The two large groups of fruit beverages are juices and nec- tars. Furthermore, certain countries produce soft drinks with low fruit content, which contain flavoring and coloring ad- ditives as well. There is no international legislation for the composition and quality of such fruit drinks.
The most important property of fruit juices with 100%
fruit content is that their composition has to be identical with liquid phase of the original fruit (except losses occurring in production, e.g., vitamins). Therefore, shaped fruit parti-
cles have to be separated with physical procedures (pressing, centrifuging, settlement, etc.). In case diffusion process is applied, solvents should not leave residues behind. Water, for example, which contains no dissolved materials, is an ideal solvent. Only those substances can be added that are permitted by international legislation (Table 13.1).
Beverages enriched with different biologically active sub- stances form a separate category. Enrichment and added ma- terials have to be labeled on the packaging.
In case of direct production, filtered and cloudy juices are directly made of clarified juices that were extracted from the fruits mechanically.
Indirect production means that beverages are made from concentrated semifinished products with dilution. If juices are made from concentrates, they are labeled as “made from concentrates.” Fruit juices available in the market can be filtered-clarified, cloudy, and contain added fibers.
Fruit nectars are juices or pulps diluted with sugar syrup.
In Europe, their minimum fruit content is defined by Council Directive 2001/112/EC for different fruits. Depending on the raw materials, nectars can be filtered or may contain fibers.
Filtered nectars are made of filtered juices. Those nectars containing fibers include not only the juice but also the fruit flesh, which is chopped to fine particles and distributed ho- mogenously. Fruit nectars are usually made of fruits that do not possess drink properties in 100% concentrated form (e.g., pulps) or the raw materials are so acidic or have so intense flavor that their sensory traits are not enjoyable (e.g., seabuckthorn, tart cherry, red currant). Other regulations for fruit nectar composition can be found in Table 13.1.
Preparation of Juices with 100%
Fruit Content
Raw Material Preparation
In the case of direct juice production, raw material reception, storage and preparation, juice extraction, and clarification are performed as described before.
If the production is indirect, the technology begins with the preparation of semifinished ingredients, the control and evaluation of raw material documentation, compositional fea- tures, and sensory properties. The necessity of flavor correc- tion is also done at this stage.
Juice Formulation
If the composition of freshly produced juice corresponds with the criteria determined in the product specification and no flavor correction is needed, it can be directly filled and preserved. In case the product is made of concentrate or more fruits or the composition needs to be modified, ingredients—juice(s), concentrate(s), deionized condensed water—have to be heated up to 50–60◦C in a mixing tank.
Taste correction, which means the addition of sugar solu- tion, lemon juice, or lemon concentrate, has to be performed
in this vessel, too. If the product is fortified with vitamins or other substances, accurately measured and dissolved ingredi- ents are added at this stage. Finally, if aroma extraction was performed during direct production, recovered aroma can be readded. If the product is manufactured from semifinished ingredients, aromas, which come from other fruits, but from identical species and varieties, can be used for flavoring. Even distribution of added substances has to be ensured.
After completing the formulation, quality parameters have to be tested. In case the composition is appropriate, the juice is ready for filling.
Production of Fruit Nectars Raw Material Preparation
Fruit nectars are usually made of semifinished ingredients (juice concentrate, fruit pulp) with dilution. Raw materials can be natural and concentrated fruit purees, but they can be combined with filtered juices or concentrates. They usually contain one fruit, but mixed nectars are also popular.
In case of direct fruit nectar manufacturing, raw material production is done as written in former chapter. If the pro- duction is indirect, technology starts with the preparation of preserved semifinished raw materials, the control and eval- uation of ingredient documentation, compositional features, and sensory properties. Then, the formula is adjusted accord- ing to raw material parameters.
If raw materials have been preserved by heat treatment and stored in closed aseptic bags, preparation means opening the closed bags.. In case the raw material is frozen, the first step is defrosting. This process requires high precision, since improper temperature and duration can be detrimental for product quality.
Formulation of Fruit Nectars
Syrup is cooked from the necessary amount of water and sugar or honey. Then the juice, puree, or concentrate is added in quantities determined by the product specification. The product can be flavored with defined amount of lemon juice or concentrate and can be enriched with vitamins. It can be sweetened with sweetening agents instead of carbohydrates.
These substances are added to the product in dissolved form after mixing the syrup and fruit ingredients. Preparation steps of nectars are identical to fruit juices.
A further grinding step is applied in colloid mills to reduce the particle size, which determines the quality and stability of nectars. There are different colloid mill solutions available, but their common feature is the application of hydrodynamic shear forces. The aim of homogenization is to further reduce the particle size of fibers and to create a fine, disperse system.
Homogenized liquid has a stable texture and there is little settling of solids during storage.
Fruit Juice, Fruit Nectar Preservation, and Packaging
Finished fruit-based beverages are filled into glass and plastic bottles or carton boxes made of combined layers. According to current legislation, the preservation of fruit juices and nectars is only permitted by heat treatment. This can be per- formed in the traditional way, so that liquids are heated up to 82–85◦C, filled at this temperature, and then pasteurized in water bath. Pasteurization is carried out at 84–88◦C for 15–40 minutes depending on the size of the packaging con- tainer. After the heat treatment, products are cooled back to room temperature.
Aseptic filling technology offers a better preservation of quality and valuable compounds. Here the liquid is pasteur- ized in a closed, flow-through system. Then the fluid is cooled under conditions that preclude post-contamination and filled into containers that have been already sterilized. As a result of mixing, applied during the formulation step, and homog- enization, significant amount of air gets into the product. In order to remove dissolved gas particles, deaeration is per- formed under vacuum at the beginning of the preservation technology. Vapors that exit the deaerator are rich in aromas, which are condensed and driven back to the juice. Deaer- ation is followed by pasteurization at 94–112◦C depending on product properties. The duration of this heat treatment is 30–60 seconds. Then the product is cooled to 25–30◦C. This heat treatment takes 2± 0.5 minutes in total. The cooled liquid is led to the filling machine, where it is filled into presterilized, multilayer boxes, which consist of aluminium, different papers, and plastic foils that are laminated. Products can also be filled into bottles specially developed for aseptic technology. The aseptic filling-closing system is a closed unit under overpressure, which hinders the post-contamination of heat-treated products.
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