Concentrated fruit juices

Dried fruits and concentrated fruit juice are very susceptible to spoilage by yeasts, because of their relatively high sugar and moisture contents. Some species of Zygosac-charomyces, Torulaspora, and Lachancea have been associated with spoilage of these products (Dijksterhuis and Samson 2006). 

Tables have been published relating Baume, Brix and specific gravity. As density is temperature dependent it is necessary to either bring the syrup to a fixed temperature or, as is more common in practice, to use temperature correction factors or tables. The relationship between density and concentration is slightly different for invert sugar or glucose syrups. The Brix scale is sometimes applied to products that are not sucrose syrups, such as concentrated fruit juice. Recipes are certainly in use that state boil to x Brix . In practice these instructions mean that the material should give the same reading as a sugar syrup of that concentration. As often happens in confectionery these practices have been proved to work empirically.

Being a food bearing the reserved description fruit juice , concentrated fruit juice , fruit juice from concentrate or dehydrated or powdered fruit juice , it has not been prepared by adding to it ... 

Ingredients Carbonated water. Concentrated fruit juices (pineapple, grapefruit) (5% when reconstituted). Citric acid. Acidity regulator (sodium citrate). Artificial sweeteners (aspartame, saccharin). Flavourings. Preservative (sodium benzoate). Antioxidants (ascorbic acid, ascorbyl palmitate). Colour (lutein)... 

Fruit juices, concentrated fruit juices (for direct consumption), and fruit nectars 0.05... 

Another reason for consuming sugar-free products is the belief that refined sugar is in some way unhealthy. Tooth friendly claims are highly specific the product must be tested to see that it does not cause a fall in pH during eating, and this system requires the use of a specialised pH electrode strapped to the teeth of a volunteer. To pass this test the product must be free of any fermentable carbohydrate and acids - this does have the odd effect in that some products which contain concentrated fruit juice fail the test and have to be re-formulated. The calorific values accepted by the authorities are not universal. The current position in the European Union is that the polyols are only partially absorbed to the extent of 2.4 kcal g 1 as opposed to 4 kcal g 1 if they are completely absorbed. For example, the polyol lactitol has the following accepted values ... 

Brix Passion fruit juice-concentrated Fruit juice-temperature effect 18.8... 

Membrane contactors can be used in osmotic distillation process to transfer water vapor, as discussed in Section 2.8. Such a process has been investigated as a means of concentrating fruit juice [58] using concentrated brine as the receiving phase for water vapor. A photograph of a pilot system is shown in Figure 2.15. 

Under proper processing conditions, fruits lose less than 30% of their original vitamin C content through the entire freezing and frozen storage period (106). Frozen concentrated fruit juices can retain over 90% of their ascorbic acid (38,106). Packing in syrup is generally protective of ascorbic acid. 

SO2 (50-100 ppm) is added to expressed grape juice to control unwanted moulds, bacteria and yeasts depending upon the condition of the grapes. It is also used in treatment of soft-fruits in order to extend the time available for jam manufacture. Sausage and meat products are treated with SO2 to extend their shelf life under refrigerated conditions. Soft drinks may contain 10 ppm (Continental Europe) -70 ppm (UK), some of which may originate from preserved concentrated fruit juices. 

Moressi, M. and Spinosi, M. (1984). Engineering factors in the production of concentrated fruit juices, II, fluid physical properties of grapes. ]. Food Technol. 5, 519-533. 

Concentrating heat-sensitive pharmaceuticals from their substrates Concentrating fruit juices Isolation of aromatic compounds... 

Refer to Figure 35-1, p. 414. Suppose you apply a pressure on the left side to force the solvent back across the membrane to the other side. This is called reverse osmosis and, as a separation technique, has many commercial applications. The most notable is the desalinization of sea water. The removal of dissolved salts in hard water to make it soft water is done extensively. Many chemistry laboratories use reverse osmosis to obtain "distilled water". It is used to treat industrial waste water and to concentrate fruit juices. 

E212 Potassium benzoate From benzoic acid Preservative Allergic reactions 0-5 Margarine, concentrated fruit juices... 

VAN Esch, F. 1992. Yeast in soft drinks and concentrated fruit juices. Brygmesteren— NR 9-20. 

Scheme of an integrated membrane process for the production of concentrated fruit juices. UF = ultrafiltration RO = reverse osmosis OD = osmotic distillation. 

Nabetani H (1996), Development of a membrane system for highly concentrated fruit juice J. Membrane (Japanese), 21,102-108. 

Applications. Sulfur dioxide is used in its gaseous or liquid form, or in the form of one of its salts mainly on dried fruits, molasses, syrups, concentrates, fruit juices and wines. Sulfur dioxide, sulfites, bisulfites and pyro-sulfites are more or less equivalent permitted as active ingredients in food worldwide. Many countries do not allow the use of sulfite for meat, fish or processed meat and fish products anymore. 

A rapid application of superheated steam which quickly distills off a small volume, 1% of the liquid being condensed. This flash distillate carries the volatile flavor constituents. Later, these flavors are added back to the concentrate. This process is employed in the production of concentrated fruit juices. 

In the advanced and late "Maillard reaction" the furosine method is not valuable since the Amadori products lead to further compounds. Therefore the amount of available lysine in severely damaged foods is underestimated. In the case of fructose rich food (e.g. special diets for diabetics or products which are sweetened with honey or concentrated fruit juice) similar false conclusions are possible since glucoselysine which is formed from fructose during the "Maillard reaction" is not a precursor for furosine. 

---