From juices

Ice lollies are made from juice (water, sugar, citric acid, flavour and colour) and are frozen into shape using moulds immersed in a cold brine solution, in a similar manner to can ice making (see Section 12.4). The moulds are made from stainless steel or nickel, and pass in rows through a brine bath at - 45°C. Different layers of confection may be built up by allowing one outside layer to freeze, sucking out the unfrozen centre and refilling with another mix. The sticks are inserted before the centre freezes solid. The moulds finally pass... 

The chromatogram of the serum from juice with poor cloud stability obtained after mash treatment with the enzyme mixture including the pectin depolymerisation enzyme combination of polygalacturonase and pectin methyl esterase is seen to be lacking the A-peak. High molecular pectin is therefore considered to be a prerequisite for a cloud stable juice. 

The efficiency of the SCC is illustrated in comparison with a traditional distillation-based essence recovery unit in Table 18.2. One can see that the aroma volatiles are preferentially stripped from the infeed in the SCC compared with the situation in a single-stage evaporator. Thus, highly concentrated aroma isolates can be produced. Flavortech [22] noted that essences of 1,500-fold maybe produced from juices if a double pass is used (the infeed is the flrst pass and the acquired essence the second pass). 

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... 

Another very important development was the production of citrus comminutes. These were produced by mixing together, in appropriate proportions, the juice, peel components and essential oils of citrus fruits and comminuting the mixture in a stone mill. The resulting product delivered a more intense flavour and cloud than could be obtained from juice alone and allowed the creation of whole fruit drinks , which have dominated the concentrates market in the United Kingdom over the past 40-50 years. 

Although conventional separators are successful in removing the volatiles from juice streams, the resulting strip will usually require further rectification and thereby concentration in order to render it a flavour component in its own right. 

Stevens and Baier (1939) produced a table that gives a collection for obtaining Brix from refractometer readings from juices or other acid-containing sugar solutions. Based on the citric acid content of juices, the corresponding collection is to be added to the refractometer reading. 

Detection of Sulphur Dioxide.—This test is made on sugars from juices decolorised by means of sulphurous acid. To a solution of 10-15 grams of the sugar in about 25 c.c. of water in a flask are added a scrap of pure zinc (or 0-3-0-4 gram of magnesium wire) and 5 c.c. of pure hydrochloric acid. In presence of sulphur dioxide, hydrogen sulphide is evolved and may be detected by the odour or by means of a strip of lead acetate paper. 

Viscosity poses a similar problem in the production of pulp wash concentrate. Pulp wash consists of juice solids obtained by countercurrent washing of pulp after its separation from juice. On a °Brix basis, pulp wash liquids are higher in pectin than juice from which the pulp has been screened (19). Concentration of pulp wash above 40°Brix is at times hampered by excessive pectin levels (20). To control viscosity processors may be forced to reduce finisher pressure to minimize pectin extraction, thereby curtailing yield. A more effective solution is to treat pulp wash with pectinases to reduce pectin levels (21). If pectinases are incorporated into the wash water, this method has the advantage of increasing total solids yield by reducing juice retention in the pulp. 

Interest in reduced-acid citrus juices originated in the early 1960 s when Kilbum and Drager (4) employed electodialysis tc remove citrate ions from juice. The Florida Department of Citrus tested the reduced-acid concept with consumers at the New York World s Fair in 1965, and followed this test with a national consumer survey in 1972. The Coca-Cola Company Foods Division... 

Costa, A. (1950a). Hemorrhagic diathesis from juice of the roots of Ferula communis behavior of the V factor of Owren. Boll. Soc. Ital. Biol. Sper. 26(7) 1043. ... 

Glycosides were obtained from juice and skin extracts from both Cabernet Sauvignon and Merlot fruit, sourced from Australian and Californian vineyards. The glycoside isolates were acid hydrolyzed at elevated temperature in a model wine medium. This hydrolysis was carried out to simulate conditions, although in an accelerated manner, that could occur as wine is stored and matured, ie volatiles will be slowly produced from their non-volatile precursors. 

Figure 3. Concentrations of five categories of volatile compounds, observed as a result of acid hydrolysis of the glycoside fractions isolated from juice and skin extracts of Napa Merlot (NMJ, NMS) and Cabernet Sauvignon (NCJ, NCS) fruit.

Figure 5-11 Shear Rate versus Shear Stress Data at 25°C Obtained on 20% Solids Concentrates Made from Juices that were Produced Using Different Finisher Screen Openings Show that Using a 0.69 mm Screen Resulted in Concentrates with the Highest Viscosity (Tanglertpaibul and Rao, 1987a).

Figure 5-15 Magnitudes of C and G" of Three Tomato Coneentrates from Juice Using a 0.84 mm Sereen as a Function of Dynamic Frequencies.

Vi cups carrot pulp (left over from juicing carrots)... 

Adsorber resin treatment can remove certain undesired substances from juices and can be used to improve colour and taste. 

Maple syrup and maple sugar from juice of Acer saccharium maple trees contains 98% saccharides, 80-98% of which is sucrose. 

Isolation of free monoterpenes from juices and wines. The... 

Submitochondrial particles (membranes from washed sonicated mitochondria) prepared from juice vesicles of Hamlin oranges harvested in September contained KCN-insensitive respiratory activity (46% of total) using a substrate mixture containing 0.05 M raalate, 0.05 M succinate, 0.01 M glutamate and 0.01 M TPP (21). 

This activity contrasts to the small (3%) KCN-insensitive respiratory activity observed when NADH was used as substrate with the mitochondria (Table I). To calculate the contribution of each oxidase to the total oxygen uptake, the titration method of Bahr and Bonner (25) was used, ( -uptake of submitochondrial particles (membranes) prepared from juice vesicles of Hamlin oranges harvested in September and January was measured in the presence and absence of ImM KCN titrated with a series of SHAM concentrations using the malate, succinate, glutamate substrate mixture (Table II). 

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