Agriculture / Solution Family

Post-Harvest Coatings & Wash Agents

Film-forming coating waxes and wash-water sanitizers — carnauba wax, shellac, and peracetic acid — for produce grading lines: gloss and moisture-loss control on fruit, plus dump-tank and flume sanitation.

Overview

Post-harvest coatings are thin surface films applied to fresh produce on the packing line to slow water loss and restore the gloss that washing removes. The two workhorse film-formers are carnauba wax, a hard plant wax that gives a durable high-gloss layer, and shellac, a resin that forms a tighter, shinier film. Peracetic acid is the companion wash-water sanitizer used upstream in dump tanks and flumes; it is not a coating itself. Specify the coating by commodity and target finish, not by a single wax.

Carnauba and shellac are usually blended rather than used alone. Carnauba is breathable and tolerant of handling; shellac seals more completely and shines more, but a heavy shellac film can restrict gas exchange enough to cause anaerobic, fermentation-type off-flavors in some commodities. That gas-exchange trade-off is the central formulation tension. A common starting point is a carnauba-dominant blend with shellac added for gloss, then adjusted per commodity and storage duration.

Grade and food-contact status are the decisive specification, not the wax chemistry alone. Carnauba and shellac are UVCB naturals sold in technical and refined grades, and only certain grades are intended for food-contact use; confirm regulatory status for your application and jurisdiction before use on edible produce. For wash-water sanitation, peracetic acid is dosed in the flume or dump tank and decomposes to acetic acid, oxygen, and water, leaving no chlorinated residue.

Where it's used
  • Gloss and surface-finish coating for citrus, apples, and other waxed produce
  • Moisture-loss (transpiration) control on fresh produce grading and packing lines
  • Carnauba / shellac blend coatings adjusted per commodity and storage duration
  • Wash-water sanitation in dump tanks and flume systems (peracetic acid)
  • Coating-grade selection for food-contact produce applications
Frequently asked questions
What are post-harvest produce coatings made of?
The two common film-formers are carnauba wax (a hard plant wax for a durable high-gloss layer) and shellac (a resin that seals tighter and shines more). They are usually blended. A wash-water sanitizer such as peracetic acid is used upstream in dump tanks and flumes and is not part of the coating film.
What is the difference between carnauba and shellac coatings?
Carnauba is breathable and handling-tolerant, giving gloss with more gas permeability. Shellac forms a tighter, glossier seal but a heavy shellac film can restrict gas exchange and cause anaerobic off-flavors in some commodities. Most lines run a carnauba-dominant blend with shellac added for shine, tuned to the commodity and storage time.
What grade of carnauba wax or shellac is used on produce?
Carnauba and shellac are sold in technical and refined grades; only certain grades are intended for food-contact use. The grade, not the CAS number, is the gating specification. Confirm regulatory status for your application and jurisdiction before use on edible produce.
Does RawSource supply produce coating waxes and wash sanitizers in bulk?
Yes. RawSource sources carnauba wax, shellac, and peracetic acid in drum, tote, and bulk quantities, with TDS and SDS available on request. Specify the grade, commodity, and food-contact requirement for an RFQ.
Disclaimer. Information on this page is provided for general reference and compiled from authoritative public sources (e.g. PubChem/ECHA). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot you purchase governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim. Always consult the current Safety Data Sheet (SDS) before handling, and confirm regulatory status, classification, and suitability for your application and jurisdiction.
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