Draw the boundary before calculating recovery
For the preparation section, incoming fruit divides into prepared feed, crowns or other removed fractions, rejected fruit and changes in material held within the section. For extraction, prepared feed divides into collected juice, wet pomace, screened rejects where included, and any material remaining in the equipment.
A whole-fruit juice recovery uses incoming fruit as its denominator. An extraction recovery uses the prepared feed entering the extraction equipment. Both can be useful, but they answer different questions. A change in crown or shell removal can change the whole-fruit figure without changing the press performance.
| Measurement | Consistent calculation basis | What it describes |
|---|---|---|
| Whole-fruit juice recovery | Collected juice mass divided by incoming fruit mass | Preparation and extraction together, within the stated boundary |
| Extraction juice recovery | Collected juice mass divided by prepared-feed mass | The selected extraction section |
| Wet pomace fraction | Wet pomace mass divided by prepared-feed mass | A material outlet, not a direct measure of soluble-solids loss |
Keep mass, volume and time consistent
Record all compared streams over the same interval, allowing for changes in tank levels and material held in conveyors or machines. A short collection period taken while a buffer is emptying can overstate the steady production rate. Likewise, filled package output may lag behind extraction during start-up.
Mass and volume are not interchangeable. Juice volume depends on density and temperature, and concentrate has a different density from its feed. Converting a fruit mass rate into a liquid volume rate requires actual recovery and density information. Adding wash, dilution or flush water changes the balance and must be recorded as a separate input.
Follow the soluble material as well as the bulk mass
Wet pomace includes insoluble material and retained liquid. Two trials can produce similar wet cake masses while losing different quantities of soluble material. Juice concentration, retained liquid and the method used to assess the cake are therefore relevant to an extraction comparison.
Screen finishing and membrane clarification create further separated streams. A membrane retentate is not the same material as press cake, and neither should disappear into a single unspecified loss figure. Sampling points should match the equipment boundary and the product stream being evaluated.
Use the measurements to size the next section
Recovered juice flow determines the duty of buffer vessels, transfer pumps and liquid treatment. For concentration, feed solids and the selected final concentration determine how much water must be removed. Packaging output follows the actual product delivered to the filler and its complete handling cycle.
An acceptance record should include feed description, production duration, collection method, intermediate inventory, added water and separate outlets. This makes a change in fruit, preparation or machine setting traceable without promising a fixed pineapple yield.