The Comprehensive Process of Manufacturing Apple Juice Concentrate
Apple juice concentrate is a versatile, flavorful ingredient used in multitudes of food and beverage products. This thick, amber-colored syrup is made by removing water from apple juice to concentrate the natural sugars, acids, flavors, and nutrients.
When fruit juice is concentrated, the process preserves the qualities that diminish over time in fresh juice. And concentrating juice reduces storage space and transportation costs compared to juice. For these reasons, there is huge demand for apple juice concentrate in the food and beverage industry.
This comprehensive guide will walk through the detailed manufacturing process of making quality apple juice concentrate from start to finish.
Selecting the Right Apple Varieties
Choosing the ideal apple cultivars is one of the most important decisions as it determines the flavor profile. Apples can impart aromatic properties and contribute sweet, tart, and acidic tastes to the juice concentrate. Some popular apple varieties used include:
- Fuji – Known for its sweetness and mildly tart flavor. It has a crisp texture and pale yellow flesh. The juice has a light amber hue.
- Gala – Gala apples are very aromatic and sweet with a mild pear-like flavor. The flesh is pale yellow and crisp. Gala juice has a light gold color.
- Granny Smith – These green apples are tart and slightly acidic. They have a bright white flesh and significant bite. Granny Smith juice has an amber color.
- Pink Lady – This variety balances sweetness and tartness with a subtly floral aroma. It has yellowish flesh and pinkish skin. The juice is gold to amber colored.
- Red Delicious – Red Delicious apples are mildly sweet with a mellow flavor. The flesh is crisp and white. Juice made from these apples can range from pale gold to bright amber.
Deciding on the proper blend of apple varieties based on flavor, juiciness, acidity, tannins, and sugars allows manufacturers to customize the end product’s characteristics.
Harvesting and Storing Apples
Apples are handpicked once mature during fall harvest. Any damaged or bruised apples are sorted out. The healthy apples should feel firm and heavy for their size. After harvest, apples need to be used immediately or stored properly to preserve freshness. The ideal storage conditions are temperatures of 32-40°F with 90-95% humidity. This slows respiration and other chemical changes. Controlled atmosphere storage with reduced oxygen and elevated carbon dioxide levels also helps extend shelf life.
How to make apple juice concentrate ?
Pre-Processing Apple Prep
Before juice extraction, the apples undergo the following pre-processing steps:
Washing
Apples are washed and rinsed thoroughly with potable water to remove any debris, dirt, pesticides or microbes from the skin’s surface. Proper cleaning is vital, especially for apples that will not be peeled before juicing.
Peeling (Optional)
If desired, the apples can be peeled using mechanical peelers or lye baths to remove the skin and outer layer.
Coring
Apple cores contain undesirable tannins and are cut out using coring machines.
Milling or Crushing
The apples need to be milled or crushed into a mash to aid in pressing out the juice. Hammermills, pounders, or grinders are used to grind apples into a uniform pulp or slurry for the next steps.
Enzyme Treatment
To increase juice yield and clarity, enzymes like pectinase are added to the pulp to break down pectins and cell walls that can trap juice.
Pressing Apples for Juice Extraction
There are a few methods used to press and extract the maximum amount of juice from the crushed apple mash. These include:
Rack and Frame Press
This uses a hydraulic press to compress mashed apples between grooved plastic racks stacked in a tower frame. The extracted juice flows down while the dry pomace is left behind.
Bladder Press
A rubber bladder inflated with water presses the apple pulp against a drum lined with drainage channels. Juice extraction is continuous.
Centrifuge
The apple slurry is pumped into a cylindrical screen rotated at high speeds. Centrifugal force separates juice from the pulp.
Once pressing is complete, the raw apple juice undergoes processing to become clarified, filtered, concentrated juice.
Clarifying and Filtering Apple Juice
The freshly pressed apple juice will contain some sediment and particles. Clarification and filtration remove these impurities:
- Enzyme Treatment – Pectinase and amylase enzymes help break down pectin, starch, proteins and other compounds that cause cloudiness in the raw juice. This enzymatic clarification improves juice yield and filterability.
- Decantation – Allowing the juice to sit undisturbed for 8-12 hours allows larger particles to settle on the bottom, clarifying the top portion.
- Centrifugation – A centrifuge can rapidly spin out denser particles from the juice.
- Finings – Substances like bentonite clay, gelatin, silica gel, or casein are added. They attract and bind suspended particles that settled out on the bottom.
- Filtration – Once coagulated with finings, the juice is filtered through media like diatomaceous earth, filter cloth, filter paper, or membrane filters to remove fine particulates.
- Carbon Filtration – Activated carbon filters help remove enzymes, polyphenols, and other compounds that cause off-colors, bitterness, or browning.
The clarified, filtered apple juice will now have a clear, brilliant appearance and fresh flavor ready for concentration.
Concentrating Apple Juice through Evaporation
To make apple juice concentrate, the clarified juice must have water removed to concentrate the juice content to 65-70% soluble apple solids. This is achieved by evaporation:
- Heat Exchangers – Juice is preheated to 85-105°F in tubular heat exchangers to prepare it for evaporation.
- Evaporators – The juice is heated to 160-210°F in multi-stage evaporators with heat from steam and vacuum conditions at 40-70 kPa. This accelerates water removal at temperatures below boiling. Forced circulation or thin film evaporators improve efficiency. 75-80% of water content is removed.
- Distillation Towers – These columns with packing material allow for additional concentration, removing alcohol, volatile compounds, and impurities.
- Stripping Columns – If desired, stripping columns can be used to remove off-flavors, aromatics, or volatiles from the apple juice concentrate.
Throughout the evaporation process, Brix refractometers help monitor the soluble solids levels until the desired concentration is achieved. Careful temperature and vacuum control preserves heat-sensitive nutrients and flavors.
Pasteurization and Packaging
The final steps in apple juice concentrate production are crucial for safety, preservation, and storage:
- Pasteurization – The concentrated juice is rapidly heated to 185-194°F for 1-2 minutes to destroy pathogenic bacteria, yeasts, and molds. Flash pasteurization minimizes impact on flavor.
- Homogenization – For a uniform and stable product, the concentrate is homogenized under pressure to evenly distribute insoluble solids.
- Cooling and Aseptic Packaging – The pasteurized concentrate is quickly cooled and filled into pre-sterilized, air-tight drums. Aseptic processing excludes contaminants and enables long-term storage.
- Metal Drums – Sterilized stainless steel drums with internal polyethylene liners are commonly used. They exclude air and light to preserve quality. Drums may contain up to 55 gallons.
- Storage – Packaged apple juice concentrate is stored refrigerated or frozen. The concentrate can last for over a year at optimal temperatures of -18°C or lower.
The resulting opaque, amber-colored apple juice concentrate will have a 65-70% soluble apple solids content and thick, syrupy texture. This concentrate provides the characteristic sweetness and apple flavor that makes it an indispensable ingredient for beverages, foods, confections and more. Proper manufacturing and handling ensures the highest quality and safety.
For more information, visit our Apple Juice Concentrate product page.