A machine selected around one delivery can meet a different lot next week. A written feed envelope keeps the material, measurement point and quotation boundary visible before a trial begins.
Fruit arriving at a processing site changes with cultivar, maturity, weather, harvest method and the time spent in transport. A machine brief that says only “apple” or “mango” hides the differences that decide whether the feed can be washed, crushed, destoned or pressed without damage. The first useful step is therefore not a bigger machine table; it is a description of the material at a named boundary.
FAO's general juice-manufacture chapter groups fruit by structure and by which parts are edible. Soft all-edible berries are comminuted, ground and pressed; firm fruit with inedible seeds is ground coarse and pressed; soft fruit with inedible skin and seeds may be pre-peeled and gently pulped. Those groups are not a cultivar specification, but they explain why the same word “fruit” can lead to different preparation and extraction duties.
Write the envelope at the transfer where the machine actually receives material. Whole fruit at the receiving bay is not the same feed as washed fruit at a crusher inlet, and mash entering a press is not screened pulp entering a buffer. Note any splitting, blending or return stream before that point. If the line may run two products, say which fraction follows which route rather than averaging them into one description.
“Solids” can mean the dry matter of the fruit, the suspended solids in a juice, or the recoverable pulp in a puree. Those are different measurements and they support different decisions. A screen choice, pump selection and thermal duty may all depend on particle size, fibrous character, viscosity behaviour and entrained air, not merely on a single percentage.
For each stream, record the condition at the handoff: particle or piece size, visible fibre, stones or seeds, foam, and the temperature at which the material is presented. Attach the method and sample point to every value. A laboratory result from a blended sample does not automatically describe the feed at a pump inlet, and a temperature measured in a tank is not the same as the temperature at a heat-exchanger inlet.
Keep the field list small enough to maintain. A useful minimum is material identity, preparation already applied, measured value or range, method, sample location, date and the party that measured it. Mark missing information as unknown. An explicit gap invites a trial; an invented number quietly becomes a purchase assumption.
Processing changes mass. Fruit mass divides into wanted product, skin, stones, fibre, press cake, wash water and losses, and some material may be reworked. FAO describes extraction as a compromise between recovering desirable components and avoiding undesirable skin or seed components. That is why a receiving rate in tonnes per hour cannot be compared directly with a packed-product rate.
Give every rate its own unit and boundary: fruit received, fruit washed, mash prepared, juice expressed, puree screened, product buffered and packages filled. Include rejects and any recirculation. When a supplier quotes a family input reference, ask which product and preparation the reference assumes. A family reference can help start a selection; it does not establish the useful output of a connected line.
The same discipline applies to batch records. A batch identified only by the day of production cannot show which fruit lot was blended, which preparation route ran, or how much material left as reject. Link the lot to the actual handoff points if traceability is part of the project, rather than adding that link after the layout is fixed.
A trial should test the envelope, not a single perfect sample. Define the sample identity, its preparation, the settings that may be varied, the observations to be made and who accepts the result. A trial can show that a machine handles a particular material under stated conditions. It cannot prove continuous plant performance, a shelf-life outcome or a customer's product approval.
Attach the envelope to the quotation as a versioned appendix. State what happens outside it: stop and review, divert or rework, or run a new trial. The Codex Alimentarius registry is the right place to check the current identity standard for a named product, but the registry is an entry point, not a machine rating and not a substitute for reading the applicable standard.
A feed envelope is modest paperwork with a large effect. It gives engineering a bounded question, gives the trial a defined sample and gives the quotation a visible limit. When the next fruit lot arrives, the discussion starts from evidence rather than from the assumption that all fruit behaves like the last delivery.
Primary sources
External links open the publisher's page. The notes identify how the source informed this article and where its scope ends.
FAO · accessed 2026-10-28
The chapter describes unit operations and fruit-specific preparation principles. It is historical technical guidance, not validation of a current installation.
Used for: Fruit categories, preparation and extraction sequence, and the yield-quality compromise.
Reading limit: The source informs context; it does not certify this equipment or replace project validation.
FAO/WHO Codex Alimentarius · accessed 2026-10-28
The registry is an entry point to current Codex texts. A product standard does not establish machinery performance or a process schedule.
Used for: The need to check the current named-product standard before fixing product identity.
Reading limit: The source informs context; it does not certify this equipment or replace project validation.
All editorial notes
A stop exposes accumulation, isolation and restart responsibilities that a steady-state line diagram can hide. The useful output is an event record, not an instant diagnosis.
Acceptance is more than a signed checklist. The evidence should show what product was observed, which cleaning surfaces were reached and what information actually changed hands.
Traceability starts with lot identity on the factory floor, not with a dashboard. A machinery specification can preserve the link between fruit, process condition and records, or quietly break it.