Processing of fruit juices

Fruit Juice Processing

• Juice is the extractable fluid content of cells or tissues.
• Fruit juices are processed for diverse reasons:
  • Fruits cannot be stored for long.
  • Fruits may have poor quality for marketing in the fresh form.
  • Easily consumed.
  • Convenient nutrition for the young, elderly, or infirm.
  • Easier to process than solid fruit.
  • Carriers of natural or synthetic nutrients.
  • Juice co-products are useful as ingredients (e.g., ice cream, confectionary, bakery).

Juice Products

• 100% Juice blends: Pure fruit juices.
• <100% Juice beverage blends: Juices with added ingredients or less than 100% pure fruit.
• Carbonated beverages: Includes carbonation in fruit juices.
• Fruit leathers: Dehydrated fruit products with a leather-like texture.
• Ice cream and sherbet: Juices used in dessert products.
• Jams and jellies: Fruit preserves made with fruit juices.
• Flavour bases: Fruit juice extracts.
• Natural colours: Colorants obtained from fruit.
• Natural nutrients/ Phytochemicals: Fruit nutrients and bioactive compounds.
• Nectars and nectar bases: Sugar, water, and other ingredients added to fruit juices.
• Syrups: Sweetened fruit juices.
• Pastes/spreads: Fruit juice based spreads.
• Pie fillings: Juices as filling for pies.
• Confectioneries: Juices used in confectionery products.
• Cocktail mixes: Fruit juices used in cocktails.
• Yoghurt/fermented dairy products: Juices used in dairy products.
• Smoothies: Fruit juices used as ingredients.
• Wines: Alcoholic beverages from fruit.
• Baby foods: Infant foods containing fruit juices.
• Sports drinks: Beverage with fruit juice added.
• Fruit flavoured waters: Fruit-flavored water.
• Baked goods: Juices in baked products.

Defining Juice (for economic fraud prevention)

• Defining juice is critical to prevent economic fraud.

Juice Designation

• Pure juice (100%): All juice, no adjustment.
• Fresh squeezed: Not pasteurized, refrigerated
• Chilled, ready to serve: All juice, refrigerated.
• Not from concentrate: Single strength, pasteurized after extraction.
• From concentrate: Made from concentrate, reconstituted and pasteurized
• Fresh frozen concentrate: Unpasteurized, single strength, frozen after extraction
• Juice blend: All juice mixture of pure juices.
• Puree: Pulp-containing, more viscous than juices, totally fruit flavored
• Nectar: Sugar, water, and acid added (25-50% juice)

Juice Designation (Continued)

• Juice drink: Low in juice, 10-20% juice.
• Juice beverage: Low in juice, 10-20% juice.
• Juice cocktail: Low in juice, 10-20% juice.
• Fruit + ade: Contains >10% fruit juice, sugar and water
• Lemonade: Contains >10% fruit juice, sugar and water, from juice concentrate
• Juice extract: Water extract, fruit extracted by water, then concentrated.
• Fruit punch: Usually >1% juice, with natural flavours.
• Natural flavoured: Usually >1% juice, natural flavour and contains less than 10% fruit juice. This must have additives
• Power drinks: Made of flavoring and water. Contains a high amount of unnatural additives

Codex General Standard for Fruit Juices and Nectars (2005)

• Fruit juice: unfermented liquid from fruit.
• Fruit juice (directly expressed): Mechanical extraction processes.
• Fruit juice from concentrate: Reconstituting concentrated juice.
• Concentrated fruit juice: Product with water removed to at least 50% greater Brix value than from the same fruit.
• Water extracted fruit juice: Whole fruit juice extracted by diffusion with water.
• Fruit nectar: Adding water, sugars, honey, syrups, or aromatics to fruit products.

Malaysia Food Regulation

• Regulation 235 (Fruit juice): Expressed juice or reconstituted product from concentrated juice; potable water is permitted and may contain sugar, according to regulations 236 to 242.
• Regulation 243 (Fruit nectar): Unfermented, pulpy or non-pulpy product made from blending fruit juice or edible part of ripe fruits; water and permitted sweetening substances are allowed.
• Regulation 352 (Fruit juice drink): Soft drink composed of potable water, unfermented fruit juice, and some fruit part. Must have at least 35% fruit juice. May contain carbon dioxide.
• Regulation 353 (Fruit drink): Soft drink made from potable water, fruit juice and some fruit parts (or substitutes), sugar additives, and at least 35% fruit juice. May contain carbon dioxide

Reconstitution Level for Concentrates

• A table showing Brix values for various fruit juices.

Orange Juice

• Definition: Defined in the United States Code of Federal Regulations as the unfermented juice from Citrus sinensis or Citrus hybrid.
• Marketing Forms: Commonly marketed as concentrate, reconstituted liquid, or NFC (Not from Concentrate).
• Additives Preservatives: Sodium benzoate, sulfur dioxide. Antioxidants: Ascorbic acid, alpha tocopherol, EDTA, BHA, BHT •Sweeteners: Corn syrup, dextrose, honey, artificial sweeteners •Tartness: Citric acid •Additional vitamins: Vitamin C ,Vitamin A, Vitamin E and beta-carotene
• Important procedures to note:

1. Fruit reception (harvesting)
2. Juice extraction (squeezing or reaming):
3. Juice clarification
4. Juice concentration (if applicable):

Typical Processing Steps for an Orange Processing Plant

• A flow chart diagram showing the steps in the processing of oranges.
  • Fruit unloading
  • Grading
  • Washing
  • Sizing
  • Extraction
  • Storage bins
  • Centrifuges
  • Finisher
  • Pasteurizer
  • Concentrate cooler
  • Defect removal
  • Oil emulsion
  • Wet peel, rag, seeds
  • Presses
  • Winterization storage
  • Dryer
  • Frozen storage tanks
  • Concentrate
  • Refrigerated aseptic storage
  • Pulp
  • Frozen drum storage
  • Peel oil
  • Animal feed
• Other processes

Juice Extraction

• Squeezing or reaming out the juice from whole or halved oranges mechanically
• After washing, oranges are sized and directed to the extractor.
• Correct extractor operation is important for quality and yield.

Squeezer-Type Extractor

• Fruit is placed between metal cups with sharpened tubes.
• Upper cup descends, and fingers mesh with tubes cutting holes.
• Fruit solids are compressed while juice is forced out through tube wall perforations.

Reamer-Type Extractor

• Oranges are sliced in half before extraction
• Cut fruits are sliced as they are passing by a stationary knife
• The sliced fruit halves are picked up by rubber suction cups and moved against a serrated reamer
• Rotating reamer express juice as the fruit moves round the conveyor (as fruits are moving around)

Three Streams from Extraction Section

• Oil emulsion: Peel oil.
• Wet peel, with pulp, rag, and seeds: Direct to feed mill.
• Pulpy juice: Clarification and concentrate or NFC production. Residual pulp to pulp washing/feed mill.

Juice Clarification

• Removal of pulp and membrane material (20-25%).
• Clarification process involves a mechanical separation method.
• Pulp is separated by using sieving process.
• Further clarification is achieved by centrifugation.

Screw-type Finisher

• Incorporating a set of paddles rotating (spirals) on a central shaft inside a cylinder.
• Paddles push the pulp against a screen ( applying centrifugal force).
• Pulp is separated from the juice.

Paddle Finisher

• Set of rotating paddles on a central shaft, inside a cylinder
• Paddles push the pulp into contact with a screen
• Pulp separated from the juice by centrifugal force.

Further Clarification (Disc Stack Centrifuge Machine)

• Clarified juice is separated into a liquid phase and solid phase.
• Juice leaves under pressure.
• Lower pulp content yields higher quality.
• Specifications on low and very low pulp percentages.

After Clarification

• Blending juices to balance flavor, color, acidity, and Brix levels.
• Cooling prior to buffer/blending tanks (for NFC juice production)

NFC (Not-from-Concentrate) Juice Production

• Minimal thermal processing.
• Physical and microbiological stability.
• Bulk processing and storage.
• Blending of juices (early and late season).
• Possible addition of pulp or volatiles.

High Temperature Short Time (HTST) Pasteurization

• Continuous-flow plate heat exchanger (PHE).
• Multiple stainless steel plates separated by polymer gaskets.
• Heating and cooling in opposite directions (counter-current).
• Corrugated surfaces for increased turbulence and faster heating/cooling.

Concentrate Production

• Juice from clarifier prepared for concentrate production.
• Homogenization breakdown of pectin, reduce viscosity and sinking pulp.
• Preheating to 95-98°C for microbial/enzyme inactivation.
• Multiple-stage vacuum concentration until °Brix is achieved (66°Brix).
• Multiple-effect tubular evaporator system utilizing vapor pressure differences to boil water in stages.

Pulp Production

• Solid fruit particles
• Different ways to use pulp (e.g. add-back, pulp wash, feed mill)
• Pulp wash: pulp is washed and the juice sugars are obtained, remaining sells as washed pulp, taken to feed mill
• Pulp into pellets destined for animal feeds.

Peel Oil Recovery

• Oil-water emulsion sent to peel oil recovery section.
• Contains peel, pulp, and pectin.
• Objective: Remove substances with little oil loss.
• Two-stage centrifugation to achieve high purity (70-90%).
• Winterisation tanks to precipitate wax, crystallization and settling.
• Storing at 1°C for 30 days

Feed Mill Operations

• Processing the fruit solids/materials remaining (about 50%)
• These parts are broken down in the feed mill
• The waste is used, for instance as animal feed or as raw material for different processing plants.
• Contains 9-15% TSS (Total Suspended Solids).