Juices concentrates

Many essential oils are used for flavoting and perfumery, eg, neroH, geranium, and ylang (see Oils, essential). The whole fmit, cmshed fmit, and puree may be used directly in foods, ice cream, cakes, and confections. Fmit juices, concentrates, and essences are more commonly employed (see Fruit juices). 

Flavor Formulas. Tables 7 and 8 give examples of modem flavor formulas. In Table 7 formula A is composed of fmit juice concentrate and essence distilled or extracted from the fmit juice. It is all natural and all from the named fmit, and is therefore termed a "natural flavor." It has a characterizing natural flavor. In Formula B the flavor is all natural, but is not all from the named fmit, ie, the fortifier is all natural but is not totally derived from the named fmit. Since the fortifier simulates, resembles, or reinforces the named flavor, eg, apple or pineapple, the flavor must be called "flavor with other natural flavors." It has a natural flavor with characterizing naturals added. Formula C is composed of both natural and artificial components with the natural usage outweighing the artificial. Therefore, it is a "flavor natural and artificial." It has a characterizing natural and artificial flavor. 

A newer juice concentration process, requiring minimal heat treatment, has been appHed commercially in Japan to citms juice concentration. The pulp is separated from the juice by ultrafiltration and pasteurized. The clarified juice containing the volatile flavorings is concentrated at 10°C by reverse osmosis (qv) and the concentrate and pulp are recombined to produce a 42—51 °Brix citms juice concentrate. The flavor of this concentrate has been judged superior to that of commercially available concentrate, and close to that of fresh juice (11). 

The product has purities typically in the 90—92% range and can be combined with thin juice, concentrated and crystallized, or concentrated and stored for later use. Crystallizing the desugarization thick juice apart from the normal beet campaign may be desired because the secondary molasses produced after the separation contains the nonsucrose components, which are the most difficult to separate from sucrose and perhaps should be set aside and sold instead of resubmitted to the columns. 

Beet juice contains about 80% of fermentable carbohydrates and nitrogenous compounds. To remove these compounds, a yeast fermentation utilising Candida utillis has been suggested (141). By so doiag, a more concentrated form of the dye becomes available. The red dye from beets is sold as beet juice concentrate, as dehydrated beet root, and as a dried powder. 

FalTing films are also used for evaporation in which the film is both entirely or partially evaporated (juice concentration). This principle is also used in ciystallizatiou (freezing). 

While theoretical compressor power requirements are reduced slightly by going to lower evaporating temperatures, the volume of vapor to be compressed and hence compressor size and cost increase so rapidly that low-temperature operation is more expensive than high-temperature operation. The requirement of low temperature for fruit-juice concentration has led to the development of an evaporator... 

Mosshammer, M.R., Stintzing, F.C., and Carle, R., Evaluation of different methods for the production of juice concentrates and fruit powders from cactus pear, Innov. Food Sci. Emerg. TechnoL, 7, 275, 2006. 

Rhamnogalacturonase may be useful in the prevention of haze formation in apple Juice concentrates. In combination with other enzymes it mi t improve liquefaction, resulting in increase juice yield and clarification. 

Maltini, E., Torreggiani, D., Fomi, E., and Lattuada, R. 1990. Osmotic properties of fruit juice concentrates. In Engineering and Food Physical Properties and Process Control (W.L.E. Spiess and H. Schubert, eds), Vol. 1, pp. 567-573. Elsevier Science, London. 

J.-P. Goiffon, P.P. Mouly and E.M. Gaydou, Anthocyanic pigments in red fruit juices, concentrated juices and syrups using liquid chromatography. Anal. Chim. Acta 382 (1999) 39-50. 

Hydrolysis of mannan-type polysaccharides by P-mannanase is dependent on substitution on and within the main-chain as well as the source of the P-mannanase employed. Characterisation of reaction products can be used to define the sub-site binding requirements of the enzymes as well as the fine-structures of the polysaccharides. Action of c/xt/o-arabinanase and em/o-galactanase on arabinans and arabinogalactans is described. Specific assays for ndo-arabinanase and arabinan (in fruit-juice concentrates) are reported. 

Interest in arabinans has increased significantly in recent years due to their identification as a major cause of haze in apple and pear juice concentrates. These problems can be relieved by using pectic enzyme mixtures containing adequate levels of e do-arabinanase to degrade 1,5-a-L-arabinan produced from branched arabinan either by the action of a-L-arabinofuranosidase or a combination of heat and low pH conditions (23). 

Measurement of Arabinan. Excess quantities of arabinan in fruit juice can lead (after prolonged storage) to hazy fruit-juice concentrates. This problem can be resolved by ensuring that the pectinase preparation employed contains adequate levels of endo-arabinanase to hydrolyse the amounts of debranched arabinan likely to be present. A limiting factor is that currently, there are no methods available for the measurement of arabinan in fruit juice or juice concentrates. 

Figure 2. Enzymic measurement of a-L-arabinan in fruit-juice concentrates, (a) Effect of time of incubation of sample with arabinofuranosidase and ndo-arabinanase. Diluted pear juice concentrate (1 10 0.1 ml) or sugar beet arabinan solution (0.1 ml) was incubated with an aliquot (0.1 ml) of arabinofuranosidase (5 units) plus ndo-arabinanase (0.2 units) at 35 C and pH 4.0. Aliquots were analysed for arabinose. (b) Arabinose determination using the NAD-Galactose Dehydrogenase method. Arabinose solution (0.2 ml, 50 digrams) was incubated with Tris-HCl buffer (2.5 ml, pH 8.6), NAD (0.1 ml, 10 m ml) and galactose dehydrogenase (20/i, 140 milliunits) at 35°C. Absorbance (340 nm) was measured after various time intervals.

Fruit juice concentrates, ready to drink fruit juices (still and carbonated)... 

Bronner, W.E. and Beecher, G.R., Extraction and measurement of prominent flavonoids in orange and grapefruit juice concentrates, J. Chromatogr. A, 705, 247, 1995. 

The volatile compounds of juices made from freshly cut pineapple fruits from different cultivars from Costa Rica, Ghana, Honduras, Cote d Ivoire, the Philippines, Reunion, South Africa, and Thailand were studied in comparison to that of commercial water phases/recovery aromas, juice concentrates as well as commercially available juices [12]. The qualitative pineapple fruit flavour profile showed several methyl esters, some characteristic sulfur-containing esters, and various hydroxy esters were responsible for the typical pineapple flavour profile. 

The world of aroma compounds is becoming more and more complex. In the early days people used aromatic products like fruit juices or fruit juice concentrates which were relatively weak and still close to the related foodstulf. Later, with more knowledge of separation techniques, infusions, extracts, oleoresins and absolutes ranging from weak to strong impact were used to impart aroma. Essential oils such as spice oils already had a very strong impact. Modern analytical technologies allowed the evaluation of the chemical compositions of extracts and essential oils, so that isolates either as powerful mixtures or even as single compounds could be obtained. 

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