The fruit juice processing industry is one of the world's major agro-based businesses. Orange juice dominates in juice trade worldwide. Juice is a liquid that is naturally contained in vegetable or fruit tissue. Juice may be supplied in concentrate form. Generally, concentrates have a noticeably different taste when compared to their "fresh-squeezed" versions. Juice should not be confused with squash, which is usually an artificial juice to be diluted with water. Common methods for preservation and processing of fruit juices include evaporation and spray drying.
Popular juices include apple, orange, lemon, cranberry, grapefruit, pineapple, tomato and grape. It has become increasingly popular to combine a variety of fruits into single juice drink. One of the most popular examples is Carrot, Orange and Ginger. Prepackaged single fruit juices have lost market share to prepackaged fruit juice combination's. A number of new companies have had considerable success supplying prepackaged fruit juice combination's on the basis of this transition. Fruit juice consumption overall, in Europe, Australia, New Zealand and the USA has increased in recent years, probably due to public perception of juices as a healthy natural nutrient source and increased public interest in health issues.
[...] Evaporator belongs to the class of the “Falling Film Evaporators” and is widely used to concentrate cloudy and clear juices obtained from citrus, tropical and continental fruits which are known to be sensitive and easily spoiled when submitted to high temperatures even for short times. Concentration occurs by making water evaporate in subsequent stages called “effects” or “effects” being used for the steam circuit, for the product run. The T.A.S.T.E. system can be generally described as a continuous, single pass, long vertical tube falling-film type, multiple-effect stages, high vacuum, no vapor recompression, high temperature short residence time evaporator. [...]
[...] This can result in the generation of undesired, off-flavor compounds. In addition, heating the juice during evaporative concentration at high temperature for a too long period of time can greatly increase the viscosity of the resulting juice concentrate. Accordingly, evaporative concentration needs to be conducted in a manner which minimizes the generation of off-flavor compounds, as well as ensuring that the resulting juice concentrate has a relatively low viscosity. Principles of recovery volatile compounds One method for preserving the delicate aroma and flavor volatiles is to strip them from the juice before Evaporative concentration. [...]
[...] The term “from concentrate” forms part of the name of this product and must not be omitted from the name on any part of the packaging. The choice of concentration in food process finds justification both in the microbiological field from the increase of the product stability achieved with the lowering of water activity and in the economic field from the diminution of the packaging, storage and transport costs. The concentration of the juices is a common method to reduce the cost of transportation of the juice. [...]
[...] The following table shows the newest method in term of juices process. Process Description Status Aseptic High temperature short time Widespread commercialization Hyperbaric High pressure Approaching Pressure commercialization Pulsed electric High KV/cm, Microsec field Actively being field researched Ultrasonic High intensity ultrasound Potential synergistic hurdle Ohmic heating Resistance-generated heat Actively being researched Membrane Physical removal of microbes Effective for clear juices Pulsed light High intensity UV to visible Effective for clear juices Magnetic field Low and High frequency/ Highly experimental intensity Irradiation Electrons, gamma or x-rays Commercially feasible Nonthermal plasma Electric discharge into Highly experimental liquids Preservatives "Natural" herbs, spices, Actively being etc. [...]
[...] The great number of evaporating effects usually employed (up to dramatically reduces steam consumption for each unit of evaporated water. As many as eight kilos of water and even more, can be evaporated for each kilo of live steam used. Figure 3 :schematic of a 4 stage effect TASTE evaporator (from www.fao.org) The stage heated by live steam is called first effect; the following, heated by the vapor released in the first effect, is called second effect and so on. [...]
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