sugar content... 

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