When manufacturers evaluate a flavour concentrate, the profile gets all the attention — but the carrier system quietly decides whether that profile survives your process. Solubility, heat stability, dosing accuracy and shelf life all trace back to the carrier. Here is how the three main systems compare, and how to match them to your application.
PG / MPG systems: the workhorse
Propylene glycol (mono propylene glycol, CAS 57-55-6) is the most widely used flavour carrier for good reason: it is an excellent solvent for a very broad range of flavour compounds, it is miscible with water, and it carries flavours efficiently at low dosage. PG-based concentrates suit applications where the concentrate is dispersed into a liquid or semi-liquid matrix and where processing temperatures are moderate.
- Best for: beverages and syrups, liquid formulations, applications requiring precise low-percentage dosing
- Watch for: labelling requirements in some markets, and PG's limits in high-fat matrices where partitioning can mute top notes
Water-soluble systems: clean and beverage-ready
Water-soluble concentrates are built on aqueous or emulsified bases and disperse directly into water-based products without clouding — critical for clear beverages, waters and functional drinks. They are also the natural choice where a formulator wants to minimise glycol content on the label.
- Best for: clear and still beverages, functional waters, cordials and dilutables
- Watch for: generally shorter shelf life than glycol systems and more sensitivity to microbial control — good manufacturing discipline matters
Oil-based systems: built for heat and fat
Oil-soluble concentrates dissolve flavour compounds in vegetable oil or triacetin carriers. Because the flavour sits in the fat phase, these systems shine in bakery, confectionery and any product that spends time at high temperature — fat-phase flavours are markedly more bake-stable than aqueous equivalents.
- Best for: bakery and baked-through applications, chocolate and compound coatings, high-fat dairy and desserts
- Watch for: dosing into water-based products requires emulsification; oil carriers are unsuitable for clear beverages
The practical decision path
Start from three questions: What is the water/fat balance of your base? What temperatures will the flavour see during processing? And what does your label need to say? Those three answers eliminate most wrong choices immediately. From there it becomes an optimisation problem — dosage rate, top-note retention and cost-in-use — which is exactly what a bench trial with your actual base resolves.
The same profile can usually be built on more than one carrier. At EC Aroma we routinely reformulate a customer's preferred profile from one system to another — a strawberry that exists as a PG concentrate can be rebuilt water-soluble for a clear drink, or oil-based for a biscuit filling — so the carrier should serve the application, never constrain it.
Not sure which system fits your product? Tell us your base matrix and process, and we'll recommend — or formulate — the right carrier. Samples from 1 kg MOQ.
Talk to our team