Topic 7 Processing of Fruit Juices PDF

Processing of fruit juices  Juice The extractable fluid contents of cells or tissues. What are the rationales for juice manufacturing?  Utilization of juice and its co- products Info source: FAO (2001) Practical reasons for juice ma...

Processing of fruit juices  Juice The extractable fluid contents of cells or tissues. What are the rationales for juice manufacturing?  Utilization of juice and its co- products Info source: FAO (2001) Practical reasons for juice manufacturing: (a) fruits cannot be kept intact over long periods (b) Fruits may have poor size, shape or blemished portions that preclude marketing them as fresh whole fruit. (c) Juices can be consumed more conveniently (d) The very young, elderly and infirm may have problems eating or peeling certain fruits (e) Can be blended to achieve balanced nutrition or act as effective carriers for other natural or synthetic nutrients. (f) Easier to process than the solid ones (g) Juice co-products: ice cream, confectionery flavours, smoothies, bakery ingredients Defining juice To prevent economic fraud  Juice designation Term Criteria Remarks Pure juice All juice No adjustment, not from 100% concentrate Fresh Not pasteurized Held refrigerated, food safety squeezed concerns Chilled, All juice Held refrigerated, made from ready to concentrate or pasteurized juice serve Not from Single strength Pasteurized after extraction. concentrate From Made from Reconstituted and pasteurized concentrate concentrate Fresh frozen Unpasteurized Single strength , frozen after extraction Juice blend All juice A mixture of pure juices Puree Pulping- More viscous than juices, totally containing fruit Nectar Pulpy or clear Sugar, water and acid added, 25- 50% juice*  Juice designation (Cont’) Term Criteria Remarks Juice drink Low in juice Contains 10-20% juice * Juice Low in juice Contains 10-20% juice * beverage Juice cocktail Low in juice Contains 10-20% juice * Fruit + ade Lemonade Contains > 10% fruit juice, sugar and water * Juice extract Water extract Fruit extracted by water, then concentrated * Fruit punch Token juice ~1% juice + natural flavours Natural Token juice Usually >1% juice, normally contain flavoured under 10% fruit juice with additives. They smell like fruits. Power drinks - made of flavorings and can be prepared to consume with water. They contain high amounts of unnatural additives.  Codex General Standard for Fruit Juices and Nectars (Codex Stan 247- 2005) Fruit juice is the unfermented but fermentable liquid obtained from the edible part of sound, appropriately mature and fresh fruit or of fruit maintained in sound condition by suitable means including post harvest surface treatments. Fruit juice: directly expressed by mechanical extraction processes. Fruit juice from concentrate :by reconstituting concentrated fruit juice. Concentrated fruit juice: is the product that has been directly expressed by mechanical extraction processes, with water being physically removed in an amount sufficient to increase the Brix level to a value at least 50% greater than the Brix value established for reconstituted juice from the same fruit. Water extracted fruit juice: is the product obtained by diffusion with water of pulpy whole fruit whose juice cannot be extracted by any physical means, or dehydrated whole fruit. Fruit nectar: is the unfermented but fermentable product obtained by adding water with or without the addition of sugars, honey and /or syrups, and or food additive sweeteners to products defined in abovementioned. Aromatics substances, volatile flavour components, pulp and cells all of which must be recovered from the same kind of fruit and be obtained by suitable physical means may be added. Malaysia Food Regulation Regulation 235 Fruit Juice Fruit juice shall be the expressed juice, or the reconstituted product of concentrated juice and potable water, of one or more species of fruits and includes the food for which a standard is prescribed in regulations 236 to 242. It may contain sugar. Regulation 243 A Fruit Nectar Fruit nectar shall be the unfermented pulpy or non-pulpy product obtained by blending the fruit juice or total edible part of sound ripe fruits of one or more types, concentrated or unconcentrated, with water and permitted sweetening substance. Regulation 352 Fruit juice drink Fruit juice drink shall be the soft drink composed of potable water, unfermented fruit juice or an unfermented mixture of the juice and other edible portions of one or more types of fruits, with or without sugar, glucose or high fructose glucose syrup and shall contain not less than 35 percent weight per volume of fruit juice. It may contain carbon dioxide. Regulation 353 Fruit drink  Juice Brix Juice Brix Juice Brix Apple 11.5 Appricot 11.7 Banana 22.0 Blueberry 10.0 Kiwi 15.4 Lemon 4.5 Orange 11.8 Loganberry 10.5 Mango 13.0 Why juices are concentrated? https://images-na.ssl-images-amazon.com/images/I/ 816yfIdm9iL._SL1500_.jpg http://cdn.dolepineapplejuice.com/media/contents/products/ 1_VqTwL0G.jpg http://www.goldencircle.com.au/-/media/goldencircle/products/juice- drink/407x573/combi-carton/pearnectar_1l_combi_3d.ashx https://i5.walmartimages.com/asr/b6a42f45-7357-48c1-ac97- f33f74a64d85_1.40f5cd125d1931a900b104852a75fe92.jpeg? odnHeight=450&odnWidth=450&odnBg=FFFFFF  Orange Juice https://orangebook.tetrapak.com/chapter/fruit- processing  Orange juice is defined in the United States Code of Federal Regulations as the “ unfermented juice obtained from mature oranges of the species of Citrus sinensis or the citrus hybrid commonly called Ambersweet. True fresh squeezed juice is difficult to market commercially because it requires special processing to preserve it. Orange juice is commonly marketed in three forms: i. as a concentrate, which is diluted with water after purchase; ii. as a reconstituted liquid, which has been concentrated and then diluted prior to sale; or iii. as a single strength, unconcentrated beverage called NFC or Not From Concentrate. The latter two types are also known as Ready to Drink (RTD) juice.  Orange Juice (additive) Preservatives such as sulfur dioxide or sodium benzoate are allowed but the amounts are strictly controlled. Ascorbic acid, alpha tocopherol, EDTA, BHA or BHT are used as antioxidants. Sweeteners may be added in the form of corn syrup, dextrose, honey, or even artificial sweeteners. Citric acid is added to provide tartness. Manufacturers may also fortify juices with extra vitamins or supplemental nutrients such as vitamin C, and less commonly, vitamins A and E and beta carotene.  For an orange processing plant More detailed information from : https://orangebook.tetrapak.com/chapter/fruit- processing Flow chart showing typical processing steps found in an orange processing plant https://orangebook.tetrapak.com/chapter/fruit- processing  Processed as soon as possible after harvesting Traile Manual inspection: r To remove dust, dirt, To removes rotten Tipping and pesticide residue and visibly damaged ramp fruit Truck unloading Prewash Destemming Pregrade Conveyor As short as possible Belt * The bin is designed with inclined multilevel internal baffles to redistribute the fruit evenly to prevent too much weight pressing on fruit. Sampling Surge Bin Fruit storage Final grading Final fruit wash A sample fruit is taken for Wash water analysis may include a mild ( juice yield, disinfectant to o Brix, acidity help to reduce and color) the microbial Extraction involves squeezing or reaming juice out of either whole or halved oranges by means of mechanical pressure. After final washing and inspection, the fruit is separated according to size into different streams or lanes. Individual oranges are directed to the most suitable extractor in order to achieve optimum juice yield. As the extraction operation determines juice yield and quality, the correct setting of extractor operating conditions is very important.  The fruit is placed between two metal cups with sharpened metal tubes at their base. The upper cup descends and the fingers on each cup mesh to express the juice as the tubes cut holes in the top and bottom of the fruit. The fruit solids are compressed while the juice is forced out through perforations found on the tube wall. https://orangebook.tetrapak.com/chapter/fruit- Points to note for producing premium orange juice from squeezer-type extractor: (a) Strain holes of 2-3 mm will break pulps into smaller pieces. Changing to holes size of 15-20 mm allows larger pulp pieces join the juice stream. The pulps will then be separated from the juice stream and treated separately. (b)Too high a squeezing pressure will express more oil from the peel into the juice stream. Grade A juice contains less than 0.035% w/v oil content. To overcome this, smaller diameter strain tube and orifice are used, so that a smaller core is cut and put less pressure on the fruits during squeezing process.  The oranges are cut into half before the juice is removed. The fruits are sliced as they pass by a stationary knife and the halves are then picked up by rubber suction cups and move against plastic serrated reamers. The rotating reamer express the juice as the orange halves travel https://orangebook.tetrapak.com/chapter/fruit-processing Three streams result from the extraction section: (a) Oil emulsion, containing oil from the peel and water, goes to peel oil recovery. (b)Wet peel, with pulp, rag, and seeds, flows directly to the feed mill. (c) Pulpy juice goes first to clarification and then to production of concentrate or NFC (Not-from-concentrate). Pulp intended for sale as pulp goes to pulp production. Residual pulp goes to pulp washing or the feed mill. Why juice needs to be clarified? Juice needs to be clarified because it contains too much pulp and membrane material (20-25%) to be processed in the evaporator After extraction, the pulpy or as NFC juice (that follows juice with (about 50% of the fruit) is pasteurization). clarified by primary finishers that separate juice from pulp. The finishing process is a mechanical separation method https://discoverkl.com/ based on sieving. The juice 2017/03/29/dkl-experiments- stream is further clarified by jussu-juice-cold-pressed-juice/ centrifugation. https://orangebook.tetrapak.com/chapter/fruit- processing After extraction, the pulpy juice (about 50% of the fruit) can be clarified by primary and secondary finishers that separate juice from pulp. This finishing process is a mechanical separation method based on sieving. The juice stream can later be further clarified by centrifugation. Briefly, the first stage involves filtration using two 2-phase centrifuge decanters in a row. The decanter may come with a stainless steel screw or paddle that conveys the pulpy juice through the unit and presses the pulp against the cylindrical screen. The juice will flow through the screen holes. With that the pulp is concentrated inside the screen and is discharged at the end of the 2-phase centrifuge decanter. As pulp is discharged through a restricted opening, the resulting back pressure in the finisher helps to squeeze out more juice from the pulp mass.  Screw-type finisher https://orangebook.tetrapak.com/chapter/fruit- processing  Paddle finisher Paddle finishers incorporate a set of paddles rotating on a central shaft within the cylinder. The paddles push the pulp against the screen, applying centrifugal force rather than pressure to separate the pulp from the juice. https://orangebook.tetrapak.com/chapter/fruit-  To further clarify the sinking pulp. A disc stack centrifuge machine can be used. When juice is flowing through between the annular slot between the conical discs rotating at between 4,000 and 10,000 rpm, the juice can be separated into a liquid phase and a solid phase. With that, clear clarified juice will leave the centrifuge under pressure. https://youtu.be/MqsngHOmS10?t=30 Producers of orange drinks and nectars frequently specify with “very low” or “low” pulp content, which refers to